The Estimation and Inclusion of Presenteeism Costs in Applied Economic Evaluation: A Systematic Review.

PubMed

Kigozi, Jesse; Jowett, Sue; Lewis, Martyn; Barton, Pelham; Coast, Joanna

2017-03-01

Given the significant costs of reduced productivity (presenteeism) in comparison to absenteeism, and overall societal costs, presenteeism has a potentially important role to play in economic evaluations. However, these costs are often excluded. The objective of this study is to review applied cost of illness studies and economic evaluations to identify valuation methods used for, and impact of including presenteeism costs in practice. A structured systematic review was carried out to explore (i) the extent to which presenteeism has been applied in cost of illness studies and economic evaluations and (ii) the overall impact of including presenteeism on overall costs and outcomes. Potential articles were identified by searching Medline, PsycINFO and NHS EED databases. A standard template was developed and used to extract information from economic evaluations and cost of illness studies incorporating presenteeism costs. A total of 28 studies were included in the systematic review which also demonstrated that presenteeism costs are rarely included in full economic evaluations. Estimation and monetisation methods differed between the instruments. The impact of disease on presenteeism whilst in paid work is high. The potential impact of presenteeism costs needs to be highlighted and greater consideration should be given to including these in economic evaluations and cost of illness studies. The importance of including presenteeism costs when conducting economic evaluation from a societal perspective should be emphasised in national economic guidelines and more methodological work is required to improve the practical application of presenteeism instruments to generate productivity cost estimates. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Medical costs and quality-adjusted life years associated with smoking: a systematic review.

PubMed

Feirman, Shari P; Glasser, Allison M; Teplitskaya, Lyubov; Holtgrave, David R; Abrams, David B; Niaura, Raymond S; Villanti, Andrea C

2016-07-27

Estimated medical costs ("T") and QALYs ("Q") associated with smoking are frequently used in cost-utility analyses of tobacco control interventions. The goal of this study was to understand how researchers have addressed the methodological challenges involved in estimating these parameters. Data were collected as part of a systematic review of tobacco modeling studies. We searched five electronic databases on July 1, 2013 with no date restrictions and synthesized studies qualitatively. Studies were eligible for the current analysis if they were U.S.-based, provided an estimate for Q, and used a societal perspective and lifetime analytic horizon to estimate T. We identified common methods and frequently cited sources used to obtain these estimates. Across all 18 studies included in this review, 50 % cited a 1992 source to estimate the medical costs associated with smoking and 56 % cited a 1996 study to derive the estimate for QALYs saved by quitting or preventing smoking. Approaches for estimating T varied dramatically among the studies included in this review. T was valued as a positive number, negative number and $0; five studies did not include estimates for T in their analyses. The most commonly cited source for Q based its estimate on the Health Utilities Index (HUI). Several papers also cited sources that based their estimates for Q on the Quality of Well-Being Scale and the EuroQol five dimensions questionnaire (EQ-5D). Current estimates of the lifetime medical care costs and the QALYs associated with smoking are dated and do not reflect the latest evidence on the health effects of smoking, nor the current costs and benefits of smoking cessation and prevention. Given these limitations, we recommend that researchers conducting economic evaluations of tobacco control interventions perform extensive sensitivity analyses around these parameter estimates.

Estimated prevalence of erosive tooth wear in permanent teeth of children and adolescents: an epidemiological systematic review and meta-regression analysis.

PubMed

Salas, M M S; Nascimento, G G; Huysmans, M C; Demarco, F F

2015-01-01

The main purpose of this systematic review was to estimate the prevalence of dental erosion in permanent teeth of children and adolescents. An electronic search was performed up to and including March 2014. Eligibility criteria included population-based studies in permanent teeth of children and adolescents aged 8-19-year-old reporting the prevalence or data that allowed the calculation of prevalence rates of tooth erosion. Data collection assessed information regarding geographic location, type of index used for clinical examination, sample size, year of publication, age, examined teeth and tissue exposure. The estimated prevalence of erosive wear was determined, followed by a meta-regression analysis. Twenty-two papers were included in the systematic review. The overall estimated prevalence of tooth erosion was 30.4% (95%IC 23.8-37.0). In the multivariate meta-regression model use of the Tooth Wear Index for clinical examination, studies with sample smaller than 1000 subjects and those conducted in the Middle East and Africa remained associated with higher dental erosion prevalence rates. Our results demonstrated that the estimated prevalence of erosive wear in permanent teeth of children and adolescents is 30.4% with high heterogeneity between studies. Additionally, the correct choice of a clinical index for dental erosion detection and the geographic location play an important role for the large variability of erosive tooth wear in permanent teeth of children and adolescents. The prevalence of tooth erosion observed in permanent teeth of children and adolescents was considerable high. Our results demonstrated that prevalence rate of erosive wear was influenced by methodological and diagnosis factors. When tooth erosion is assessed, the clinical index should be considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Risk of myocardial infarction and stroke in bipolar disorder: a systematic review and exploratory meta-analysis

PubMed Central

Prieto, M.L.; Cuéllar-Barboza, A.B.; Bobo, W.V.; Roger, V.L.; Bellivier, F.; Leboyer, M.; West, C.P.; Frye, M.A.

2016-01-01

Objective To review the evidence on and estimate the risk of myocardial infarction and stroke in bipolar disorder. Method A systematic search using MEDLINE, EMBASE, PsycINFO, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and bibliographies (1946 – May, 2013) was conducted. Case-control and cohort studies of bipolar disorder patients age 15 or older with myocardial infarction or stroke as outcomes were included. Two independent reviewers extracted data and assessed quality. Estimates of effect were summarized using random-effects meta-analysis. Results Five cohort studies including 13 115 911 participants (27 092 bipolar) were included. Due to the use of registers, different statistical methods, and inconsistent adjustment for confounders, there was significant methodological heterogeneity among studies. The exploratory meta-analysis yielded no evidence for a significant increase in the risk of myocardial infarction: [relative risk (RR): 1.09, 95% CI 0.96–1.24, P = 0.20; I2 = 6%]. While there was evidence of significant study heterogeneity, the risk of stroke in bipolar disorder was significantly increased (RR 1.74, 95% CI 1.29–2.35; P = 0.0003; I2 = 83%). Conclusion There may be a differential risk of myocardial infarction and stroke in patients with bipolar disorder. Confidence in these pooled estimates was limited by the small number of studies, significant heterogeneity and dissimilar methodological features. PMID:24850482

Efficiently estimating salmon escapement uncertainty using systematically sampled data

USGS Publications Warehouse

Reynolds, Joel H.; Woody, Carol Ann; Gove, Nancy E.; Fair, Lowell F.

2007-01-01

Fish escapement is generally monitored using nonreplicated systematic sampling designs (e.g., via visual counts from towers or hydroacoustic counts). These sampling designs support a variety of methods for estimating the variance of the total escapement. Unfortunately, all the methods give biased results, with the magnitude of the bias being determined by the underlying process patterns. Fish escapement commonly exhibits positive autocorrelation and nonlinear patterns, such as diurnal and seasonal patterns. For these patterns, poor choice of variance estimator can needlessly increase the uncertainty managers have to deal with in sustaining fish populations. We illustrate the effect of sampling design and variance estimator choice on variance estimates of total escapement for anadromous salmonids from systematic samples of fish passage. Using simulated tower counts of sockeye salmon Oncorhynchus nerka escapement on the Kvichak River, Alaska, five variance estimators for nonreplicated systematic samples were compared to determine the least biased. Using the least biased variance estimator, four confidence interval estimators were compared for expected coverage and mean interval width. Finally, five systematic sampling designs were compared to determine the design giving the smallest average variance estimate for total annual escapement. For nonreplicated systematic samples of fish escapement, all variance estimators were positively biased. Compared to the other estimators, the least biased estimator reduced bias by, on average, from 12% to 98%. All confidence intervals gave effectively identical results. Replicated systematic sampling designs consistently provided the smallest average estimated variance among those compared.

Internal robustness: systematic search for systematic bias in SN Ia data

NASA Astrophysics Data System (ADS)

Amendola, Luca; Marra, Valerio; Quartin, Miguel

2013-04-01

A great deal of effort is currently being devoted to understanding, estimating and removing systematic errors in cosmological data. In the particular case of Type Ia supernovae, systematics are starting to dominate the error budget. Here we propose a Bayesian tool for carrying out a systematic search for systematic contamination. This serves as an extension to the standard goodness-of-fit tests and allows not only to cross-check raw or processed data for the presence of systematics but also to pin-point the data that are most likely contaminated. We successfully test our tool with mock catalogues and conclude that the Union2.1 data do not possess a significant amount of systematics. Finally, we show that if one includes in Union2.1 the supernovae that originally failed the quality cuts, our tool signals the presence of systematics at over 3.8σ confidence level.

A Practical Guide to Conducting a Systematic Review and Meta-analysis of Health State Utility Values.

PubMed

Petrou, Stavros; Kwon, Joseph; Madan, Jason

2018-05-10

Economic analysts are increasingly likely to rely on systematic reviews and meta-analyses of health state utility values to inform the parameter inputs of decision-analytic modelling-based economic evaluations. Beyond the context of economic evaluation, evidence from systematic reviews and meta-analyses of health state utility values can be used to inform broader health policy decisions. This paper provides practical guidance on how to conduct a systematic review and meta-analysis of health state utility values. The paper outlines a number of stages in conducting a systematic review, including identifying the appropriate evidence, study selection, data extraction and presentation, and quality and relevance assessment. The paper outlines three broad approaches that can be used to synthesise multiple estimates of health utilities for a given health state or condition, namely fixed-effect meta-analysis, random-effects meta-analysis and mixed-effects meta-regression. Each approach is illustrated by a synthesis of utility values for a hypothetical decision problem, and software code is provided. The paper highlights a number of methodological issues pertinent to the conduct of meta-analysis or meta-regression. These include the importance of limiting synthesis to 'comparable' utility estimates, for example those derived using common utility measurement approaches and sources of valuation; the effects of reliance on limited or poorly reported published data from primary utility assessment studies; the use of aggregate outcomes within analyses; approaches to generating measures of uncertainty; handling of median utility values; challenges surrounding the disentanglement of utility estimates collected serially within the context of prospective observational studies or prospective randomised trials; challenges surrounding the disentanglement of intervention effects; and approaches to measuring model validity. Areas of methodological debate and avenues for future research are highlighted.

Efficacy and safety of pharmacological agents in the treatment of erythema migrans in early Lyme borreliosis-systematic review protocol.

PubMed

Torbahn, Gabriel; Hofmann, Heidelore; Allert, Roman; Freitag, Michael H; Dersch, Rick; Fingerle, Volker; Sommer, Harriet; Motschall, Edith; Meerpohl, Jörg J; Schmucker, Christine

2016-05-03

Erythema migrans represents an early cutaneous and most common manifestation of Lyme borreliosis. Recommendations regarding pharmacological agents, dose and duration of treatment are subject of intense debate. This review aims to explore differences in efficacy and safety between pharmacological treatments and control treatment. To identify relevant studies, we will conduct a systematic literature search. We will include randomised controlled trials (RCTs) and non-RCTs. Eligible comparative studies need to (1) consider patients with a diagnosis of erythema migrans resulting from Lyme borreliosis and (2) compare different pharmacological agents against each other, against any other non-pharmacological treatment, placebo or no treatment. Two review authors will independently assess included studies for risk of bias according to the methods of the Cochrane Handbook for Systematic Reviews of Interventions and related to specific study designs. We will address patient-relevant outcomes including clinical remission of cutaneous symptoms, any treatment-related adverse events, quality of life and progressive symptoms such as neuroborreliosis or Lyme carditis and flu-like symptoms. Provided that the identified trials are comparable in terms of clinical issues, combined estimates will be provided. Estimations of treatment effects will be calculated based on a random effects model. Heterogeneity will be evaluated based on I (2) and chi-square test. In case of significant heterogeneity, a pooled estimate will not be provided, but heterogeneity will be investigated on the basis of methodological and clinical study aspects. We plan subgroup analysis to reveal potential differences in the effect estimates between patient populations and treatment specifications. We will consider risk of bias using sensitivity analyses to decide whether to rely on the pooled estimates. The quality of a body of evidence for individual outcomes will be assessed using the GRADE approach. Benefits and harms of pharmacological treatment in erythema migrans have not yet been adequately assessed. This systematic review will evaluate and summarise available evidence addressing benefits and harms of different pharmacological treatments. In addition, this summary of clinical evidence will inform decision-making between clinicians and patients and will play an important part in patient care. CRD42016037932.

Matched Comparison Group Design Standards in Systematic Reviews of Early Childhood Interventions.

PubMed

Thomas, Jaime; Avellar, Sarah A; Deke, John; Gleason, Philip

2017-06-01

Systematic reviews assess the quality of research on program effectiveness to help decision makers faced with many intervention options. Study quality standards specify criteria that studies must meet, including accounting for baseline differences between intervention and comparison groups. We explore two issues related to systematic review standards: covariate choice and choice of estimation method. To help systematic reviews develop/refine quality standards and support researchers in using nonexperimental designs to estimate program effects, we address two questions: (1) How well do variables that systematic reviews typically require studies to account for explain variation in key child and family outcomes? (2) What methods should studies use to account for preexisting differences between intervention and comparison groups? We examined correlations between baseline characteristics and key outcomes using Early Childhood Longitudinal Study-Birth Cohort data to address Question 1. For Question 2, we used simulations to compare two methods-matching and regression adjustment-to account for preexisting differences between intervention and comparison groups. A broad range of potential baseline variables explained relatively little of the variation in child and family outcomes. This suggests the potential for bias even after accounting for these variables, highlighting the need for systematic reviews to provide appropriate cautions about interpreting the results of moderately rated, nonexperimental studies. Our simulations showed that regression adjustment can yield unbiased estimates if all relevant covariates are used, even when the model is misspecified, and preexisting differences between the intervention and the comparison groups exist.

Hyper-X Mach 10 Trajectory Reconstruction

NASA Technical Reports Server (NTRS)

Karlgaard, Christopher D.; Martin, John G.; Tartabini, Paul V.; Thornblom, Mark N.

2005-01-01

This paper discusses the formulation and development of a trajectory reconstruction tool for the NASA X-43A/Hyper-X high speed research vehicle, and its implementation for the reconstruction and analysis of flight test data. Extended Kalman filtering techniques are employed to reconstruct the trajectory of the vehicle, based upon numerical integration of inertial measurement data along with redundant measurements of the vehicle state. The equations of motion are formulated in order to include the effects of several systematic error sources, whose values may also be estimated by the filtering routines. Additionally, smoothing algorithms have been implemented in which the final value of the state (or an augmented state that includes other systematic error parameters to be estimated) and covariance are propagated back to the initial time to generate the best-estimated trajectory, based upon all available data. The methods are applied to the problem of reconstructing the trajectory of the Hyper-X vehicle from data obtained during the Mach 10 test flight, which occurred on November 16th 2004.

Ultrasonographic fetal head position to predict mode of delivery: a systematic review and bivariate meta-analysis.

PubMed

Verhoeven, C J M; Rückert, M E P F; Opmeer, B C; Pajkrt, E; Mol, B W J

2012-07-01

We performed a systematic review to determine whether sonographic assessment of occipital position of the fetal head can contribute to the prediction of the mode of delivery. We performed a systematic literature search of electronic databases from inception to May 2011. Two reviewers independently extracted data from the included studies. We used a bivariate model to estimate point estimates for sensitivity and specificity curves for the outcome Cesarean delivery. Eligible studies were cohort studies or cross-sectional studies that reported on both the position of the fetal head, as assessed by ultrasound, before or at the beginning of active labor as well as the outcome of labor in women at term. We included 11 primary articles reporting on 5053 women, of whom 898 had a Cesarean section. All studies indicated disappointing values for sensitivity and specificity in the prediction of Cesarean section. Summary point estimates of sensitivity and specificity were 0.39 (95% CI, 0.32-0.48) and 0.71 (95% CI, 0.67-0.74), respectively. Sonographic assessment of occipital position of the fetal head before delivery should not be used in the prediction of mode of delivery. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Application of minimal important differences in degenerative knee disease outcomes: a systematic review and case study to inform BMJ Rapid Recommendations.

PubMed

Devji, Tahira; Guyatt, Gordon H; Lytvyn, Lyubov; Brignardello-Petersen, Romina; Foroutan, Farid; Sadeghirad, Behnam; Buchbinder, Rachelle; Poolman, Rudolf W; Harris, Ian A; Carrasco-Labra, Alonso; Siemieniuk, Reed A C; Vandvik, Per O

2017-05-11

To identify the most credible anchor-based minimal important differences (MIDs) for patient important outcomes in patients with degenerative knee disease, and to inform BMJ Rapid Recommendations for arthroscopic surgery versus conservative management DESIGN: Systematic review. Estimates of anchor-based MIDs, and their credibility, for knee symptoms and health-related quality of life (HRQoL). MEDLINE, EMBASE and PsycINFO. We included original studies documenting the development of anchor-based MIDs for patient-reported outcomes (PROs) reported in randomised controlled trials included in the linked systematic review and meta-analysis and judged by the parallel BMJ Rapid Recommendations panel as critically important for informing their recommendation: measures of pain, function and HRQoL. 13 studies reported 95 empirically estimated anchor-based MIDs for 8 PRO instruments and/or their subdomains that measure knee pain, function or HRQoL. All studies used a transition rating (global rating of change) as the anchor to ascertain the MID. Among PROs with more than 1 estimated MID, we found wide variation in MID values. Many studies suffered from serious methodological limitations. We identified the following most credible MIDs: Western Ontario and McMaster University Osteoarthritis Index (WOMAC; pain: 12, function: 13), Knee injury and Osteoarthritis Outcome Score (KOOS; pain: 12, activities of daily living: 8) and EuroQol five dimensions Questionnaire (EQ-5D; 0.15). We were able to distinguish between more and less credible MID estimates and provide best estimates for key instruments that informed evidence presentation in the associated systematic review and judgements made by the Rapid Recommendation panel. CRD42016047912. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Filtering Methods for Error Reduction in Spacecraft Attitude Estimation Using Quaternion Star Trackers

NASA Technical Reports Server (NTRS)

Calhoun, Philip C.; Sedlak, Joseph E.; Superfin, Emil

2011-01-01

Precision attitude determination for recent and planned space missions typically includes quaternion star trackers (ST) and a three-axis inertial reference unit (IRU). Sensor selection is based on estimates of knowledge accuracy attainable from a Kalman filter (KF), which provides the optimal solution for the case of linear dynamics with measurement and process errors characterized by random Gaussian noise with white spectrum. Non-Gaussian systematic errors in quaternion STs are often quite large and have an unpredictable time-varying nature, particularly when used in non-inertial pointing applications. Two filtering methods are proposed to reduce the attitude estimation error resulting from ST systematic errors, 1) extended Kalman filter (EKF) augmented with Markov states, 2) Unscented Kalman filter (UKF) with a periodic measurement model. Realistic assessments of the attitude estimation performance gains are demonstrated with both simulation and flight telemetry data from the Lunar Reconnaissance Orbiter.

Carbohydrate intake, obesity, metabolic syndrome and cancer risk? A two-part systematic review and meta-analysis protocol to estimate attributability

PubMed Central

Sartorius, B; Sartorius, K; Aldous, C; Madiba, T E; Stefan, C; Noakes, T

2016-01-01

Introduction Linkages between carbohydrates, obesity and cancer continue to demonstrate conflicting results. Evidence suggests inconclusive direct linkages between carbohydrates and specific cancers. Conversely, obesity has been strongly linked to a wide range of cancers. The purpose of the study is to explore linkages between carbohydrate intake and cancer types using a two-step approach. First the study will evaluate the linkages between carbohydrate intake and obesity, potentially stratified by metabolic syndrome status. Second, the estimated attributable fraction of obesity ascribed to carbohydrate intake will be multiplied against obesity attributable fractions for cancer types to give estimated overall attributable fraction for carbohydrate versus cancer type. Methods and analysis We will perform a comprehensive search to identify all possible published and unpublished studies that have assessed risk factors for obesity including dietary carbohydrate intake. Scientific databases, namely PubMed MEDLINE, EMBASE, EBSCOhost and ISI Web of Science will be searched. Following study selection, paper/data acquisition, and data extraction and synthesis, we will appraise the quality of studies and risk of bias, as well as assess heterogeneity. Meta-weighted attributable fractions of obesity due to carbohydrate intake will be estimated after adjusting for other potential confounding factors (eg, physical inactivity, other dietary intake). Furthermore, previously published systematic reviews assessing the cancer-specific risk associated with obesity will also be drawn. These estimates will be linked with the attributability of carbohydrate intake in part 1 to estimate the cancer-specific burden that can be attributed to dietary carbohydrates. This systematic review protocol has been developed according to the ‘Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015’. Ethics and dissemination The current study will be based on published literature and data, and, as such, ethics approval is not required. The final results of this two part systematic review (plus multiplicative calculations) will be published in a relevant international peer-reviewed journal. Trial registration number PROSPERO CRD42015023257. PMID:26729382

Risk of myocardial infarction and stroke in bipolar disorder: a systematic review and exploratory meta-analysis.

PubMed

Prieto, M L; Cuéllar-Barboza, A B; Bobo, W V; Roger, V L; Bellivier, F; Leboyer, M; West, C P; Frye, M A

2014-11-01

To review the evidence on and estimate the risk of myocardial infarction and stroke in bipolar disorder. A systematic search using MEDLINE, EMBASE, PsycINFO, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and bibliographies (1946 - May, 2013) was conducted. Case-control and cohort studies of bipolar disorder patients age 15 or older with myocardial infarction or stroke as outcomes were included. Two independent reviewers extracted data and assessed quality. Estimates of effect were summarized using random-effects meta-analysis. Five cohort studies including 13 115 911 participants (27 092 bipolar) were included. Due to the use of registers, different statistical methods, and inconsistent adjustment for confounders, there was significant methodological heterogeneity among studies. The exploratory meta-analysis yielded no evidence for a significant increase in the risk of myocardial infarction: [relative risk (RR): 1.09, 95% CI 0.96-1.24, P = 0.20; I(2)  = 6%]. While there was evidence of significant study heterogeneity, the risk of stroke in bipolar disorder was significantly increased (RR 1.74, 95% CI 1.29-2.35; P = 0.0003; I(2)  = 83%). There may be a differential risk of myocardial infarction and stroke in patients with bipolar disorder. Confidence in these pooled estimates was limited by the small number of studies, significant heterogeneity and dissimilar methodological features. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prevalence of UTI among Iranian infants with prolonged jaundice, and its main causes: A systematic review and meta-analysis study.

PubMed

Tola, H H; Ranjbaran, M; Omani-Samani, R; Sadeghi, M

2018-04-01

An extremely variable and high prevalence of urinary tract infection (UTI) in infants with prolonged jaundice has been reported in Iran. However, there is no research from the area that has attempted to estimate pooled prevalence of UTI from considerably diverse evidence. Therefore, this systematic review and meta-analysis study aimed to estimate the prevalence of UTI in infants with prolonged jaundice who were admitted into clinics or hospitals in Iran. A systematic review and meta-analysis was conducted of published articles on UTI prevalence in infants with prolonged jaundice in Iran. Electronic databases were searched, including Web of Sciences, PubMed/Medline, Scopus, Iranian Scientific Information Database (SID) and Iranmedex, for both English and Persian language articles published between January, 2000 and March, 2017. All possible combinations of the following keywords were used: jaundice, icterus, hyperbilirubinemia during infancy, infection and neonatal. Nine studies that reported prevalence of UTI in infants with prolonged jaundice were included. The overall prevalence of UTI was estimated using random-effects meta-analysis models. A total of 1750 infants were pooled to estimate the overall prevalence of UTI in infants with prolonged jaundice. The prevalence reported by the studies included in this literature review was extremely variable and ranged 0.6-53.9%. The overall prevalence was 11% (95% Confidence Interval (CI): 5.0-18.0), and Escherichia coli was found to be the main cause of UTI. The overall prevalence of UTI was 11%, and E. coli was the main cause of UTI in infants with prolonged jaundice. Screening of UTI should be considered for infants with prolonged jaundice. Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Chronic pain and opioid misuse: a review of reviews.

PubMed

Voon, Pauline; Karamouzian, Mohammad; Kerr, Thomas

2017-08-15

The crisis of prescription opioid (PO) related harms has focused attention toward identifying and treating high-risk populations. This review aims to synthesize systematic reviews on the epidemiology and clinical management of comorbid chronic pain and PO or other substance misuse. A systematic database search was conducted to identify systematic reviews published between 2000 and 2016. Eligible studies were systematic reviews related to chronic non-cancer pain and PO or other substance misuse. Evidence from the included reviews was synthesized according to epidemiology and clinical management themes. Of 1908 identified articles, 18 systematic reviews were eligible for final inclusion. Two meta-analyses estimated the prevalence of chronic non-cancer pain in individuals using POs non-medically to be approximately 48% to 60%, which is substantially higher than the prevalence of chronic non-cancer pain in general population samples (11% to 19%). Five systematic reviews estimated the rates of PO or other opioid use in chronic pain populations with substantial variation in results (0.05% to 81%), likely due to widely varying definitions of dependence, substance use disorder, misuse, addiction, and abuse. Several clinical assessment and treatment approaches were identified, including: standardized assessment instruments; urine drug testing; medication counts; prescription drug monitoring programs; blood level monitoring; treatment agreements; opioid selection; dosing and dispensing strategies; and opioid agonist treatment. However, the reviews commonly noted serious limitations, inconsistencies, and imprecision of studies, and a lack of evidence on effectiveness or clinical utility for the majority of these strategies. Overall, current systematic reviews have found a lack of high-quality evidence or consistent findings on the prevalence, risk factors, and optimal clinical assessment and treatment approaches related to concurrent chronic pain and substance misuse. Given the role of systematic reviews in guiding evidence-based medicine and health policy, there is an urgent need for high-quality primary research to guide future systematic reviews to address the escalating epidemic of harms related to chronic pain and substance misuse.

Association of Hypertensive Disorders of Pregnancy With Risk of Neurodevelopmental Disorders in Offspring: A Systematic Review and Meta-analysis.

PubMed

Maher, Gillian M; O'Keeffe, Gerard W; Kearney, Patricia M; Kenny, Louise C; Dinan, Timothy G; Mattsson, Molly; Khashan, Ali S

2018-06-06

Although research suggests an association between hypertensive disorders of pregnancy (HDP) and autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and other neurodevelopmental disorders in offspring, consensus is lacking. Given the increasing prevalence of hypertension in pregnancy, it is important to examine the association of HDP with neurodevelopmental outcome. To synthesize the published literature on the association between HDP and risk of neurodevelopmental disorders in offspring in a systematic review and meta-analysis. On the basis of a preprepared protocol, a systematic search of PubMed, CINAHL, Embase, PsycINFO, and Web of Science was performed from inception through June 7, 2017, supplemented by hand searching of reference lists. Two investigators independently reviewed titles, abstracts, and full-text articles. English-language cohort and case-control studies were included in which HDP and neurodevelopmental disorders were reported. Data extraction and quality appraisal were performed independently by 2 reviewers. Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed throughout. Random-effects meta-analyses of estimated pooled odds ratios (ORs) for HDP and ASD and for HDP and ADHD. Stand-alone estimates were reported for all other neurodevelopmental disorders. Of 1166 studies identified, 61 unique articles met inclusion criteria. Twenty studies reported estimates for ASD. Eleven of these (including 777 518 participants) reported adjusted estimates, with a pooled adjusted OR of 1.35 (95% CI, 1.11-1.64). Ten studies reported estimates for ADHD. Six of these (including 1 395 605 participants) reported adjusted estimates, with a pooled adjusted OR of 1.29 (95% CI, 1.22-1.36). Subgroup analyses according to type of exposure (ie, preeclampsia or other HDP) showed no statistically significant differences for ASD or ADHD. Thirty-one studies met inclusion criteria for all other neurodevelopmental disorders. Individual estimates reported for these were largely inconsistent, with few patterns of association observed. Exposure to HDP may be associated with an increase in the risk of ASD and ADHD. These findings highlight the need for greater pediatric surveillance of infants exposed to HDP to allow early intervention that may improve neurodevelopmental outcome.

Component Analysis of Errors on PERSIANN Precipitation Estimates over Urmia Lake Basin, IRAN

NASA Astrophysics Data System (ADS)

Ghajarnia, N.; Daneshkar Arasteh, P.; Liaghat, A. M.; Araghinejad, S.

2016-12-01

In this study, PERSIANN daily dataset is evaluated from 2000 to 2011 in 69 pixels over Urmia Lake basin in northwest of Iran. Different analytical approaches and indexes are used to examine PERSIANN precision in detection and estimation of rainfall rate. The residuals are decomposed into Hit, Miss and FA estimation biases while continues decomposition of systematic and random error components are also analyzed seasonally and categorically. New interpretation of estimation accuracy named "reliability on PERSIANN estimations" is introduced while the changing manners of existing categorical/statistical measures and error components are also seasonally analyzed over different rainfall rate categories. This study yields new insights into the nature of PERSIANN errors over Urmia lake basin as a semi-arid region in the middle-east, including the followings: - The analyzed contingency table indexes indicate better detection precision during spring and fall. - A relatively constant level of error is generally observed among different categories. The range of precipitation estimates at different rainfall rate categories is nearly invariant as a sign for the existence of systematic error. - Low level of reliability is observed on PERSIANN estimations at different categories which are mostly associated with high level of FA error. However, it is observed that as the rate of precipitation increase, the ability and precision of PERSIANN in rainfall detection also increases. - The systematic and random error decomposition in this area shows that PERSIANN has more difficulty in modeling the system and pattern of rainfall rather than to have bias due to rainfall uncertainties. The level of systematic error also considerably increases in heavier rainfalls. It is also important to note that PERSIANN error characteristics at each season varies due to the condition and rainfall patterns of that season which shows the necessity of seasonally different approach for the calibration of this product. Overall, we believe that different error component's analysis performed in this study, can substantially help any further local studies for post-calibration and bias reduction of PERSIANN estimations.

A Systematic Review and Meta-Analyses Show that Carbapenem Use and Medical Devices Are the Leading Risk Factors for Carbapenem-Resistant Pseudomonas aeruginosa

PubMed Central

Voor in ‘t holt, Anne F.; Severin, Juliëtte A.; Lesaffre, Emmanuel M. E. H.

2014-01-01

A systematic review and meta-analyses were performed to identify the risk factors associated with carbapenem-resistant Pseudomonas aeruginosa and to identify sources and reservoirs for the pathogen. A systematic search of PubMed and Embase databases from 1 January 1987 until 27 January 2012 identified 1,662 articles, 53 of which were included in a systematic review and 38 in a random-effects meta-analysis study. The use of carbapenem, use of fluoroquinolones, use of vancomycin, use of other antibiotics, having medical devices, intensive care unit (ICU) admission, having underlying diseases, patient characteristics, and length of hospital stay were significant risk factors in multivariate analyses. The meta-analyses showed that carbapenem use (odds ratio [OR] = 7.09; 95% confidence interval [CI] = 5.43 to 9.25) and medical devices (OR = 5.11; 95% CI = 3.55 to 7.37) generated the highest pooled estimates. Cumulative meta-analyses showed that the pooled estimate of carbapenem use was stable and that the pooled estimate of the risk factor “having medical devices” increased with time. We conclude that our results highlight the importance of antibiotic stewardship and the thoughtful use of medical devices in helping prevent outbreaks of carbapenem-resistant P. aeruginosa. PMID:24550343

Real-world persistence with fingolimod for the treatment of multiple sclerosis: A systematic review and meta-analysis.

PubMed

Kantor, Daniel; Johnson, Kristen; Vieira, Maria Cecilia; Signorovitch, James; Li, Nanxin; Gao, Wei; Koo, Valerie; Duchesneau, Emilie; Herrera, Vivian

2018-05-15

To systematically review reports of fingolimod persistence in the treatment of relapsing-remitting multiple sclerosis (RRMS) across data sources and practice settings, and to develop a consensus estimate of the 1-year real-world persistence rate. A systematic literature review was conducted (MEDLINE, EMBASE, and abstracts from selected conferences [2013-2015]) to identify observational studies reporting 1-year fingolimod persistence among adult patients with RRMS (sample size ≥50). A random-effects meta-analysis was performed to estimate a synthesized 1-year persistence rate and to assess heterogeneity across studies. Of 527 publications identified, 25 real-world studies reporting 1-year fingolimod persistence rates were included. The studies included patients from different data sources (e.g., administrative claims, electronic medical records, or registries), used different definitions of persistence (e.g., based on prescriptions refills, patient report, or prescription orders), and spanned multiple geographic regions. Reported 1-year persistence rates ranged from 72%-100%, and exhibited statistical evidence of heterogeneity (I 2  = 93% of the variability due to heterogeneity across studies). The consensus estimate of the 1-year persistence rate was 82% (95% confidence interval: 79%-85%). Across heterogeneous study designs and patient populations found in real-world studies, the consensus 1-year fingolimod persistence rate exceeded 80%, consistent with persistence rates identified in the recently-completed trial, PREFERMS. Copyright © 2018. Published by Elsevier B.V.

Flood frequency analysis - the challenge of using historical data

NASA Astrophysics Data System (ADS)

Engeland, Kolbjorn

2015-04-01

Estimates of high flood quantiles are needed for many applications, .e.g. dam safety assessments are based on the 1000 years flood, whereas the dimensioning of important infrastructure requires estimates of the 200 year flood. The flood quantiles are estimated by fitting a parametric distribution to a dataset of high flows comprising either annual maximum values or peaks over a selected threshold. Since the record length of data is limited compared to the desired flood quantile, the estimated flood magnitudes are based on a high degree of extrapolation. E.g. the longest time series available in Norway are around 120 years, and as a result any estimation of a 1000 years flood will require extrapolation. One solution is to extend the temporal dimension of a data series by including information about historical floods before the stream flow was systematically gaugeded. Such information could be flood marks or written documentation about flood events. The aim of this study was to evaluate the added value of using historical flood data for at-site flood frequency estimation. The historical floods were included in two ways by assuming: (1) the size of (all) floods above a high threshold within a time interval is known; and (2) the number of floods above a high threshold for a time interval is known. We used a Bayesian model formulation, with MCMC used for model estimation. This estimation procedure allowed us to estimate the predictive uncertainty of flood quantiles (i.e. both sampling and parameter uncertainty is accounted for). We tested the methods using 123 years of systematic data from Bulken in western Norway. In 2014 the largest flood in the systematic record was observed. From written documentation and flood marks we had information from three severe floods in the 18th century and they were likely to exceed the 2014 flood. We evaluated the added value in two ways. First we used the 123 year long streamflow time series and investigated the effect of having several shorter series' which could be supplemented with a limited number of known large flood events. Then we used the three historical floods from the 18th century combined with the whole and subsets of the 123 years of systematic observations. In the latter case several challenges were identified: i) The possibility to transfer water levels to river streamflows due to man made changes in the river profile, (ii) The stationarity of the data might be questioned since the three largest historical floods occurred during the "little ice age" with different climatic conditions compared to today.

The retention time of inorganic mercury in the brain — A systematic review of the evidence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rooney, James P.K., E-mail: jrooney@rcsi.ie

2014-02-01

Reports from human case studies indicate a half-life for inorganic mercury in the brain in the order of years—contradicting older radioisotope studies that estimated half-lives in the order of weeks to months in duration. This study systematically reviews available evidence on the retention time of inorganic mercury in humans and primates to better understand this conflicting evidence. A broad search strategy was used to capture 16,539 abstracts on the Pubmed database. Abstracts were screened to include only study types containing relevant information. 131 studies of interest were identified. Only 1 primate study made a numeric estimate for the half-life ofmore » inorganic mercury (227–540 days). Eighteen human mercury poisoning cases were followed up long term including autopsy. Brain inorganic mercury concentrations at death were consistent with a half-life of several years or longer. 5 radionucleotide studies were found, one of which estimated head half-life (21 days). This estimate has sometimes been misinterpreted to be equivalent to brain half-life—which ignores several confounding factors including limited radioactive half-life and radioactive decay from surrounding tissues including circulating blood. No autopsy cohort study estimated a half-life for inorganic mercury, although some noted bioaccumulation of brain mercury with age. Modelling studies provided some extreme estimates (69 days vs 22 years). Estimates from modelling studies appear sensitive to model assumptions, however predications based on a long half-life (27.4 years) are consistent with autopsy findings. In summary, shorter estimates of half-life are not supported by evidence from animal studies, human case studies, or modelling studies based on appropriate assumptions. Evidence from such studies point to a half-life of inorganic mercury in human brains of several years to several decades. This finding carries important implications for pharmcokinetic modelling of mercury and potentially for the regulatory toxicology of mercury.« less

The Problem With Estimating Public Health Spending.

PubMed

Leider, Jonathon P

2016-01-01

Accurate information on how much the United States spends on public health is critical. These estimates affect planning efforts; reflect the value society places on the public health enterprise; and allows for the demonstration of cost-effectiveness of programs, policies, and services aimed at increasing population health. Yet, at present, there are a limited number of sources of systematic public health finance data. Each of these sources is collected in different ways, for different reasons, and so yields strikingly different results. This article aims to compare and contrast all 4 current national public health finance data sets, including data compiled by Trust for America's Health, the Association of State and Territorial Health Officials (ASTHO), the National Association of County and City Health Officials (NACCHO), and the Census, which underlie the oft-cited National Health Expenditure Account estimates of public health activity. In FY2008, ASTHO estimates that state health agencies spent $24 billion ($94 per capita on average, median $79), while the Census estimated all state governmental agencies including state health agencies spent $60 billion on public health ($200 per capita on average, median $166). Census public health data suggest that local governments spent an average of $87 per capita (median $57), whereas NACCHO estimates that reporting LHDs spent $64 per capita on average (median $36) in FY2008. We conclude that these estimates differ because the various organizations collect data using different means, data definitions, and inclusion/exclusion criteria--most notably around whether to include spending by all agencies versus a state/local health department, and whether behavioral health, disability, and some clinical care spending are included in estimates. Alongside deeper analysis of presently underutilized Census administrative data, we see harmonization efforts and the creation of a standardized expenditure reporting system as a way to meaningfully systematize reporting of public health spending and revenue.

Stillbirth With Group B Streptococcus Disease Worldwide: Systematic Review and Meta-analyses

PubMed Central

Seale, Anna C; Blencowe, Hannah; Bianchi-Jassir, Fiorella; Embleton, Nicholas; Bassat, Quique; Ordi, Jaume; Menéndez, Clara; Cutland, Clare; Briner, Carmen; Berkley, James A; Lawn, Joy E; Baker, Carol J; Bartlett, Linda; Gravett, Michael G; Heath, Paul T; Ip, Margaret; Le Doare, Kirsty; Rubens, Craig E; Saha, Samir K; Schrag, Stephanie; Meulen, Ajoke Sobanjo-ter; Vekemans, Johan; Madhi, Shabir A

2017-01-01

Abstract Background There are an estimated 2.6 million stillbirths each year, many of which are due to infections, especially in low- and middle-income contexts. This paper, the eighth in a series on the burden of group B streptococcal (GBS) disease, aims to estimate the percentage of stillbirths associated with GBS disease. Methods We conducted systematic literature reviews (PubMed/Medline, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde, World Health Organization Library Information System, and Scopus) and sought unpublished data from investigator groups. Studies were included if they reported original data on stillbirths (predominantly ≥28 weeks’ gestation or ≥1000 g, with GBS isolated from a sterile site) as a percentage of total stillbirths. We did meta-analyses to derive pooled estimates of the percentage of GBS-associated stillbirths, regionally and worldwide for recent datasets. Results We included 14 studies from any period, 5 with recent data (after 2000). There were no data from Asia. We estimated that 1% (95% confidence interval [CI], 0–2%) of all stillbirths in developed countries and 4% (95% CI, 2%–6%) in Africa were associated with GBS. Conclusions GBS is likely an important cause of stillbirth, especially in Africa. However, data are limited in terms of geographic spread, with no data from Asia, and cases worldwide are probably underestimated due to incomplete case ascertainment. More data, using standardized, systematic methods, are critical, particularly from low- and middle-income contexts where the highest burden of stillbirths occurs. These data are essential to inform interventions, such as maternal GBS vaccination. PMID:29117322

Traumatic Spinal Injury: Global Epidemiology and Worldwide Volume.

PubMed

Kumar, Ramesh; Lim, Jaims; Mekary, Rania A; Rattani, Abbas; Dewan, Michael C; Sharif, Salman Y; Osorio-Fonseca, Enrique; Park, Kee B

2018-05-01

Traumatic spinal injury (TSI) results from injury to bony, ligamentous, and/or neurologic structures of the spinal column and can cause significant morbidity and mortality. The global burden of TSI is poorly understood, so we performed a systematic review and meta-analysis to estimate the global volume of TSI. We performed a systematic review through PubMed, Embase, and Cochrane Databases on TSI studies reported from 2000 to 2016. Collected data were used to perform a meta-analysis to estimate the annual incidence of TSI across World Health Organization regions and World Bank income groups using random-effect models. Incorporating global population figures, the annual worldwide volume of TSI was estimated. A total of 102 studies were included in the systematic review and 19 studies in the meta-analysis. The overall global incidence of TSI was 10.5 cases per 100,000 persons, resulting in an estimated 768,473 [95% confidence interval, 597,213-939,732] new cases of TSI annually worldwide. The incidence of TSI was higher in low- and middle-income countries (8.72 per 100,000 persons) compared with high-income countries (13.69 per 100,000 persons). Road traffic accidents, followed by falls, were the most common mechanism of TSI worldwide. Overall, 48.8% of patients with TSI required surgery. TSI is a major source of morbidity and mortality throughout the world. Largely preventable mechanisms, including road traffic accidents and falls, are the main causes of TSI globally. Further investigation is needed to delineate local and regional TSI incidences and causes, especially in low- and middle-income countries. Copyright © 2018 Elsevier Inc. All rights reserved.

Factors mediating HIV risk among female sex workers in Europe: a systematic review and ecological analysis

PubMed Central

Platt, Lucy; Jolley, Emma; Rhodes, Tim; Hope, Vivian; Latypov, Alisher; Reynolds, Lucy; Wilson, David

2013-01-01

Objectives We reviewed the epidemiology of HIV and selected sexually transmitted infections (STIs) among female sex workers (FSWs) in WHO-defined Europe. There were three objectives: (1) to assess the prevalence of HIV and STIs (chlamydia, syphilis and gonorrhoea); (2) to describe structural and individual-level risk factors associated with prevalence and (3) to examine the relationship between structural-level factors and national estimates of HIV prevalence among FSWs. Design A systematic search of published and unpublished literature measuring HIV/STIs and risk factors among FSWs, identified through electronic databases published since 2005. ‘Best’ estimates of HIV prevalence were calculated from the systematic review to provide national level estimates of HIV. Associations between HIV prevalence and selected structural-level indicators were assessed using linear regression models. Studies reviewed Of the 1993 papers identified in the search, 73 peer-reviewed and grey literature documents were identified as meeting our criteria of which 63 papers provided unique estimates of HIV and STI prevalence and nine reported multivariate risk factors for HIV/STI among FSWs. Results HIV in Europe remains low among FSWs who do not inject drugs (<1%), but STIs are high, particularly syphilis in the East and gonorrhoea. FSWs experience high levels of violence and structural risk factors associated with HIV, including lack of access to services and working on the street. Linear regression models showed HIV among FSWs to link with injecting drug use and imprisonment. Conclusions Findings show that HIV prevention interventions should be nested inside strategies that address the social welfare of sex workers, highlighting in turn the need to target the social determinants of health and inequality, including regarding access to services, experience of violence and migration. Future epidemiological and intervention studies of HIV among vulnerable populations need to better systematically delineate how microenvironmental and macroenvironmental factors combine to increase or reduce HIV/STI risk. PMID:23883879

Prevalence of placenta previa among deliveries in Mainland China: A PRISMA-compliant systematic review and meta-analysis.

PubMed

Fan, Dazhi; Wu, Song; Wang, Wen; Xin, Lihong; Tian, Guo; Liu, Li; Feng, Jinping; Guo, Xiaoling; Liu, Zhengping

2016-10-01

Placenta previa is characterized by the abnormal placenta overlying the endocervical os, and it is known as one of the most feared adverse maternal and fetal-neonatal complications in obstetrics. We aimed to obtain overall and regional estimates of placenta previa prevalence among deliveries in Mainland China. The research was performed a systematic review, following the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies, and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement for reporting systematic reviews and meta-analysis. Electronic databases were searched and included hospital-based studies that reported placenta previa prevalence in Mainland China. Random-effects meta-analyses were used to pool prevalence estimates of placenta previa. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. For exploring the geographical distributions of placenta previa, the ArcGIS software (Esri) was used to construct the map of prevalence. A total of 80 articles and 86 datasets (including 1,298,548 subjects and 14,199 placenta previa cases) from 1965 through 2015 were included. The pooled overall prevalence of placenta previa among deliveries was 1.24% (95% confidence interval [CI], 1.12-1.36) in Mainland China during 1965 to 2015. And, the trend in the prevalence of placenta previa was steady. The occurrence rate of placenta previa in the region groups Northeast, North, Northwest, Central China, East, South, and Southwest was 1.20%, 1.01%, 1.10%, 1.15%, 0.93%, 1.42%, and 2.01%, respectively. The prevalence map based on a geographic information system showed an unequal geographic distribution. The results showed that placenta previa is currently a high-burden disease in Mainland China. This review would be useful for the design of placenta previa planning and implementation adequate health care systems and treatment programs in Mainland China.

Estimating the incubation period of acute Q fever, a systematic review.

PubMed

Todkill, D; Fowler, T; Hawker, J I

2018-04-01

Estimates of the incubation period for Q fever vary substantially between different reviews and expert advice documents. We systematically reviewed and quality appraised the literature to provide an evidence-based estimate of the incubation period of the Q fever by the aerosolised infection route. Medline (OVIDSP) and EMBASE were searched with the search limited to human studies and English language. Eligible studies included persons with symptomatic, acute Q fever, and defined exposure to Coxiella burnetti. After review of 7115 titles and abstracts, 320 records were screened at full-text level. Of these, 23 studies contained potentially useful data and were quality assessed, with eight studies (with 403 individual cases where the derivation of incubation period was possible) being of sufficient quality and providing individual-level data to produce a pooled summary. We found a median incubation period of 18 days, with 95% of cases expected to occur between 7 and 32 days after exposure.

The French-Canadian data set of Demirjian for dental age estimation: a systematic review and meta-analysis.

PubMed

Jayaraman, Jayakumar; Wong, Hai Ming; King, Nigel M; Roberts, Graham J

2013-07-01

Estimation of age of an individual can be performed by evaluating the pattern of dental development. A dataset for age estimation based on the dental maturity of a French-Canadian population was published over 35 years ago and has become the most widely accepted dataset. The applicability of this dataset has been tested on different population groups. To estimate the observed differences between Chronological age (CA) and Dental age (DA) when the French Canadian dataset was used to estimate the age of different population groups. A systematic search of literature for papers utilizing the French Canadian dataset for age estimation was performed. All language articles from PubMed, Embase and Cochrane databases were electronically searched for terms 'Demirjian' and 'Dental age' published between January 1973 and December 2011. A hand search of articles was also conducted. A total of 274 studies were identified from which 34 studies were included for qualitative analysis and 12 studies were included for quantitative assessment and meta-analysis. When synthesizing the estimation results from different population groups, on average, the Demirjian dataset overestimated the age of females by 0.65 years (-0.10 years to +2.82 years) and males by 0.60 years (-0.23 years to +3.04 years). The French Canadian dataset overestimates the age of the subjects by more than six months and hence this dataset should be used only with considerable caution when estimating age of group of subjects of any global population. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Directly comparing gravitational wave data to numerical relativity simulations: systematics

NASA Astrophysics Data System (ADS)

Lange, Jacob; O'Shaughnessy, Richard; Healy, James; Lousto, Carlos; Zlochower, Yosef; Shoemaker, Deirdre; Lovelace, Geoffrey; Pankow, Christopher; Brady, Patrick; Scheel, Mark; Pfeiffer, Harald; Ossokine, Serguei

2017-01-01

We compare synthetic data directly to complete numerical relativity simulations of binary black holes. In doing so, we circumvent ad-hoc approximations introduced in semi-analytical models previously used in gravitational wave parameter estimation and compare the data against the most accurate waveforms including higher modes. In this talk, we focus on the synthetic studies that test potential sources of systematic errors. We also run ``end-to-end'' studies of intrinsically different synthetic sources to show we can recover parameters for different systems.

Should we search Chinese biomedical databases when performing systematic reviews?

PubMed

Cohen, Jérémie F; Korevaar, Daniël A; Wang, Junfeng; Spijker, René; Bossuyt, Patrick M

2015-03-06

Chinese biomedical databases contain a large number of publications available to systematic reviewers, but it is unclear whether they are used for synthesizing the available evidence. We report a case of two systematic reviews on the accuracy of anti-cyclic citrullinated peptide for diagnosing rheumatoid arthritis. In one of these, the authors did not search Chinese databases; in the other, they did. We additionally assessed the extent to which Cochrane reviewers have searched Chinese databases in a systematic overview of the Cochrane Library (inception to 2014). The two diagnostic reviews included a total of 269 unique studies, but only 4 studies were included in both reviews. The first review included five studies published in the Chinese language (out of 151) while the second included 114 (out of 118). The summary accuracy estimates from the two reviews were comparable. Only 243 of the published 8,680 Cochrane reviews (less than 3%) searched one or more of the five major Chinese databases. These Chinese databases index about 2,500 journals, of which less than 6% are also indexed in MEDLINE. All 243 Cochrane reviews evaluated an intervention, 179 (74%) had at least one author with a Chinese affiliation; 118 (49%) addressed a topic in complementary or alternative medicine. Although searching Chinese databases may lead to the identification of a large amount of additional clinical evidence, Cochrane reviewers have rarely included them in their search strategy. We encourage future initiatives to evaluate more systematically the relevance of searching Chinese databases, as well as collaborative efforts to allow better incorporation of Chinese resources in systematic reviews.

Mean population salt intake estimated from 24-h urine samples and spot urine samples: a systematic review and meta-analysis.

PubMed

Huang, Liping; Crino, Michelle; Wu, Jason H Y; Woodward, Mark; Barzi, Federica; Land, Mary-Anne; McLean, Rachael; Webster, Jacqui; Enkhtungalag, Batsaikhan; Neal, Bruce

2016-02-01

Estimating equations based on spot urine samples have been identified as a possible alternative approach to 24-h urine collections for determining mean population salt intake. This review compares estimates of mean population salt intake based upon spot and 24-h urine samples. We systematically searched for all studies that reported estimates of daily salt intake based upon both spot and 24-h urine samples for the same population. The associations between the two were quantified and compared overall and in subsets of studies. A total of 538 records were identified, 108 were assessed as full text and 29 were included. The included studies involved 10,414 participants from 34 countries and made 71 comparisons available for the primary analysis. Overall average population salt intake estimated from 24-h urine samples was 9.3 g/day compared with 9.0 g/day estimated from the spot urine samples. Estimates based upon spot urine samples had excellent sensitivity (97%) and specificity (100%) at classifying mean population salt intake as above or below the World Health Organization maximum target of 5 g/day. Compared with the 24-h samples, estimates based upon spot urine overestimated intake at lower levels of consumption and underestimated intake at higher levels of consumption. Estimates of mean population salt intake based upon spot urine samples can provide countries with a good indication of mean population salt intake and whether action on salt consumption is required. Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by US Government employees and is in the public domain in the US.

Estimating the coverage of mental health programmes: a systematic review.

PubMed

De Silva, Mary J; Lee, Lucy; Fuhr, Daniela C; Rathod, Sujit; Chisholm, Dan; Schellenberg, Joanna; Patel, Vikram

2014-04-01

The large treatment gap for people suffering from mental disorders has led to initiatives to scale up mental health services. In order to track progress, estimates of programme coverage, and changes in coverage over time, are needed. Systematic review of mental health programme evaluations that assess coverage, measured either as the proportion of the target population in contact with services (contact coverage) or as the proportion of the target population who receive appropriate and effective care (effective coverage). We performed a search of electronic databases and grey literature up to March 2013 and contacted experts in the field. Methods to estimate the numerator (service utilization) and the denominator (target population) were reviewed to explore methods which could be used in programme evaluations. We identified 15 735 unique records of which only seven met the inclusion criteria. All studies reported contact coverage. No study explicitly measured effective coverage, but it was possible to estimate this for one study. In six studies the numerator of coverage, service utilization, was estimated using routine clinical information, whereas one study used a national community survey. The methods for estimating the denominator, the population in need of services, were more varied and included national prevalence surveys case registers, and estimates from the literature. Very few coverage estimates are available. Coverage could be estimated at low cost by combining routine programme data with population prevalence estimates from national surveys.

Medical marijuana laws and adolescent marijuana use in the United States: a systematic review and meta‐analysis

PubMed Central

Sarvet, Aaron L.; Wall, Melanie M.; Fink, David S.; Greene, Emily; Le, Aline; Boustead, Anne E.; Pacula, Rosalie Liccardo; Keyes, Katherine M.; Cerdá, Magdalena; Galea, Sandro

2018-01-01

Abstract Aims To conduct a systematic review and meta‐analysis of studies in order to estimate the effect of US medical marijuana laws (MMLs) on past‐month marijuana use prevalence among adolescents. Methods A total of 2999 papers from 17 literature sources were screened systematically. Eleven studies, developed from four ongoing large national surveys, were meta‐analyzed. Estimates of MML effects on any past‐month marijuana use prevalence from included studies were obtained from comparisons of pre–post MML changes in MML states to changes in non‐MML states over comparable time‐periods. These estimates were standardized and entered into a meta‐analysis model with fixed‐effects for each study. Heterogeneity among the study estimates by national data survey was tested with an omnibus F‐test. Estimates of effects on additional marijuana outcomes, of MML provisions (e.g. dispensaries) and among demographic subgroups were abstracted and summarized. Key methodological and modeling characteristics were also described. Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were followed. Results None of the 11 studies found significant estimates of pre–post MML changes compared with contemporaneous changes in non‐MML states for marijuana use prevalence among adolescents. The meta‐analysis yielded a non‐significant pooled estimate (standardized mean difference) of −0.003 (95% confidence interval = −0.012, +0.007). Four studies compared MML with non‐MML states on pre‐MML differences and all found higher rates of past‐month marijuana use in MML states pre‐MML passage. Additional tests of specific MML provisions, of MML effects on additional marijuana outcomes and among subgroups generally yielded non‐significant results, although limited heterogeneity may warrant further study. Conclusions Synthesis of the current evidence does not support the hypothesis that US medical marijuana laws (MMLs) until 2014 have led to increases in adolescent marijuana use prevalence. Limited heterogeneity exists among estimates of effects of MMLs on other patterns of marijuana use, of effects within particular population subgroups and of effects of specific MML provisions. PMID:29468763

The Limitations of Model-Based Experimental Design and Parameter Estimation in Sloppy Systems.

PubMed

White, Andrew; Tolman, Malachi; Thames, Howard D; Withers, Hubert Rodney; Mason, Kathy A; Transtrum, Mark K

2016-12-01

We explore the relationship among experimental design, parameter estimation, and systematic error in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex biological processes it is unknown what are the relevant physical mechanisms that must be included to explain system behaviors. As a consequence, models are often overly complex, with many practically unidentifiable parameters. Furthermore, which mechanisms are relevant/irrelevant vary among experiments. By selecting complementary experiments, experimental design may inadvertently make details that were ommitted from the model become relevant. When this occurs, the model will have a large systematic error and fail to give a good fit to the data. We use a simple hyper-model of model error to quantify a model's discrepancy and apply it to two models of complex biological processes (EGFR signaling and DNA repair) with optimally selected experiments. We find that although parameters may be accurately estimated, the discrepancy in the model renders it less predictive than it was in the sloppy regime where systematic error is small. We introduce the concept of a sloppy system-a sequence of models of increasing complexity that become sloppy in the limit of microscopic accuracy. We explore the limits of accurate parameter estimation in sloppy systems and argue that identifying underlying mechanisms controlling system behavior is better approached by considering a hierarchy of models of varying detail rather than focusing on parameter estimation in a single model.

The Limitations of Model-Based Experimental Design and Parameter Estimation in Sloppy Systems

PubMed Central

Tolman, Malachi; Thames, Howard D.; Mason, Kathy A.

2016-01-01

We explore the relationship among experimental design, parameter estimation, and systematic error in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex biological processes it is unknown what are the relevant physical mechanisms that must be included to explain system behaviors. As a consequence, models are often overly complex, with many practically unidentifiable parameters. Furthermore, which mechanisms are relevant/irrelevant vary among experiments. By selecting complementary experiments, experimental design may inadvertently make details that were ommitted from the model become relevant. When this occurs, the model will have a large systematic error and fail to give a good fit to the data. We use a simple hyper-model of model error to quantify a model’s discrepancy and apply it to two models of complex biological processes (EGFR signaling and DNA repair) with optimally selected experiments. We find that although parameters may be accurately estimated, the discrepancy in the model renders it less predictive than it was in the sloppy regime where systematic error is small. We introduce the concept of a sloppy system–a sequence of models of increasing complexity that become sloppy in the limit of microscopic accuracy. We explore the limits of accurate parameter estimation in sloppy systems and argue that identifying underlying mechanisms controlling system behavior is better approached by considering a hierarchy of models of varying detail rather than focusing on parameter estimation in a single model. PMID:27923060

Stillbirth With Group B Streptococcus Disease Worldwide: Systematic Review and Meta-analyses.

PubMed

Seale, Anna C; Blencowe, Hannah; Bianchi-Jassir, Fiorella; Embleton, Nicholas; Bassat, Quique; Ordi, Jaume; Menéndez, Clara; Cutland, Clare; Briner, Carmen; Berkley, James A; Lawn, Joy E; Baker, Carol J; Bartlett, Linda; Gravett, Michael G; Heath, Paul T; Ip, Margaret; Le Doare, Kirsty; Rubens, Craig E; Saha, Samir K; Schrag, Stephanie; Meulen, Ajoke Sobanjo-Ter; Vekemans, Johan; Madhi, Shabir A

2017-11-06

There are an estimated 2.6 million stillbirths each year, many of which are due to infections, especially in low- and middle-income contexts. This paper, the eighth in a series on the burden of group B streptococcal (GBS) disease, aims to estimate the percentage of stillbirths associated with GBS disease. We conducted systematic literature reviews (PubMed/Medline, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde, World Health Organization Library Information System, and Scopus) and sought unpublished data from investigator groups. Studies were included if they reported original data on stillbirths (predominantly ≥28 weeks' gestation or ≥1000 g, with GBS isolated from a sterile site) as a percentage of total stillbirths. We did meta-analyses to derive pooled estimates of the percentage of GBS-associated stillbirths, regionally and worldwide for recent datasets. We included 14 studies from any period, 5 with recent data (after 2000). There were no data from Asia. We estimated that 1% (95% confidence interval [CI], 0-2%) of all stillbirths in developed countries and 4% (95% CI, 2%-6%) in Africa were associated with GBS. GBS is likely an important cause of stillbirth, especially in Africa. However, data are limited in terms of geographic spread, with no data from Asia, and cases worldwide are probably underestimated due to incomplete case ascertainment. More data, using standardized, systematic methods, are critical, particularly from low- and middle-income contexts where the highest burden of stillbirths occurs. These data are essential to inform interventions, such as maternal GBS vaccination. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Diagnostic Performance of CT for Diagnosis of Fat-Poor Angiomyolipoma in Patients With Renal Masses: A Systematic Review and Meta-Analysis.

PubMed

Woo, Sungmin; Suh, Chong Hyun; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup

2017-11-01

The purpose of this article is to systematically review and perform a meta-analysis of the diagnostic performance of CT for diagnosis of fat-poor angiomyolipoma (AML) in patients with renal masses. MEDLINE and EMBASE were systematically searched up to February 2, 2017. We included diagnostic accuracy studies that used CT for diagnosis of fat-poor AML in patients with renal masses, using pathologic examination as the reference standard. Two independent reviewers assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity of included studies were calculated and were pooled and plotted in a hierarchic summary ROC plot. Sensitivity analyses using several clinically relevant covariates were performed to explore heterogeneity. Fifteen studies (2258 patients) were included. Pooled sensitivity and specificity were 0.67 (95% CI, 0.48-0.81) and 0.97 (95% CI, 0.89-0.99), respectively. Substantial and considerable heterogeneity was present with regard to sensitivity and specificity (I 2 = 91.21% and 78.53%, respectively). At sensitivity analyses, the specificity estimates were comparable and consistently high across all subgroups (0.93-1.00), but sensitivity estimates showed significant variation (0.14-0.82). Studies using pixel distribution analysis (n = 3) showed substantially lower sensitivity estimates (0.14; 95% CI, 0.04-0.40) compared with the remaining 12 studies (0.81; 95% CI, 0.76-0.85). CT shows moderate sensitivity and excellent specificity for diagnosis of fat-poor AML in patients with renal masses. When methods other than pixel distribution analysis are used, better sensitivity can be achieved.

A systematic review of the reporting of tinnitus prevalence and severity.

PubMed

McCormack, Abby; Edmondson-Jones, Mark; Somerset, Sarah; Hall, Deborah

2016-07-01

There is no standard diagnostic criterion for tinnitus, although some clinical assessment instruments do exist for identifying patient complaints. Within epidemiological studies the presence of tinnitus is determined primarily by self-report, typically in response to a single question. Using these methods prevalence figures vary widely. Given the variety of published estimates worldwide, we assessed and collated published prevalence estimates of tinnitus and tinnitus severity, creating a narrative synthesis of the data. The variability between prevalence estimates was investigated in order to determine any barriers to data synthesis and to identify reasons for heterogeneity. and analysis: A systematic review included all adult population studies reporting the prevalence of tinnitus from January 1980 to July 2015. We searched five databases (Embase, Medline, PsychInfo, CINAHL and Web Of Science), using a combination of medical subject headings (MeSH) and relevant text words. Observational studies including cross-sectional studies were included, but studies estimating the incidence of tinnitus (e.g. cohort studies) were outside the scope of this systematic review. The databases identified 875 papers and a further 16 were identified through manual searching. After duplicates were removed, 515 remained. On the basis of the title, abstract and full-text screening, 400, 48 and 27 papers respectively were removed. This left 40 papers, reporting 39 different studies, for data extraction. Sixteen countries were represented, with the majority of the studies from the European region (38.5%). Publications since 2010 represented half of all included studies (48.7%). Overall prevalence figures for each study ranged from 5.1% to 42.7%. For the 12 studies that used the same definition of tinnitus, prevalence ranged from 11.9% to 30.3%. Twenty-six studies (66.7%) reported tinnitus prevalence by different age groups, and generally showed an increase in prevalence as age increases. Half the studies reported tinnitus prevalence by gender. The pattern generally showed higher tinnitus prevalence among males than females. There were 8 different types of definitions of tinnitus, the most common being "tinnitus lasting for more than five minutes at a time" (34.3%). Only seven studies gave any justification for the question that was used, or acknowledged the lack of standard questions for tinnitus. There is widespread inconsistency in defining and reporting tinnitus, leading to variability in prevalence estimates among studies. Nearly half of the included studies had a high risk of bias and this limits the generalisability of prevalence estimates. In addition, the available prevalence data is heterogeneous thereby preventing the ability to pool the data and perform meta-analyses. Sources of heterogeneity include different diagnostic criteria, different age groups, different study focus and differences in reporting and analysis of the results. Heterogeneity thus made comparison across studies impracticable. Deriving global estimates of the prevalence of tinnitus involves combining results from studies which are consistent in their definition and measurement of tinnitus, survey methodology and in the reporting and analysis of the results. Ultimately comparison among studies is unachievable without such consistency. The strength of this systematic review is in providing a record of all the available, recent epidemiological data in each global region and in making recommendations for promoting standardisation. Copyright © 2016 Elsevier B.V. All rights reserved.

Microcephaly Prevalence in Infants Born to Zika Virus-Infected Women: A Systematic Review and Meta-Analysis

PubMed Central

2017-01-01

Zika virus is an emergent flavivirus transmitted by Aedes genus mosquitoes that recently reached the Americas and was soon implicated in an increase of microcephaly incidence. The objective of the present study is to systematically review the published data and perform a meta-analysis to estimate the prevalence of microcephaly in babies born to Zika virus-infected women during pregnancy. We searched PubMed and Cochrane databases, included cohort studies, and excluded case reports and case series publications. We extracted sample sizes and the number of microcephaly cases from eight studies, which permitted a calculation of prevalence rates that are pooled in a random-effects model meta-analysis. We estimated the prevalence of microcephaly of 2.3% (95% CI = 1.0–5.3%) among all pregnancies. Limitations include mixed samples of women infected at different pregnancy times, since it is known that infection at the first trimester is associated with higher risk to congenital anomalies. The estimates are deceptively low, given the devastating impact the infection causes over children and their families. We hope our study contributes to public health knowledge to fight Zika virus epidemics to protect mothers and their newborns. PMID:28783051

Toxocariasis in North America: a systematic review.

PubMed

Lee, Rachel M; Moore, Laura B; Bottazzi, Maria Elena; Hotez, Peter J

2014-08-01

Toxocariasis is an important neglected tropical disease that can manifest as visceral or ocular larva migrans, or covert toxocariasis. All three forms pose a public health problem and cause significant morbidity in areas of high prevalence. To determine the burden of toxocariasis in North America, we conducted a systematic review of the literature following PRISMA guidelines. We found 18 articles with original prevalence, incidence, or case data for toxocariasis. Prevalence estimates ranged from 0.6% in a Canadian Inuit community to 30.8% in Mexican children with asthma. Commonly cited risk factors included: African-American race, poverty, male sex, and pet ownership or environmental contamination by animal feces. Increased prevalence of Toxocara spp. infection was linked in a group of case control studies conducted in Mexico to several high risk groups including waste pickers, asthmatic children, and inpatient psychiatry patients. Further research is needed to determine the true current burden of toxocariasis in North America; however the prevalence estimates gathered in this review suggest that the burden of disease is significant.

Toxocariasis in North America: A Systematic Review

PubMed Central

Bottazzi, Maria Elena; Hotez, Peter J.

2014-01-01

Toxocariasis is an important neglected tropical disease that can manifest as visceral or ocular larva migrans, or covert toxocariasis. All three forms pose a public health problem and cause significant morbidity in areas of high prevalence. To determine the burden of toxocariasis in North America, we conducted a systematic review of the literature following PRISMA guidelines. We found 18 articles with original prevalence, incidence, or case data for toxocariasis. Prevalence estimates ranged from 0.6% in a Canadian Inuit community to 30.8% in Mexican children with asthma. Commonly cited risk factors included: African-American race, poverty, male sex, and pet ownership or environmental contamination by animal feces. Increased prevalence of Toxocara spp. infection was linked in a group of case control studies conducted in Mexico to several high risk groups including waste pickers, asthmatic children, and inpatient psychiatry patients. Further research is needed to determine the true current burden of toxocariasis in North America; however the prevalence estimates gathered in this review suggest that the burden of disease is significant. PMID:25166906

Evaluation of Simulation Models that Estimate the Effect of Dietary Strategies on Nutritional Intake: A Systematic Review.

PubMed

Grieger, Jessica A; Johnson, Brittany J; Wycherley, Thomas P; Golley, Rebecca K

2017-05-01

Background: Dietary simulation modeling can predict dietary strategies that may improve nutritional or health outcomes. Objectives: The study aims were to undertake a systematic review of simulation studies that model dietary strategies aiming to improve nutritional intake, body weight, and related chronic disease, and to assess the methodologic and reporting quality of these models. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guided the search strategy with studies located through electronic searches [Cochrane Library, Ovid (MEDLINE and Embase), EBSCOhost (CINAHL), and Scopus]. Study findings were described and dietary modeling methodology and reporting quality were critiqued by using a set of quality criteria adapted for dietary modeling from general modeling guidelines. Results: Forty-five studies were included and categorized as modeling moderation, substitution, reformulation, or promotion dietary strategies. Moderation and reformulation strategies targeted individual nutrients or foods to theoretically improve one particular nutrient or health outcome, estimating small to modest improvements. Substituting unhealthy foods with healthier choices was estimated to be effective across a range of nutrients, including an estimated reduction in intake of saturated fatty acids, sodium, and added sugar. Promotion of fruits and vegetables predicted marginal changes in intake. Overall, the quality of the studies was moderate to high, with certain features of the quality criteria consistently reported. Conclusions: Based on the results of reviewed simulation dietary modeling studies, targeting a variety of foods rather than individual foods or nutrients theoretically appears most effective in estimating improvements in nutritional intake, particularly reducing intake of nutrients commonly consumed in excess. A combination of strategies could theoretically be used to deliver the best improvement in outcomes. Study quality was moderate to high. However, given the lack of dietary simulation reporting guidelines, future work could refine the quality tool to harmonize consistency in the reporting of subsequent dietary modeling studies. © 2017 American Society for Nutrition.

Cost-of-illness studies in heart failure: a systematic review 2004-2016.

PubMed

Lesyuk, Wladimir; Kriza, Christine; Kolominsky-Rabas, Peter

2018-05-02

Heart failure is a major and growing medical and economic problem worldwide as 1-2% of the healthcare budget are spent for heart failure. The prevalence of heart failure has increased over the past decades and it is expected that there will be further raise due to the higher proportion of elderly in the western societies. In this context cost-of-illness studies can significantly contribute to a better understanding of the drivers and problems which lead to the increasing costs in heart failure. The aim of this study was to perform a systematic review of published cost-of-illness studies related to heart failure to highlight the increasing cost impact of heart failure. A systematic review was conducted from 2004 to 2016 to identify cost-of-illness studies related to heart failure, searching PubMed (Medline), Cochrane, Science Direct (Embase), Scopus and CRD York Database. Of the total of 16 studies identified, 11 studies reported prevalence-based estimates, 2 studies focused on incidence-based data and 3 articles presented both types of cost data. A large variation concerning cost components and estimates can be noted. Only three studies estimated indirect costs. Most of the included studies have shown that the costs for hospital admission are the most expensive cost element. Estimates for annual prevalence-based costs for heart failure patients range from $868 for South Korea to $25,532 for Germany. The lifetime costs for heart failure patients have been estimated to $126.819 per patient. Our review highlights the considerable and growing economic burden of heart failure on the health care systems. The cost-of-illness studies included in this review show large variations in methodology used and the cost results vary consequently. High quality data from cost-of-illness studies with a robust methodology applied can inform policy makers about the major cost drivers of heart failure and can be used as the basis of further economic evaluations.

Prevalence of Orofacial Clefts among Live Births in China: A Systematic Review and Meta-Analysis.

PubMed

Wang, Mengying; Yuan, Yuan; Wang, Zifan; Liu, Dongjing; Wang, Zhuqing; Sun, Feng; Wang, Ping; Zhu, Hongping; Li, Jing; Wu, Tao; Beaty, Terri H

2017-07-17

Orofacial clefts (OFCs) are common human birth defects in China. However, studies on the prevalence of OFCs present inconsistent results. The overall prevalence and geographic distribution of OFCs are poorly described in China. Thus, we conducted a systematic review and meta-analysis to estimate the prevalence of OFCs. The systematic review and meta-analysis were conducted on the basis of an established protocol (PROSPERO 2015: CRD42015030198). We systematically searched for articles in four electronic databases, including Embase, PubMed, Wanfang Database, and China National Knowledge Infrastructure (CNKI) to identify relevant studies about prevalence of OFCs in China. Meta-analysis, including subgroup analysis, was conducted to estimate the pooled prevalence. A total of 41 studies published between 1986 and 2015 were included in our analysis. The sample size ranged from 2,586 to 4,611,808 live births. The random-effects model of meta-analysis showed that the overall prevalence of OFCs in China was 1.4 per 1000 live births (95% confidence interval [CI], 1.1-1.7). In subgroup analysis based on geographic regions, we found that OFC prevalence in Southwest (2.3 per 1000 live births, 95% CI, 1.1-4.7) was higher than that in other regions of China. There were no significant time trends of OFCs during the study period (p-value = 0.47). The overall prevalence of OFCs in China was 1.4 per 1000 live births. No significant secular trend of prevalence has been found in this analysis. Further studies need to be conducted to explore the etiology of OFC to better control the risk of this common birth defect. Birth Defects Research 109:1011-1019, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Asthma and lung cancer, after accounting for co-occurring respiratory diseases and allergic conditions: a systematic review protocol.

PubMed

Denholm, Rachel; Crellin, Elizabeth; Arvind, Ashwini; Quint, Jennifer

2017-01-16

Asthma is one of the most frequently diagnosed respiratory diseases in the UK, and commonly co-occurs with other respiratory and allergic diseases, such as chronic obstructive pulmonary disease (COPD) and atopic dermatitis. Previous studies have shown an increased risk of lung cancer related to asthma, but the evidence is mixed when accounting for co-occurring respiratory diseases and allergic conditions. A systematic review of published data that investigate the relationship between asthma and lung cancer, accounting for co-occurring respiratory and allergic diseases, will be conducted to investigate the independent association of asthma with lung cancer. A systematic review will be conducted, and include original reports of cohort, cross-sectional and case-control studies of the association of asthma with lung cancer after accounting for co-occurring respiratory diseases. Articles published up to June 2016 will be included, and their selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A standardised data extraction form will be developed and pretested, and descriptive analyses will be used to summarise the available literature. If appropriate, pooled effect estimates of the association between asthma and lung cancer, given adjustment for a specific co-occurring condition will be estimated using random effects models. Potential sources of heterogeneity and between study heterogeneity will also be investigated. The study will be a review of published data and does not require ethical approval. Results will be disseminated through a peer-reviewed publication. International Prospective Register for Systematic Reviews (PROSPERO) number CRD42016043341. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Incidence and characteristics of kidney stones in patients with horseshoe kidney: A systematic review and meta-analysis

PubMed Central

Pawar, Aditya S.; Thongprayoon, Charat; Cheungpasitporn, Wisit; Sakhuja, Ankit; Mao, Michael A.; Erickson, Stephen B.

2018-01-01

Introduction: The horseshoe kidney (HSK) is the most common type of renal fusion anomaly. The incidence and characteristics of kidney stones in patients with HSK are not well studied. The aim of this meta-analysis was to evaluate the incidence and types of kidney stones in patients with HSK. Methods: A systematic literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases' inception through November 2016. Studies assessing the incidence and types of kidney stones in patients with HSK were included. We applied a random-effects model to estimate the incidence of kidney stones. The study protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052037). Results: A total of 14 observational studies with 943 patients (522 adults and 421 pediatric) with HSK were enrolled. The estimated pooled incidence of kidney stones was 36% (95% confidence interval [CI], 15%–59%) in adults with the HSK. Kidney stones were less common in pediatric patients with HSK with an estimated pooled incidence of 3% (95% CI, 2%–5%). The mean age of adult stone formers with HSK was 44.9 ± 6.2 years, and 75% were males. Within reported studies, 89.2% of kidney stones were calcium-based stones (64.2% calcium oxalate [CaOx], 18.8% calcium phosphate [CaP], and 6.2% mixed CaOx/CaP), followed by struvite stones (4.2%), uric acid stones (3.8%), and others (2.8%). Conclusions: Kidney stones are very common in adult patients with HSK with an estimated incidence of 36%. Calcium-based stones are the most prevalent kidney stones in adults with HSKs. These findings may impact the prevention and clinical management of kidney stones in patients with HSK. PMID:29416282

The economic burden of physical inactivity: a systematic review and critical appraisal.

PubMed

Ding, Ding; Kolbe-Alexander, Tracy; Nguyen, Binh; Katzmarzyk, Peter T; Pratt, Michael; Lawson, Kenny D

2017-10-01

To summarise the literature on the economic burden of physical inactivity in populations, with emphases on appraising the methodologies and providing recommendations for future studies. Systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO registration number CRD42016047705). Electronic databases for peer-reviewed and grey literature were systematically searched, followed by reference searching and consultation with experts. Studies that examined the economic consequences of physical inactivity in a population/population-based sample, with clearly stated methodologies and at least an abstract/summary written in English. Of the 40 eligible studies, 27 focused on direct healthcare costs only, 13 also estimated indirect costs and one study additionally estimated household costs. For direct costs, 23 studies used a population attributable fraction (PAF) approach with estimated healthcare costs attributable to physical inactivity ranging from 0.3% to 4.6% of national healthcare expenditure; 17 studies used an econometric approach, which tended to yield higher estimates than those using a PAF approach. For indirect costs, 10 studies used a human capital approach, two used a friction cost approach and one used a value of a statistical life approach. Overall, estimates varied substantially, even within the same country, depending on analytical approaches, time frame and other methodological considerations. Estimating the economic burden of physical inactivity is an area of increasing importance that requires further development. There is a marked lack of consistency in methodological approaches and transparency of reporting. Future studies could benefit from cross-disciplinary collaborations involving economists and physical activity experts, taking a societal perspective and following best practices in conducting and reporting analysis, including accounting for potential confounding, reverse causality and comorbidity, applying discounting and sensitivity analysis, and reporting assumptions, limitations and justifications for approaches taken. We have adapted the Consolidated Health Economic Evaluation Reporting Standards checklist as a guide for future estimates of the economic burden of physical inactivity and other risk factors. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bao, C.; Hanany, S.; Baccigalupi, C.

We extend a general maximum likelihood foreground estimation for cosmic microwave background (CMB) polarization data to include estimation of instrumental systematic effects. We focus on two particular effects: frequency band measurement uncertainty and instrumentally induced frequency dependent polarization rotation. We assess the bias induced on the estimation of the B-mode polarization signal by these two systematic effects in the presence of instrumental noise and uncertainties in the polarization and spectral index of Galactic dust. Degeneracies between uncertainties in the band and polarization angle calibration measurements and in the dust spectral index and polarization increase the uncertainty in the extracted CMBmore » B-mode power, and may give rise to a biased estimate. We provide a quantitative assessment of the potential bias and increased uncertainty in an example experimental configuration. For example, we find that with 10% polarized dust, a tensor to scalar ratio of r = 0.05, and the instrumental configuration of the E and B experiment balloon payload, the estimated CMB B-mode power spectrum is recovered without bias when the frequency band measurement has 5% uncertainty or less, and the polarization angle calibration has an uncertainty of up to 4°.« less

Characterizing unknown systematics in large scale structure surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwal, Nishant; Ho, Shirley; Myers, Adam D.

Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data,more » we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study.« less

A systematic review of lumped-parameter equivalent circuit models for real-time estimation of lithium-ion battery states

NASA Astrophysics Data System (ADS)

Nejad, S.; Gladwin, D. T.; Stone, D. A.

2016-06-01

This paper presents a systematic review for the most commonly used lumped-parameter equivalent circuit model structures in lithium-ion battery energy storage applications. These models include the Combined model, Rint model, two hysteresis models, Randles' model, a modified Randles' model and two resistor-capacitor (RC) network models with and without hysteresis included. Two variations of the lithium-ion cell chemistry, namely the lithium-ion iron phosphate (LiFePO4) and lithium nickel-manganese-cobalt oxide (LiNMC) are used for testing purposes. The model parameters and states are recursively estimated using a nonlinear system identification technique based on the dual Extended Kalman Filter (dual-EKF) algorithm. The dynamic performance of the model structures are verified using the results obtained from a self-designed pulsed-current test and an electric vehicle (EV) drive cycle based on the New European Drive Cycle (NEDC) profile over a range of operating temperatures. Analysis on the ten model structures are conducted with respect to state-of-charge (SOC) and state-of-power (SOP) estimation with erroneous initial conditions. Comparatively, both RC model structures provide the best dynamic performance, with an outstanding SOC estimation accuracy. For those cell chemistries with large inherent hysteresis levels (e.g. LiFePO4), the RC model with only one time constant is combined with a dynamic hysteresis model to further enhance the performance of the SOC estimator.

Planck intermediate results: XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

DOE PAGES

Aghanim, N.; Ashdown, M.; Aumont, J.; ...

2016-12-12

This study describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducingmore » significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. Finally, in a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.« less

Planck intermediate results: XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aghanim, N.; Ashdown, M.; Aumont, J.

This study describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducingmore » significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. Finally, in a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.« less

Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

NASA Astrophysics Data System (ADS)

Planck Collaboration; Aghanim, N.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battye, R.; Benabed, K.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Carron, J.; Challinor, A.; Chiang, H. C.; Colombo, L. P. L.; Combet, C.; Comis, B.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Di Valentino, E.; Dickinson, C.; Diego, J. M.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fantaye, Y.; Finelli, F.; Forastieri, F.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Gerbino, M.; Ghosh, T.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hivon, E.; Huang, Z.; Ilić, S.; Jaffe, A. H.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knox, L.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leahy, J. P.; Levrier, F.; Liguori, M.; Lilje, P. B.; López-Caniego, M.; Ma, Y.-Z.; Macías-Pérez, J. F.; Maggio, G.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Matarrese, S.; Mauri, N.; McEwen, J. D.; Meinhold, P. R.; Melchiorri, A.; Mennella, A.; Migliaccio, M.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Mottet, S.; Naselsky, P.; Natoli, P.; Oxborrow, C. A.; Pagano, L.; Paoletti, D.; Partridge, B.; Patanchon, G.; Patrizii, L.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Plaszczynski, S.; Polastri, L.; Polenta, G.; Puget, J.-L.; Rachen, J. P.; Racine, B.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Ruiz-Granados, B.; Salvati, L.; Sandri, M.; Savelainen, M.; Scott, D.; Sirri, G.; Sunyaev, R.; Suur-Uski, A.-S.; Tauber, J. A.; Tenti, M.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Valiviita, J.; Van Tent, F.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; White, M.; Zacchei, A.; Zonca, A.

2016-12-01

This paper describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducing significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. In a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.

Systematic reviews of diagnostic tests in endocrinology: an audit of methods, reporting, and performance.

PubMed

Spencer-Bonilla, Gabriela; Singh Ospina, Naykky; Rodriguez-Gutierrez, Rene; Brito, Juan P; Iñiguez-Ariza, Nicole; Tamhane, Shrikant; Erwin, Patricia J; Murad, M Hassan; Montori, Victor M

2017-07-01

Systematic reviews provide clinicians and policymakers estimates of diagnostic test accuracy and their usefulness in clinical practice. We identified all available systematic reviews of diagnosis in endocrinology, summarized the diagnostic accuracy of the tests included, and assessed the credibility and clinical usefulness of the methods and reporting. We searched Ovid MEDLINE, EMBASE, and Cochrane CENTRAL from inception to December 2015 for systematic reviews and meta-analyses reporting accuracy measures of diagnostic tests in endocrinology. Experienced reviewers independently screened for eligible studies and collected data. We summarized the results, methods, and reporting of the reviews. We performed subgroup analyses to categorize diagnostic tests as most useful based on their accuracy. We identified 84 systematic reviews; half of the tests included were classified as helpful when positive, one-fourth as helpful when negative. Most authors adequately reported how studies were identified and selected and how their trustworthiness (risk of bias) was judged. Only one in three reviews, however, reported an overall judgment about trustworthiness and one in five reported using adequate meta-analytic methods. One in four reported contacting authors for further information and about half included only patients with diagnostic uncertainty. Up to half of the diagnostic endocrine tests in which the likelihood ratio was calculated or provided are likely to be helpful in practice when positive as are one-quarter when negative. Most diagnostic systematic reviews in endocrine lack methodological rigor, protection against bias, and offer limited credibility. Substantial efforts, therefore, seem necessary to improve the quality of diagnostic systematic reviews in endocrinology.

Estimation of shortwave hemispherical reflectance (albedo) from bidirectionally reflected radiance data

NASA Technical Reports Server (NTRS)

Starks, Patrick J.; Norman, John M.; Blad, Blaine L.; Walter-Shea, Elizabeth A.; Walthall, Charles L.

1991-01-01

An equation for estimating albedo from bidirectional reflectance data is proposed. The estimates of albedo are found to be greater than values obtained with simultaneous pyranometer measurements. Particular attention is given to potential sources of systematic errors including extrapolation of bidirectional reflectance data out to a view zenith angle of 90 deg, the use of inappropriate weighting coefficients in the numerator of the albedo equation, surface shadowing caused by the A-frame instrumentation used to measure the incoming and outgoing radiation fluxes, errors in estimates of the denominator of the proposed albedo equation, and a 'hot spot' contribution in bidirectional data measured by a modular multiband radiometer.

Dose-response relationship between cigarette smoking and site-specific cancer risk: protocol for a systematic review with an original design combining umbrella and traditional reviews.

PubMed

Lugo, Alessandra; Bosetti, Cristina; Peveri, Giulia; Rota, Matteo; Bagnardi, Vincenzo; Gallus, Silvano

2017-11-01

Only a limited number of meta-analyses providing risk curve functions of dose-response relationships between various smoking-related variables and cancer-specific risk are available. To identify all relevant original publications on the issue, we will conduct a series of comprehensive systematic reviews based on three subsequent literature searches: (1) an umbrella review, to identify meta-analyses, pooled analyses and systematic reviews published before 28 April 2017 on the association between cigarette smoking and the risk of 28 (namely all) malignant neoplasms; (2) for each cancer site, an updated review of original publications on the association between cigarette smoking and cancer risk, starting from the last available comprehensive review identified through the umbrella review; and (3) a review of all original articles on the association between cigarette smoking and site-specific cancer risk included in the publications identified through the umbrella review and the updated reviews. The primary outcomes of interest will be (1) the excess incidence/mortality of various cancers for smokers compared with never smokers; and (2) the dose-response curves describing the association between smoking intensity, duration and time since stopping and incidence/mortality for various cancers. For each cancer site, we will perform a meta-analysis by pooling study-specific estimates for smoking status. We will also estimate the dose-response curves for other smoking-related variables through random-effects meta-regression models based on a non-linear dose-response relationship framework. Ethics approval is not required for this study. Main results will be published in peer-reviewed journals and will also be included in a publicly available website. We will provide therefore the most complete and updated estimates on the association between various measures of cigarette smoking and site-specific cancer risk. This will allow us to obtain precise estimates on the cancer burden attributable to cigarette smoking. This protocol was registered in the International Prospective Register of Systematic Reviews (CRD42017063991). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Systematic review of the incidence of sudden cardiac death in the United States.

PubMed

Kong, Melissa H; Fonarow, Gregg C; Peterson, Eric D; Curtis, Anne B; Hernandez, Adrian F; Sanders, Gillian D; Thomas, Kevin L; Hayes, David L; Al-Khatib, Sana M

2011-02-15

The need for consistent and current data describing the true incidence of sudden cardiac arrest (SCA) and/or sudden cardiac death (SCD) was highlighted during the most recent Sudden Cardiac Arrest Thought Leadership Alliance's (SCATLA) Think Tank meeting of national experts with broad representation of key stakeholders, including thought leaders and representatives from the American College of Cardiology, American Heart Association, and the Heart Rhythm Society. As such, to evaluate the true magnitude of this public health problem, we performed a systematic literature search in MEDLINE using the MeSH headings, "death, sudden" OR the terms "sudden cardiac death" OR "sudden cardiac arrest" OR "cardiac arrest" OR "cardiac death" OR "sudden death" OR "arrhythmic death." Study selection criteria included peer-reviewed publications of primary data used to estimate SCD incidence in the U.S. We used Web of Science's Cited Reference Search to evaluate the impact of each primary estimate on the medical literature by determining the number of times each "primary source" has been cited. The estimated U.S. annual incidence of SCD varied widely from 180,000 to >450,000 among 6 included studies. These different estimates were in part due to different data sources (with data age ranging from 1980 to 2007), definitions of SCD, case ascertainment criteria, methods of estimation/extrapolation, and sources of case ascertainment. The true incidence of SCA and/or SCD in the U.S. remains unclear, with a wide range in the available estimates that are badly dated. As reliable estimates of SCD incidence are important for improving risk stratification and prevention, future efforts are clearly needed to establish uniform definitions of SCA and SCD and then to prospectively and precisely capture cases of SCA and SCD in the overall U.S. population. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Exposure to traffic-related air pollution and risk of development of childhood asthma: A systematic review and meta-analysis.

PubMed

Khreis, Haneen; Kelly, Charlotte; Tate, James; Parslow, Roger; Lucas, Karen; Nieuwenhuijsen, Mark

2017-03-01

The question of whether children's exposure to traffic-related air pollution (TRAP) contributes to their development of asthma is unresolved. We conducted a systematic review and performed meta-analyses to analyze the association between TRAP and asthma development in childhood. We systematically reviewed epidemiological studies published until 8 September 2016 and available in the Embase, Ovid MEDLINE (R), and Transport databases. We included studies that examined the association between children's exposure to TRAP metrics and their risk of 'asthma' incidence or lifetime prevalence, from birth to age 18years old. We extracted key characteristics of each included study using a predefined data items template and these were tabulated. We used the Critical Appraisal Skills Programme checklists to assess the validity of each included study. Where four or more independent risk estimates were available for a continuous pollutant exposure, we conducted overall and age-specific meta-analyses, and four sensitivity analyses for each summary meta-analytic exposure-outcome association. Forty-one studies met our eligibility criteria. There was notable variability in asthma definitions, TRAP exposure assessment methods and confounder adjustment. The overall random-effects risk estimates (95% CI) were 1.08 (1.03, 1.14) per 0.5×10 -5 m -1 black carbon (BC), 1.05 (1.02, 1.07) per 4μg/m 3 nitrogen dioxide (NO 2 ), 1.48 (0.89, 2.45) per 30μg/m 3 nitrogen oxides (NO x ), 1.03 (1.01, 1.05) per 1μg/m 3 Particulate Matter <2.5μm in diameter (PM 2.5 ), and 1.05 (1.02, 1.08) per 2μg/m 3 Particulate Matter <10μm in diameter (PM 10 ). Sensitivity analyses supported these findings. Across the main analysis and age-specific analysis, the least heterogeneity was seen for the BC estimates, some heterogeneity for the PM 2.5 and PM 10 estimates and the most heterogeneity for the NO 2 and NO x estimates. The overall risk estimates from the meta-analyses showed statistically significant associations for BC, NO 2 , PM 2.5 , PM 10 exposures and risk of asthma development. Our findings support the hypothesis that childhood exposure to TRAP contributes to their development of asthma. Future meta-analyses would benefit from greater standardization of study methods including exposure assessment harmonization, outcome harmonization, confounders' harmonization and the inclusion of all important confounders in individual studies. PROSPERO 2014: CRD42014015448. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimating the coverage of mental health programmes: a systematic review

PubMed Central

De Silva, Mary J; Lee, Lucy; Fuhr, Daniela C; Rathod, Sujit; Chisholm, Dan; Schellenberg, Joanna; Patel, Vikram

2014-01-01

Background The large treatment gap for people suffering from mental disorders has led to initiatives to scale up mental health services. In order to track progress, estimates of programme coverage, and changes in coverage over time, are needed. Methods Systematic review of mental health programme evaluations that assess coverage, measured either as the proportion of the target population in contact with services (contact coverage) or as the proportion of the target population who receive appropriate and effective care (effective coverage). We performed a search of electronic databases and grey literature up to March 2013 and contacted experts in the field. Methods to estimate the numerator (service utilization) and the denominator (target population) were reviewed to explore methods which could be used in programme evaluations. Results We identified 15 735 unique records of which only seven met the inclusion criteria. All studies reported contact coverage. No study explicitly measured effective coverage, but it was possible to estimate this for one study. In six studies the numerator of coverage, service utilization, was estimated using routine clinical information, whereas one study used a national community survey. The methods for estimating the denominator, the population in need of services, were more varied and included national prevalence surveys case registers, and estimates from the literature. Conclusions Very few coverage estimates are available. Coverage could be estimated at low cost by combining routine programme data with population prevalence estimates from national surveys. PMID:24760874

Wave-optics uncertainty propagation and regression-based bias model in GNSS radio occultation bending angle retrievals

NASA Astrophysics Data System (ADS)

Gorbunov, Michael E.; Kirchengast, Gottfried

2018-01-01

A new reference occultation processing system (rOPS) will include a Global Navigation Satellite System (GNSS) radio occultation (RO) retrieval chain with integrated uncertainty propagation. In this paper, we focus on wave-optics bending angle (BA) retrieval in the lower troposphere and introduce (1) an empirically estimated boundary layer bias (BLB) model then employed to reduce the systematic uncertainty of excess phases and bending angles in about the lowest 2 km of the troposphere and (2) the estimation of (residual) systematic uncertainties and their propagation together with random uncertainties from excess phase to bending angle profiles. Our BLB model describes the estimated bias of the excess phase transferred from the estimated bias of the bending angle, for which the model is built, informed by analyzing refractivity fluctuation statistics shown to induce such biases. The model is derived from regression analysis using a large ensemble of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) RO observations and concurrent European Centre for Medium-Range Weather Forecasts (ECMWF) analysis fields. It is formulated in terms of predictors and adaptive functions (powers and cross products of predictors), where we use six main predictors derived from observations: impact altitude, latitude, bending angle and its standard deviation, canonical transform (CT) amplitude, and its fluctuation index. Based on an ensemble of test days, independent of the days of data used for the regression analysis to establish the BLB model, we find the model very effective for bias reduction and capable of reducing bending angle and corresponding refractivity biases by about a factor of 5. The estimated residual systematic uncertainty, after the BLB profile subtraction, is lower bounded by the uncertainty from the (indirect) use of ECMWF analysis fields but is significantly lower than the systematic uncertainty without BLB correction. The systematic and random uncertainties are propagated from excess phase to bending angle profiles, using a perturbation approach and the wave-optical method recently introduced by Gorbunov and Kirchengast (2015), starting with estimated excess phase uncertainties. The results are encouraging and this uncertainty propagation approach combined with BLB correction enables a robust reduction and quantification of the uncertainties of excess phases and bending angles in the lower troposphere.

Methodological Considerations in Social Cost Studies of Addictive Substances: A Systematic Literature Review.

PubMed

Verhaeghe, Nick; Lievens, Delfine; Annemans, Lieven; Vander Laenen, Freya; Putman, Koen

2016-01-01

Alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals' use is associated with a higher likelihood of developing several diseases and injuries and, as a consequence, considerable health-care expenditures. There is yet a lack of consistent methodologies to estimate the economic impact of addictive substances to society. The aim was to assess the methodological approaches applied in social cost studies estimating the economic impact of alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals. A systematic literature review through the electronic databases, Medline (PubMed) and Web of Science, was performed. Studies in English published from 1997 examining the social costs of the addictive substances alcohol, tobacco, illicit drugs, and psychoactive pharmaceuticals were eligible for inclusion. Twelve social cost studies met the inclusion criteria. In all studies, the direct and indirect costs were measured, but the intangible costs were seldom taken into account. A wide variety in cost items included across studies was observed. Sensitivity analyses to address the uncertainty around certain cost estimates were conducted in eight studies considered in the review. Differences in cost items included in cost-of-illness studies limit the comparison across studies. It is clear that it is difficult to deal with all consequences of substance use in cost-of-illness studies. Future social cost studies should be based on sound methodological principles in order to result in more reliable cost estimates of the economic burden of substance use.

Global prevalence of diabetes mellitus in patients with tuberculosis: a systematic review and meta-analysis protocol.

PubMed

Tankeu, Aurel T; Bigna, Jean Joël; Nansseu, Jobert Richie; Endomba, Francky Teddy A; Wafeu, Guy Sadeu; Kaze, Arnaud D; Noubiap, Jean Jacques

2017-06-09

Diabetes mellitus (DM) is an important risk factor for active tuberculosis (TB), which also adversely affect TB treatment outcomes. The escalating global DM epidemic is fuelling the burden of TB and should therefore be a major target in the strategy for ending TB. This review aims to estimate the global prevalence of DM in patients with TB. This systematic review will include cross-sectional, case-control or cohort studies of populations including patients diagnosed with TB that have reported the prevalence of DM using one of the fourth standard recommendations for screening and diagnosis. This protocol is written in accordance with recommendations from the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 statement. Relevant abstracts published in English/French from inception to 31 December 2016 will be searched in PubMed, Excerpta Medica Database and online journals. Two investigators will independently screen, select studies, extract data and assess the risk of bias in each study. The study-specific estimates will be pooled through a random-effects meta-analysis model to obtain an overall summary estimate of the prevalence of diabetes across the studies. Heterogeneity will be assessed, and we will pool studies judged to be clinically homogenous. On the other hand, statistical heterogeneity will be evaluated by the χ² test on Cochrane's Q statistic. Funnel-plots analysis and Egger's test will be used to investigate publication bias. Results will be presented by continent or geographic regions. This study is based on published data. An ethical approval is therefore not required. This systematic review and meta-analysis is expected to inform healthcare providers as well as general population on the co-occurrence of DM and TB. The final report will be published as an original article in a peer-reviewed journal, and will also be presented at conferences and submitted to relevant health authorities. We also plan to update the review every 5 years. PROSPERO International Prospective Register of Systematic Reviews (CRD42016049901). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A systematic review to assess comparative effectiveness studies in epidural steroid injections for lumbar spinal stenosis and to estimate reimbursement amounts.

PubMed

Bresnahan, Brian W; Rundell, Sean D; Dagadakis, Marissa C; Sullivan, Sean D; Jarvik, Jeffrey G; Nguyen, Hiep; Friedly, Janna L

2013-08-01

To systematically appraise published comparative effectiveness evidence (clinical and economic) of epidural steroid injections (ESI) for lumbar spinal stenosis and to estimate Medicare reimbursement amounts for ESI procedures. TYPE: Systematic review. PubMed, Embase, and CINAHL were searched through August 2012 for key words that pertain to low back pain, spinal stenosis or sciatica, and epidural steroid injection. We used institutional and Medicare reimbursement amounts for our cost estimation. Articles published in English that assessed ESIs for adults with lumbar spinal stenosis versus a comparison intervention were included. Our search identified 146 unique articles, and 138 were excluded due to noncomparative study design, not having a study population with lumbar spinal stenosis, not having an appropriate outcome, or not being in English. We fully summarized 6 randomized controlled trials and 2 large observational studies. Randomized controlled trial articles were reviewed, and the study population, sample size, treatment groups, ESI dosage, ESI approaches, concomitant interventions, outcomes, and follow-up time were reported. Descriptive resource use estimates for ESIs were calculated with use of data from our institution during 2010 and Medicare-based reimbursement amounts. ESIs or anesthetic injections alone resulted in better short-term improvement in walking distance compared with control injections. However, there were no longer-term differences. No differences between ESIs versus anesthetic in self-reported improvement in pain were reported. Transforaminal approaches had better improvement in pain scores (≤4 months) compared with interlaminar injections. Two observational studies indicated increased rates of lumbar ESI in Medicare beneficiaries. Our sample included 279 patients who received at least 1 ESI during 2010, with an estimated mean total outpatient reimbursement for one ESI procedure "event" to be $637, based on 2010 Medicare reimbursement amounts ($505 technical and $132 professional payments). This systematic review of ESI for treating lumbar spinal stenosis found a limited amount of data that suggest that ESI is effective in some patients for improving select short-term outcomes, but results differed depending on study design, outcome measures used, and comparison groups evaluated. Overall, there are relatively few comparative clinical or economic studies for ESI procedures for lumbar spinal stenosis in adults, which indicated a need for additional evidence. Copyright © 2013. Published by Elsevier Inc.

Cost-effectiveness of health-related lifestyle advice delivered by peer or lay advisors: synthesis of evidence from a systematic review

PubMed Central

2013-01-01

Background Development of new peer or lay health-related lifestyle advisor (HRLA) roles is one response to the need to enhance public engagement in, and improve cost-effectiveness of, health improvement interventions. This article synthesises evidence on the cost-effectiveness of HRLA interventions aimed at adults in developed countries, derived from the first systematic review of the effectiveness, cost-effectiveness, equity and acceptability of different types of HRLA role. Methods The best available evidence on the cost-effectiveness of HRLA interventions was obtained using systematic searches of 20 electronic databases and key journals, as well as searches of the grey literature and the internet. Interventions were classified according to the primary health behaviour targeted and intervention costs were estimated where necessary. Lifetime health gains were estimated (in quality-adjusted life years, where possible), based on evidence of effectiveness of HRLAs in combination with published estimates of the lifetime health gains resulting from lifestyle changes, and assumptions over relapse. Incremental cost-effectiveness ratios are reported. Results Evidence of the cost-effectiveness of HRLAs was identified from 24 trials included in the systematic review. The interventions were grouped into eight areas. We found little evidence of effectiveness of HRLAs for promotion of exercise/improved diets. Where HRLAs were effective cost-effectiveness varied considerably: Incremental Cost effectiveness Ratios were estimated at £6,000 for smoking cessation; £14,000 for a telephone based type 2 diabetes management; and £250,000 or greater for promotion of mammography attendance and for HIV prevention amongst drug users. We lacked sufficient evidence to estimate ICERs for breastfeeding promotion and mental health promotion, or to assess the impact of HRLAs on health inequalities. Conclusions Overall, there is limited evidence suggesting that HRLAs are cost-effective in terms of changing health-related knowledge, behaviours or health outcomes. The evidence that does exist indicates that HRLAs are only cost-effective when they target behaviours likely to have a large impact on overall health-related quality of life. Further development of HRLA interventions needs to target specific population health needs where potential exists for significant improvement, and include rigorous evaluation to ensure that HRLAs provide sufficient value for money. PMID:24304826

Clinical manifestations associated with neurocysticercosis: a systematic review.

PubMed

Carabin, Hélène; Ndimubanzi, Patrick Cyaga; Budke, Christine M; Nguyen, Hai; Qian, Yingjun; Cowan, Linda Demetry; Stoner, Julie Ann; Rainwater, Elizabeth; Dickey, Mary

2011-05-01

The clinical manifestations of neurocysticercosis (NCC) are poorly understood. This systematic review aims to estimate the frequencies of different manifestations, complications and disabilities associated with NCC. A systematic search of the literature published from January 1, 1990, to June 1, 2008, in 24 different electronic databases and 8 languages was conducted. Meta-analyses were conducted when appropriate. A total of 1569 documents were identified, and 21 included in the analysis. Among patients seen in neurology clinics, seizures/epilepsy were the most common manifestations (78.8%, 95%CI: 65.1%-89.7%) followed by headaches (37.9%, 95%CI: 23.3%-53.7%), focal deficits (16.0%, 95%CI: 9.7%-23.6%) and signs of increased intracranial pressure (11.7%, 95%CI: 6.0%-18.9%). All other manifestations occurred in less than 10% of symptomatic NCC patients. Only four studies reported on the mortality rate of NCC. NCC is a pleomorphic disease linked to a range of manifestations. Although definitions of manifestations were very rarely provided, and varied from study to study, the proportion of NCC cases with seizures/epilepsy and the proportion of headaches were consistent across studies. These estimates are only applicable to patients who are ill enough to seek care in neurology clinics and likely over estimate the frequency of manifestations among all NCC cases.

Prevention of Friction Blisters in Outdoor Pursuits: A Systematic Review.

PubMed

Worthing, Robert M; Percy, Raechel L; Joslin, Jeremy D

2017-06-01

The purpose of this systematic review was to determine if sock, antiperspirant, or barrier strategies were effective in prevention of friction blisters in wilderness and outdoor pursuits. A search of PubMed and EMBASE was conducted. Title, abstract, and full text articles were screened by 2 authors using predetermined inclusion and exclusion criteria to identify prospective controlled trials investigating prevention methods for friction blisters involving the foot. Only blisters associated with wilderness and outdoor pursuits (running, hiking, marching, etc.) were considered. Extraction of a predetermined data set was accomplished using a piloted form. Confidence in effect estimates were determined utilizing the Scottish Intercollegiate Guidelines Network methodology checklist. Literature search resulted in 806 discrete articles. After screening, 11 studies were identified for inclusion in systematic review. Included studies investigated 5 sock, 3 antiperspirant, and 3 barrier strategies. Only 2 articles were determined to have moderate confidence in effect estimate. Clinical and methodologic diversity precluded meta-analysis. Despite the high frequency, discomfort, and associated cost there is a paucity of high-quality quality evidence in support of socks, antiperspirants, or barriers for the prevention of friction blisters. Moderate confidence in effect estimate suggests that paper tape may be an effective form of barrier prevention. Published by Elsevier Inc.

Prevalence of Chagas disease in pregnant women and congenital transmission of Trypanosoma cruzi in Brazil: a systematic review and meta-analysis.

PubMed

Martins-Melo, Francisco Rogerlândio; Lima, Mauricélia da Silveira; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Heukelbach, Jörg

2014-08-01

To estimate the prevalence of Chagas disease in pregnant women and the risk of congenital transmission of Trypanosoma cruzi infection in Brazil, through a systematic review and meta-analysis. We searched electronic databases, grey literature and reference lists of included publications to identify epidemiological studies on the prevalence of Chagas disease in pregnant women and on the congenital transmission rate of T. cruzi infection in Brazil published between January 1980 and June 2013. Pooled estimates and 95% confidence intervals (95% CIs) were calculated using fixed- and random-effects models. Sixteen articles were included - 12 studies on the prevalence of Chagas disease in pregnant women (549,359 pregnant women) and nine on congenital transmission rates (1687 children born to infected mothers). Prevalence of Chagas disease in pregnant women ranged from 0.1% to 8.5%, and congenital transmission rates from 0% to 5.2%. The pooled prevalence of Chagas disease among pregnant women across studies was 1.1% (95% CI: 0.6-2.0); the pooled congenital transmission rate was 1.7% (95% CI: 0.9-3.1). In 2010, 34,629 pregnant women were estimated to be infected with T. cruzi, and 312-1073 children born (mean: 589 cases) with congenital infection. Congenital Chagas disease is a neglected public health problem in Brazil. Systematic congenital Chagas disease control programs through routine prenatal screening for T. cruzi should be widely implemented in Brazil's endemic areas, to identify infected pregnant women and newborns at risk of congenital infection. © 2014 John Wiley & Sons Ltd.

Estimating the encounter rate variance in distance sampling

USGS Publications Warehouse

Fewster, R.M.; Buckland, S.T.; Burnham, K.P.; Borchers, D.L.; Jupp, P.E.; Laake, J.L.; Thomas, L.

2009-01-01

The dominant source of variance in line transect sampling is usually the encounter rate variance. Systematic survey designs are often used to reduce the true variability among different realizations of the design, but estimating the variance is difficult and estimators typically approximate the variance by treating the design as a simple random sample of lines. We explore the properties of different encounter rate variance estimators under random and systematic designs. We show that a design-based variance estimator improves upon the model-based estimator of Buckland et al. (2001, Introduction to Distance Sampling. Oxford: Oxford University Press, p. 79) when transects are positioned at random. However, if populations exhibit strong spatial trends, both estimators can have substantial positive bias under systematic designs. We show that poststratification is effective in reducing this bias. ?? 2008, The International Biometric Society.

Clinical outcomes after estimated versus calculated activity of radioiodine for the treatment of hyperthyroidism: systematic review and meta-analysis.

PubMed

de Rooij, A; Vandenbroucke, J P; Smit, J W A; Stokkel, M P M; Dekkers, O M

2009-11-01

Despite the long experience with radioiodine for hyperthyroidism, controversy remains regarding the optimal method to determine the activity that is required to achieve long-term euthyroidism. To compare the effect of estimated versus calculated activity of radioiodine in hyperthyroidism. Design Systematic review and meta-analysis. We searched the databases Medline, EMBASE, Web of Science, and Cochrane Library for randomized and nonrandomized studies, comparing the effect of activity estimation methods with dosimetry for hyperthyroidism. The main outcome measure was the frequency of treatment success, defined as persistent euthyroidism after radioiodine treatment at the end of follow-up in the dose estimated and calculated dosimetry group. Furthermore, we assessed the cure rates of hyperthyroidism. Three randomized and five nonrandomized studies, comparing the effect of estimated versus calculated activity of radioiodine on clinical outcomes for the treatment of hyperthyroidism, were included. The weighted mean relative frequency of successful treatment outcome (euthyroidism) was 1.03 (95% confidence interval (CI) 0.91-1.16) for estimated versus calculated activity; the weighted mean relative frequency of cure of hyperthyroidism (eu- or hypothyroidism) was 1.03 (95% CI 0.96-1.10). Subgroup analysis showed a relative frequency of euthyroidism of 1.03 (95% CI 0.84-1.26) for Graves' disease and of 1.05 (95% CI 0.91-1.19) for toxic multinodular goiter. The two main methods used to determine the activity in the treatment of hyperthyroidism with radioiodine, estimated and calculated, resulted in an equally successful treatment outcome. However, the heterogeneity of the included studies is a strong limitation that prevents a definitive conclusion from this meta-analysis.

A systematic review of studies eliciting willingness-to-pay per quality-adjusted life year: does it justify CE threshold?

PubMed

Nimdet, Khachapon; Chaiyakunapruk, Nathorn; Vichansavakul, Kittaya; Ngorsuraches, Surachat

2015-01-01

A number of studies have been conducted to estimate willingness to pay (WTP) per quality-adjusted life years (QALY) in patients or general population for various diseases. However, there has not been any systematic review summarizing the relationship between WTP per QALY and cost-effectiveness (CE) threshold based on World Health Organization (WHO) recommendation. To systematically review willingness-to-pay per quality-adjusted-life-year (WTP per QALY) literature, to compare WTP per QALY with Cost-effectiveness (CE) threshold recommended by WHO, and to determine potential influencing factors. We searched MEDLINE, EMBASE, Psyinfo, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Center of Research Dissemination (CRD), and EconLit from inception through 15 July 2014. To be included, studies have to estimate WTP per QALY in health-related issues using stated preference method. Two investigators independently reviewed each abstract, completed full-text reviews, and extracted information for included studies. We compared WTP per QALY to GDP per capita, analyzed, and summarized potential influencing factors. Out of 3,914 articles founded, 14 studies were included. Most studies (92.85%) used contingent valuation method, while only one study used discrete choice experiments. Sample size varied from 104 to 21,896 persons. The ratio between WTP per QALY and GDP per capita varied widely from 0.05 to 5.40, depending on scenario outcomes (e.g., whether it extended/saved life or improved quality of life), severity of hypothetical scenarios, duration of scenario, and source of funding. The average ratio of WTP per QALY and GDP per capita for extending life or saving life (2.03) was significantly higher than the average for improving quality of life (0.59) with the mean difference of 1.43 (95% CI, 1.81 to 1.06). This systematic review provides an overview summary of all studies estimating WTP per QALY studies. The variation of ratio of WTP per QALY and GDP per capita depended on several factors may prompt discussions on the CE threshold policy. Our research work provides a foundation for defining future direction of decision criteria for an evidence-informed decision making system.

A systematic review and meta-analysis of vertical transmission route of HIV in Ethiopia.

PubMed

Endalamaw, Aklilu; Demsie, Amare; Eshetie, Setegn; Habtewold, Tesfa Dejenie

2018-06-22

The burden of mother-to-child transmission rate of HIV is high and risk factors are common in Ethiopia. This systematic review and meta-analysis intended to provide the pooled estimation of mother-to-child transmission rate and its risk factors in Ethiopia. We searched PubMed, Google Scholar, EMBASE and Web of Science electronic databases for all available references. We included observational studies including case-control, cohort, and cross-sectional studies. The search was further limited to studies conducted in Ethiopia and publish in English. Heterogeneity was checked using the I 2 statistic. Egger's test and the funnel plot were used to assess publication bias. A meta-analysis using a weighted inverse variance random-effects model was performed. A total of 18 studies with 6253 individuals were included in this systematic review and meta-analysis. Of these, 14 studies with 4624 individuals were used to estimate the prevalence. The estimated pooled prevalence of mother-to-child transmission of HIV was 11.4% (95% CI = 9.1-13.7). The pooled adjusted odds ratio (AOR) of mother-to-child transmission of HIV for the infants from rural area was 3.8 (95% CI = 1.4 to 6.3), infants delivered at home was 3.2 (95% CI = 1.2 to 5.2), infant didn't take antiretroviral prophylaxis was 5.8 (95% CI = 1.5 to 10.3), mother didn't take antiretroviral prophylaxis was 6.1 (95% CI = 2.5 to 9.6), mothers didn't receive PMTCT intervention was 5.1 (95% CI = 1.6, 8.6), and on mixed feeding was 4.3 (95% CI = 1.8 to 6.7). This systematic review and meta-analysis showed that mother-to-child transmission rate of HIV was high in Ethiopia. Being from the rural residence, home delivery, not taking antiretroviral prophylaxis, the absence of PMTCT intervention, and mixed infant feeding practices increased the risk of HIV transmission. It is registered in the Prospero database: (PROSPERO 2017: CRD42017078232 ).

A polar-region-adaptable systematic bias collaborative measurement method for shipboard redundant rotational inertial navigation systems

NASA Astrophysics Data System (ADS)

Wang, Lin; Wu, Wenqi; Wei, Guo; Lian, Junxiang; Yu, Ruihang

2018-05-01

The shipboard redundant rotational inertial navigation system (RINS) configuration, including a dual-axis RINS and a single-axis RINS, can satisfy the demand of marine INSs of especially high reliability as well as achieving trade-off between position accuracy and cost. Generally, the dual-axis RINS is the master INS, and the single-axis RINS is the hot backup INS for high reliability purposes. An integrity monitoring system performs a fault detection function to ensure sailing safety. However, improving the accuracy of the backup INS in case of master INS failure has not been given enough attention. Without the aid of any external information, a systematic bias collaborative measurement method based on an augmented Kalman filter is proposed for the redundant RINSs. Estimates of inertial sensor biases can be used by the built-in integrity monitoring system to monitor the RINS running condition. On the other hand, a position error prediction model is designed for the single-axis RINS to estimate the systematic error caused by its azimuth gyro bias. After position error compensation, the position information provided by the single-axis RINS still remains highly accurate, even if the integrity monitoring system detects a dual-axis RINS fault. Moreover, use of a grid frame as a navigation frame makes the proposed method applicable in any area, including the polar regions. Semi-physical simulation and experiments including sea trials verify the validity of the method.

Screening for Chlamydia trachomatis: a systematic review of the economic evaluations and modelling

PubMed Central

Roberts, T E; Robinson, S; Barton, P; Bryan, S; Low, N

2006-01-01

Objective To review systematically and critically, evidence used to derive estimates of costs and cost effectiveness of chlamydia screening. Methods Systematic review. A search of 11 electronic bibliographic databases from the earliest date available to August 2004 using keywords including chlamydia, pelvic inflammatory disease, economic evaluation, and cost. We included studies of chlamydia screening in males and/or females over 14 years, including studies of diagnostic tests, contact tracing, and treatment as part of a screening programme. Outcomes included cases of chlamydia identified and major outcomes averted. We assessed methodological quality and the modelling approach used. Results Of 713 identified papers we included 57 formal economic evaluations and two cost studies. Most studies found chlamydia screening to be cost effective, partner notification to be an effective adjunct, and testing with nucleic acid amplification tests, and treatment with azithromycin to be cost effective. Methodological problems limited the validity of these findings: most studies used static models that are inappropriate for infectious diseases; restricted outcomes were used as a basis for policy recommendations; and high estimates of the probability of chlamydia associated complications might have overestimated cost effectiveness. Two high quality dynamic modelling studies found opportunistic screening to be cost effective but poor reporting or uncertainty about complication rates make interpretation difficult. Conclusion The inappropriate use of static models to study interventions to prevent a communicable disease means that uncertainty remains about whether chlamydia screening programmes are cost effective or not. The results of this review can be used by health service managers in the allocation of resources, and health economists and other researchers who are considering further research in this area. PMID:16731666

Prevalence of placenta previa among deliveries in Mainland China

PubMed Central

Fan, Dazhi; Wu, Song; Wang, Wen; Xin, Lihong; Tian, Guo; Liu, Li; Feng, Jinping; Guo, Xiaoling; Liu, Zhengping

2016-01-01

Abstract Background: Placenta previa is characterized by the abnormal placenta overlying the endocervical os, and it is known as one of the most feared adverse maternal and fetal-neonatal complications in obstetrics. Objectives: We aimed to obtain overall and regional estimates of placenta previa prevalence among deliveries in Mainland China. Methods: The research was performed a systematic review, following the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies, and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement for reporting systematic reviews and meta-analysis. Electronic databases were searched and included hospital-based studies that reported placenta previa prevalence in Mainland China. Random-effects meta-analyses were used to pool prevalence estimates of placenta previa. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. For exploring the geographical distributions of placenta previa, the ArcGIS software (Esri) was used to construct the map of prevalence. Results: A total of 80 articles and 86 datasets (including 1,298,548 subjects and 14,199 placenta previa cases) from 1965 through 2015 were included. The pooled overall prevalence of placenta previa among deliveries was 1.24% (95% confidence interval [CI], 1.12–1.36) in Mainland China during 1965 to 2015. And, the trend in the prevalence of placenta previa was steady. The occurrence rate of placenta previa in the region groups Northeast, North, Northwest, Central China, East, South, and Southwest was 1.20%, 1.01%, 1.10%, 1.15%, 0.93%, 1.42%, and 2.01%, respectively. The prevalence map based on a geographic information system showed an unequal geographic distribution. Conclusions: The results showed that placenta previa is currently a high-burden disease in Mainland China. This review would be useful for the design of placenta previa planning and implementation adequate health care systems and treatment programs in Mainland China. PMID:27749592

Presentation approaches for enhancing interpretability of patient-reported outcomes (PROs) in meta-analysis: a protocol for a systematic survey of Cochrane reviews.

PubMed

Devji, Tahira; Johnston, Bradley C; Patrick, Donald L; Bhandari, Mohit; Thabane, Lehana; Guyatt, Gordon H

2017-09-27

Meta-analyses of clinical trials often provide sufficient information for decision-makers to evaluate whether chance can explain apparent differences between interventions. Interpretation of the magnitude and importance of treatment effects beyond statistical significance can, however, be challenging, particularly for patient-reported outcomes (PROs) measured using questionnaires with which clinicians have limited familiarity. The objectives of our study are to systematically evaluate Cochrane systematic review authors' approaches to calculation, reporting and interpretation of pooled estimates of patient-reported outcome measures (PROMs) in meta-analyses. We will conduct a methodological survey of a random sample of Cochrane systematic reviews published from 1 January 2015 to 1 April 2017 that report at least one statistically significant pooled result for at least one PRO in the abstract. Author pairs will independently review all titles, abstracts and full texts identified by the literature search, and they will extract data using a standardised data extraction form. We will extract the following: year of publication, number of included trials, number of included participants, clinical area, type of intervention(s) and control(s), type of meta-analysis and use of the Grading of Recommendations, Assessment, Development and Evaluation approach to rate the quality of evidence, as well as information regarding the characteristics of PROMs, calculation and presentation of PROM effect estimates and interpretation of PROM effect estimates. We will document and summarise the methods used for the analysis, reporting and interpretation of each summary effect measure. We will summarise categorical variables with frequencies and percentages and continuous outcomes as means and/or medians and associated measures of dispersion. Ethics approval for this study is not required. We will disseminate the results of this review in peer-reviewed publications and conference presentations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Publication Bias and Nonreporting Found in Majority of Systematic Reviews and Meta-analyses in Anesthesiology Journals.

PubMed

Hedin, Riley J; Umberham, Blake A; Detweiler, Byron N; Kollmorgen, Lauren; Vassar, Matt

2016-10-01

Systematic reviews and meta-analyses are used by clinicians to derive treatment guidelines and make resource allocation decisions in anesthesiology. One cause for concern with such reviews is the possibility that results from unpublished trials are not represented in the review findings or data synthesis. This problem, known as publication bias, results when studies reporting statistically nonsignificant findings are left unpublished and, therefore, not included in meta-analyses when estimating a pooled treatment effect. In turn, publication bias may lead to skewed results with overestimated effect sizes. The primary objective of this study is to determine the extent to which evaluations for publication bias are conducted by systematic reviewers in highly ranked anesthesiology journals and which practices reviewers use to mitigate publication bias. The secondary objective of this study is to conduct publication bias analyses on the meta-analyses that did not perform these assessments and examine the adjusted pooled effect estimates after accounting for publication bias. This study considered meta-analyses and systematic reviews from 5 peer-reviewed anesthesia journals from 2007 through 2015. A PubMed search was conducted, and full-text systematic reviews that fit inclusion criteria were downloaded and coded independently by 2 authors. Coding was then validated, and disagreements were settled by consensus. In total, 207 systematic reviews were included for analysis. In addition, publication bias evaluation was performed for 25 systematic reviews that did not do so originally. We used Egger regression, Duval and Tweedie trim and fill, and funnel plots for these analyses. Fifty-five percent (n = 114) of the reviews discussed publication bias, and 43% (n = 89) of the reviews evaluated publication bias. Funnel plots and Egger regression were the most common methods for evaluating publication bias. Publication bias was reported in 34 reviews (16%). Thirty-six of the 45 (80.0%) publication bias analyses indicated the presence of publication bias by trim and fill analysis, whereas Egger regression indicated publication bias in 23 of 45 (51.1%) analyses. The mean absolute percent difference between adjusted and observed point estimates was 15.5%, the median was 6.2%, and the range was 0% to 85.5%. Many of these reviews reported following published guidelines such as PRISMA or MOOSE, yet only half appropriately addressed publication bias in their reviews. Compared with previous research, our study found fewer reviews assessing publication bias and greater likelihood of publication bias among reviews not performing these evaluations.

Estimating the Burden of Pneumococcal Pneumonia among Adults: A Systematic Review and Meta-Analysis of Diagnostic Techniques

PubMed Central

Said, Maria A.; Johnson, Hope L.; Nonyane, Bareng A. S.; Deloria-Knoll, Maria; O′Brien, Katherine L.

2013-01-01

Background Pneumococcal pneumonia causes significant morbidity and mortality among adults. Given limitations of diagnostic tests for non-bacteremic pneumococcal pneumonia, most studies report the incidence of bacteremic or invasive pneumococcal disease (IPD), and thus, grossly underestimate the pneumococcal pneumonia burden. We aimed to develop a conceptual and quantitative strategy to estimate the non-bacteremic disease burden among adults with community-acquired pneumonia (CAP) using systematic study methods and the availability of a urine antigen assay. Methods and Findings We performed a systematic literature review of studies providing information on the relative yield of various diagnostic assays (BinaxNOW® S. pneumoniae urine antigen test (UAT) with blood and/or sputum culture) in diagnosing pneumococcal pneumonia. We estimated the proportion of pneumococcal pneumonia that is bacteremic, the proportion of CAP attributable to pneumococcus, and the additional contribution of the Binax UAT beyond conventional diagnostic techniques, using random effects meta-analytic methods and bootstrapping. We included 35 studies in the analysis, predominantly from developed countries. The estimated proportion of pneumococcal pneumonia that is bacteremic was 24.8% (95% CI: 21.3%, 28.9%). The estimated proportion of CAP attributable to pneumococcus was 27.3% (95% CI: 23.9%, 31.1%). The Binax UAT diagnosed an additional 11.4% (95% CI: 9.6, 13.6%) of CAP beyond conventional techniques. We were limited by the fact that not all patients underwent all diagnostic tests and by the sensitivity and specificity of the diagnostic tests themselves. We address these resulting biases and provide a range of plausible values in order to estimate the burden of pneumococcal pneumonia among adults. Conclusions Estimating the adult burden of pneumococcal disease from bacteremic pneumococcal pneumonia data alone significantly underestimates the true burden of disease in adults. For every case of bacteremic pneumococcal pneumonia, we estimate that there are at least 3 additional cases of non-bacteremic pneumococcal pneumonia. PMID:23565216

Relation of phosphodiesterase type 5 inhibitors and malignant melanoma: a meta-analysis and systematic review.

PubMed

Wang, Jie; Shen, Yigen; Wang, Jiaoni; Xue, Yangjing; Liao, Lianming; Thapa, Saroj; Ji, Kangting

2017-07-11

Data on the association between using PDE5 inhibitors and malignant melanoma are conflicting. To estimate the relation of using PDE5 inhibitors with risk of malignant melanoma, Medline (Ovid) and Embase (Ovid) databases were searched up to February 2017, and a random effects model was used to calculate the summary risk estimates. Five observational studies were included. Five studies reports encompassed a total of 15,979 melanoma cases occurring among 1, 188,414 participants. The pooled multivariable-adjusted RR of melanoma in patients with using PDE5 inhibitors was 1.12 (95% CI: 1.03-1.21, I2 = 0.48). Findings from this systematic review support that PDE5 inhibitor use is associated with increased risk of melanoma in ED patients, the result remains inclusive and warrants further study in the future.

Epidemiology and economic burden of measles, mumps, pertussis, and varicella in Germany: a systematic review.

PubMed

Damm, Oliver; Witte, Julian; Wetzka, Stefanie; Prosser, Christine; Braun, Sebastian; Welte, Robert; Greiner, Wolfgang

2016-09-01

Despite the availability of vaccines and the existence of public vaccination recommendations, outbreaks of vaccine-preventable childhood diseases still cause public health debate. The objective of this systematic review was to provide an overview of the current epidemiology and economic burden of measles, mumps, pertussis, and varicella in Germany. We systematically reviewed studies published since 2000. The literature search was conducted using PubMed and EMBASE. Also, we used German notification data to give an up-to-date overview of the epidemiology of the four diseases under consideration. Thirty-six studies were included in our review. Results suggest that there is still considerable morbidity due to childhood diseases in Germany. Studies providing cost estimates are scarce. Comparative analyses of different data sources (notification data vs. claims data) revealed a potential underestimation of incidence estimates when using notification data. Furthermore, several studies showed regional differences in incidence of some of the diseases under consideration. Our findings underline the need for improved vaccination and communication strategies targeting all susceptible age and risk groups on a national and local level.

Comparing different stimulus configurations for population receptive field mapping in human fMRI

PubMed Central

Alvarez, Ivan; de Haas, Benjamin; Clark, Chris A.; Rees, Geraint; Schwarzkopf, D. Samuel

2015-01-01

Population receptive field (pRF) mapping is a widely used approach to measuring aggregate human visual receptive field properties by recording non-invasive signals using functional MRI. Despite growing interest, no study to date has systematically investigated the effects of different stimulus configurations on pRF estimates from human visual cortex. Here we compared the effects of three different stimulus configurations on a model-based approach to pRF estimation: size-invariant bars and eccentricity-scaled bars defined in Cartesian coordinates and traveling along the cardinal axes, and a novel simultaneous “wedge and ring” stimulus defined in polar coordinates, systematically covering polar and eccentricity axes. We found that the presence or absence of eccentricity scaling had a significant effect on goodness of fit and pRF size estimates. Further, variability in pRF size estimates was directly influenced by stimulus configuration, particularly for higher visual areas including V5/MT+. Finally, we compared eccentricity estimation between phase-encoded and model-based pRF approaches. We observed a tendency for more peripheral eccentricity estimates using phase-encoded methods, independent of stimulus size. We conclude that both eccentricity scaling and polar rather than Cartesian stimulus configuration are important considerations for optimal experimental design in pRF mapping. While all stimulus configurations produce adequate estimates, simultaneous wedge and ring stimulation produced higher fit reliability, with a significant advantage in reduced acquisition time. PMID:25750620

Systematic sampling of discrete and continuous populations: sample selection and the choice of estimator

Treesearch

Harry T. Valentine; David L. R. Affleck; Timothy G. Gregoire

2009-01-01

Systematic sampling is easy, efficient, and widely used, though it is not generally recognized that a systematic sample may be drawn from the population of interest with or without restrictions on randomization. The restrictions or the lack of them determine which estimators are unbiased, when using the sampling design as the basis for inference. We describe the...

Technical Packages in Injury and Violence Prevention to Move Evidence into Practice: Systematic Reviews and Beyond

PubMed Central

Haegerich, Tamara M.; David-Ferdon, Corinne; Noonan, Rita K.; Manns, Brian J.; Billie, Holly C.

2016-01-01

Injury and violence prevention strategies have greater potential for impact when they are based on scientific evidence. Systematic reviews of the scientific evidence can contribute key information about which policies and programs might have the greatest impact when implemented. However, systematic reviews have limitations, such as lack of implementation guidance and contextual information, that can limit the application of knowledge. “Technical packages,” developed by knowledge brokers such as the federal government, nonprofit agencies, and academic institutions, have the potential to be an efficient mechanism for making information from systematic reviews actionable. Technical packages provide information about specific evidence-based prevention strategies, along with the estimated costs and impacts, and include accompanying implementation and evaluation guidance to facilitate adoption, implementation, and performance measurement. We describe how systematic reviews can inform the development of technical packages for practitioners, provide examples of technical packages in injury and violence prevention, and explain how enhancing review methods and reporting could facilitate the use and applicability of scientific evidence. PMID:27604301

The Incidence of Postpartum Hemorrhage in Pregnant Women with Placenta Previa: A Systematic Review and Meta-Analysis.

PubMed

Fan, Dazhi; Xia, Qing; Liu, Li; Wu, Shuzhen; Tian, Guo; Wang, Wen; Wu, Song; Guo, Xiaoling; Liu, Zhengping

2017-01-01

The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of PPH in different countries, to date, no research has reviewed them. The aim of this study was to calculate the average point incidence of PPH in women with placenta previa. A systematic review and meta-analysis of observational studies estimating PPH in women with placenta previa was conducted through literature searches in four databases in Jul 2016. This study was totally conducted according to the MOOSE guidelines and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard. From 1148 obtained studies, 11 included in the meta-analysis, which involved 5146 unique pregnant women with placenta previa. The overall pooled incidence of PPH was 22.3% (95% CI 15.8-28.7%). In the subgroup, the prevalence was 27.4% in placenta previas, and was 14.5% in low-lying placenta previa; the highest prevalence was estimated in Northern America (26.3%, 95%CI 11.0-41.6%), followed by the Asia (20.7%, 95%CI 12.8-28.6%), Australia (19.2%, 95% CI 17.2-21.1%) and Europe (17.8%, 95% CI, 11.5%-24.0%). The summary estimate of the incidence of PPH among women with placenta previa was considerable in this systematic review. The results will be crucial in prevention, treatment, and identification of PPH among pregnant women with placenta previa and will be contributed to the planning and implantation of relevant public health strategies.

The effect of English-language restriction on systematic review-based meta-analyses: a systematic review of empirical studies.

PubMed

Morrison, Andra; Polisena, Julie; Husereau, Don; Moulton, Kristen; Clark, Michelle; Fiander, Michelle; Mierzwinski-Urban, Monika; Clifford, Tammy; Hutton, Brian; Rabb, Danielle

2012-04-01

The English language is generally perceived to be the universal language of science. However, the exclusive reliance on English-language studies may not represent all of the evidence. Excluding languages other than English (LOE) may introduce a language bias and lead to erroneous conclusions. We conducted a comprehensive literature search using bibliographic databases and grey literature sources. Studies were eligible for inclusion if they measured the effect of excluding randomized controlled trials (RCTs) reported in LOE from systematic review-based meta-analyses (SR/MA) for one or more outcomes. None of the included studies found major differences between summary treatment effects in English-language restricted meta-analyses and LOE-inclusive meta-analyses. Findings differed about the methodological and reporting quality of trials reported in LOE. The precision of pooled estimates improved with the inclusion of LOE trials. Overall, we found no evidence of a systematic bias from the use of language restrictions in systematic review-based meta-analyses in conventional medicine. Further research is needed to determine the impact of language restriction on systematic reviews in particular fields of medicine.

Prevalence of asthma among Middle Eastern children: A systematic review.

PubMed

Mirzaei, Masoud; Karimi, Mehran; Beheshti, Shima; Mohammadi, Masoud

2017-01-01

Background: The prevalence of asthma and allergy has increased during the last decades, especially in children. However, little is known about it in the Middle East region. This systematic review is aimed to estimate the prevalence of asthma among the Middle Eastern children. Methods: Local and international scientific databases including SID, Iranmedex, Medline and Science Direct were systematically searched for relevant keywords including; asthma, prevalence, children, International Study of Asthma and Allergies in Childhood (ISACC) and the names of Middle Eastern countries for the period of 1996-2011. Papers in Persian and English which met the defined criteria were included into the study. Bibliographies of the extracted articles were also searched. After extraction of data, heterogeneity between studies and publication bias were measured using Egger's-test. Effect size was pooled by the random-effect model. Since significant heterogeneity was found between studies, univariate meta-regression analyses were done to assess the association of variables with the overall results. Results: Fifty studies in the Middle East examined the prevalence of asthma and allergy in children under the age of 18 years according to the ISAAC criteria and were included. A total number of 289,717 children were examined in the included studies and the prevalence varied from 0.7 % in Isfahan to 22.3 % in Bagdad. The total prevalence of diagnosed asthma was calculated 7.53 % (95% Cl: 6.38-8.75). Prevalence of asthma in the 13-14 years age group was 7.57% (95% Cl: 5.78-9.29) and in 6-7 years age group was 7.43% (95% Cl: 5.75-9.10). The prevalence of asthma among girls, based on random effect model, was 6.30% (95% Cl: 4.97-7.61) and among boys, it was 8.91% (95% Cl: 6.80-11.04). Conclusion: The prevalence of asthma in the Middle East is lower than most developed countries. However, there is not enough longitudinal data to estimate the trend over time. In order to have more accurate estimates and to provide evidence for proper planning, standard epidemiologic studies should be conducted in countries of the region.

Association between use of systematic reviews and national policy recommendations on screening newborn babies for rare diseases: systematic review and meta-analysis.

PubMed

Taylor-Phillips, Sian; Stinton, Chris; Ferrante di Ruffano, Lavinia; Seedat, Farah; Clarke, Aileen; Deeks, Jonathan J

2018-05-09

To understand whether international differences in recommendations of whether to screen for rare diseases using the newborn blood spot test might in part be explained by use of systematic review methods. Systematic review and meta-analysis. Website searches of 26 national screening organisations. Journal articles, papers, legal documents, presentations, conference abstracts, or reports relating to a national recommendation on whether to screen for any condition using the newborn blood spot test, with no restrictions on date or language. Two reviewers independently assessed whether the recommendation for or against screening included systematic reviews, and data on test accuracy, benefits of early detection, and potential harms of overdiagnosis. The odds of recommending screening according to the use of systematic review methods was estimated across conditions using meta-analysis. 93 reports were included that assessed 104 conditions across 14 countries, totalling 276 recommendations (units of analysis). Screening was favoured in 159 (58%) recommendations, not favoured in 98 (36%), and not recommended either way in 19 (7%). Only 60 (22%) of the recommendations included a systematic review. Use of a systematic review was associated with a reduced probability of screening being recommended (23/60 (38%) v 136/216 (63%), odds ratio 0.17, 95% confidence interval 0.07 to 0.43). Of the recommendations, evidence for test accuracy, benefits of early detection, and overdiagnosis was not considered in 115 (42%), 83 (30%), and 211 (76%), respectively. Using systematic review methods is associated with a reduced probability of screening being recommended. Many national policy reviews of screening for rare conditions using the newborn blood spot test do not assess the evidence on the key benefits and harms of screening. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Models for estimating and projecting global, regional and national prevalence and disease burden of asthma: protocol for a systematic review.

PubMed

Bhuia, Mohammad Romel; Nwaru, Bright I; Weir, Christopher J; Sheikh, Aziz

2017-05-17

Models that have so far been used to estimate and project the prevalence and disease burden of asthma are in most cases inadequately described and irreproducible. We aim systematically to describe and critique the existing models in relation to their strengths, limitations and reproducibility, and to determine the appropriate models for estimating and projecting the prevalence and disease burden of asthma. We will search the following electronic databases to identify relevant literature published from 1980 to 2017: Medline, Embase, WHO Library and Information Services and Web of Science Core Collection. We will identify additional studies by searching the reference list of all the retrieved papers and contacting experts. We will include observational studies that used models for estimating and/or projecting prevalence and disease burden of asthma regarding human population of any age and sex. Two independent reviewers will assess the studies for inclusion and extract data from included papers. Data items will include authors' names, publication year, study aims, data source and time period, study population, asthma outcomes, study methodology, model type, model settings, study variables, methods of model derivation, methods of parameter estimation and/or projection, model fit information, key findings and identified research gaps. A detailed critical narrative synthesis of the models will be undertaken in relation to their strengths, limitations and reproducibility. A quality assessment checklist and scoring framework will be used to determine the appropriate models for estimating and projecting the prevalence anddiseaseburden of asthma. We will not collect any primary data for this review, and hence there is no need for formal National Health Services Research Ethics Committee approval. We will present our findings at scientific conferences and publish the findings in the peer-reviewed scientific journal. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Increasing the demand for childhood vaccination in developing countries: a systematic review

PubMed Central

2009-01-01

Background Attempts to maintain or increase vaccination coverage almost all focus on supply side interventions: improving availability and delivery of vaccines. The effectiveness and cost-effectiveness of efforts to increase demand is uncertain. Methods We performed a systematic review of studies that provided quantitative estimates of the impact of demand side interventions on uptake of routine childhood vaccination. We retrieved studies published up to Sept 2008. Results The initial search retrieved 468 potentially eligible studies, including four systematic reviews and eight original studies of the impact of interventions to increase demand for vaccination. We identified only two randomised controlled trials. Interventions with an impact on vaccination uptake included knowledge translation (KT) (mass media, village resource rooms and community discussions) and non-KT initiatives (incentives, economic empowerment, household visits by extension workers). Most claimed to increase vaccine coverage by 20 to 30%. Estimates of the cost per vaccinated child varied considerably with several in the range of $10-20 per vaccinated child. Conclusion Most studies reviewed here represented a low level of evidence. Mass media campaigns may be effective, but the impact depends on access to media and may be costly if run at a local level. The persistence of positive effects has not been investigated. The economics of demand side interventions have not been adequately assessed, but available data suggest that some may be very cost-effective. PMID:19828063

Global assessment of exposure to faecal contamination through drinking water based on a systematic review.

PubMed

Bain, Robert; Cronk, Ryan; Hossain, Rifat; Bonjour, Sophie; Onda, Kyle; Wright, Jim; Yang, Hong; Slaymaker, Tom; Hunter, Paul; Prüss-Ustün, Annette; Bartram, Jamie

2014-08-01

To estimate exposure to faecal contamination through drinking water as indicated by levels of Escherichia coli (E. coli) or thermotolerant coliform (TTC) in water sources. We estimated coverage of different types of drinking water source based on household surveys and censuses using multilevel modelling. Coverage data were combined with water quality studies that assessed E. coli or TTC including those identified by a systematic review (n = 345). Predictive models for the presence and level of contamination of drinking water sources were developed using random effects logistic regression and selected covariates. We assessed sensitivity of estimated exposure to study quality, indicator bacteria and separately considered nationally randomised surveys. We estimate that 1.8 billion people globally use a source of drinking water which suffers from faecal contamination, of these 1.1 billion drink water that is of at least 'moderate' risk (>10 E. coli or TTC per 100 ml). Data from nationally randomised studies suggest that 10% of improved sources may be 'high' risk, containing at least 100 E. coli or TTC per 100 ml. Drinking water is found to be more often contaminated in rural areas (41%, CI: 31%-51%) than in urban areas (12%, CI: 8-18%), and contamination is most prevalent in Africa (53%, CI: 42%-63%) and South-East Asia (35%, CI: 24%-45%). Estimates were not sensitive to the exclusion of low quality studies or restriction to studies reporting E. coli. Microbial contamination is widespread and affects all water source types, including piped supplies. Global burden of disease estimates may have substantially understated the disease burden associated with inadequate water services. © 2014 The Authors. Tropical Medicine and International Health published by John Wiley & Sons Ltd.

Global assessment of exposure to faecal contamination through drinking water based on a systematic review

PubMed Central

Bain, Robert; Cronk, Ryan; Hossain, Rifat; Bonjour, Sophie; Onda, Kyle; Wright, Jim; Yang, Hong; Slaymaker, Tom; Hunter, Paul; Prüss-Ustün, Annette; Bartram, Jamie

2014-01-01

Objectives To estimate exposure to faecal contamination through drinking water as indicated by levels of Escherichia coli (E. coli) or thermotolerant coliform (TTC) in water sources. Methods We estimated coverage of different types of drinking water source based on household surveys and censuses using multilevel modelling. Coverage data were combined with water quality studies that assessed E. coli or TTC including those identified by a systematic review (n = 345). Predictive models for the presence and level of contamination of drinking water sources were developed using random effects logistic regression and selected covariates. We assessed sensitivity of estimated exposure to study quality, indicator bacteria and separately considered nationally randomised surveys. Results We estimate that 1.8 billion people globally use a source of drinking water which suffers from faecal contamination, of these 1.1 billion drink water that is of at least ‘moderate’ risk (>10 E. coli or TTC per 100 ml). Data from nationally randomised studies suggest that 10% of improved sources may be ‘high’ risk, containing at least 100 E. coli or TTC per 100 ml. Drinking water is found to be more often contaminated in rural areas (41%, CI: 31%–51%) than in urban areas (12%, CI: 8–18%), and contamination is most prevalent in Africa (53%, CI: 42%–63%) and South-East Asia (35%, CI: 24%–45%). Estimates were not sensitive to the exclusion of low quality studies or restriction to studies reporting E. coli. Conclusions Microbial contamination is widespread and affects all water source types, including piped supplies. Global burden of disease estimates may have substantially understated the disease burden associated with inadequate water services. PMID:24811893

How long do patients with chronic disease expect to live? A systematic review of the literature

PubMed Central

Salem, Joseph

2016-01-01

Objective To systematically identify and summarise the literature on perceived life expectancy among individuals with non-cancer chronic disease. Setting Published and grey literature up to and including September 2016 where adults with non-cancer chronic disease were asked to estimate their own life expectancy. Participants From 6837 screened titles, 9 articles were identified that met prespecified criteria for inclusion. Studies came from the UK, Netherlands and USA. A total of 729 participants were included (heart failure (HF) 573; chronic obstructive pulmonary disease (COPD) 89; end-stage renal failure 62; chronic kidney disease (CKD) 5). No papers reporting on other lung diseases, neurodegenerative disease or cirrhosis were found. Primary and secondary outcome measures All measures of self-estimated life expectancy were accepted. Self-estimated life expectancy was compared, where available, with observed survival, physician-estimated life expectancy and model-estimated life expectancy. Meta-analysis was not conducted due to the heterogeneity of the patient groups and study methodologies. Results Among patients with HF, median self-estimated life expectancy was 40% longer than predicted by a validated model. Outpatients receiving haemodialysis were more optimistic about prognosis than their nephrologists and overestimated their chances of surviving 5 years. Patients with HF and COPD were approximately three times more likely to die in the next year than they predicted. Data available for patients with CKD were of insufficient quality to draw conclusions. Conclusions Individuals with chronic disease may have unrealistically optimistic expectations of their prognosis. More research is needed to understand how perceived life expectancy affects behaviour. Meanwhile, clinicians should attempt to identify each patient's prognostic preferences and provide information in a way that they can understand and use to inform their decisions. Trial registration number CRD42015020732. PMID:28039288

Estimating cetacean density and abundance in the Central and Western Mediterranean Sea through aerial surveys: Implications for management

NASA Astrophysics Data System (ADS)

Panigada, Simone; Lauriano, Giancarlo; Donovan, Greg; Pierantonio, Nino; Cañadas, Ana; Vázquez, José Antonio; Burt, Louise

2017-07-01

Systematic, effective monitoring of animal population parameters underpins successful conservation strategy and wildlife management, but it is often neglected in many regions, including much of the Mediterranean Sea. Nonetheless, a series of systematic multispecies aerial surveys was carried out in the seas around Italy to gather important baseline information on cetacean occurrence, distribution and abundance. The monitored areas included the Pelagos Sanctuary, the Tyrrhenian Sea, portions of the Seas of Corsica and Sardinia, the Ionian Seas as well as the Gulf of Taranto. Overall, approximately 48,000 km were flown in either spring, summer and winter between 2009-2014, covering an area of 444,621 km2. The most commonly observed species were the striped dolphin and the fin whale, with 975 and 83 recorded sightings, respectively. Other sighted cetacean species were the common bottlenose dolphin, the Risso's dolphin, the sperm whale, the pilot whale and the Cuvier's beaked whale. Uncorrected model- and design-based estimates of density and abundance for striped dolphins and fin whales were produced, resulting in a best estimate (model-based) of around 95,000 striped dolphins (CV=11.6%; 95% CI=92,900-120,300) occurring in the Pelagos Sanctuary, Central Tyrrhenian and Western Seas of Corsica and Sardinia combined area in summer 2010. Estimates were also obtained for each individual study region and year. An initial attempt to estimate perception bias for striped dolphins is also provided. The preferred summer 2010 uncorrected best estimate (design-based) for the same areas for fin whales was around 665 (CV=33.1%; 95% CI=350-1260). Estimates are also provided for the individual study regions and years. The results represent baseline data to develop efficient, long-term, systematic monitoring programmes, essential to evaluate trends, as required by a number of national and international frameworks, and stress the need to ensure that surveys are undertaken regularly and at a sufficient spatial scale. The management implications of the results are discussed also in light of a possible decline of fin whales abundance over the period from the mid-1990s to the present. Further work to understand changes in distribution and to allow for improved spatial models is emphasized.

Serum uric acid and cancer mortality and incidence: a systematic review and meta-analysis.

PubMed

Dovell, Frances; Boffetta, Paolo

2018-07-01

Elevated serum uric acid (SUA) is a marker of chronic inflammation and has been suggested to be associated with increased risk of cancer, but its antioxidant capacity would justify an anticancer effect. Previous meta-analyses did not include all available results. We conducted a systematic review of prospective studies on SUA level and risk of all cancers and specific cancers, a conducted a meta-analysis based on random-effects models for high versus low SUA level as well as for an increase in 1 mg/dl SUA. The relative risk of all cancers for high versus low SUA level was 1.11 (95% confidence interval: 0.94-1.27; 11 risk estimates); that for a mg/dl increase in SUA level was 1.03 (95% confidence interval: 0.99-1.07). Similar results were obtained for lung cancer (six risk estimates) and colon cancer (four risk estimates). Results for other cancers were sparse. Elevated SUA levels appear to be associated with a modest increase in overall cancer risk, although the combined risk estimate did not reach the formal level of statistical significance. Results for specific cancers were limited and mainly negative.

Prevalence of Transgender Depends on the "Case" Definition: A Systematic Review.

PubMed

Collin, Lindsay; Reisner, Sari L; Tangpricha, Vin; Goodman, Michael

2016-04-01

A systematic review and meta-analysis was conducted to evaluate how various definitions of transgender affect prevalence estimates. To evaluate the epidemiology of transgender and examine how various definitions of transgender affect prevalence estimates and to compare findings across studies that used different methodologies, in different countries, and over different periods. PubMed, EMBASE, and Medline were searched to identify studies reporting prevalence estimates of transgender in a population. All studies were grouped based on the case definition applied to the numerator. Summary estimates were derived using a random-effects model for total prevalence of transgender and for male-to-female and female-to-male subgroups. Overall and stratum-specific meta-prevalence estimates (mPs) and 95% confidence intervals (CIs) were accompanied by tests for heterogeneity and meta-regressions to assess sources of heterogeneity. The main outcome measure was population prevalence of transgender. Secondary outcomes included gender-specific prevalence estimates for male-to-female and female to male subgroups. Thirty-two studies met the inclusion criteria for systematic review. Of those, 27 studies provided necessary data for a meta-analysis. Overall mP estimates per 100,000 population were 9.2 (95% CI = 4.9-13.6) for surgical or hormonal gender affirmation therapy and 6.8 (95% CI = 4.6-9.1) for transgender-related diagnoses. Of studies assessing self-reported transgender identity, the mP was 871 (95% CI = 519-1,224); however, this result was influenced by a single outlier study. After removal of that study, the mP changed to 355 (95% CI = 144-566). Significant heterogeneity was observed in most analyses. The empirical literature on the prevalence of transgender highlights the importance of adhering to specific case definitions because the results can range by orders of magnitude. Standardized and routine collection of data on transgender status and gender identity is recommended. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A low proportion of systematic reviews in physical therapy are registered: a survey of 150 published systematic reviews.

PubMed

Oliveira, Crystian B; Elkins, Mark R; Lemes, Ítalo Ribeiro; de Oliveira Silva, Danilo; Briani, Ronaldo V; Monteiro, Henrique Luiz; Azevedo, Fábio Mícolis de; Pinto, Rafael Zambelli

Systematic reviews provide the best evidence about the effectiveness of healthcare interventions. Although systematic reviews are conducted with explicit and transparent methods, discrepancies might occur between the protocol and the publication. To estimate the proportion of systematic reviews of physical therapy interventions that are registered, the methodological quality of (un)registered systematic reviews and the prevalence of outcome reporting bias in registered systematic reviews. A random sample of 150 systematic reviews published in 2015 indexed on the PEDro database. We included systematic reviews written in English, Italian, Portuguese and Spanish. A checklist for assessing the methodological quality of systematic reviews tool was used. Relative risk was calculated to explore the association between meta-analysis results and the changes in the outcomes. Twenty-nine (19%) systematic reviews were registered. Funding and publication in a journal with an impact factor higher than 5.0 were associated with registration. Registered systematic reviews demonstrated significantly higher methodological quality (median=8) than unregistered systematic reviews (median=5). Nine (31%) registered systematic reviews demonstrated discrepancies between protocol and publication with no evidence that such discrepancies were applied to favor the statistical significance of the intervention (RR=1.16; 95% CI: 0.63-2.12). A low proportion of systematic reviews in the physical therapy field are registered. The registered systematic reviews showed high methodological quality without evidence of outcome reporting bias. Further strategies should be implemented to encourage registration. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Estimating post-marketing exposure to pharmaceutical products using ex-factory distribution data.

PubMed

Telfair, Tamara; Mohan, Aparna K; Shahani, Shalini; Klincewicz, Stephen; Atsma, Willem Jan; Thomas, Adrian; Fife, Daniel

2006-10-01

The pharmaceutical industry has an obligation to identify adverse reactions to drug products during all phases of drug development, including the post-marketing period. Estimates of population exposure to pharmaceutical products are important to the post-marketing surveillance of drugs, and provide a context for assessing the various risks and benefits, including drug safety, associated with drug treatment. This paper describes a systematic approach to estimating post-marketing drug exposure using ex-factory shipment data to estimate the quantity of medication available, and dosage information (stratified by indication or other factors as appropriate) to convert the quantity of medication to person time of exposure. Unlike the non-standardized methods often used to estimate exposure, this approach provides estimates whose calculations are explicit, documented, and consistent across products and over time. The methods can readily be carried out by an individual or small group specializing in this function, and lend themselves to automation. The present estimation approach is practical and relatively uncomplicated to implement. We believe it is a useful innovation. Copyright 2006 John Wiley & Sons, Ltd.

Accuracy of administrative data for surveillance of healthcare-associated infections: a systematic review

PubMed Central

van Mourik, Maaike S M; van Duijn, Pleun Joppe; Moons, Karel G M; Bonten, Marc J M; Lee, Grace M

2015-01-01

Objective Measuring the incidence of healthcare-associated infections (HAI) is of increasing importance in current healthcare delivery systems. Administrative data algorithms, including (combinations of) diagnosis codes, are commonly used to determine the occurrence of HAI, either to support within-hospital surveillance programmes or as free-standing quality indicators. We conducted a systematic review evaluating the diagnostic accuracy of administrative data for the detection of HAI. Methods Systematic search of Medline, Embase, CINAHL and Cochrane for relevant studies (1995–2013). Methodological quality assessment was performed using QUADAS-2 criteria; diagnostic accuracy estimates were stratified by HAI type and key study characteristics. Results 57 studies were included, the majority aiming to detect surgical site or bloodstream infections. Study designs were very diverse regarding the specification of their administrative data algorithm (code selections, follow-up) and definitions of HAI presence. One-third of studies had important methodological limitations including differential or incomplete HAI ascertainment or lack of blinding of assessors. Observed sensitivity and positive predictive values of administrative data algorithms for HAI detection were very heterogeneous and generally modest at best, both for within-hospital algorithms and for formal quality indicators; accuracy was particularly poor for the identification of device-associated HAI such as central line associated bloodstream infections. The large heterogeneity in study designs across the included studies precluded formal calculation of summary diagnostic accuracy estimates in most instances. Conclusions Administrative data had limited and highly variable accuracy for the detection of HAI, and their judicious use for internal surveillance efforts and external quality assessment is recommended. If hospitals and policymakers choose to rely on administrative data for HAI surveillance, continued improvements to existing algorithms and their robust validation are imperative. PMID:26316651

Effects of 21st birthday brief interventions on college student celebratory drinking: A systematic review and meta-analysis.

PubMed

Steinka-Fry, Katarzyna T; Tanner-Smith, Emily E; Grant, Sean

2015-11-01

College students' 21st birthday celebrations often involve consumption of extreme amounts of alcohol as well as alcohol-related risks. This systematic review aims to determine whether birthday-focused, individually-targeted, no-contact (email or letter-based) brief alcohol interventions (BAIs) reduce college students' 21st birthday celebratory drinking. A systematic search identified 9 randomized evaluations with 10 interventions to reduce 21st birthday drinking. Quantity of alcohol consumed and estimated blood alcohol concentration (BAC) were measured. Random-effects meta-analysis was used to summarize the effects of the interventions. There was no evidence that birthday-focused BAIs reduce quantities of alcohol consumed during birthday celebrations (g = 0.05, 95% CI [-0.03 to 0.13]). The interventions were associated with significant reductions in estimated BAC levels (g = 0.20, 95% CI [0.07 to 0.33]), but this effect was small in absolute terms. The quality of this body of evidence was very low, as evaluated using the GRADE approach. In particular, it was limited by substantial participant attrition post-randomization due to included studies' recruitment and randomization procedures. There is no evidence that birthday-focused, individually-targeted BAIs reduce the quantity of alcohol consumed by students during 21st birthday celebrations, although these interventions may yield small beneficial effects on estimated BAC. Many methodological concerns were identified in included studies. This area of research would benefit from theory-based RCTs that are well-designed and executed. Future research should also investigate strategies other than birthday-focused, individually-targeted, brief interventions to curb 21st birthday celebratory drinking. Copyright © 2015 Elsevier Ltd. All rights reserved.

Risk of Motor Vehicle Accidents Related to Sleepiness at the Wheel: A Systematic Review and Meta-Analysis.

PubMed

Bioulac, Stéphanie; Franchi, Jean-Arthur Micoulaud; Arnaud, Mickael; Sagaspe, Patricia; Moore, Nicholas; Salvo, Francesco; Philip, Pierre

2017-10-01

Sleepiness at the wheel is widely believed to be a cause of motor vehicle accidents. Nevertheless, a systematic review of studies investigating this relationship has not yet been published. The objective of this study was to quantify the relationship between sleepiness at the wheel and motor vehicle accidents. A systematic review was performed using Medline, Scopus, and ISI Web of Science. The outcome measure of interest was motor vehicle accident defined as involving four- or two-wheeled vehicles in road traffic, professional and nonprofessional drivers, with or without objective consequences. The exposure was sleepiness at the wheel defined as self-reported sleepiness at the wheel. Studies were included if they provided adjusted risk estimates of motor vehicle accidents related to sleepiness at the wheel. Risk estimates and 95% confidence intervals (95% CIs) were extracted and pooled as odds ratios (ORs) using a random-effect model. Heterogeneity was quantified using Q statistics and the I2 index. The potential causes of heterogeneity were investigated using meta-regressions. Ten cross-sectional studies (51,520 participants), six case-control studies (4904 participants), and one cohort study (13,674 participants) were included. Sleepiness at the wheel was associated with an increased risk of motor vehicle accidents (pooled OR 2.51 [95% CI 1.87; 3.39]). A significant heterogeneity was found between the individual risk estimates (Q = 93.21; I2 = 83%). Sleepiness at the wheel increases the risk of motor vehicle accidents and should be considered when investigating fitness to drive. Further studies are required to explore the nature of this relationship. PROSPERO 2015 CRD42015024805. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Ecological validity of cost-effectiveness models of universal HPV vaccination: A systematic literature review.

PubMed

Favato, Giampiero; Easton, Tania; Vecchiato, Riccardo; Noikokyris, Emmanouil

2017-05-09

The protective (herd) effect of the selective vaccination of pubertal girls against human papillomavirus (HPV) implies a high probability that one of the two partners involved in intercourse is immunised, hence preventing the other from this sexually transmitted infection. The dynamic transmission models used to inform immunisation policy should include consideration of sexual behaviours and population mixing in order to demonstrate an ecological validity, whereby the scenarios modelled remain faithful to the real-life social and cultural context. The primary aim of this review is to test the ecological validity of the universal HPV vaccination cost-effectiveness modelling available in the published literature. The research protocol related to this systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42016034145). Eight published economic evaluations were reviewed. None of the studies showed due consideration of the complexities of human sexual behaviour and the impact this may have on the transmission of HPV. Our findings indicate that all the included models might be affected by a different degree of ecological bias, which implies an inability to reflect the natural demographic and behavioural trends in their outcomes and, consequently, to accurately inform public healthcare policy. In particular, ecological bias have the effect to over-estimate the preference-based outcomes of selective immunisation. A relatively small (15-20%) over-estimation of quality-adjusted life years (QALYs) gained with selective immunisation programmes could induce a significant error in the estimate of cost-effectiveness of universal immunisation, by inflating its incremental cost effectiveness ratio (ICER) beyond the acceptability threshold. The results modelled here demonstrate the limitations of the cost-effectiveness studies for HPV vaccination, and highlight the concern that public healthcare policy might have been built upon incomplete studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of 21st Birthday Brief Interventions on College Student Celebratory Drinking: A Systematic Review and Meta-Analysis

PubMed Central

Steinka-Fry, Katarzyna T.; Tanner-Smith, Emily E.; Grant, Sean

2015-01-01

Introduction College students' 21st birthday celebrations often involve consumption of extreme amounts of alcohol as well as alcohol-related risks. This systematic review aims to determine whether birthday-focused, individually-targeted, no-contact (email or letter-based) brief alcohol interventions (BAIs) reduce college students' 21st birthday celebratory drinking. Methods A systematic search identified 9 randomized evaluations with 10 interventions to reduce 21st birthday drinking. Quantity of alcohol consumed and estimated blood alcohol concentration (BAC) were measured. Random-effects meta-analysis was used to summarize the effects of the interventions. Results There was no evidence that birthday-focused BAIs reduce quantities of alcohol consumed during birthday celebrations (ḡ = 0.05, 95% CI [-0.03 to 0.13]). The interventions were associated with significant reductions in estimated BAC levels (ḡ = 0.20, 95% CI [0.07 to 0.33]), but this effect was small in absolute terms. The quality of this body of evidence was very low, as evaluated using the GRADE approach. In particular, it was limited by substantial participant attrition post-randomization due to included studies' recruitment and randomization procedures. Conclusions There is no evidence that birthday-focused, individually-targeted BAIs reduce the quantity of alcohol consumed by students during 21st birthday celebrations, although these interventions may yield small beneficial effects on estimated BAC. Many methodological concerns were identified in included studies. This area of research would benefit from theory-based RCTs that are well-designed and executed. Future research should also investigate strategies other than birthday-focused, individually-targeted, brief interventions to curb 21st birthday celebratory drinking. PMID:26093502

Improved Analysis of GW150914 Using a Fully Spin-Precessing Waveform Model

NASA Astrophysics Data System (ADS)

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A.; Billingsley, G.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. 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M.; Fauchon-Jones, E.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Fenyvesi, E.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gaebel, S.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Geng, P.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jian, L.; Jiménez-Forteza, F.; Johnson, W. W.; Johnson-McDaniel, N. K.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; K, Haris; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chi-Woong; Kim, Chunglee; Kim, J.; Kim, K.; Kim, N.; Kim, W.; Kim, Y.-M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kissel, J. S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Lewis, J. B.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nedkova, K.; Nelemans, G.; Nelson, T. J. N.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T.; Shahriar, M. S.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stevenson, S. P.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tornasi, Z.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van der Sluys, M. V.; van Heijningen, J. V.; Vano-Vinuales, A.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J. L.; Wu, D. S.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Boyle, M.; Brügmann, B.; Campanelli, M.; Chu, T.; Clark, M.; Haas, R.; Hemberger, D.; Hinder, I.; Kidder, L. E.; Kinsey, M.; Laguna, P.; Ossokine, S.; Pan, Y.; Röver, C.; Scheel, M.; Szilagyi, B.; Teukolsky, S.; Zlochower, Y.; LIGO Scientific Collaboration; Virgo Collaboration

2016-10-01

This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [Abbott et al. Phys. Rev. Lett. 116, 061102 (2016).]. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] presented parameter estimation of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and an 11-dimensional nonprecessing effective-one-body (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here, we present new results that include a 15-dimensional precessing-spin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement with the parameters estimated previously [Abbott et al. Phys. Rev. Lett. 116, 241102 (2016).], and we quote updated component masses of 35-3+5 M⊙ and 3 0-4+3 M⊙ (where errors correspond to 90% symmetric credible intervals). We also present slightly tighter constraints on the dimensionless spin magnitudes of the two black holes, with a primary spin estimate <0.65 and a secondary spin estimate <0.75 at 90% probability. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] estimated the systematic parameter-extraction errors due to waveform-model uncertainty by combining the posterior probability densities of precessing IMRPhenom and nonprecessing EOBNR. Here, we find that the two precessing-spin models are in closer agreement, suggesting that these systematic errors are smaller than previously quoted.

Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing.

PubMed

Halder, Julia B; Benton, Joanne; Julé, Amélie M; Guérin, Phillipe J; Olliaro, Piero L; Basáñez, María-Gloria; Walker, Martin

2017-10-01

Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)'s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance. We performed a systematic literature review to identify studies concluding after 2000 that collected IPD suitable for estimating drug efficacy against STH. We included studies that administered a variety of anthelmintics with follow ups less than 60 days after treatment. We estimated the number of IPD and extracted cohort- and study-level meta-data. We estimate that there exist individual data on approximately 35,000 participants from 129 studies conducted in 39 countries, including 34 out of 103 countries where PCT is recommended. We find significant heterogeneity in diagnostic methods, times of outcome assessment, and the reported measure of efficacy. We also quantify cohorts comprising pre-school age children, pregnant women, and co-infected participants, including with HIV. We argue that establishing a global IPD repository would improve the capacity to monitor and evaluate the efficacy of anthelmintic drugs, respond to changes and safeguard the ongoing effectiveness of PCT. Establishing a fair, transparent data governance policy will be key for the engagement of the global STH community.

Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing

PubMed Central

Halder, Julia B.; Benton, Joanne; Julé, Amélie M.; Guérin, Phillipe J.; Olliaro, Piero L.; Basáñez, María-Gloria; Walker, Martin

2017-01-01

Background Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance. Methodology We performed a systematic literature review to identify studies concluding after 2000 that collected IPD suitable for estimating drug efficacy against STH. We included studies that administered a variety of anthelmintics with follow ups less than 60 days after treatment. We estimated the number of IPD and extracted cohort- and study-level meta-data. Principal findings We estimate that there exist individual data on approximately 35,000 participants from 129 studies conducted in 39 countries, including 34 out of 103 countries where PCT is recommended. We find significant heterogeneity in diagnostic methods, times of outcome assessment, and the reported measure of efficacy. We also quantify cohorts comprising pre-school age children, pregnant women, and co-infected participants, including with HIV. Conclusions We argue that establishing a global IPD repository would improve the capacity to monitor and evaluate the efficacy of anthelmintic drugs, respond to changes and safeguard the ongoing effectiveness of PCT. Establishing a fair, transparent data governance policy will be key for the engagement of the global STH community. PMID:29088274

Stated time preferences for health: a systematic review and meta analysis of private and social discount rates.

PubMed

Mahboub-Ahari, Alireza; Pourreza, Abolghasem; Sari, Ali Akbari; Rahimi Foroushani, Abbas; Heydari, Hassan

2014-01-01

The present study aimed to provide better insight on methodological issues related to time preference studies, and to estimate private and social discount rates, using a rigorous systematic review and meta-analysis. We searched PubMed, EMBASE and Proquest databases in June 2013. All studies had estimated private and social time preference rates for health outcomes through stated preference approach, recognized eligible for inclusion. We conducted both fixed and random effect meta-analyses using mean discount rate and standard deviation of the included studies. I-square statistics was used for testing heterogeneity of the studies. Private and social discount rates were estimated separately via Stata11 software. Out of 44 screened full texts, 8 population-based empirical studies were included in qualitative synthesis. Reported time preference rates for own health were from 0.036 to 0.07 and for social health from 0.04 to 0.2. Private and social discount rates were estimated at 0.056 (95% CI: 0.038, 0.074) and 0.066 (95% CI: 0.064, 0.068), respectively. Considering the impact of time preference on healthy behaviors and because of timing issues, individual's time preference as a key determinant of policy making should be taken into account. Direct translation of elicited discount rates to the official discount rates has been remained questionable. Decisions about the proper discount rate for health context, may need a cross-party consensus among health economists and policy makers.

Assessment of dietary sodium intake using a food frequency questionnaire and 24-hour urinary sodium excretion: a systematic literature review.

PubMed

McLean, Rachael M; Farmer, Victoria L; Nettleton, Alice; Cameron, Claire M; Cook, Nancy R; Campbell, Norman R C

2017-12-01

Food frequency questionnaires (FFQs) are often used to assess dietary sodium intake, although 24-hour urinary excretion is the most accurate measure of intake. The authors conducted a systematic review to investigate whether FFQs are a reliable and valid way of measuring usual dietary sodium intake. Results from 18 studies are described in this review, including 16 validation studies. The methods of study design and analysis varied widely with respect to FFQ instrument, number of 24-hour urine collections collected per participant, methods used to assess completeness of urine collections, and statistical analysis. Overall, there was poor agreement between estimates from FFQ and 24-hour urine. The authors suggest a framework for validation and reporting based on a consensus statement (2004), and recommend that all FFQs used to estimate dietary sodium intake undergo validation against multiple 24-hour urine collections. ©2017 Wiley Periodicals, Inc.

Clinical Manifestations Associated with Neurocysticercosis: A Systematic Review

PubMed Central

Carabin, Hélène; Ndimubanzi, Patrick Cyaga; Budke, Christine M.; Nguyen, Hai; Qian, Yingjun; Cowan, Linda Demetry; Stoner, Julie Ann; Rainwater, Elizabeth; Dickey, Mary

2011-01-01

Background The clinical manifestations of neurocysticercosis (NCC) are poorly understood. This systematic review aims to estimate the frequencies of different manifestations, complications and disabilities associated with NCC. Methods A systematic search of the literature published from January 1, 1990, to June 1, 2008, in 24 different electronic databases and 8 languages was conducted. Meta-analyses were conducted when appropriate. Results A total of 1569 documents were identified, and 21 included in the analysis. Among patients seen in neurology clinics, seizures/epilepsy were the most common manifestations (78.8%, 95%CI: 65.1%–89.7%) followed by headaches (37.9%, 95%CI: 23.3%–53.7%), focal deficits (16.0%, 95%CI: 9.7%–23.6%) and signs of increased intracranial pressure (11.7%, 95%CI: 6.0%–18.9%). All other manifestations occurred in less than 10% of symptomatic NCC patients. Only four studies reported on the mortality rate of NCC. Conclusions NCC is a pleomorphic disease linked to a range of manifestations. Although definitions of manifestations were very rarely provided, and varied from study to study, the proportion of NCC cases with seizures/epilepsy and the proportion of headaches were consistent across studies. These estimates are only applicable to patients who are ill enough to seek care in neurology clinics and likely over estimate the frequency of manifestations among all NCC cases. PMID:21629722

Whole-body vibration and the risk of low back pain and sciatica: a systematic review and meta-analysis.

PubMed

Burström, Lage; Nilsson, Tohr; Wahlström, Jens

2015-05-01

The aim of this systematic literature review was to evaluate the association between whole-body vibration (WBV) and low back pain (LBP) and sciatica with special attention given to exposure estimates. Moreover, the aim was to estimate the magnitude of such an association using meta-analysis and to compare our findings with previous reviews. The authors systematically searched the PubMed (National Library of Medicine, Bethesda), Nioshtic2 (National Institute for Occupational Safety and Health (NIOSH, Morgantown), and ScienceDirect (Elsevier, Amsterdam) databases for records up to December 31, 2013. Two of the authors independently assessed studies to determine their eligibility, validity, and possible risk of bias. The literature search gave a total of 306 references out of which 28 studies were reviewed and 20 were included in the meta-analysis. Exposure to WBV was associated with increased prevalence of LBP and sciatica [pooled odds ratio (OR) = 2.17, 95% confidence interval (CI) 1.61-2.91 and OR 1.92, 95% CI 1.38-2.67, respectively]. Workers exposed to high vibration levels had a pooled risk estimate of 1.5 for both outcomes when compared with workers exposed to low levels of vibration. The results also indicate that some publication bias could have occurred especially for sciatica. This review shows that there is scientific evidence that exposure to WBV increases the risk of LBP and sciatica.

Forest resources of southeast Alaska, 2000: results of a single-phase systematic sample.

Treesearch

Willem W.S. van Hees

2003-01-01

A baseline assessment of forest resources in southeast Alaska was made by using a single-phase, unstratified, systematic-grid sample, with ground plots established at each grid intersection. Ratio-of-means estimators were used to develop population estimates. Forests cover an estimated 48 percent of the 22.9-million-acre southeast Alaska inventory unit. Dominant forest...

Log Pearson type 3 quantile estimators with regional skew information and low outlier adjustments

USGS Publications Warehouse

Griffis, V.W.; Stedinger, Jery R.; Cohn, T.A.

2004-01-01

The recently developed expected moments algorithm (EMA) [Cohn et al., 1997] does as well as maximum likelihood estimations at estimating log‐Pearson type 3 (LP3) flood quantiles using systematic and historical flood information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B. Another issue addressed by Bulletin 17B is the treatment of low outliers. A Monte Carlo study compares the performance of Bulletin 17B using the entire sample with and without regional skew with estimators that use regional skew and censor low outliers, including an extended EMA estimator, the conditional probability adjustment (CPA) from Bulletin 17B, and an estimator that uses probability plot regression (PPR) to compute substitute values for low outliers. Estimators that neglect regional skew information do much worse than estimators that use an informative regional skewness estimator. For LP3 data the low outlier rejection procedure generally results in no loss of overall accuracy, and the differences between the MSEs of the estimators that used an informative regional skew are generally modest in the skewness range of real interest. Samples contaminated to model actual flood data demonstrate that estimators which give special treatment to low outliers significantly outperform estimators that make no such adjustment.

Log Pearson type 3 quantile estimators with regional skew information and low outlier adjustments

NASA Astrophysics Data System (ADS)

Griffis, V. W.; Stedinger, J. R.; Cohn, T. A.

2004-07-01

The recently developed expected moments algorithm (EMA) [, 1997] does as well as maximum likelihood estimations at estimating log-Pearson type 3 (LP3) flood quantiles using systematic and historical flood information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B. Another issue addressed by Bulletin 17B is the treatment of low outliers. A Monte Carlo study compares the performance of Bulletin 17B using the entire sample with and without regional skew with estimators that use regional skew and censor low outliers, including an extended EMA estimator, the conditional probability adjustment (CPA) from Bulletin 17B, and an estimator that uses probability plot regression (PPR) to compute substitute values for low outliers. Estimators that neglect regional skew information do much worse than estimators that use an informative regional skewness estimator. For LP3 data the low outlier rejection procedure generally results in no loss of overall accuracy, and the differences between the MSEs of the estimators that used an informative regional skew are generally modest in the skewness range of real interest. Samples contaminated to model actual flood data demonstrate that estimators which give special treatment to low outliers significantly outperform estimators that make no such adjustment.

Hepatitis C bio-behavioural surveys in people who inject drugs-a systematic review of sensitivity to the theoretical assumptions of respondent driven sampling.

PubMed

Buchanan, Ryan; Khakoo, Salim I; Coad, Jonathan; Grellier, Leonie; Parkes, Julie

2017-07-11

New, more effective and better-tolerated therapies for hepatitis C (HCV) have made the elimination of HCV a feasible objective. However, for this to be achieved, it is necessary to have a detailed understanding of HCV epidemiology in people who inject drugs (PWID). Respondent-driven sampling (RDS) can provide prevalence estimates in hidden populations such as PWID. The aims of this systematic review are to identify published studies that use RDS in PWID to measure the prevalence of HCV, and compare each study against the STROBE-RDS checklist to assess their sensitivity to the theoretical assumptions underlying RDS. Searches were undertaken in accordance with PRISMA systematic review guidelines. Included studies were English language publications in peer-reviewed journals, which reported the use of RDS to recruit PWID to an HCV bio-behavioural survey. Data was extracted under three headings: (1) survey overview, (2) survey outcomes, and (3) reporting against selected STROBE-RDS criteria. Thirty-one studies met the inclusion criteria. They varied in scale (range 1-15 survey sites) and the sample sizes achieved (range 81-1000 per survey site) but were consistent in describing the use of standard RDS methods including: seeds, coupons and recruitment incentives. Twenty-seven studies (87%) either calculated or reported the intention to calculate population prevalence estimates for HCV and two used RDS data to calculate the total population size of PWID. Detailed operational and analytical procedures and reporting against selected criteria from the STROBE-RDS checklist varied between studies. There were widespread indications that sampling did not meet the assumptions underlying RDS, which led to two studies being unable to report an estimated HCV population prevalence in at least one survey location. RDS can be used to estimate a population prevalence of HCV in PWID and estimate the PWID population size. Accordingly, as a single instrument, it is a useful tool for guiding HCV elimination. However, future studies should report the operational conduct of each survey in accordance with the STROBE-RDS checklist to indicate sensitivity to the theoretical assumptions underlying the method. PROSPERO CRD42015019245.

Causal Inference for fMRI Time Series Data with Systematic Errors of Measurement in a Balanced On/Off Study of Social Evaluative Threat.

PubMed

Sobel, Michael E; Lindquist, Martin A

2014-07-01

Functional magnetic resonance imaging (fMRI) has facilitated major advances in understanding human brain function. Neuroscientists are interested in using fMRI to study the effects of external stimuli on brain activity and causal relationships among brain regions, but have not stated what is meant by causation or defined the effects they purport to estimate. Building on Rubin's causal model, we construct a framework for causal inference using blood oxygenation level dependent (BOLD) fMRI time series data. In the usual statistical literature on causal inference, potential outcomes, assumed to be measured without systematic error, are used to define unit and average causal effects. However, in general the potential BOLD responses are measured with stimulus dependent systematic error. Thus we define unit and average causal effects that are free of systematic error. In contrast to the usual case of a randomized experiment where adjustment for intermediate outcomes leads to biased estimates of treatment effects (Rosenbaum, 1984), here the failure to adjust for task dependent systematic error leads to biased estimates. We therefore adjust for systematic error using measured "noise covariates" , using a linear mixed model to estimate the effects and the systematic error. Our results are important for neuroscientists, who typically do not adjust for systematic error. They should also prove useful to researchers in other areas where responses are measured with error and in fields where large amounts of data are collected on relatively few subjects. To illustrate our approach, we re-analyze data from a social evaluative threat task, comparing the findings with results that ignore systematic error.

An algorithm for computing moments-based flood quantile estimates when historical flood information is available

USGS Publications Warehouse

Cohn, T.A.; Lane, W.L.; Baier, W.G.

1997-01-01

This paper presents the expected moments algorithm (EMA), a simple and efficient method for incorporating historical and paleoflood information into flood frequency studies. EMA can utilize three types of at-site flood information: systematic stream gage record; information about the magnitude of historical floods; and knowledge of the number of years in the historical period when no large flood occurred. EMA employs an iterative procedure to compute method-of-moments parameter estimates. Initial parameter estimates are calculated from systematic stream gage data. These moments are then updated by including the measured historical peaks and the expected moments, given the previously estimated parameters, of the below-threshold floods from the historical period. The updated moments result in new parameter estimates, and the last two steps are repeated until the algorithm converges. Monte Carlo simulations compare EMA, Bulletin 17B's [United States Water Resources Council, 1982] historically weighted moments adjustment, and maximum likelihood estimators when fitting the three parameters of the log-Pearson type III distribution. These simulations demonstrate that EMA is more efficient than the Bulletin 17B method, and that it is nearly as efficient as maximum likelihood estimation (MLE). The experiments also suggest that EMA has two advantages over MLE when dealing with the log-Pearson type III distribution: It appears that EMA estimates always exist and that they are unique, although neither result has been proven. EMA can be used with binomial or interval-censored data and with any distributional family amenable to method-of-moments estimation.

An algorithm for computing moments-based flood quantile estimates when historical flood information is available

NASA Astrophysics Data System (ADS)

Cohn, T. A.; Lane, W. L.; Baier, W. G.

This paper presents the expected moments algorithm (EMA), a simple and efficient method for incorporating historical and paleoflood information into flood frequency studies. EMA can utilize three types of at-site flood information: systematic stream gage record; information about the magnitude of historical floods; and knowledge of the number of years in the historical period when no large flood occurred. EMA employs an iterative procedure to compute method-of-moments parameter estimates. Initial parameter estimates are calculated from systematic stream gage data. These moments are then updated by including the measured historical peaks and the expected moments, given the previously estimated parameters, of the below-threshold floods from the historical period. The updated moments result in new parameter estimates, and the last two steps are repeated until the algorithm converges. Monte Carlo simulations compare EMA, Bulletin 17B's [United States Water Resources Council, 1982] historically weighted moments adjustment, and maximum likelihood estimators when fitting the three parameters of the log-Pearson type III distribution. These simulations demonstrate that EMA is more efficient than the Bulletin 17B method, and that it is nearly as efficient as maximum likelihood estimation (MLE). The experiments also suggest that EMA has two advantages over MLE when dealing with the log-Pearson type III distribution: It appears that EMA estimates always exist and that they are unique, although neither result has been proven. EMA can be used with binomial or interval-censored data and with any distributional family amenable to method-of-moments estimation.

Optimal strategies to consider when peer reviewing a systematic review and meta-analysis.

PubMed

Moher, David

2015-11-02

Systematic reviews are popular. A recent estimate indicates that 11 new systematic reviews are published daily. Nevertheless, evidence indicates that the quality of reporting of systematic reviews is not optimal. One likely reason is that the authors' reports have received inadequate peer review. There are now many different types of systematic reviews and peer reviewing them can be enhanced by using a reporting guideline to supplement whatever template the journal editors have asked you, as a peer reviewer, to use. Additionally, keeping up with the current literature, whether as a content expert or being aware of advances in systematic review methods is likely be make for a more comprehensive and effective peer review. Providing a brief summary of what the systematic review has reported is an important first step in the peer review process (and not performed frequently enough). At its core, it provides the authors with some sense of what the peer reviewer believes was performed (Methods) and found (Results). Importantly, it also provides clarity regarding any potential problems in the methods, including statistical approaches for meta-analysis, results, and interpretation of the systematic review, for which the peer reviewer can seek explanations from the authors; these clarifications are best presented as questions to the authors.

Is chocolate consumption associated with health outcomes? An umbrella review of systematic reviews and meta-analyses.

PubMed

Veronese, Nicola; Demurtas, Jacopo; Celotto, Stefano; Caruso, Maria Gabriella; Maggi, Stefania; Bolzetta, Francesco; Firth, Joseph; Smith, Lee; Schofield, Patricia; Koyanagi, Ai; Yang, Lin; Solmi, Marco; Stubbs, Brendon

2018-06-01

The literature regarding the potential health benefits of chocolate consumption are unclear and the epidemiological credibility has not been systematically scrutinized, while the strength of the evidence is undetermined. We therefore aimed to map and grade the diverse health outcomes associated with chocolate consumption using an umbrella review of systematic reviews. Umbrella review of systematic reviews of observational and intervention studies (randomized placebo-controlled trials, RCTs). For each association, random-effects summary effect size, 95% confidence interval, and 95% prediction interval were estimated. We also assessed heterogeneity, evidence for small-study effect and evidence for excess significance bias. For significant outcomes of the RCTs, the GRADE assessment was furtherly used. From 240 articles returned, 10 systematic reviews were included (8 of which included a meta-analysis), including a total of 84 studies (36 prospective observational studies and 48 interventional). Nineteen different outcomes were included. Among observational studies, including a total of 1,061,637 participants, the best available evidence suggests that chocolate consumption is associated with reduced risk of cardiovascular disease (CVD) death (n = 4 studies), acute myocardial infarction (n = 6), stroke (n = 5) and diabetes (n = 6), although this was based on a weak evidence of credibility. Across meta-analyses of intervention studies, chocolate consumption was positively associated with flow-mediated dilatation at 90-150 min (n = 3) and at 2-18 weeks (n = 3), and insulin resistance markers (n = 2). However, using the GRADE assessment, the evidence for these outcomes was low or very low. Data from two systematic reviews, reported that chocolate consumption was not associated with better depressive mood or cognitive function. There is weak evidence to suggest that chocolate consumption may be associated with favorable health outcomes. Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

A model-based correction for outcome reporting bias in meta-analysis.

PubMed

Copas, John; Dwan, Kerry; Kirkham, Jamie; Williamson, Paula

2014-04-01

It is often suspected (or known) that outcomes published in medical trials are selectively reported. A systematic review for a particular outcome of interest can only include studies where that outcome was reported and so may omit, for example, a study that has considered several outcome measures but only reports those giving significant results. Using the methodology of the Outcome Reporting Bias (ORB) in Trials study of (Kirkham and others, 2010. The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews. British Medical Journal 340, c365), we suggest a likelihood-based model for estimating the effect of ORB on confidence intervals and p-values in meta-analysis. Correcting for bias has the effect of moving estimated treatment effects toward the null and hence more cautious assessments of significance. The bias can be very substantial, sometimes sufficient to completely overturn previous claims of significance. We re-analyze two contrasting examples, and derive a simple fixed effects approximation that can be used to give an initial estimate of the effect of ORB in practice.

Health-care workers' occupational exposures to body fluids in 21 countries in Africa: systematic review and meta-analysis.

PubMed

Auta, Asa; Adewuyi, Emmanuel O; Tor-Anyiin, Amom; Aziz, David; Ogbole, Esther; Ogbonna, Brian O; Adeloye, Davies

2017-12-01

To estimate the lifetime and 12-month prevalence of occupational exposure to body fluids among health-care workers in Africa. Embase®, PubMed® and CINAHL databases were systematically searched for studies published between January 2000 and August 2017 that reported the prevalence of occupational exposure to blood or other body fluids among health-care workers in Africa. The continent-wide prevalence of exposure was estimated using random-effects meta-analysis. Of the 904 articles identified, 65 studies from 21 African countries were included. The estimated pooled lifetime and 12-month prevalence of occupational exposure to body fluids were 65.7% (95% confidence interval, CI: 59.7-71.6) and 48.0% (95% CI: 40.7-55.3), respectively. Exposure was largely due to percutaneous injury, which had an estimated 12-month prevalence of 36.0% (95% CI: 31.2-40.8). The pooled 12-month prevalence of occupational exposure among medical doctors (excluding surgeons), nurses (including midwives and nursing assistants) and laboratory staff (including laboratory technicians) was 46.6% (95% CI: 33.5-59.7), 44.6% (95% CI: 34.1-55.0) and 34.3% (95% CI: 21.8-46.7), respectively. The risk of exposure was higher among health-care workers with no training on infection prevention and those who worked more than 40 hours per week. The evidence available suggests that almost one half of health-care workers in Africa were occupationally exposed to body fluids annually. However, a lack of data from some countries was a major limitation. National governments and health-care institutions across Africa should prioritize efforts to minimize occupational exposure among health-care workers.

Health-care workers’ occupational exposures to body fluids in 21 countries in Africa: systematic review and meta-analysis

PubMed Central

Adewuyi, Emmanuel O; Tor-Anyiin, Amom; Aziz, David; Ogbole, Esther; Ogbonna, Brian O; Adeloye, Davies

2017-01-01

Abstract Objective To estimate the lifetime and 12-month prevalence of occupational exposure to body fluids among health-care workers in Africa. Methods Embase®, PubMed® and CINAHL databases were systematically searched for studies published between January 2000 and August 2017 that reported the prevalence of occupational exposure to blood or other body fluids among health-care workers in Africa. The continent-wide prevalence of exposure was estimated using random-effects meta-analysis. Findings Of the 904 articles identified, 65 studies from 21 African countries were included. The estimated pooled lifetime and 12-month prevalence of occupational exposure to body fluids were 65.7% (95% confidence interval, CI: 59.7–71.6) and 48.0% (95% CI: 40.7–55.3), respectively. Exposure was largely due to percutaneous injury, which had an estimated 12-month prevalence of 36.0% (95% CI: 31.2–40.8). The pooled 12-month prevalence of occupational exposure among medical doctors (excluding surgeons), nurses (including midwives and nursing assistants) and laboratory staff (including laboratory technicians) was 46.6% (95% CI: 33.5–59.7), 44.6% (95% CI: 34.1–55.0) and 34.3% (95% CI: 21.8–46.7), respectively. The risk of exposure was higher among health-care workers with no training on infection prevention and those who worked more than 40 hours per week. Conclusion The evidence available suggests that almost one half of health-care workers in Africa were occupationally exposed to body fluids annually. However, a lack of data from some countries was a major limitation. National governments and health-care institutions across Africa should prioritize efforts to minimize occupational exposure among health-care workers. PMID:29200524

Test-retest reliability of the diagnosis of schizoaffective disorder in childhood and adolescence - A systematic review and meta-analysis.

PubMed

Salamon, Sarah; Santelmann, Hanno; Franklin, Jeremy; Baethge, Christopher

2018-04-01

Reliability of schizoaffective disorder (SAD) diagnoses is low in adults but unclear in children and adolescents (CAD). We estimate the test-retest reliability of SAD and its key differential diagnoses (schizophrenia, bipolar disorder, and unipolar depression). Systematic literature search of Medline, Embase, and PsycInfo for studies on test-retest reliability of SAD, in CAD. Cohen's kappa was extracted from studies. We performed meta-analysis for kappa, including subgroup and sensitivity analysis (PROSPERO protocol: CRD42013006713). Out of > 4000 records screened, seven studies were included. We estimated kappa values of 0.27 [95%-CI: 0.07 0.47] for SAD, 0.56 [0.29; 0.83] for schizophrenia, 0.64 [0.55; 0.74] for bipolar disorder, and 0.66 [0.52; 0.81] for unipolar depression. In 5/7 studies kappa of SAD was lower than that of schizophrenia; similar trends emerged for bipolar disorder (4/5) and unipolar depression (2/3). Estimates of positive agreement of SAD diagnoses supported these results. The number of studies and patients included is low. The point-estimate of the test-retest reliability of schizoaffective disorder is only fair, and lower than that of its main differential diagnoses. All kappa values under study were lower in children and adolescents samples than those reported for adults. Clinically, schizoaffective disorder should be diagnosed in strict adherence to the operationalized criteria and ought to be re-evaluated regularly. Should larger studies confirm the insufficient reliability of schizoaffective disorder in children and adolescents, the clinical value of the diagnosis is highly doubtful. Copyright © 2017. Published by Elsevier B.V.

Prevalence of attention deficit hyperactivity disorder among children and adolescents in Spain: a systematic review and meta-analysis of epidemiological studies

PubMed Central

2012-01-01

Background Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed neuropsychiatric disorder in childhood, but the frequency of the condition is not well established in many countries. The aim of the present study was to quantify the overall prevalence of ADHD among children and adolescents in Spain by means of a systematic review and meta-analysis. Methods PubMed/MEDLINE, IME, IBECS and TESEO were comprehensively searched. Original reports were selected if they provided data on prevalence estimates of ADHD among people under 18 years old in Spain and were cross-sectional, observational epidemiological studies. Information from included studies was systematically extracted and evaluated. Overall pooled-prevalence estimates of ADHD were calculated using random-effects models. Sources of heterogeneity were explored by means sub-groups analyses and univariate meta-regressions. Results Fourteen epidemiological studies (13,026 subjects) were selected. The overall pooled-prevalence of ADHD was estimated at 6.8% [95% confidence interval (CI) 4.9 – 8.8%] representing 361,580 (95% CI 260,550 – 467,927) children and adolescents in the community. There was significant heterogeneity (P < 0.001), which was incompletely explained by subgroup analyses and meta-regressions. Conclusions Our findings suggest that the prevalence of ADHD among children and adolescents in Spain is consistent with previous studies conducted in other countries and regions. This study represents a first step in estimating the national burden of ADHD that will be essential to building evidence-based programs and services. PMID:23057832

Alcohol consumption and the intention to engage in unprotected sex: systematic review and meta-analysis of experimental studies.

PubMed

Rehm, Jürgen; Shield, Kevin D; Joharchi, Narges; Shuper, Paul A

2012-01-01

To review and analyse in experimentally controlled studies the impact of alcohol consumption on intentions to engage in unprotected sex. To draw conclusions with respect to the question of whether alcohol has an independent effect on the incidence of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). A systematic review and meta-analysis of randomized controlled studies examined the association between blood alcohol content (BAC) and self-perceived likelihood of using a condom during intercourse. The systematic review and meta-analysis were conducted according to internationally standardized protocols (Preferred Reporting Items for Systematic Reviews and Meta-Analyses: PRISMA). The meta-analysis included an estimate of the dose-response effect, tests for publication bias and sensitivity analyses. Of the 12 studies included in the quantitative synthesis, our pooled analysis indicated that an increase in BAC of 0.1 mg/ml resulted in an increase of 5.0% (95% CI: 2.8-7.1%) in the indicated likelihood (indicated by a Likert scale) of engaging in unprotected sex. After adjusting for potential publication bias, this estimate dropped to 2.9% (95% CI: 2.0-3.9%). Thus, the larger the alcohol intake and the subsequent level of BAC, the higher the intentions to engage in unsafe sex. The main results were homogeneous, persisted in sensitivity analyses and after correction for publication bias. Alcohol use is an independent risk factor for intentions to engage in unprotected sex, and as risky sex intentions have been shown to be linked to actual risk behavior, the role of alcohol consumption in the transmission of HIV and other STIs may be of public health importance. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

Impact of ambient temperature on morbidity and mortality: An overview of reviews.

PubMed

Song, Xuping; Wang, Shigong; Hu, Yuling; Yue, Man; Zhang, Tingting; Liu, Yu; Tian, Jinhui; Shang, Kezheng

2017-05-15

The objectives were (i) to conduct an overview of systematic reviews to summarize evidence from and evaluate the methodological quality of systematic reviews assessing the impact of ambient temperature on morbidity and mortality; and (ii) to reanalyse meta-analyses of cold-induced cardiovascular morbidity in different age groups. The registration number is PROSPERO-CRD42016047179. PubMed, Embase, the Cochrane Library, Web of Science, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Global Health were systematically searched to identify systematic reviews. Two reviewers independently selected studies for inclusion, extracted data, and assessed quality. The Assessment of Multiple Systematic Reviews (AMSTAR) checklist was used to assess the methodological quality of included systematic reviews. Estimates of morbidity and mortality risk in association with heat exposure, cold exposure, heatwaves, cold spells and diurnal temperature ranges (DTRs) were the primary outcomes. Twenty-eight systematic reviews were included in the overview of systematic reviews. (i) The median (interquartile range) AMSTAR scores were 7 (1.75) for quantitative reviews and 3.5 (1.75) for qualitative reviews. (ii) Heat exposure was identified to be associated with increased risk of cardiovascular, cerebrovascular and respiratory mortality, but was not found to have an impact on cardiovascular or cerebrovascular morbidity. (iii) Reanalysis of the meta-analyses indicated that cold-induced cardiovascular morbidity increased in youth and middle-age (RR=1.009, 95% CI: 1.004-1.015) as well as the elderly (RR=1.013, 95% CI: 1.007-1.018). (iv) The definitions of temperature exposure adopted by different studies included various temperature indicators and thresholds. In conclusion, heat exposure seemed to have an adverse effect on mortality and cold-induced cardiovascular morbidity increased in the elderly. Developing definitions of temperature exposure at the regional level may contribute to more accurate evaluations of the health effects of temperature. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of severe and moderate acute malnutrition in low- and middle-income settings: a systematic review, meta-analysis and Delphi process

PubMed Central

2013-01-01

Background Globally, moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) affect approximately 52 million children under five. This systematic review evaluates the effectiveness of interventions for SAM including the World Health Organization (WHO) protocol for inpatient management and community-based management with ready-to-use-therapeutic food (RUTF), as well as interventions for MAM in children under five years in low- and middle-income countries. Methods We systematically searched the literature and included 14 studies in the meta-analysis. Study quality was assessed using CHERG adaptation of GRADE criteria. A Delphi process was undertaken to complement the systematic review in estimating case fatality and recovery rates that were necessary for modelling in the Lives Saved Tool (LiST). Results Case fatality rates for inpatient treatment of SAM using the WHO protocol ranged from 3.4% to 35%. For community-based treatment of SAM, children given RUTF were 51% more likely to achieve nutritional recovery than the standard care group. For the treatment of MAM, children in the RUSF group were significantly more likely to recover and less likely to be non-responders than in the CSB group. In both meta-analyses, weight gain in the intervention group was higher, and although statistically significant, these differences were small. Overall limitations in our analysis include considerable heterogeneity in many outcomes and an inability to evaluate intervention effects separate from commodity effect. The Delphi process indicated that adherence to standardized protocols for the treatment of SAM and MAM should have a marked positive impact on mortality and recovery rates; yet, true consensus was not achieved. Conclusions Gaps in our ability to estimate effectiveness of overall treatment approaches for SAM and MAM persist. In addition to further impact studies conducted in a wider range of settings, more high quality program evaluations need to be conducted and the results disseminated. PMID:24564235

Genital Chlamydia Prevalence in Europe and Non-European High Income Countries: Systematic Review and Meta-Analysis

PubMed Central

Redmond, Shelagh M.; Alexander-Kisslig, Karin; Woodhall, Sarah C.; van den Broek, Ingrid V. F.; van Bergen, Jan; Ward, Helen; Uusküla, Anneli; Herrmann, Björn; Andersen, Berit; Götz, Hannelore M.; Sfetcu, Otilia; Low, Nicola

2015-01-01

Background Accurate information about the prevalence of Chlamydia trachomatis is needed to assess national prevention and control measures. Methods We systematically reviewed population-based cross-sectional studies that estimated chlamydia prevalence in European Union/European Economic Area (EU/EEA) Member States and non-European high income countries from January 1990 to August 2012. We examined results in forest plots, explored heterogeneity using the I2 statistic, and conducted random effects meta-analysis if appropriate. Meta-regression was used to examine the relationship between study characteristics and chlamydia prevalence estimates. Results We included 25 population-based studies from 11 EU/EEA countries and 14 studies from five other high income countries. Four EU/EEA Member States reported on nationally representative surveys of sexually experienced adults aged 18–26 years (response rates 52–71%). In women, chlamydia point prevalence estimates ranged from 3.0–5.3%; the pooled average of these estimates was 3.6% (95% CI 2.4, 4.8, I2 0%). In men, estimates ranged from 2.4–7.3% (pooled average 3.5%; 95% CI 1.9, 5.2, I2 27%). Estimates in EU/EEA Member States were statistically consistent with those in other high income countries (I2 0% for women, 6% for men). There was statistical evidence of an association between survey response rate and estimated chlamydia prevalence; estimates were higher in surveys with lower response rates, (p = 0.003 in women, 0.018 in men). Conclusions Population-based surveys that estimate chlamydia prevalence are at risk of participation bias owing to low response rates. Estimates obtained in nationally representative samples of the general population of EU/EEA Member States are similar to estimates from other high income countries. PMID:25615574

Prenatal ambient air pollution exposure and the risk of stillbirth: systematic review and meta-analysis of the empirical evidence.

PubMed

Siddika, Nazeeba; Balogun, Hamudat A; Amegah, Adeladza K; Jaakkola, Jouni J K

2016-09-01

Individual studies on the relations between ambient air pollution and the risk of stillbirth have provided contradictory results. We conducted a systematic review and meta-analysis to summarise the existing evidence. We conducted a systematic search of three databases: PubMed, Scopus and Web of Science, from their time of inception to mid-April, 2015. Original studies of any epidemiological design were included. Data from eligible studies were extracted by two investigators. To calculate the summary effect estimates (EE), the random effects model was used with their corresponding 95% CI. 13 studies met the inclusion criteria. Although not reaching statistical significance, all the summary effect estimates for the risk of stillbirth were systematically elevated in relation to mean prenatal exposure to NO2 per 10 ppb (EE=1.066, 95% CI 0.965 to 1.178, n=3), CO per 0.4 ppm (EE=1.025, 95% CI 0.985 to 1.066, n=3), SO2 per 3 ppb (EE=1.022, 95% CI 0.984 to 1.062, n=3,), PM2.5 per 4 μg/m(3) (EE=1.021, 95% CI 0.996 to 1.046, n=2) and PM10 per 10 μg/m(3) (EE=1.014, 95% CI 0.948 to 1.085, n=2). The effect estimates for SO2, CO, PM10 and O3 were highest for the third trimester exposure. Two time series studies used a lag term of not more than 6 days preceding stillbirth, and both found increased effect estimates for some pollutants. The body of evidence suggests that exposure to ambient air pollution increases the risk of stillbirth. Further studies are needed to strengthen the evidence. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Comparison of two independent systematic reviews of trials of recombinant human bone morphogenetic protein-2 (rhBMP-2): the Yale Open Data Access Medtronic Project.

PubMed

Low, Jeffrey; Ross, Joseph S; Ritchie, Jessica D; Gross, Cary P; Lehman, Richard; Lin, Haiqun; Fu, Rongwei; Stewart, Lesley A; Krumholz, Harlan M

2017-02-15

It is uncertain whether the replication of systematic reviews, particularly those with the same objectives and resources, would employ similar methods and/or arrive at identical findings. We compared the results and conclusions of two concurrent systematic reviews undertaken by two independent research teams provided with the same objectives, resources, and individual participant-level data. Two centers in the USA and UK were each provided with participant-level data on 17 multi-site clinical trials of recombinant human bone morphogenetic protein-2 (rhBMP-2). The teams were blinded to each other's methods and findings until after publication. We conducted a retrospective structured comparison of the results of the two systematic reviews. The main outcome measures included (1) trial inclusion criteria; (2) statistical methods; (3) summary efficacy and risk estimates; and (4) conclusions. The two research teams' meta-analyses inclusion criteria were broadly similar but differed slightly in trial inclusion and research methodology. They obtained similar results in summary estimates of most clinical outcomes and adverse events. Center A incorporated all trials into summary estimates of efficacy and harms, while Center B concentrated on analyses stratified by surgical approach. Center A found a statistically significant, but small, benefit whereas Center B reported no advantage. In the analysis of harms, neither showed an increased cancer risk at 48 months, although Center B reported a significant increase at 24 months. Conclusions reflected these differences in summary estimates of benefit balanced with small but potentially important risk of harm. Two independent groups given the same research objectives, data, resources, funding, and time produced broad general agreement but differed in several areas. These differences, the importance of which is debatable, indicate the value of the availability of data to allow for more than a single approach and a single interpretation of the data. PROSPERO CRD42012002040 and CRD42012001907 .

A systematic review with meta-analysis of the prevalence of gastroesophageal reflux in congenital diaphragmatic hernia pediatric survivors.

PubMed

Arcos-Machancoses, J V; Ruiz Hernández, C; Martin de Carpi, J; Pinillos Pisón, S

2018-02-09

Congenital diaphragmatic hernia survivors are a well-known group at risk for developing gastroesophageal reflux disease that may be particularly long-term severe. The aim of this study is to provide a systematic review of the prevalence of gastroesophageal reflux in infant and children survivors treated for congenital diaphragmatic hernia.Electronic and manual searches were performed with keywords related to congenital diaphragmatic hernia, gastroesophageal reflux disease, and epidemiology terms. Summary estimates of the prevalence were calculated. Effect model was chosen depending on heterogeneity (I2). Factors potentially related with the prevalence, including study quality or the diagnostic strategy followed, were assessed by subgroup and meta-regression analyses. Risk of publication bias was studied by funnel plot analysis and the Egger test.The search yielded 140 articles, 26 of which were included in the analyses and provided 34 estimates of prevalence: 21 in patients aged 12 months or younger, and 13 in older children. The overall prevalence of gastroesophageal reflux disease in infants was 52.7% (95% confidence interval [CI]: 43.2% to 62.1%, I2 = 88.7%) and, in children over 1 year old, 35.1% (95% CI: 25.4% to 45.3%, I2 = 73.5%). Significant clinical and statistical heterogeneity was found. The strategy chosen for gastroesophageal reflux diagnosis influenced the reported prevalence. The only estimate obtained with a systematic use of multichannel intraluminal impedance provided a higher prevalence in both age groups: 83.3% (95% CI: 67.2% to 93.6%) and 61.1% (95% CI: 43.5% to 76.9%) respectively. This last prevalence did not significantly differ from that obtained using only low risk of bias estimates.As a conclusion, gastroesophageal reflux disease is commonly observed after congenital diaphragmatic hernia repair and is almost constantly present in the first months of life. It may be underdiagnosed if systematically esophageal monitoring is not performed. This should be considered when proposing follow-up and management protocols for congenital diaphragmatic hernia survivors. © The Author(s) 2018. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

BACKWARD ESTIMATION OF STOCHASTIC PROCESSES WITH FAILURE EVENTS AS TIME ORIGINS1

PubMed Central

Gary Chan, Kwun Chuen; Wang, Mei-Cheng

2011-01-01

Stochastic processes often exhibit sudden systematic changes in pattern a short time before certain failure events. Examples include increase in medical costs before death and decrease in CD4 counts before AIDS diagnosis. To study such terminal behavior of stochastic processes, a natural and direct way is to align the processes using failure events as time origins. This paper studies backward stochastic processes counting time backward from failure events, and proposes one-sample nonparametric estimation of the mean of backward processes when follow-up is subject to left truncation and right censoring. We will discuss benefits of including prevalent cohort data to enlarge the identifiable region and large sample properties of the proposed estimator with related extensions. A SEER–Medicare linked data set is used to illustrate the proposed methodologies. PMID:21359167

How to apply the optimal estimation method to your lidar measurements for improved retrievals of temperature and composition

NASA Astrophysics Data System (ADS)

Sica, R. J.; Haefele, A.; Jalali, A.; Gamage, S.; Farhani, G.

2018-04-01

The optimal estimation method (OEM) has a long history of use in passive remote sensing, but has only recently been applied to active instruments like lidar. The OEM's advantage over traditional techniques includes obtaining a full systematic and random uncertainty budget plus the ability to work with the raw measurements without first applying instrument corrections. In our meeting presentation we will show you how to use the OEM for temperature and composition retrievals for Rayleigh-scatter, Ramanscatter and DIAL lidars.

Reliability and validity of depression assessment among persons with HIV in sub-Saharan Africa: systematic review and meta-analysis

PubMed Central

Tsai, Alexander C.

2014-01-01

OBJECTIVES To systematically review the reliability and validity of instruments used to screen for major depressive disorder or assess depression symptom severity among persons with HIV in sub-Saharan Africa. DESIGN Systematic review and meta-analysis. METHODS A systematic evidence search protocol was applied to seven bibliographic databases. Studies examining the reliability and/or validity of depression assessment tools were selected for inclusion if they were based on data collected from HIV-positive adults in any African member state of the United Nations. Random-effects meta-analysis was employed to calculate pooled estimates of depression prevalence. In a subgroup of studies of criterion-related validity, the bivariate random-effects model was used to calculate pooled estimates of sensitivity and specificity. RESULTS Of 1,117 records initially identified, I included 13 studies of 5,373 persons with HIV in 7 sub-Saharan African countries. Reported estimates of Cronbach’s alpha ranged from 0.63–0.95, and analyses of internal structure generally confirmed the existence of a depression-like construct accounting for a substantial portion of variance. The pooled prevalence of probable depression was 29.5% (95% CI, 20.5–39.4), while the pooled prevalence of major depressive disorder was 13.9% (95% CI, 9.7–18.6). The Center for Epidemiologic Studies-Depression scale was the most frequently studied instrument, with a pooled sensitivity of 0.82 (95% CI, 0.73–0.87) for detecting major depressive disorder. CONCLUSIONS Depression screening instruments yielded relatively high false positive rates. Overall, few studies described the reliability and/or validity of depression instruments in sub-Saharan Africa. PMID:24853307

The Incidence of Postpartum Hemorrhage in Pregnant Women with Placenta Previa: A Systematic Review and Meta-Analysis

PubMed Central

Liu, Li; Wu, Shuzhen; Tian, Guo; Wang, Wen; Wu, Song; Guo, Xiaoling; Liu, Zhengping

2017-01-01

Background The global burden of postpartum hemorrhage (PPH) in women with placenta previa is a major public health concern. Although there are different reports on the incidence of PPH in different countries, to date, no research has reviewed them. Objective The aim of this study was to calculate the average point incidence of PPH in women with placenta previa. Methods A systematic review and meta-analysis of observational studies estimating PPH in women with placenta previa was conducted through literature searches in four databases in Jul 2016. This study was totally conducted according to the MOOSE guidelines and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard. Results From 1148 obtained studies, 11 included in the meta-analysis, which involved 5146 unique pregnant women with placenta previa. The overall pooled incidence of PPH was 22.3% (95% CI 15.8–28.7%). In the subgroup, the prevalence was 27.4% in placenta previas, and was 14.5% in low-lying placenta previa; the highest prevalence was estimated in Northern America (26.3%, 95%CI 11.0–41.6%), followed by the Asia (20.7%, 95%CI 12.8–28.6%), Australia (19.2%, 95% CI 17.2–21.1%) and Europe (17.8%, 95% CI, 11.5%-24.0%). Conclusions The summary estimate of the incidence of PPH among women with placenta previa was considerable in this systematic review. The results will be crucial in prevention, treatment, and identification of PPH among pregnant women with placenta previa and will be contributed to the planning and implantation of relevant public health strategies. PMID:28107460

A Systematic Review of Studies Eliciting Willingness-to-Pay per Quality-Adjusted Life Year: Does It Justify CE Threshold?

PubMed Central

Nimdet, Khachapon; Chaiyakunapruk, Nathorn; Vichansavakul, Kittaya; Ngorsuraches, Surachat

2015-01-01

Background A number of studies have been conducted to estimate willingness to pay (WTP) per quality-adjusted life years (QALY) in patients or general population for various diseases. However, there has not been any systematic review summarizing the relationship between WTP per QALY and cost-effectiveness (CE) threshold based on World Health Organization (WHO) recommendation. Objective To systematically review willingness-to-pay per quality-adjusted-life-year (WTP per QALY) literature, to compare WTP per QALY with Cost-effectiveness (CE) threshold recommended by WHO, and to determine potential influencing factors. Methods We searched MEDLINE, EMBASE, Psyinfo, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Center of Research Dissemination (CRD), and EconLit from inception through 15 July 2014. To be included, studies have to estimate WTP per QALY in health-related issues using stated preference method. Two investigators independently reviewed each abstract, completed full-text reviews, and extracted information for included studies. We compared WTP per QALY to GDP per capita, analyzed, and summarized potential influencing factors. Results Out of 3,914 articles founded, 14 studies were included. Most studies (92.85%) used contingent valuation method, while only one study used discrete choice experiments. Sample size varied from 104 to 21,896 persons. The ratio between WTP per QALY and GDP per capita varied widely from 0.05 to 5.40, depending on scenario outcomes (e.g., whether it extended/saved life or improved quality of life), severity of hypothetical scenarios, duration of scenario, and source of funding. The average ratio of WTP per QALY and GDP per capita for extending life or saving life (2.03) was significantly higher than the average for improving quality of life (0.59) with the mean difference of 1.43 (95% CI, 1.81 to 1.06). Conclusion This systematic review provides an overview summary of all studies estimating WTP per QALY studies. The variation of ratio of WTP per QALY and GDP per capita depended on several factors may prompt discussions on the CE threshold policy. Our research work provides a foundation for defining future direction of decision criteria for an evidence-informed decision making system. PMID:25855971

Who perpetrates violence against children? A systematic analysis of age-specific and sex-specific data.

PubMed

Devries, Karen; Knight, Louise; Petzold, Max; Merrill, Katherine G; Maxwell, Lauren; Williams, Abigail; Cappa, Claudia; Chan, Ko Ling; Garcia-Moreno, Claudia; Hollis, NaTasha; Kress, Howard; Peterman, Amber; Walsh, Sophie D; Kishor, Sunita; Guedes, Alessandra; Bott, Sarah; Butron Riveros, Betzabe C; Watts, Charlotte; Abrahams, Naeemah

2018-01-01

The epidemiology of violence against children is likely to differ substantially by sex and age of the victim and the perpetrator. Thus far, investment in effective prevention strategies has been hindered by lack of clarity in the burden of childhood violence across these dimensions. We produced the first age-specific and sex-specific prevalence estimates by perpetrator type for physical, sexual and emotional violence against children globally. We used random effects meta-regression to estimate prevalence. Estimates were adjusted for relevant quality covariates, variation in definitions of violence and weighted by region-specific, age-specific and sex-specific population data to ensure estimates reflect country population structures. Secondary data from 600 population or school-based representative datasets and 43 publications obtained via systematic literature review, representing 13 830 estimates from 171 countries. Estimates for recent violence against children aged 0-19 were included. The most common perpetrators of physical and emotional violence for both boys and girls across a range of ages are household members, with prevalence often surpassing 50%, followed by student peers. Children reported experiencing more emotional than physical violence from both household members and students. The most common perpetrators of sexual violence against girls aged 15-19 years are intimate partners; however, few data on other perpetrators of sexual violence against children are systematically collected internationally. Few age-specific and sex-specific data are available on violence perpetration by schoolteachers; however, existing data indicate high prevalence of physical violence from teachers towards students. Data from other authority figures, strangers, siblings and other adults are limited, as are data on neglect of children. Without further investment in data generation on violence exposure from multiple perpetrators for boys and girls of all ages, progress towards Sustainable Development Goals 4, 5 and 16 may be slow. Despite data gaps, evidence shows violence from household members, peers in school and for girls, from intimate partners, should be prioritised for prevention. PROSPERO 2015: CRD42015024315.

Meta-analysis: prevalence of HIV infection and syphilis among MSM in China.

PubMed

Gao, L; Zhang, L; Jin, Q

2009-09-01

The prevalence of HIV/AIDS and other sexually transmitted diseases is rapidly rising among men who have sex with men (MSM) in China. The aim is to systematically review the published studies and summarise the estimates of HIV prevalence among MSM in China. Published articles, both in English and in Chinese, on HIV prevalence among MSM in China until 15 September 2008 were systematically reviewed. Meta-analysis was used to quantitatively summarise the estimates, and the prevalence of syphilis presented in the included studies was also analysed. Twenty-six eligible studies, published during 2001-2008, were included in this review. Their results were frequently heterogeneous. The meta-analyses showed that MSM form a high-risk population for HIV infection in China with a summary prevalence of 2.5% (95% CI 0.9% to 3.3%). A much higher prevalence of syphilis (9.1%) may indicate a potential of more severe HIV epidemic in the future because of their common high-risk behaviours. MSM are a high-risk population for HIV infection in China. An effective strategy for prevention and control is required for this specific population. Differences between sampling methods, sample sizes and study locations may explain some of the inconsistencies found in the included studies.

Multifidelity Analysis and Optimization for Supersonic Design

NASA Technical Reports Server (NTRS)

Kroo, Ilan; Willcox, Karen; March, Andrew; Haas, Alex; Rajnarayan, Dev; Kays, Cory

2010-01-01

Supersonic aircraft design is a computationally expensive optimization problem and multifidelity approaches over a significant opportunity to reduce design time and computational cost. This report presents tools developed to improve supersonic aircraft design capabilities including: aerodynamic tools for supersonic aircraft configurations; a systematic way to manage model uncertainty; and multifidelity model management concepts that incorporate uncertainty. The aerodynamic analysis tools developed are appropriate for use in a multifidelity optimization framework, and include four analysis routines to estimate the lift and drag of a supersonic airfoil, a multifidelity supersonic drag code that estimates the drag of aircraft configurations with three different methods: an area rule method, a panel method, and an Euler solver. In addition, five multifidelity optimization methods are developed, which include local and global methods as well as gradient-based and gradient-free techniques.

Risk factors for first time incidence sciatica: a systematic review.

PubMed

Cook, Chad E; Taylor, Jeffrey; Wright, Alexis; Milosavljevic, Steven; Goode, Adam; Whitford, Maureen

2014-06-01

Characteristically, sciatica involves radiating leg pain that follows a dermatomal pattern along the distribution of the sciatic nerve. To our knowledge, there are no studies that have investigated risk factors associated with first time incidence sciatica. The purpose of the systematic review was to identify the longitudinal risk factors associated with first time incidence sciatica and to report incidence rates for the condition. For the purposes of this review, first time incidence sciatica was defined as either of the following: 1) no prior history of sciatica or 2) transition from a pain-free state to sciatica. Studies included subjects of any age from longitudinal, observational, cohort designs. The study was a systematic review. Eight of the 239 articles identified by electronic search strategies met the inclusion criteria. Risk factors and their respective effect estimates were reported using descriptive analysis and the preferred reporting items for systematic reviews and meta-analyses guidelines. Modifiable risk factors included smoking, obesity, occupational factors and health status. Non-modifiable factors included age, gender and social class. Incidence rates varied among the included studies, in part reflecting the variability in the operationalized definition of sciatica but ranged from <1% to 37%. A majority of the identified risk factors associated with first time sciatica are modifiable, suggesting the potential benefits of primary prevention. In addition, those risk factors are also associated with unhealthy lifestyles, which may function concomitantly toward the development of sciatica. Sciatica as a diagnosis is inconsistently defined among studies. © 2013 John Wiley & Sons, Ltd.

Technical Note: Introduction of variance component analysis to setup error analysis in radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Yukinori, E-mail: ymatsuo@kuhp.kyoto-u.ac.

Purpose: The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy. Methods: Balanced data according to the one-factor random effect model were assumed. Results: Analysis-of-variance (ANOVA)-based computation was applied to estimate the values and their confidence intervals (CIs) for systematic and random errors and the population mean of setup errors. The conventional method overestimates systematic error, especially in hypofractionated settings. The CI for systematic error becomes much wider than that for random error. The ANOVA-based estimation can be extended to a multifactor model considering multiplemore » causes of setup errors (e.g., interpatient, interfraction, and intrafraction). Conclusions: Variance component analysis may lead to novel applications to setup error analysis in radiotherapy.« less

Mismatch and G-Stack Modulated Probe Signals on SNP Microarrays

PubMed Central

Binder, Hans; Fasold, Mario; Glomb, Torsten

2009-01-01

Background Single nucleotide polymorphism (SNP) arrays are important tools widely used for genotyping and copy number estimation. This technology utilizes the specific affinity of fragmented DNA for binding to surface-attached oligonucleotide DNA probes. We analyze the variability of the probe signals of Affymetrix GeneChip SNP arrays as a function of the probe sequence to identify relevant sequence motifs which potentially cause systematic biases of genotyping and copy number estimates. Methodology/Principal Findings The probe design of GeneChip SNP arrays enables us to disentangle different sources of intensity modulations such as the number of mismatches per duplex, matched and mismatched base pairings including nearest and next-nearest neighbors and their position along the probe sequence. The effect of probe sequence was estimated in terms of triple-motifs with central matches and mismatches which include all 256 combinations of possible base pairings. The probe/target interactions on the chip can be decomposed into nearest neighbor contributions which correlate well with free energy terms of DNA/DNA-interactions in solution. The effect of mismatches is about twice as large as that of canonical pairings. Runs of guanines (G) and the particular type of mismatched pairings formed in cross-allelic probe/target duplexes constitute sources of systematic biases of the probe signals with consequences for genotyping and copy number estimates. The poly-G effect seems to be related to the crowded arrangement of probes which facilitates complex formation of neighboring probes with at minimum three adjacent G's in their sequence. Conclusions The applied method of “triple-averaging” represents a model-free approach to estimate the mean intensity contributions of different sequence motifs which can be applied in calibration algorithms to correct signal values for sequence effects. Rules for appropriate sequence corrections are suggested. PMID:19924253

Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis.

PubMed

Akolekar, R; Beta, J; Picciarelli, G; Ogilvie, C; D'Antonio, F

2015-01-01

To estimate procedure-related risks of miscarriage following amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and a meta-analysis. A search of MEDLINE, EMBASE, CINHAL and The Cochrane Library (2000-2014) was performed to review relevant citations reporting procedure-related complications of amniocentesis and CVS. Only studies reporting data on more than 1000 procedures were included in this review to minimize the effect of bias from smaller studies. Heterogeneity between studies was estimated using Cochran's Q, the I(2) statistic and Egger bias. Meta-analysis of proportions was used to derive weighted pooled estimates for the risk of miscarriage before 24 weeks' gestation. Incidence-rate difference meta-analysis was used to estimate pooled procedure-related risks. The weighted pooled risks of miscarriage following invasive procedures were estimated from analysis of controlled studies including 324 losses in 42 716 women who underwent amniocentesis and 207 losses in 8899 women who underwent CVS. The risk of miscarriage prior to 24 weeks in women who underwent amniocentesis and CVS was 0.81% (95% CI, 0.58-1.08%) and 2.18% (95% CI, 1.61-2.82%), respectively. The background rates of miscarriage in women from the control group that did not undergo any procedures were 0.67% (95% CI, 0.46-0.91%) for amniocentesis and 1.79% (95% CI, 0.61-3.58%) for CVS. The weighted pooled procedure-related risks of miscarriage for amniocentesis and CVS were 0.11% (95% CI, -0.04 to 0.26%) and 0.22% (95% CI, -0.71 to 1.16%), respectively. The procedure-related risks of miscarriage following amniocentesis and CVS are much lower than are currently quoted. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Technical Packages in Injury and Violence Prevention to Move Evidence Into Practice: Systematic Reviews and Beyond.

PubMed

Haegerich, Tamara M; David-Ferdon, Corinne; Noonan, Rita K; Manns, Brian J; Billie, Holly C

2016-09-07

Injury and violence prevention strategies have greater potential for impact when they are based on scientific evidence. Systematic reviews of the scientific evidence can contribute key information about which policies and programs might have the greatest impact when implemented. However, systematic reviews have limitations, such as lack of implementation guidance and contextual information, that can limit the application of knowledge. "Technical packages," developed by knowledge brokers such as the federal government, nonprofit agencies, and academic institutions, have the potential to be an efficient mechanism for making information from systematic reviews actionable. Technical packages provide information about specific evidence-based prevention strategies, along with the estimated costs and impacts, and include accompanying implementation and evaluation guidance to facilitate adoption, implementation, and performance measurement. We describe how systematic reviews can inform the development of technical packages for practitioners, provide examples of technical packages in injury and violence prevention, and explain how enhancing review methods and reporting could facilitate the use and applicability of scientific evidence. © The Author(s) 2016.

Fundamental and applied aspects of the chemistry of radioactive iodine in gas and aqueous media

NASA Astrophysics Data System (ADS)

Kulyukhin, Sergei A.

2012-10-01

The results of investigations carried out in the past 15-20 years in the chemistry of radioactive iodine in the gas phase and in aqueous media of various compositions are described systematically and analyzed. The prospects for practical application of the obtained data in various fields of nuclear power industry including accidents at nuclear power plants and enterprises engaged in spent nuclear fuel reprocessing are estimated. The bibliography includes 206 references.

Lifestyle interventions based on the diabetes prevention program delivered via eHealth: A systematic review and meta-analysis.

PubMed

Joiner, Kevin L; Nam, Soohyun; Whittemore, Robin

2017-07-01

The objective was to describe Diabetes Prevention Program (DPP)-based lifestyle interventions delivered via electronic, mobile, and certain types of telehealth (eHealth) and estimate the magnitude of the effect on weight loss. A systematic review was conducted. PubMed and EMBASE were searched for studies published between January 2003 and February 2016 that met inclusion and exclusion criteria. An overall estimate of the effect on mean percentage weight loss across all the interventions was initially conducted. A stratified meta-analysis was also conducted to determine estimates of the effect across the interventions classified according to whether behavioral support by counselors post-baseline was not provided, provided remotely with communication technology, or face-to-face. Twenty-two studies met the inclusion/exclusion criteria, in which 26 interventions were evaluated. Samples were primarily white and college educated. Interventions included Web-based applications, mobile phone applications, text messages, DVDs, interactive voice response telephone calls, telehealth video conferencing, and video on-demand programing. Nine interventions were stand-alone, delivered post-baseline exclusively via eHealth. Seventeen interventions included additional behavioral support provided by counselors post-baseline remotely with communication technology or face-to-face. The estimated overall effect on mean percentage weight loss from baseline to up to 15months of follow-up across all the interventions was -3.98%. The subtotal estimate across the stand-alone eHealth interventions (-3.34%) was less than the estimate across interventions with behavioral support given by a counselor remotely (-4.31%), and the estimate across interventions with behavioral support given by a counselor in-person (-4.65%). There is promising evidence of the efficacy of DPP-based eHealth interventions on weight loss. Further studies are needed particularly in racially and ethnically diverse populations with limited levels of educational attainment. Future research should also focus on ways to optimize behavioral support. Copyright © 2017 Elsevier Inc. All rights reserved.

Systematic review on the primary and secondary reporting of the prevalence of ghostwriting in the medical literature.

PubMed

Stretton, Serina

2014-07-14

Ghostwriting of industry-sponsored articles is unethical and is perceived to be common practice. To systematically review how evidence for the prevalence of ghostwriting is reported in the medical literature. MEDLINE via PubMed 1966+, EMBASE 1966+, The Cochrane Library 1988+, Medical Writing 1998+, The American Medical Writers Association (AMWA) Journal 1986+, Council of Science Editors Annual Meetings 2007+, and the Peer Review Congress 1994+ were searched electronically (23 May 2013) using the search terms ghostwrit*, ghostauthor*, ghost AND writ*, ghost AND author*. All publication types were considered; only publications reporting a numerical estimate of possible ghostwriting prevalence were included. Two independent reviewers screened the publications; discrepancies were resolved by consensus. Data to be collected included a numerical estimate of the prevalence of possible ghostwriting (primary outcome measure), definitions of ghostwriting reported, source of the reported prevalence, publication type and year, study design and sample population. Of the 848 publications retrieved and screened for eligibility, 48 reported numerical estimates for the prevalence of possible ghostwriting. Sixteen primary publications reported findings from cross-sectional surveys or descriptive analyses of published articles; 32 secondary publications cited published or unpublished evidence. Estimates on the prevalence of possible ghostwriting in primary and secondary publications varied markedly. Primary estimates were not suitable for meta-analysis because of the various definitions of ghostwriting used, study designs and types of populations or samples. Secondary estimates were not always reported or cited correctly or appropriately. Evidence for the prevalence of ghostwriting in the medical literature is limited and can be outdated, misleading or mistaken. Researchers should not inflate estimates using non-standard definitions of ghostwriting nor conflate ghostwriting with other unethical authorship practices. Editors and peer reviewers should not accept articles that incorrectly cite or interpret primary publications that report the prevalence of ghostwriting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Systematic review on the primary and secondary reporting of the prevalence of ghostwriting in the medical literature

PubMed Central

Stretton, Serina

2014-01-01

Background Ghostwriting of industry-sponsored articles is unethical and is perceived to be common practice. Objective To systematically review how evidence for the prevalence of ghostwriting is reported in the medical literature. Data sources MEDLINE via PubMed 1966+, EMBASE 1966+, The Cochrane Library 1988+, Medical Writing 1998+, The American Medical Writers Association (AMWA) Journal 1986+, Council of Science Editors Annual Meetings 2007+, and the Peer Review Congress 1994+ were searched electronically (23 May 2013) using the search terms ghostwrit*, ghostauthor*, ghost AND writ*, ghost AND author*. Eligibility criteria All publication types were considered; only publications reporting a numerical estimate of possible ghostwriting prevalence were included. Data extraction Two independent reviewers screened the publications; discrepancies were resolved by consensus. Data to be collected included a numerical estimate of the prevalence of possible ghostwriting (primary outcome measure), definitions of ghostwriting reported, source of the reported prevalence, publication type and year, study design and sample population. Results Of the 848 publications retrieved and screened for eligibility, 48 reported numerical estimates for the prevalence of possible ghostwriting. Sixteen primary publications reported findings from cross-sectional surveys or descriptive analyses of published articles; 32 secondary publications cited published or unpublished evidence. Estimates on the prevalence of possible ghostwriting in primary and secondary publications varied markedly. Primary estimates were not suitable for meta-analysis because of the various definitions of ghostwriting used, study designs and types of populations or samples. Secondary estimates were not always reported or cited correctly or appropriately. Conclusions Evidence for the prevalence of ghostwriting in the medical literature is limited and can be outdated, misleading or mistaken. Researchers should not inflate estimates using non-standard definitions of ghostwriting nor conflate ghostwriting with other unethical authorship practices. Editors and peer reviewers should not accept articles that incorrectly cite or interpret primary publications that report the prevalence of ghostwriting. PMID:25023129

The global economic burden of dengue: a systematic analysis.

PubMed

Shepard, Donald S; Undurraga, Eduardo A; Halasa, Yara A; Stanaway, Jeffrey D

2016-08-01

Dengue is a serious global burden. Unreported and unrecognised apparent dengue virus infections make it difficult to estimate the true extent of dengue and current estimates of the incidence and costs of dengue have substantial uncertainty. Objective, systematic, comparable measures of dengue burden are needed to track health progress, assess the application and financing of emerging preventive and control strategies, and inform health policy. We estimated the global economic burden of dengue by country and super-region (groups of epidemiologically similar countries). We used the latest dengue incidence estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease Study 2013 and several other data sources to assess the economic burden of symptomatic dengue cases in the 141 countries and territories with active dengue transmission. From the scientific literature and regressions, we estimated cases and costs by setting, including the non-medical setting, for all countries and territories. Our global estimates suggest that in 2013 there were a total of 58·40 million symptomatic dengue virus infections (95% uncertainty interval [95% UI] 24 million-122 million), including 13 586 fatal cases (95% UI 4200-34 700), and that the total annual global cost of dengue illness was US$8·9 billion (95% UI 3·7 billion-19·7 billion). The global distribution of dengue cases is 18% admitted to hospital, 48% ambulatory, and 34% non-medical. The global cost of dengue is substantial and, if control strategies could reduce dengue appreciably, billions of dollars could be saved globally. In estimating dengue costs by country and setting, this study contributes to the needs of policy makers, donors, developers, and researchers for economic assessments of dengue interventions, particularly with the licensure of the first dengue vaccine and promising developments in other technologies. Sanofi Pasteur. Copyright © 2016 Elsevier Ltd. All rights reserved.

Micro-costing studies in the health and medical literature: protocol for a systematic review

PubMed Central

2014-01-01

Background Micro-costing is a cost estimation method that allows for precise assessment of the economic costs of health interventions. It has been demonstrated to be particularly useful for estimating the costs of new interventions, for interventions with large variability across providers, and for estimating the true costs to the health system and to society. However, existing guidelines for economic evaluations do not provide sufficient detail of the methods and techniques to use when conducting micro-costing analyses. Therefore, the purpose of this study is to review the current literature on micro-costing studies of health and medical interventions, strategies, and programs to assess the variation in micro-costing methodology and the quality of existing studies. This will inform current practice in conducting and reporting micro-costing studies and lead to greater standardization in methodology in the future. Methods/Design We will perform a systematic review of the current literature on micro-costing studies of health and medical interventions, strategies, and programs. Using rigorously designed search strategies, we will search Ovid MEDLINE, EconLit, BIOSIS Previews, Embase, Scopus, and the National Health Service Economic Evaluation Database (NHS EED) to identify relevant English-language articles. These searches will be supplemented by a review of the references of relevant articles identified. Two members of the review team will independently extract detailed information on the design and characteristics of each included article using a standardized data collection form. A third reviewer will be consulted to resolve discrepancies. We will use checklists that have been developed for critical appraisal of health economics studies to evaluate the quality and potential risk of bias of included studies. Discussion This systematic review will provide useful information to help standardize the methods and techniques for conducting and reporting micro-costing studies in research, which can improve the quality and transparency of future studies and enhance comparability and interpretation of findings. In the long run, these efforts will facilitate clinical and health policy decision-making about resource allocation. Trial registration Systematic review registration: PROSPERO CRD42014007453. PMID:24887208

A global systematic review of Chagas disease prevalence among migrants.

PubMed

Conners, Erin E; Vinetz, Joseph M; Weeks, John R; Brouwer, Kimberly C

2016-04-01

Human migration has been identified as a potential factor for increased Chagas disease risk and has transformed the disease from a Latin American problem to a global one. We conducted a systematic review of the scientific literature between 2004-2014 in order to: summarize recent seroprevalence estimates of Chagas disease among Latin American migrants, in both endemic and non-endemic settings; compare seroprevalence estimates in migrants to countrywide prevalence estimates; and identify risk factors for Chagas disease among migrants. A total of 320 studies were screened and 23 studies were included. We found evidence that the prevalence of Chagas disease is higher than expected in some migrant groups and that reliance on blood donor screening prevalence estimates underestimates the burden of disease. Overall there is a dearth of high quality epidemiologic studies on the prevalence of Chagas disease in migrants, especially among intra-regional migrants within Latin America. Given that this zoonotic disease cannot likely be eradicated, improved surveillance and reporting is vital to continuing control efforts. More accurate health surveillance of both Latin American migrants and the Chagas disease burden will help countries appropriately scale up their response to this chronic disease. Overall, improved estimates of Chagas disease among migrants would likely serve to highlight the real need for better screening, diagnostics, and treatment of individuals living with the disease. Copyright © 2016 Elsevier B.V. All rights reserved.

A critical appraisal of the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing interventions: a systematic review of reviews

PubMed Central

Jin, Ying-Hui; Wang, Guo-Hao; Sun, Yi-Rong; Li, Qi; Zhao, Chen; Li, Ge; Si, Jin-Hua; Li, Yan; Lu, Cui; Shang, Hong-Cai

2016-01-01

Objective To assess the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing (TCMN) interventions in Chinese journals. These interventions include acupressure, massage, Tai Chi, Qi Gong, electroacupuncture and use of Chinese herbal medicines—for example, in enemas, foot massage and compressing the umbilicus. Design A systematic literature search for systematic reviews and meta-analyses of TCMN interventions was performed. Review characteristics were extracted. The methodological quality and the quality of the evidence were evaluated using the Assessment of Multiple Systematic Reviews (AMSTAR) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) approaches. Result We included 20 systematic reviews and meta-analyses, and a total of 11 TCMN interventions were assessed in the 20 reviews. The compliance with AMSTAR checklist items ranged from 4.5 to 8 and systematic reviews/meta-analyses were, on average, of medium methodological quality. The quality of the evidence we assessed ranged from very low to moderate; no high-quality evidence was found. The top two causes for downrating confidence in effect estimates among the 31 bodies of evidence assessed were the risk of bias and inconsistency. Conclusions There is room for improvement in the methodological quality of systematic reviews/meta-analyses of TCMN interventions published in Chinese journals. Greater efforts should be devoted to ensuring a more comprehensive search strategy, clearer specification of the interventions of interest in the eligibility criteria and identification of meaningful outcomes for clinicians and patients (consumers). The overall quality of evidence among reviews remains suboptimal, which raise concerns about their roles in influencing clinical practice. Thus, the conclusions in reviews we assessed must be treated with caution and their roles in influencing clinical practice should be limited. A critical appraisal of systematic reviews/meta-analyses of TCMN interventions is particularly important to provide sound guidance for TCMN. PMID:28186925

Reporting of sources of funding in systematic reviews in periodontology and implant dentistry.

PubMed

Faggion, C M; Atieh, M; Zanicotti, D G

2014-02-01

Industry-supported clinical trials may present better outcomes than those supported by other sources. The aim of this paper was to assess whether systematic reviews (SRs) published in periodontology and implant dentistry report and discuss the influence of funding sources on study results. Two reviewers conducted a comprehensive search in PubMed and the Cochrane Database of Systematic Reviews independently and in duplicate to identify SRs published up to 11 November 2012. Speciality dental journals and the reference lists of included SRs were also scrutinised. Information on the reporting and discussion of funding sources of primary studies included in the SRs was extracted independently and in duplicate. Any disagreement regarding SR selection or data extraction was discussed until consensus was achieved. Of 146 SRs included in the assessment, only 45 (31%) reported the funding sources of primary studies. Fourteen (10%) SRs discussed the potential influence of funding sources on study results, that is, sponsorship bias. Funding sources are inadequately reported and discussed in SRs in periodontology and implant dentistry. Assessment, reporting, and critical appraisal of potential sponsorship bias of meta-analytic estimates are paramount to provide proper guidance for clinical treatments.

Descriptive epidemiology of cervical dystonia.

PubMed

Defazio, Giovanni; Jankovic, Joseph; Giel, Jennifer L; Papapetropoulos, Spyridon

2013-01-01

Cervical dystonia (CD), the most common form of adult-onset focal dystonia, has a heterogeneous clinical presentation with variable clinical features, leading to difficulties and delays in diagnosis. Owing to the lack of reviews specifically focusing on the frequency of primary CD in the general population, we performed a systematic literature search to examine its prevalence/incidence and analyze methodological differences among studies. We performed a systematic literature search to examine the prevalence data of primary focal CD. Sixteen articles met our methodological criteria. Because the reported prevalence estimates were found to vary widely across studies, we analyzed methodological differences and other factors to determine whether true differences exist in prevalence rates among geographic areas (and by gender and age distributions), as well as to facilitate recommendations for future studies. Prevalence estimates ranged from 20-4,100 cases/million. Generally, studies that relied on service-based and record-linkage system data likely underestimated the prevalence of CD, whereas population-based studies suffered from over-ascertainment. The more methodologically robust studies yielded a range of estimates of 28-183 cases/million. Despite the varying prevalence estimates, an approximate 2:1 female:male ratio was consistent among many studies. Three studies estimated incidence, ranging from 8-12 cases/million person-years. Although several studies have attempted to estimate the prevalence and incidence of CD, there is a need for additional well-designed epidemiological studies on primary CD that include large populations; use defined CD diagnostic criteria; and stratify for factors such as age, gender, and ethnicity.

Improved Analysis of GW150914 Using a Fully Spin-Precessing Waveform Model

NASA Technical Reports Server (NTRS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Camp, J. B.;

Association between childhood allergic diseases, educational attainment and occupational status in later life: systematic review protocol

PubMed Central

von Kobyletzki, Laura Beate; Beckman, Linda; Smeeth, Liam; McKee, Martin; Abuabara, Katrina; Langan, Sinead

2017-01-01

Introduction Childhood allergic diseases may prevent affected children from achieving their academic potential. Potential mechanisms include absence from school due to illness and medical appointments. Experience of symptoms in classes or leisure time, and stigma associated with visible signs and symptoms, including skin disease, requirements for medication during school time or the need for specific diets, may also contribute to reduced educational attainment. Studies have investigated the association between specific allergic diseases and educational attainment. The aim of this study is to systematically review the literature on allergic diseases, educational attainment and occupational status, and if possible, calculate meta-analytic summary estimates for the associations. Methods Systematic electronic searches in Medline, EMBASE, Cochrane, Cumulative Index to Nursing & Allied Health Literature (CINAHL), PsycINFO and education Resources Information Center (ERIC); hand search in reference lists of included papers and conference reports; search for unpublished studies in clinical trial registers and the New York Academy of Medicine Grey Literature Report; data extraction; and study quality assessment (Newcastle-Ottawa Scale) will be performed. Analysis Data will be summarised descriptively, and meta-analysis including meta-regression to explore sources of heterogeneities will be performed if possible. Ethics and dissemination Dissemination in a peer-reviewed, open-access, international scientific journal is planned. PROSPERO registration number CRD42017058036. PMID:29025838

The reliability of the Glasgow Coma Scale: a systematic review.

PubMed

Reith, Florence C M; Van den Brande, Ruben; Synnot, Anneliese; Gruen, Russell; Maas, Andrew I R

2016-01-01

The Glasgow Coma Scale (GCS) provides a structured method for assessment of the level of consciousness. Its derived sum score is applied in research and adopted in intensive care unit scoring systems. Controversy exists on the reliability of the GCS. The aim of this systematic review was to summarize evidence on the reliability of the GCS. A literature search was undertaken in MEDLINE, EMBASE and CINAHL. Observational studies that assessed the reliability of the GCS, expressed by a statistical measure, were included. Methodological quality was evaluated with the consensus-based standards for the selection of health measurement instruments checklist and its influence on results considered. Reliability estimates were synthesized narratively. We identified 52 relevant studies that showed significant heterogeneity in the type of reliability estimates used, patients studied, setting and characteristics of observers. Methodological quality was good (n = 7), fair (n = 18) or poor (n = 27). In good quality studies, kappa values were ≥0.6 in 85%, and all intraclass correlation coefficients indicated excellent reliability. Poor quality studies showed lower reliability estimates. Reliability for the GCS components was higher than for the sum score. Factors that may influence reliability include education and training, the level of consciousness and type of stimuli used. Only 13% of studies were of good quality and inconsistency in reported reliability estimates was found. Although the reliability was adequate in good quality studies, further improvement is desirable. From a methodological perspective, the quality of reliability studies needs to be improved. From a clinical perspective, a renewed focus on training/education and standardization of assessment is required.

Systematic review and meta-analysis estimating association of cysticercosis and neurocysticercosis with epilepsy.

PubMed

Debacq, Gabrielle; Moyano, Luz M; Garcia, Héctor H; Boumediene, Farid; Marin, Benoit; Ngoungou, Edgard B; Preux, Pierre-Marie

2017-03-01

We reviewed studies that analyzed cysticercosis (CC), neurocysticercosis (NCC) and epilepsy across Latin America, Asia and Sub-Saharan Africa, to estimate the odds ratio and etiologic fraction of epilepsy due to CC in tropical regions. We conducted a systematic review of the literature on cysticercosis and epilepsy in the tropics, collecting data from case-control and cross-sectional studies. Exposure criteria for CC included one or more of the following: serum ELISA or EITB positivity, presence of subcutaneous cysts (both not verified and unverified by histology), histology consistent with calcified cysts, and brain CT scan consistent with NCC. A common odds-ratio was then estimated using meta-analysis. 37 studies from 23 countries were included (n = 24,646 subjects, 14,934 with epilepsy and 9,712 without epilepsy). Of these, 29 were case-control (14 matched). The association between CC and epilepsy was significant in 19 scientific articles. Odds ratios ranged from 0.2 to 25.4 (a posteriori power 4.5-100%) and the common odds ratio was 2.7 (95% CI 2.1-3.6, p <0.001). Three subgroup analyses performed gave odds ratios as: 2.2 (EITB-based studies), 3.2 (CT-based studies), 1.9 (neurologist-confirmed epilepsy; door-to-door survey and at least one matched control per case). Etiologic fraction was estimated to be 63% in the exposed group among the population. Despite differences in findings, this meta-analysis suggests that cysticercosis is a significant contributor to late-onset epilepsy in tropical regions around the world, and its impact may vary depending on transmission intensity.

Estimating the proportion of healthcare-associated infections that are reasonably preventable and the related mortality and costs.

PubMed

Umscheid, Craig A; Mitchell, Matthew D; Doshi, Jalpa A; Agarwal, Rajender; Williams, Kendal; Brennan, Patrick J

2011-02-01

To estimate the proportion of healthcare-associated infections (HAIs) in US hospitals that are "reasonably preventable," along with their related mortality and costs. To estimate preventability of catheter-associated bloodstream infections (CABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), and ventilator-associated pneumonia (VAP), we used a federally sponsored systematic review of interventions to reduce HAIs. Ranges of preventability included the lowest and highest risk reductions reported by US studies of "moderate" to "good" quality published in the last 10 years. We used the most recently published national data to determine the annual incidence of HAIs and associated mortality. To estimate incremental cost of HAIs, we performed a systematic review, which included costs from studies in general US patient populations. To calculate ranges for the annual number of preventable infections and deaths and annual costs, we multiplied our infection, mortality, and cost figures with our ranges of preventability for each HAI. As many as 65%-70% of cases of CABSI and CAUTI and 55% of cases of VAP and SSI may be preventable with current evidence-based strategies. CAUTI may be the most preventable HAI. CABSI has the highest number of preventable deaths, followed by VAP. CABSI also has the highest cost impact; costs due to preventable cases of VAP, CAUTI, and SSI are likely less. Our findings suggest that 100% prevention of HAIs may not be attainable with current evidence-based prevention strategies; however, comprehensive implementation of such strategies could prevent hundreds of thousands of HAIs and save tens of thousands of lives and billions of dollars.

Quantum chemical approach to estimating the thermodynamics of metabolic reactions.

PubMed

Jinich, Adrian; Rappoport, Dmitrij; Dunn, Ian; Sanchez-Lengeling, Benjamin; Olivares-Amaya, Roberto; Noor, Elad; Even, Arren Bar; Aspuru-Guzik, Alán

2014-11-12

Thermodynamics plays an increasingly important role in modeling and engineering metabolism. We present the first nonempirical computational method for estimating standard Gibbs reaction energies of metabolic reactions based on quantum chemistry, which can help fill in the gaps in the existing thermodynamic data. When applied to a test set of reactions from core metabolism, the quantum chemical approach is comparable in accuracy to group contribution methods for isomerization and group transfer reactions and for reactions not including multiply charged anions. The errors in standard Gibbs reaction energy estimates are correlated with the charges of the participating molecules. The quantum chemical approach is amenable to systematic improvements and holds potential for providing thermodynamic data for all of metabolism.

Towards an Early Software Effort Estimation Based on Functional and Non-Functional Requirements

NASA Astrophysics Data System (ADS)

Kassab, Mohamed; Daneva, Maya; Ormandjieva, Olga

The increased awareness of the non-functional requirements as a key to software project and product success makes explicit the need to include them in any software project effort estimation activity. However, the existing approaches to defining size-based effort relationships still pay insufficient attention to this need. This paper presents a flexible, yet systematic approach to the early requirements-based effort estimation, based on Non-Functional Requirements ontology. It complementarily uses one standard functional size measurement model and a linear regression technique. We report on a case study which illustrates the application of our solution approach in context and also helps evaluate our experiences in using it.

Estimating the HI gas fractions of galaxies in the local Universe

NASA Astrophysics Data System (ADS)

Zhang, Wei; Li, Cheng; Kauffmann, Guinevere; Zou, Hu; Catinella, Barbara; Shen, Shiyin; Guo, Qi; Chang, Ruixiang

2009-08-01

We use a sample of 800 galaxies with HI mass measurements from the HyperLeda catalogue and optical photometry from the fourth data release of the Sloan Digital Sky Survey (SDSS) to calibrate a new photometric estimator of the HI-to-stellar-mass ratio for nearby galaxies. Our estimator, which is motivated by the Kennicutt-Schmidt star formation law, is log10(GHI/S) = -1.73238(g - r) + 0.215182μi - 4.08451, where μi is the i-band surface brightness and g - r is the optical colour estimated from the g- and r-band Petrosian apparent magnitudes. This estimator has a scatter of σ = 0.31 dex in log (GHI/S), compared to σ ~ 0.4 dex for previous estimators that were based on colour alone. We investigate whether the residuals in our estimate of log (GHI/S) depend in a systematic way on a variety of different galaxy properties. We find no effect as a function of stellar mass or 4000 Å break strength, but there is a systematic effect as a function of the concentration index of the light. We then apply our estimator to a sample of 105 emission-line galaxies in the SDSS Data Release 4 (DR4) and derive an estimate of the HI mass function, which is in excellent agreement with recent results from HI blind surveys. Finally, we re-examine the well-known relation between gas-phase metallicity and stellar mass, and ask whether there is a dependence on HI-to-stellar-mass ratio, as predicted by chemical evolution models. We do find that gas-poor galaxies are more metal rich at fixed stellar mass. We compare our results with the semi-analytic models of De Lucia & Blaizot, which include supernova feedback, as well as the cosmological infall of gas.

Flameless Combustion Workshop

DTIC Science & Technology

2005-09-20

Flame volume, and flame length during the HiTAC condition were further studied numerically and systematically. A simple HiTAC flame volume can be...oxygen concentration (stoichiometric ratio) is included, was derived to describe the local influence of buoyancy force along the chemical flame length . It...and low oxygen concentration oxidizer condition. Furthermore, the maximum entrainments along the flame length are estimated. 6. NO emission formed by

Improved enteral tolerance following step procedure: systematic literature review and meta-analysis.

PubMed

Fernandes, Melissa A; Usatin, Danielle; Allen, Isabel E; Rhee, Sue; Vu, Lan

2016-10-01

Surgical management of children with short bowel syndrome (SBS) changed with the introduction of the serial transverse enteroplasty procedure (STEP). We conducted a systematic review and meta-analysis using MEDLINE and SCOPUS to determine if children with SBS had improved enteral tolerance following STEP. Studies were included if information about a child's pre- and post-STEP enteral tolerance was provided. A random effects meta-analysis provided a summary estimate of the proportion of children with enteral tolerance increase following STEP. From 766 abstracts, seven case series involving 86 children were included. Mean percent tolerance of enteral nutrition improved from 35.1 to 69.5. Sixteen children had no enteral improvement following STEP. A summary estimate showed that 87 % (95 % CI 77-95 %) of children who underwent STEP had an increase in enteral tolerance. Compilation of the literature supports the belief that SBS subjects' enteral tolerance improves following STEP. Enteral nutritional tolerance is a measure of efficacy of STEP and should be presented as a primary or secondary outcome. By standardizing data collection on children undergoing STEP procedure, better determination of nutritional benefit from STEP can be ascertained.

The epidemiology of substance use among street children in resource-constrained settings: a systematic review and meta-analysis

PubMed Central

Embleton, Lonnie; Mwangi, Ann; Vreeman, Rachel; Ayuku, David; Braitstein, Paula

2013-01-01

Aims To compile and analyze critically the literature published on street children and substance use in resource-constrained settings. Methods We searched the literature systematically and used meta-analytical procedures to synthesize literature that met the review’s inclusion criteria. Pooled-prevalence estimates and 95% confidence intervals (CI) were calculated using the random-effects model for life-time substance use by geographical region as well as by type of substance used. Results Fifty studies from 22 countries were included into the review. Meta-analysis of combined life-time substance use from 27 studies yielded an overall drug use pooled-prevalence estimate of 60% (95% CI = 51–69%). Studies from 14 countries contributed to an overall pooled prevalence for street children’s reported inhalant use of 47% (95% CI = 36–58%). This review reveals significant gaps in the literature, including a dearth of data on physical and mental health outcomes, HIV and mortality in association with street children’s substance use. Conclusions Street children from resource-constrained settings reported high life-time substance use. Inhalants are the predominant substances used, followed by tobacco, alcohol and marijuana. PMID:23844822

Risk of thromboembolism with thrombopoietin receptor agonists in adult patients with thrombocytopenia: Systematic review and meta-analysis of randomized controlled trials.

PubMed

Catalá-López, Ferrán; Corrales, Inmaculada; de la Fuente-Honrubia, César; González-Bermejo, Diana; Martín-Serrano, Gloria; Montero, Dolores; Saint-Gerons, Diego Macías

2015-12-21

Romiplostim and eltrombopag are thrombopoietin receptor (TPOr) agonists that promote megakaryocyte differentiation, proliferation and platelet production. In 2012, a systematic review and meta-analysis reported a non-statistically significant increased risk of thromboembolic events for these drugs, but analyses were limited by lack of statistical power. Our objective was to update the 2012 meta-analysis examining whether TPOr agonists affect thromboembolism occurrence in adult thrombocytopenic patients. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). Updated searches were conduced on PubMed, Cochrane Central, and publicly available registries (up to December 2014). RCTs using romiplostim or eltrombopag in at least one group were included. Relative risks (RR), absolute risk ratios (ARR) and number needed to harm (NNH) were estimated. Heterogeneity was analyzed using Cochran's Q test and I(2) statistic. Fifteen studies with 3026 adult thrombocytopenic patients were included. Estimated frequency of thromboembolism was 3.69% (95% CI: 2.95-4.61%) for TPOr agonists and 1.46% (95% CI: 0.89-2.40%) for controls. TPOr agonists were associated with a RR of thromboembolism of 1.81 (95% CI: 1.04-3.14) and an ARR of 2.10% (95% CI: 0.03-3.90%) meaning a NNH of 48. Overall, we did not find evidence of statistical heterogeneity (p=0.43; I(2)=1.60%). Our updated meta-analysis suggested that TPOr agonists are associated with a higher risk of thromboemboembolic events compared with controls, and supports the current recommendations included in the European product information on this respect. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

The role of phacoemulsification in glaucoma therapy: A systematic review and meta-analysis.

PubMed

Masis, Marisse; Mineault, Patrick J; Phan, Eileen; Lin, Shan C

2017-09-06

Cataract extraction is a safe and effective surgery that has been performed in its modern form for several decades. Many studies have noted that cataract extraction could also have a clinically significant role in the control of comorbid glaucoma. Lens extraction decreases the pressure within the eye, and intraocular pressure (IOP) is the only controllable risk factor in glaucoma proven to be effective. A systematic analysis of current evidence is needed to establish strong practice patterns and identify areas where further research is required. We performed systematic review and meta-analysis of the clinical data to estimate the net effect of cataract surgery on IOP. A total of 37 treatment arms from 32 different studies from January 1997 to January 2017 were included. IOP reduction was highly correlated across follow-up periods. For angle-closure glaucoma, results showed an IOP decrease of -6.4 mmHg (95% CI: -9.4 to -3.4) at final follow-up (12 months and longer). For the open-angle glaucoma group, there was an overall IOP change of -2.7 mmHg (95% CI -3.7 to -1.7) from baseline. For pseudoexfoliation glaucoma further research is needed to reach an adequate evidence-based conclusion. The influence of inherent sources of bias, including loss to follow-up, washout and medication use, and lack of a control group, was evaluated numerically. These sources of bias pulled the IOP estimate in opposite directions and are therefore unlikely to affect the main conclusions substantially. Future prospective clinical trials, including other outcomes such as quality of life, clinical severity information, and cost-effectiveness analysis, are needed to determine the role of phacoemulsification alone within the glaucoma treatment algorithm. Copyright © 2017 Elsevier Inc. All rights reserved.

Consumption of whole grains and cereal fiber in relation to cancer risk: a systematic review of longitudinal studies

PubMed Central

Makarem, Nour; Nicholson, Joseph M.; Bandera, Elisa V.; McKeown, Nicola M.

2016-01-01

Context: Evidence from previous reviews is supportive of the hypothesis that whole grains may protect against various cancers. However, the reviews did not report risk estimates for both whole grains and cereal fiber and only case–control studies were evaluated. It is unclear whether longitudinal studies support this conclusion. Objective: To evaluate associations between whole grains and cereal fiber in relation to risk of lifestyle-related cancers data from longitudinal studies was evaluated. Data Sources: The following 3 databases were systematically searched: PubMed, EMBASE, and Cochrane CENTRAL. Study Selection: A total of 43 longitudinal studies conducted in Europe and North America that reported multivariable-adjusted risk estimates for whole grains (n = 14), cereal fiber (n = 23), or both (n = 6) in relation to lifestyle-related cancers were included. Data Extraction: Information on study location, cohort name, follow-up duration, sample characteristics, dietary assessment method, risk estimates, and confounders was extracted. Data Synthesis: Of 20 studies examining whole grains and cancer, 6 studies reported a statistically significant 6%–47% reduction in risk, but 14 studies showed no association. Of 29 studies examining cereal fiber intake in relation to cancer, 8 showed a statistically significant 6%–49% reduction in risk, whereas 21 studies reported no association. Conclusions: This systematic review concludes that most studies were suggestive of a null association. Whole grains and cereal fiber may protect against gastrointestinal cancers, but these findings require confirmation in additional studies. PMID:27257283

Validity of segmental bioelectrical impedance analysis for estimating fat-free mass in children including overweight individuals.

PubMed

Ohta, Megumi; Midorikawa, Taishi; Hikihara, Yuki; Masuo, Yoshihisa; Sakamoto, Shizuo; Torii, Suguru; Kawakami, Yasuo; Fukunaga, Tetsuo; Kanehisa, Hiroaki

2017-02-01

This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length) 2 /Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part. In the model-development group, the BI index of each of the 3 segments and whole body was significantly correlated to the measured FFM (R 2 = 0.867-0.932, standard error of estimation = 0.18-1.44 kg (5.9%-8.7%)). There was no significant difference between the measured and predicted FFM values without systematic error. The application of each equation derived in the model-development group to the cross-validation and overweight groups did not produce significant differences between the measured and predicted FFM values and systematic errors, with an exception that the arm FFM in the overweight group was overestimated. Segmental bioelectrical impedance analysis is useful for predicting the FFM of each of whole-body and body segments in children including overweight individuals, although the application for estimating arm FFM in overweight individuals requires a certain modification.

Cognitive Impairment in Euthymic Pediatric Bipolar Disorder: A Systematic Review and Meta-Analysis.

PubMed

Elias, Liana R; Miskowiak, Kamilla W; Vale, Antônio M O; Köhler, Cristiano A; Kjærstad, Hanne L; Stubbs, Brendon; Kessing, Lars V; Vieta, Eduard; Maes, Michael; Goldstein, Benjamin I; Carvalho, André F

2017-04-01

To perform a systematic review and meta-analysis of studies investigating neurocognition in euthymic youths with bipolar disorder (BD) compared to healthy controls (HCs). A systematic literature search was conducted in the PubMed/MEDLINE, PsycINFO, and EMBASE databases from inception up until March 23, 2016, for original peer-reviewed articles that investigated neurocognition in euthymic youths with BD compared to HCs. Effect sizes (ES) for individual tests were extracted. In addition, results were grouped according to cognitive domain. This review complied with the PRISMA statement guidelines. A total of 24 studies met inclusion criteria (N = 1,146; 510 with BD). Overall, euthymic youths with BD were significantly impaired in verbal learning, verbal memory, working memory, visual learning, and visual memory, with moderate to large ESs (Hedge's g 0.76-0.99); significant impairments were not observed for attention/vigilance, reasoning and problem solving, and/or processing speed. Heterogeneity was moderate to large (I 2  ≥ 50%) for most ES estimates. Differences in the definition of euthymia across studies explained the heterogeneity in the ES estimate for verbal learning and memory. We also found evidence for other potential sources of heterogeneity in several ES estimates including co-occurring attention-deficit/hyperactivity disorder (ADHD) and anxiety disorders, and the use of medications. In addition, the use of different neuropsychological tests appeared to contribute to heterogeneity of some estimates (e.g., attention/vigilance domain). Euthymic youths with BD exhibit significant cognitive dysfunction encompassing verbal learning and memory, working memory, and/or visual learning and memory domains. These data indicate that for a subset of individuals with BD, neurodevelopmental factors may contribute to cognitive dysfunction. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Research Review: Test-retest reliability of standardized diagnostic interviews to assess child and adolescent psychiatric disorders: a systematic review and meta-analysis.

PubMed

Duncan, Laura; Comeau, Jinette; Wang, Li; Vitoroulis, Irene; Boyle, Michael H; Bennett, Kathryn

2018-02-19

A better understanding of factors contributing to the observed variability in estimates of test-retest reliability in published studies on standardized diagnostic interviews (SDI) is needed. The objectives of this systematic review and meta-analysis were to estimate the pooled test-retest reliability for parent and youth assessments of seven common disorders, and to examine sources of between-study heterogeneity in reliability. Following a systematic review of the literature, multilevel random effects meta-analyses were used to analyse 202 reliability estimates (Cohen's kappa = ҡ) from 31 eligible studies and 5,369 assessments of 3,344 children and youth. Pooled reliability was moderate at ҡ = .58 (CI 95% 0.53-0.63) and between-study heterogeneity was substantial (Q = 2,063 (df = 201), p < .001 and I 2  = 79%). In subgroup analysis, reliability varied across informants for specific types of psychiatric disorder (ҡ = .53-.69 for parent vs. ҡ = .39-.68 for youth) with estimates significantly higher for parents on attention deficit hyperactivity disorder, oppositional defiant disorder and the broad groupings of externalizing and any disorder. Reliability was also significantly higher in studies with indicators of poor or fair study methodology quality (sample size <50, retest interval <7 days). Our findings raise important questions about the meaningfulness of published evidence on the test-retest reliability of SDIs and the usefulness of these tools in both clinical and research contexts. Potential remedies include the introduction of standardized study and reporting requirements for reliability studies, and exploration of other approaches to assessing and classifying child and adolescent psychiatric disorder. © 2018 Association for Child and Adolescent Mental Health.

Systematic Error Modeling and Bias Estimation

PubMed Central

Zhang, Feihu; Knoll, Alois

2016-01-01

This paper analyzes the statistic properties of the systematic error in terms of range and bearing during the transformation process. Furthermore, we rely on a weighted nonlinear least square method to calculate the biases based on the proposed models. The results show the high performance of the proposed approach for error modeling and bias estimation. PMID:27213386

Global Birth Prevalence of Spina Bifida by Folic Acid Fortification Status: A Systematic Review and Meta-Analysis.

PubMed

Atta, Callie A M; Fiest, Kirsten M; Frolkis, Alexandra D; Jette, Nathalie; Pringsheim, Tamara; St Germaine-Smith, Christine; Rajapakse, Thilinie; Kaplan, Gilaad G; Metcalfe, Amy

2016-01-01

Birth defects remain a significant source of worldwide morbidity and mortality. Strong scientific evidence shows that folic acid fortification of a region's food supply leads to a decrease in spina bifida (a birth defect of the spine). Still, many countries around the world have yet to approve mandatory fortification through government legislation. We sought to perform a systematic review and meta-analysis of period prevalence of spina bifida by folic acid fortification status, geographic region, and study population. An expert research librarian used terms related to neural tube defects and epidemiology from primary research from 1985 to 2010 to search in EMBASE and MEDLINE. We searched the reference lists of included articles and key review articles identified by experts. Inclusion criteria included studies in English or French reporting on prevalence published between January 1985 and December 2010 that (1) were primary research, (2) were population-based, and (3) reported a point or period prevalence estimate of spina bifida (i.e., prevalence estimate with confidence intervals or case numerator and population denominator). Two independent reviewers screened titles and abstracts for eligible articles, then 2 authors screened full texts in duplicate for final inclusion. Disagreements were resolved through consensus or a third party. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA, abstracting data related to case ascertainment, study population, folic acid fortification status, geographic region, and prevalence estimate independently and in duplicate. We extracted overall data and any subgroups reported by age, gender, time period, or type of spina bifida. We classified each period prevalence estimate as "mandatory" or "voluntary" folic acid fortification according to each country's folic acid fortification status at the time data were collected (as determined by a well-recognized fortification monitoring body, Food Fortification Initiative). We determined study quality on the basis of sample representativeness, standardization of data collection and birth defect assessment, and statistical analyses. We analyzed study-level period prevalence estimates by using a random effects model (α level of < 0.05) for all meta-analyses. We stratified pooled period prevalence estimates by birth population, fortification status, and continent. Of 4078 studies identified, we included 179 studies in the systematic review and 123 in a meta-analysis. In studies of live births (LBs) alone, period prevalences of spina bifida were (1) lower in geographical regions with mandatory (33.86 per 100,000 LBs) versus voluntary (48.35 per 100,000 LBs) folic acid fortification, and (2) lower in studies of LBs, stillbirths, and terminations of pregnancy in regions with mandatory (35.22 per 100,000 LBs) versus voluntary (52.29 per 100,000 LBs) fortification. In LBs, stillbirths, and terminations of pregnancy studies, the lowest pooled prevalence estimate was in North America (38.70 per 100,000). Case ascertainment, surveillance methods, and reporting varied across these population-based studies. Mandatory legislation enforcing folic acid fortification of the food supply lags behind the evidence, particularly in Asian and European countries. This extensive literature review shows that spina bifida is significantly more common in world regions without government legislation regulating full-coverage folic acid fortification of the food supply (i.e., Asia, Europe) and that mandatory folic acid fortification resulted in a lower prevalence of spina bifida regardless of the type of birth cohort. African data were scarce, but needed, as many African nations are beginning to adopt folic acid legislation.

Utility of Equations to Estimate Peak Oxygen Uptake and Work Rate From a 6-Minute Walk Test in Patients With COPD in a Clinical Setting.

PubMed

Kirkham, Amy A; Pauhl, Katherine E; Elliott, Robyn M; Scott, Jen A; Doria, Silvana C; Davidson, Hanan K; Neil-Sztramko, Sarah E; Campbell, Kristin L; Camp, Pat G

2015-01-01

To determine the utility of equations that use the 6-minute walk test (6MWT) results to estimate peak oxygen uptake ((Equation is included in full-text article.)o2) and peak work rate with chronic obstructive pulmonary disease (COPD) patients in a clinical setting. This study included a systematic review to identify published equations estimating peak (Equation is included in full-text article.)o2 and peak work rate in watts in COPD patients and a retrospective chart review of data from a hospital-based pulmonary rehabilitation program. The following variables were abstracted from the records of 42 consecutively enrolled COPD patients: measured peak (Equation is included in full-text article.)o2 and peak work rate achieved during a cycle ergometer cardiopulmonary exercise test, 6MWT distance, age, sex, weight, height, forced expiratory volume in 1 second, forced vital capacity, and lung diffusion capacity. Estimated peak (Equation is included in full-text article.)o2 and peak work rate were estimated from 6MWT distance using published equations. The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work to prescribe aerobic exercise intensities of 60% and 80% was calculated. Eleven equations from 6 studies were identified. Agreement between estimated and measured values was poor to moderate (intraclass correlation coefficients = 0.11-0.63). The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work rate to prescribe exercise intensities of 60% and 80% of measured values ranged from mean differences of 12 to 35 and 16 to 47 percentage points, respectively. There is poor to moderate agreement between measured peak (Equation is included in full-text article.)o2 and peak work rate and estimations from equations that use 6MWT distance, and the use of the estimated values for prescription of aerobic exercise intensity would result in large error. Equations estimating peak (Equation is included in full-text article.)o2 and peak work rate are of low utility for prescribing exercise intensity in pulmonary rehabilitation programs.

Malnutrition in childhood cancer patients: a review on its prevalence and possible causes.

PubMed

Brinksma, Aeltsje; Huizinga, Gea; Sulkers, Esther; Kamps, Willem; Roodbol, Petrie; Tissing, Wim

2012-08-01

To perform a systematic literature review for critical evaluation of prevalence and factors contributing to malnutrition in childhood cancer. A systematic search resulting in 46 suitable articles. Due to lack of uniform criteria and adequate studies, the prevalence rates of malnutrition can only be estimated. Based on strengths and weaknesses of included references, prevalence rates are estimated to be 0-10% for leukemia, 20-50% for neuroblastoma, and 0-30% for other malignancies. Whether energy deficiency or inflammation contributed to malnutrition could not be confirmed because the occurrence of energy deficit (low energy intake, increased metabolic rate) or inflammation (related to cachexia) was not convincing. Also, a relationship between these factors and malnutrition was not studied. Longitudinal studies are needed to determine which children are at risk of malnutrition, and to investigate the impact of energy deficiency and inflammation on the nutritional status and body composition of childhood cancer patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Clinical MR-mammography: are computer-assisted methods superior to visual or manual measurements for curve type analysis? A systematic approach.

PubMed

Baltzer, Pascal Andreas Thomas; Freiberg, Christian; Beger, Sebastian; Vag, Tibor; Dietzel, Matthias; Herzog, Aimee B; Gajda, Mieczyslaw; Camara, Oumar; Kaiser, Werner A

2009-09-01

Enhancement characteristics after administration of a contrast agent are regarded as a major criterion for differential diagnosis in magnetic resonance mammography (MRM). However, no consensus exists about the best measurement method to assess contrast enhancement kinetics. This systematic investigation was performed to compare visual estimation with manual region of interest (ROI) and computer-aided diagnosis (CAD) analysis for time curve measurements in MRM. A total of 329 patients undergoing surgery after MRM (1.5 T) were analyzed prospectively. Dynamic data were measured using visual estimation, including ROI as well as CAD methods, and classified depending on initial signal increase and delayed enhancement. Pathology revealed 469 lesions (279 malignant, 190 benign). Kappa agreement between the methods ranged from 0.78 to 0.81. Diagnostic accuracies of 74.4% (visual), 75.7% (ROI), and 76.6% (CAD) were found without statistical significant differences. According to our results, curve type measurements are useful as a diagnostic criterion in breast lesions irrespective of the method used.

Frequency of autoimmune diseases in myasthenia gravis: a systematic review.

PubMed

Mao, Zhi-Feng; Yang, Long-Xiu; Mo, Xue-An; Qin, Chao; Lai, Yong-Rong; He, Ning-Yu; Li, Tong; Hackett, Maree L

2011-03-01

The course of myasthenia gravis (MG) may get complicated by the development of other autoimmune diseases. Estimates of the frequency of autoimmune diseases will help inform patients and physicians, direct health policy discussion, provide etiologic clues, and optimize the management of MG. However, the frequency of autoimmune diseases in people with MG is still uncertain. A systematic search for English language studies was conducted by MEDLINE and EMBASE from 1960 through 2010. Incidence studies and case series of all MG subtypes with information about autoimmune diseases were included; 25 studies met the inclusion criteria. Although there was considerable heterogeneity, the pooled estimate of the coexisting autoimmune diseases in MG was 13% (95% confidence interval, 12%-14%). Autoimmune thyroid disease seems to occur more frequently than other autoimmune conditions in MG patients. Heterogeneity in study estimates could be explained by ascertainment bias and case mix. Furthermore, autoimmune diseases occurred significantly more often in females and anti-acetylcholine receptor seropositive MG patients. Patients with MG have an increased frequency of coexisting autoimmune diseases. Autoimmune diseases seem to occur more often in female and seropositive MG patients. Further research is needed to expand our understanding of these associations.

Impact of tobacco control interventions on smoking initiation, cessation, and prevalence: a systematic review.

PubMed

Wilson, Lisa M; Avila Tang, Erika; Chander, Geetanjali; Hutton, Heidi E; Odelola, Olaide A; Elf, Jessica L; Heckman-Stoddard, Brandy M; Bass, Eric B; Little, Emily A; Haberl, Elisabeth B; Apelberg, Benjamin J

2012-01-01

Policymakers need estimates of the impact of tobacco control (TC) policies to set priorities and targets for reducing tobacco use. We systematically reviewed the independent effects of TC policies on smoking behavior. We searched MEDLINE (through January 2012) and EMBASE and other databases through February 2009, looking for studies published after 1989 in any language that assessed the effects of each TC intervention on smoking prevalence, initiation, cessation, or price participation elasticity. Paired reviewers extracted data from studies that isolated the impact of a single TC intervention. We included 84 studies. The strength of evidence quantifying the independent effect on smoking prevalence was high for increasing tobacco prices and moderate for smoking bans in public places and antitobacco mass media campaigns. Limited direct evidence was available to quantify the effects of health warning labels and bans on advertising and sponsorship. Studies were too heterogeneous to pool effect estimates. We found evidence of an independent effect for several TC policies on smoking prevalence. However, we could not derive precise estimates of the effects across different settings because of variability in the characteristics of the intervention, level of policy enforcement, and underlying tobacco control environment.

Dietary assessment in minority ethnic groups: a systematic review of instruments for portion-size estimation in the United Kingdom

PubMed Central

Almiron-Roig, Eva; Aitken, Amanda; Galloway, Catherine

2017-01-01

Context: Dietary assessment in minority ethnic groups is critical for surveillance programs and for implementing effective interventions. A major challenge is the accurate estimation of portion sizes for traditional foods and dishes. Objective: The aim of this systematic review was to assess records published up to 2014 describing a portion-size estimation element (PSEE) applicable to the dietary assessment of UK-residing ethnic minorities. Data sources, selection, and extraction: Electronic databases, internet sites, and theses repositories were searched, generating 5683 titles, from which 57 eligible full-text records were reviewed. Data analysis: Forty-two publications about minority ethnic groups (n = 20) or autochthonous populations (n = 22) were included. The most common PSEEs (47%) were combination tools (eg, food models and portion-size lists), followed by portion-size lists in questionnaires/guides (19%) and image-based and volumetric tools (17% each). Only 17% of PSEEs had been validated against weighed data. Conclusions: When developing ethnic-specific dietary assessment tools, it is important to consider customary portion sizes by sex and age, traditional household utensil usage, and population literacy levels. Combining multiple PSEEs may increase accuracy, but such methods require validation. PMID:28340101

Impact of Tobacco Control Interventions on Smoking Initiation, Cessation, and Prevalence: A Systematic Review

PubMed Central

Wilson, Lisa M.; Avila Tang, Erika; Chander, Geetanjali; Hutton, Heidi E.; Odelola, Olaide A.; Elf, Jessica L.; Heckman-Stoddard, Brandy M.; Bass, Eric B.; Little, Emily A.; Haberl, Elisabeth B.; Apelberg, Benjamin J.

2012-01-01

Background. Policymakers need estimates of the impact of tobacco control (TC) policies to set priorities and targets for reducing tobacco use. We systematically reviewed the independent effects of TC policies on smoking behavior. Methods. We searched MEDLINE (through January 2012) and EMBASE and other databases through February 2009, looking for studies published after 1989 in any language that assessed the effects of each TC intervention on smoking prevalence, initiation, cessation, or price participation elasticity. Paired reviewers extracted data from studies that isolated the impact of a single TC intervention. Findings. We included 84 studies. The strength of evidence quantifying the independent effect on smoking prevalence was high for increasing tobacco prices and moderate for smoking bans in public places and antitobacco mass media campaigns. Limited direct evidence was available to quantify the effects of health warning labels and bans on advertising and sponsorship. Studies were too heterogeneous to pool effect estimates. Interpretations. We found evidence of an independent effect for several TC policies on smoking prevalence. However, we could not derive precise estimates of the effects across different settings because of variability in the characteristics of the intervention, level of policy enforcement, and underlying tobacco control environment. PMID:22719777

ABERRANT RESTING-STATE BRAIN ACTIVITY IN POSTTRAUMATIC STRESS DISORDER: A META-ANALYSIS AND SYSTEMATIC REVIEW.

PubMed

Koch, Saskia B J; van Zuiden, Mirjam; Nawijn, Laura; Frijling, Jessie L; Veltman, Dick J; Olff, Miranda

2016-07-01

About 10% of trauma-exposed individuals develop PTSD. Although a growing number of studies have investigated resting-state abnormalities in PTSD, inconsistent results suggest a need for a meta-analysis and a systematic review. We conducted a systematic literature search in four online databases using keywords for PTSD, functional neuroimaging, and resting-state. In total, 23 studies matched our eligibility criteria. For the meta-analysis, we included 14 whole-brain resting-state studies, reporting data on 663 participants (298 PTSD patients and 365 controls). We used the activation likelihood estimation approach to identify concurrence of whole-brain hypo- and hyperactivations in PTSD patients during rest. Seed-based studies could not be included in the quantitative meta-analysis. Therefore, a separate qualitative systematic review was conducted on nine seed-based functional connectivity studies. The meta-analysis showed consistent hyperactivity in the ventral anterior cingulate cortex and the parahippocampus/amygdala, but hypoactivity in the (posterior) insula, cerebellar pyramis and middle frontal gyrus in PTSD patients, compared to healthy controls. Partly concordant with these findings, the systematic review on seed-based functional connectivity studies showed enhanced salience network (SN) connectivity, but decreased default mode network (DMN) connectivity in PTSD. Combined, these altered resting-state connectivity and activity patterns could represent neurobiological correlates of increased salience processing and hypervigilance (SN), at the cost of awareness of internal thoughts and autobiographical memory (DMN) in PTSD. However, several discrepancies between findings of the meta-analysis and systematic review were observed, stressing the need for future studies on resting-state abnormalities in PTSD patients. © 2016 Wiley Periodicals, Inc.

Earth before life.

PubMed

Marzban, Caren; Viswanathan, Raju; Yurtsever, Ulvi

2014-01-09

A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth. Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g., confidence or prediction intervals) are produced. It is shown that such models for which the interval estimate for the time origin of the genome includes the age of the Earth are consistent with observed data. The appearance of life after the formation of the Earth is consistent with the data set under examination.

Glenohumeral Internal Rotation Deficit and Injuries: A Systematic Review and Meta-analysis

PubMed Central

Johnson, Jordan E.; Fullmer, Joshua A.; Nielsen, Chaseton M.; Johnson, Joshua K.; Moorman, Claude T.

2018-01-01

Background: There is an association between throwing activity and glenohumeral internal rotation deficit (GIRD). An 18° to 20° deficit has been adopted as the standard definition of pathological GIRD, but specific findings as to how GIRD relates to an injury are inconsistent. Purpose: To systematically review the literature to clarify the definition of GIRD diagnosis for adolescent and adult overhead athletes and to examine the association between GIRD and an increased risk of injuries in these athletes. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed. Observational studies comparing glenohumeral internal rotation range of motion (ROM) in injured and uninjured overhead athletes were included for the meta-analysis. Studies of adolescent and adult athletes were analyzed separately. ROM was compared for the injured and uninjured groups, and a weighted mean GIRD was estimated. To account for potential heterogeneity across studies, both fixed- and random-effects models were used to calculate a standardized mean difference (SMD). Results: Nine studies of level 3 or 4 evidence were included. From these, 12 study groups (4 adolescent, 8 adult) comprising 819 overhead athletes (226 injured, 593 uninjured) were included in the meta-analysis. The estimated SMD in GIRD between the injured and uninjured groups was 0.46 (95% CI, 0.15-0.77; P < .01) for the overall sample. The between-group effect was larger for adults (SMD, 0.60 [95% CI, 0.18 to 1.02]; P < .01) than adolescents (SMD, 0.20 [95% CI, –0.24 to 0.63]; P = .13). The weighted mean GIRD for the injured and uninjured groups was 13.8° ± 5.6° and 9.6° ± 3.0°, respectively, which also differed by age group. Moderate study heterogeneity was observed (I 2 = 69.0%). Conclusion: Based on this systematic review, the current definition of pathological GIRD may be too conservative, and a distinct definition may be required for adolescent and adult athletes. While the results indicate a link between internal rotation deficits and upper extremity injuries in the overhead athlete, higher quality prospective research is needed to clarify the role that GIRD plays in future injuries to overhead athletes of various ages. PMID:29845083

Association between physical activity, sedentary behavior, and fitness with health related quality of life in healthy children and adolescents

PubMed Central

Bermejo-Cantarero, Alberto; Álvarez-Bueno, Celia; Martinez-Vizcaino, Vicente; García-Hermoso, Antonio; Torres-Costoso, Ana Isabel; Sánchez-López, Mairena

2017-01-01

Abstract Background: Health related quality of life (HRQoL) is a subjective, multidimensional and changing over time construct. When HRQoL is decreased, a child is less likely to be able to develop normally and mature into a healthy adult. Physical inactivity is a priority public health problem. Evidence suggests how even moderate levels of physical activity or high fitness levels are associated with benefits for the health in children and adolescents. The aims of this systematic review are to examine the evidence about the relationship between physical activity, sedentary behavior, and fitness with HRQoL, and estimate the effects of interventions that have tested the effectiveness of the increase of the physical activity, the improvement of the physical fitness or the avoidance of sedentary behaviors in HRQoL in healthy subjects aged under 18 years old. Methods: This systematic review and meta-analysis protocol was conducted following the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) statement. To identify relevant studies, the following electronic databases will be searched: MEDLINE, EMBASE, Cochrane Database, Web of Science, and PEDro. Reference lists of relevant studies will be examined for links to potential related articles. The methodological quality of the observational included studies will be scored using a quality assessment checklist. For the intervention studies, the risk of bias will be estimated using The Cochrane Collaboration tool for assessing risk of bias. Reviewers will determine whether a meta-analysis is possible when data have been extracted. If it is, subgroup analyses will be carried out by age and socioeconomic status, and by the different dimensions of the HRQoL. If is not possible, a descriptive analysis will be conducted. Conclusion: To our knowledge, this systematic review and meta-analysis will be the first that synthesizes the existing results about the relationship between physical activity, sedentary behavior, physical fitness, and HRQoL, and the effect of physical activity interventions on HRQoL, in healthy subjects under 18 years old. This study will clarify this relationship and will provide evidence for decision-making. Limitations may include the quality of the selected studies and their characteristics. Only studies published in English and Spanish will be included. Systematic review registration: PROSPERO CRD42015025823. PMID:28328839

Association between physical activity, sedentary behavior, and fitness with health related quality of life in healthy children and adolescents: A protocol for a systematic review and meta-analysis.

PubMed

Bermejo-Cantarero, Alberto; Álvarez-Bueno, Celia; Martinez-Vizcaino, Vicente; García-Hermoso, Antonio; Torres-Costoso, Ana Isabel; Sánchez-López, Mairena

2017-03-01

Health related quality of life (HRQoL) is a subjective, multidimensional and changing over time construct. When HRQoL is decreased, a child is less likely to be able to develop normally and mature into a healthy adult. Physical inactivity is a priority public health problem. Evidence suggests how even moderate levels of physical activity or high fitness levels are associated with benefits for the health in children and adolescents. The aims of this systematic review are to examine the evidence about the relationship between physical activity, sedentary behavior, and fitness with HRQoL, and estimate the effects of interventions that have tested the effectiveness of the increase of the physical activity, the improvement of the physical fitness or the avoidance of sedentary behaviors in HRQoL in healthy subjects aged under 18 years old. This systematic review and meta-analysis protocol was conducted following the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) statement. To identify relevant studies, the following electronic databases will be searched: MEDLINE, EMBASE, Cochrane Database, Web of Science, and PEDro. Reference lists of relevant studies will be examined for links to potential related articles. The methodological quality of the observational included studies will be scored using a quality assessment checklist. For the intervention studies, the risk of bias will be estimated using The Cochrane Collaboration tool for assessing risk of bias. Reviewers will determine whether a meta-analysis is possible when data have been extracted. If it is, subgroup analyses will be carried out by age and socioeconomic status, and by the different dimensions of the HRQoL. If is not possible, a descriptive analysis will be conducted. To our knowledge, this systematic review and meta-analysis will be the first that synthesizes the existing results about the relationship between physical activity, sedentary behavior, physical fitness, and HRQoL, and the effect of physical activity interventions on HRQoL, in healthy subjects under 18 years old. This study will clarify this relationship and will provide evidence for decision-making. Limitations may include the quality of the selected studies and their characteristics. Only studies published in English and Spanish will be included. PROSPERO CRD42015025823.

Single- versus double-row repair for full-thickness rotator cuff tears using suture anchors. A systematic review and meta-analysis of basic biomechanical studies.

PubMed

Hohmann, Erik; König, Anya; Kat, Cor-Jacques; Glatt, Vaida; Tetsworth, Kevin; Keough, Natalie

2018-07-01

The purpose of this study was to perform a systematic review and meta-analysis comparing single- and double-row biomechanical studies to evaluate load to failure, mode of failure and gap formation. A systematic review of MEDLINE, Embase, Scopus and Google Scholar was performed from 1990 through 2016. The inclusion criteria were: documentation of ultimate load to failure, failure modes and documentation of elongation or gap formation. Studies were excluded if the study protocol did not use human specimens. Publication bias was assessed by funnel plot and Egger's test. The risk of bias was established using the Cochrane Collaboration's risk of bias tool. Heterogeneity was assessed using χ 2 and I 2 statistic. Eight studies were included. The funnel plot was asymmetric suggesting publication bias, which was confirmed by Egger's test (p = 0.04). The pooled estimate for load to failure demonstrated significant differences (SMD 1.228, 95% CI: 0.55-5.226, p = 0.006, I 2  = 60.47%), favouring double-row repair. There were no differences for failure modes. The pooled estimate for elongation/gap formation demonstrated significant differences (SMD 0.783, 95% CI: 0.169-1.398, p = 0.012, I 2  = 58.8%), favouring double-row repair. The results of this systematic review and meta-analysis suggest that double-row repair is able to tolerate a significantly greater load to failure. Gap formation was also significantly lower in the double-row repair group, but both of these findings should be interpreted with caution because of the inherent interstudy heterogeneity. Systematic review and meta-analysis.

A systematic review on human exposure to organophosphorus pesticides in Iran.

PubMed

Shadboorestan, Amir; Vardanjani, Hossein Molavi; Abdollahi, Mohammad; Goharbari, Mohammad Hadi; Khanjani, Narges

2016-07-02

Human exposure to organophosphorus (OP) pesticides is a serious health challenge. We conducted a systematic review by searching international and national databases for published literature on any human exposure to OPs in Iran from 1990 to March 2015. Qualified papers were in two categories including studies in which biomarkers of exposure were assessed (n = 13; total no. of subjects = 759) and studies that had reported prevalence of OPs-induced poisoning (OPP) and mortality (n = 26; total no. of subjects = 5428). The mean level of activity of acetyl-cholinesterase and butyryl-cholinesterase were 68.65% and 74.2%, respectively. Overall proportion (%) of OPP was estimated (16; 95% CI, 14 to 19).

Epidemiology of chronic obstructive pulmonary disease in the global HIV-infected population: a systematic review and meta-analysis protocol.

PubMed

Bigna, Jean Joel R; Kenne, Angeladine Malaha; Asangbeh, Serra Lem

2017-03-29

Evidence suggests a relationship between human immunodeficiency virus (HIV) infection and chronic obstructive pulmonary disease (COPD). Although the high burden of COPD and the HIV disease is clearly demonstrated, to the best of our knowledge, there is a lack of summary and meta-analysis data on the epidemiology of COPD in the global HIV-infected population to date. The present protocol for a systematic review and meta-analysis intends to summarize existing data on the prevalence, incidence, and risk factors of COPD in the global HIV-infected population. The present review will include cohort, cross-sectional, and case-control studies conducted among HIV infected people, which report prevalence, incidence, and factors associated with COPD or enough data for their estimation. We will consider published and unpublished studies in English and French language, regardless of geographical location. Relevant records will be searched using PubMed/Medline, and Scopus from inception to December 31st, 2016. Reference lists of eligible papers and relevant review articles will be screened. Two investigators will independently screen, select studies, and extract data, with discrepancies resolved by consensus or arbitrarily by a third investigator. Risk of bias and methodological quality of the included studies will be assessed using the Newcastle-Ottawa Scale. Funnel-plots and Egger's test will be used to determine publication bias. The study-specific estimates will be pooled through a random-effects meta-analysis model to obtain an overall summary estimate. To keep the effect of studies with extremely small or extremely large estimates on the overall estimate to a minimum, the variance of the study-specific prevalence/incidence will be stabilized with the Freeman-Tukey single arc-sine transformation. The heterogeneity will be evaluated by the χ 2 test on Cochrane's Q statistic. Results will be presented by geographic region and by antiretroviral therapy status. We plan to summarize data on factors associated with COPD in narrative format. This systematic review and meta-analysis will give an overview of the epidemiology of COPD in the global HIV population to inform policy-makers and to provide accurate data that can underpin effective interventions for optimizing their detection and management. PROSPERO CRD42016052639 .

A Descriptive Epidemiology of Screen-Based Media Use in Youth: A Review and Critique

ERIC Educational Resources Information Center

Marshall, Simon J.; Gorely, Trish; Biddle, Stuart J. H.

2006-01-01

The purpose of this systematic review was to (i) estimate the prevalence and dose of television (TV) viewing, video game playing and computer use, and (ii) assess age-related and (iii) secular trends in TV viewing among youth ([less than or equal] 18 yr). Ninety studies published in English language journals between 1949 and 2004 were included,…

The impact of prenatal exposure to air pollution on childhood wheezing and asthma: A systematic review.

PubMed

Hehua, Zhang; Qing, Chang; Shanyan, Gao; Qijun, Wu; Yuhong, Zhao

2017-11-01

There has been no clear consensus about whether prenatal exposure to air pollution contributes to the development of wheezing and asthma in children. We conducted a systematic review to analyze the association between exposure to different pollutants during pregnancy and the development of childhood wheezing and asthma. We systematically reviewed epidemiological studies published through June 6, 2017 available in the MEDLINE and Web of Science databases. We included studies that examined the association between prenatal exposure to any air pollutants except tobacco smoke and the incidence or prevalence of "wheezing" or "asthma" from birth to 14 years of age. We extracted key characteristics of each included study using a template of predefined data items. We used the Critical Appraisal Skills Programme checklists to assess the validity of each included study. We conducted overall and subgroup meta-analyses for each summary exposure-outcome association. Pooled odds ratios (OR) with 95% confidence intervals (CI) were estimated by using a random effects model. Eighteen studies met our eligibility criteria. There was notable variability in exposure assessment methods. The overall random effects risk estimates (95% CI) of different pollutants were 1.04 (0.94-1.15) aromatic hydrocarbons (PAH), 1.04 (1.01-1.07) NO 2 , 1.4 (0.97-2.03) PM 2.5 for childhood wheeze and 1.07 (1.01-1.14) NO 2 , 1 (0.97-1.03) PM 2.5 , 1.02 (0.98-1.07) SO 2 , 1.08 (1.05-1.12) PM 10 for childhood asthma. Minimal heterogeneity was seen for PAH and SO 2 , while some heterogeneity was observed for PM 10 , PM 2.5 and NO 2 . The overall and subgroup risk estimates from the meta-analyses showed statistically significant associations between prenatal exposures to NO 2 , SO 2 , and PM 10 and the risk of wheezing and asthma development in childhood. There is insufficient evidence to show an effect of prenatal exposure to BC, CO, and O 3 on childhood wheezing and asthma. Further studies are needed to examine the individual compounds' effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Seroprevalence of hepatitis C virus among people living with HIV/AIDS in Latin America and the Caribbean: a systematic review.

PubMed

Tengan, Fatima Mitiko; Ibrahim, Karim Yakub; Dantas, Bianca Peixoto; Manchiero, Caroline; Magri, Mariana Cavalheiro; Bernardo, Wanderley Marques

2016-11-09

Studies have shown that the immunosuppression induced by the human immunodeficiency virus (HIV) accelerates the natural history of liver disease associated with hepatitis C virus (HCV), with 3- to 5-fold higher odds of coinfected individuals developing cirrhosis. However, estimates of the seroprevalence of hepatitis C among people living with HIV/acquired immune deficiency syndrome (AIDS) (PLHA) in Latin America and the Caribbean (LAC) are widely variable. We performed a systematic review to estimate the seroprevalence of HCV among PLHA. We searched studies on HIV and HCV infections in LAC included in the PubMed, LILACS and Embase databases in December of 2014 with no time or language restrictions. The following combinations of search terms were used in the PubMed and Embase databases: (HIV OR Acquired Immunodeficiency Syndrome Virus OR AIDS OR HTLV OR Human Immunodeficiency Virus OR Human T Cell) AND (HCV OR HEPATITIS C OR HEPATITIS C VIRUS OR HEPACIVIRUS) AND (name of an individual country or territory in LAC). The following search terms were used in the LILACS database: (HIV OR AIDS OR Virus da Imunodeficiencia Humana) AND (HCV OR Hepatite C OR Hepacivirus). An additional 11 studies were identified through manual searches. A total of 2,380 publications were located, including 617 duplicates; the remaining articles were reviewed to select studies for inclusion in this study. A total of 37 studies were selected for systematic review, including 23 from Brazil, 5 from Argentina, 3 from Cuba, 1 from Puerto Rico, 1 from Chile, 1 from Colombia, 1 from Mexico, 1 from Peru and 1 from Venezuela. The estimated seroprevalence of HCV infection varied from 0.8 to 58.5 % (mean 17.37; median 10.91), with the highest in Argentina and Brazil and the lowest in Venezuela and Colombia. Investigation of HCV infection among PLHA and of HIV infection among people living with HCV is highly recommended because it allows for better follow up, counseling and treatment of HIV/HCV-coinfected patients. Future studies with larger sample sizes are needed in both South and Central America to understand and address the risk factors associated with the acquisition of infection.

Social capital, mortality, cardiovascular events and cancer: a systematic review of prospective studies.

PubMed

Choi, Minkyoung; Mesa-Frias, Marco; Nuesch, Eveline; Hargreaves, James; Prieto-Merino, David; Bowling, Ann; Snith, G Davey; Ebrahim, Shah; Dale, Caroline; Casas, Juan P

2014-12-01

Social capital is considered to be an important determinant of life expectancy and cardiovascular health. Evidence on the association between social capital and all-cause mortality, cardiovascular disease (CVD) and cancer was systematically reviewed. Prospective studies examining the association of social capital with these outcomes were systematically sought in Medline, Embase and PsycInfo, all from inception to 8 October 2012. We categorized the findings from studies according to seven dimensions of social capital, including social participation, social network, civic participation,social support, trust, norm of reciprocity and sense of community, and pooled the estimates across studies to obtain summary relative risks of the health outcomes for each social capital dimension. We excluded studies focusing on children, refugees or immigrants and studies conducted in the former Soviet Union. Fourteen prospective studies were identified. The pooled estimates showed no association between most social capital dimensions and all-cause mortality, CVD or cancer. Limited evidence was found for association of increased mortality with social participation and civic participation when comparing the most extreme risk comparisons. Evidence to support an association between social capital and health outcomes is limited. Lack of consensus on measurements for social capital hinders the comparability of studies and weakens the evidence base.

Health impact assessment of active transportation: A systematic review.

PubMed

Mueller, Natalie; Rojas-Rueda, David; Cole-Hunter, Tom; de Nazelle, Audrey; Dons, Evi; Gerike, Regine; Götschi, Thomas; Int Panis, Luc; Kahlmeier, Sonja; Nieuwenhuijsen, Mark

2015-07-01

Walking and cycling for transportation (i.e. active transportation, AT), provide substantial health benefits from increased physical activity (PA). However, risks of injury from exposure to motorized traffic and their emissions (i.e. air pollution) exist. The objective was to systematically review studies conducting health impact assessment (HIA) of a mode shift to AT on grounds of associated health benefits and risks. Systematic database searches of MEDLINE, Web of Science and Transportation Research International Documentation were performed by two independent researchers, augmented by bibliographic review, internet searches and expert consultation to identify peer-reviewed studies from inception to December 2014. Thirty studies were included, originating predominantly from Europe, but also the United States, Australia and New Zealand. They compromised of mostly HIA approaches of comparative risk assessment and cost-benefit analysis. Estimated health benefit-risk or benefit-cost ratios of a mode shift to AT ranged between -2 and 360 (median=9). Effects of increased PA contributed the most to estimated health benefits, which strongly outweighed detrimental effects of traffic incidents and air pollution exposure on health. Despite different HIA methodologies being applied with distinctive assumptions on key parameters, AT can provide substantial net health benefits, irrespective of geographical context. Copyright © 2015 Elsevier Inc. All rights reserved.

Toxoplasmosis and epilepsy--systematic review and meta analysis.

PubMed

Ngoungou, Edgard B; Bhalla, Devender; Nzoghe, Amandine; Dardé, Marie-Laure; Preux, Pierre-Marie

2015-02-01

Toxoplasmosis is an important, widespread, parasitic infection caused by Toxoplasma gondii. The chronic infection in immunocompetent patients, usually considered as asymptomatic, is now suspected to be a risk factor for various neurological disorders, including epilepsy. We aimed to conduct a systematic review and meta-analysis of the available literature to estimate the risk of epilepsy due to toxoplasmosis. A systematic literature search was conducted of several databases and journals to identify studies published in English or French, without date restriction, which looked at toxoplasmosis (as exposure) and epilepsy (as disease) and met certain other inclusion criteria. The search was based on keywords and suitable combinations in English and French. Fixed and random effects models were used to determine odds ratios, and statistical significance was set at 5.0%. Six studies were identified, with an estimated total of 2888 subjects, of whom 1280 had epilepsy (477 positive for toxoplasmosis) and 1608 did not (503 positive for toxoplasmosis). The common odds ratio (calculated) by random effects model was 2.25 (95% CI 1.27-3.9), p = 0.005. Despite the limited number of studies, and a lack of high-quality data, toxoplasmosis should continue to be regarded as an epilepsy risk factor. More and better studies are needed to determine the real impact of this parasite on the occurrence of epilepsy.

Accounting for Multiple Births in Neonatal and Perinatal Trials: Systematic Review and Case Study

PubMed Central

Hibbs, Anna Maria; Black, Dennis; Palermo, Lisa; Cnaan, Avital; Luan, Xianqun; Truog, William E; Walsh, Michele C; Ballard, Roberta A

2010-01-01

Objectives To determine the prevalence in the neonatal literature of statistical approaches accounting for the unique clustering patterns of multiple births. To explore the sensitivity of an actual trial to several analytic approaches to multiples. Methods A systematic review of recent perinatal trials assessed the prevalence of studies accounting for clustering of multiples. The NO CLD trial served as a case study of the sensitivity of the outcome to several statistical strategies. We calculated odds ratios using non-clustered (logistic regression) and clustered (generalized estimating equations, multiple outputation) analyses. Results In the systematic review, most studies did not describe the randomization of twins and did not account for clustering. Of those studies that did, exclusion of multiples and generalized estimating equations were the most common strategies. The NO CLD study included 84 infants with a sibling enrolled in the study. Multiples were more likely than singletons to be white and were born to older mothers (p<0.01). Analyses that accounted for clustering were statistically significant; analyses assuming independence were not. Conclusions The statistical approach to multiples can influence the odds ratio and width of confidence intervals, thereby affecting the interpretation of a study outcome. A minority of perinatal studies address this issue. PMID:19969305

Accounting for multiple births in neonatal and perinatal trials: systematic review and case study.

PubMed

Hibbs, Anna Maria; Black, Dennis; Palermo, Lisa; Cnaan, Avital; Luan, Xianqun; Truog, William E; Walsh, Michele C; Ballard, Roberta A

2010-02-01

To determine the prevalence in the neonatal literature of statistical approaches accounting for the unique clustering patterns of multiple births and to explore the sensitivity of an actual trial to several analytic approaches to multiples. A systematic review of recent perinatal trials assessed the prevalence of studies accounting for clustering of multiples. The Nitric Oxide to Prevent Chronic Lung Disease (NO CLD) trial served as a case study of the sensitivity of the outcome to several statistical strategies. We calculated odds ratios using nonclustered (logistic regression) and clustered (generalized estimating equations, multiple outputation) analyses. In the systematic review, most studies did not describe the random assignment of twins and did not account for clustering. Of those studies that did, exclusion of multiples and generalized estimating equations were the most common strategies. The NO CLD study included 84 infants with a sibling enrolled in the study. Multiples were more likely than singletons to be white and were born to older mothers (P < .01). Analyses that accounted for clustering were statistically significant; analyses assuming independence were not. The statistical approach to multiples can influence the odds ratio and width of confidence intervals, thereby affecting the interpretation of a study outcome. A minority of perinatal studies address this issue. Copyright 2010 Mosby, Inc. All rights reserved.

A systematic review of the social and economic burden of influenza in low- and middle-income countries.

PubMed

de Francisco Shapovalova, Natasha; Donadel, Morgane; Jit, Mark; Hutubessy, Raymond

2015-11-27

The economic burden of seasonal influenza outbreaks as well as influenza pandemics in lower- and middle-income countries (LMIC) has yet to be specifically systematically reviewed. The aim of this systematic review is to assess the evidence of influenza economic burden assessment methods in LMIC and to quantify the economic consequences of influenza disease in these countries, including broader opportunity costs in terms of impaired social progress and economic development. We conducted an all language literature search across 5 key databases using an extensive list of key words for the time period 1950-2013. We included studies which explored direct costs (medical and non-medical), indirect costs (productivity losses), and broader economic impact in LMIC associated with different influenza outcomes such as confirmed seasonal influenza infection, influenza-like illnesses, and pandemic influenza. We included 62 full-text studies in English, Spanish, Russian, Chinese languages, mostly from the countries of Latin American and the Caribbean and East Asia and Pacific with pertinent cost data found in 39 papers. Estimates for direct and indirect costs were the highest in Latin American and the Caribbean. Compared to high-income economies, direct costs in LMIC were lower and productivity losses higher. Evidence on broader impact of influenza included impact on the wider national economy, security dimension, medical insurance policy, legal frameworks, distributional impact, and investment flows. The economic burden of influenza in LMIC encompasses multiple dimensions such as direct costs to the health service and households, indirect costs due to productivity losses as well as broader detriments to the wider economy. Evidence from sub-Saharan Africa and in pregnant women remains very limited. Heterogeneity of methods used to estimate cost components makes data synthesis challenging. There is a strong need for standardizing research, data collection and evaluation methods for both direct and indirect cost components. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experiences of Domestic Violence and Mental Disorders: A Systematic Review and Meta-Analysis

PubMed Central

Trevillion, Kylee; Oram, Siân; Feder, Gene; Howard, Louise M.

2012-01-01

Background Little is known about the extent to which being a victim of domestic violence is associated with different mental disorders in men and women. We aimed to estimate the prevalence and odds of being a victim of domestic violence by diagnostic category and sex. Methods Study design: Systematic review and meta-analysis. Data Sources: Eighteen biomedical and social sciences databases (including MEDLINE, EMBASE, PsycINFO); journal hand searches; scrutiny of references and citation tracking of included articles; expert recommendations, and an update of a systematic review on victimisation and mental disorder. Inclusion criteria: observational and intervention studies reporting prevalence or odds of being a victim of domestic violence in men and women (aged ≥16 years), using validated diagnostic measures of mental disorder. Procedure: Data were extracted and study quality independently appraised by two reviewers. Analysis: Random effects meta-analyses were used to pool estimates of prevalence and odds. Results Forty-one studies were included. There is a higher risk of experiencing adult lifetime partner violence among women with depressive disorders (OR 2.77 (95% CI 1.96–3.92), anxiety disorders (OR 4.08 (95% CI 2.39–6.97), and PTSD (OR 7.34 95% CI 4.50–11.98), compared to women without mental disorders. Insufficient data were available to calculate pooled odds for other mental disorders, family violence (i.e. violence perpetrated by a non-partner), or violence experienced by men. Individual studies reported increased odds for women and men for all diagnostic categories, including psychoses, with a higher prevalence reported for women. Few longitudinal studies were found so the direction of causality could not be investigated. Conclusions There is a high prevalence and increased likelihood of being a victim of domestic violence in men and women across all diagnostic categories, compared to people without disorders. Longitudinal studies are needed to identify pathways to being a victim of domestic violence to optimise healthcare responses. PMID:23300562

The effect of early in-hospital medication review on health outcomes: a systematic review.

PubMed

Hohl, Corinne M; Wickham, Maeve E; Sobolev, Boris; Perry, Jeff J; Sivilotti, Marco L A; Garrison, Scott; Lang, Eddy; Brasher, Penny; Doyle-Waters, Mary M; Brar, Baljeet; Rowe, Brian H; Lexchin, Joel; Holland, Richard

2015-07-01

Adverse drug events are an important cause of emergency department visits, unplanned admissions and prolonged hospital stays. Our objective was to synthesize the evidence on the effect of early in-hospital pharmacist-led medication review on patient-oriented outcomes based on observed data. We systematically searched eight bibliographic reference databases, electronic grey literature, medical journals, conference proceedings, trial registries and bibliographies of relevant papers. We included studies that employed random or quasi-random methods to allocate subjects to pharmacist-led medication review or control. Medication review had to include, at a minimum, obtaining a best possible medication history and reviewing medications for appropriateness and adverse drug events. The intervention had to be initiated within 24 h of emergency department presentation or 72 h of admission. We extracted data in duplicate and pooled outcomes from clinically homogeneous studies of the same design using random effects meta-analysis. We retrieved 4549 titles of which seven were included, reporting the outcomes of 3292 patients. We pooled data from studies of the same design, and found no significant differences in length of hospital admission (weighted mean difference [WMD] -0.04 days, 95% confidence interval [CI] -1.63, 1.55), mortality (odds ratio [OR] 1.09, 95% CI 0.69, 1.72), readmissions (OR 1.15, 95% CI 0.81, 1.63) or emergency department revisits at 3 months (OR 0.60, 95% CI 0.27, 1.32). Two large studies reporting reductions in readmissions could not be included in our pooled estimates due to differences in study design. Wide confidence intervals suggest that additional research is likely to influence the effect size estimates and clarify the effect of medication review on patient-oriented outcomes. This systematic review failed to identify an effect of pharmacist-led medication review on health outcomes. © 2015 The British Pharmacological Society.

Concurrent use of alcohol interactive medications and alcohol in older adults: a systematic review of prevalence and associated adverse outcomes.

PubMed

Holton, Alice E; Gallagher, Paul; Fahey, Tom; Cousins, Gráinne

2017-07-17

Older adults are susceptible to adverse effects from the concurrent use of medications and alcohol. The aim of this study was to systematically review the prevalence of concurrent use of alcohol and alcohol-interactive (AI) medicines in older adults and associated adverse outcomes. A systematic search was performed using MEDLINE (PubMed), Embase, Scopus and Web of Science (January 1990 to June 2016), and hand searching references of retrieved articles. Observational studies reporting on the concurrent use of alcohol and AI medicines in the same or overlapping recall periods in older adults were included. Two independent reviewers verified that studies met the inclusion criteria, critically appraised included studies and extracted relevant data. A narrative synthesis is provided. Twenty studies, all cross-sectional, were included. Nine studies classified a wide range of medicines as AI using different medication compendia, thus resulting in heterogeneity across studies. Three studies investigated any medication use and eight focused on psychotropic medications. Based on the quality assessment of included studies, the most reliable estimate of concurrent use in older adults ranges between 21 and 35%. The most reliable estimate of concurrent use of psychotropic medications and alcohol ranges between 7.4 and 7.75%. No study examined longitudinal associations with adverse outcomes. Three cross-sectional studies reported on falls with mixed findings, while one study reported on the association between moderate alcohol consumption and adverse drug reactions at hospital admission. While there appears to be a high propensity for alcohol-medication interactions in older adults, there is a lack of consensus regarding what constitutes an AI medication. An explicit list of AI medications needs to be derived and validated prospectively to quantify the magnitude of risk posed by the concurrent use of alcohol for adverse outcomes in older adults. This will allow for risk stratification of older adults at the point of prescribing, and prioritise alcohol screening and brief alcohol interventions in high-risk groups.

Reproducibility of Interferon Gamma (IFN-γ) Release Assays. A Systematic Review

PubMed Central

Tagmouti, Saloua; Slater, Madeline; Benedetti, Andrea; Kik, Sandra V.; Banaei, Niaz; Cattamanchi, Adithya; Metcalfe, John; Dowdy, David; van Zyl Smit, Richard; Dendukuri, Nandini

2014-01-01

Rationale: Interferon gamma (IFN-γ) release assays for latent tuberculosis infection result in a larger-than-expected number of conversions and reversions in occupational screening programs, and reproducibility of test results is a concern. Objectives: Knowledge of the relative contribution and extent of the individual sources of variability (immunological, preanalytical, or analytical) could help optimize testing protocols. Methods: We performed a systematic review of studies published by October 2013 on all potential sources of variability of commercial IFN-γ release assays (QuantiFERON-TB Gold In-Tube and T-SPOT.TB). The included studies assessed test variability under identical conditions and under different conditions (the latter both overall and stratified by individual sources of variability). Linear mixed effects models were used to estimate within-subject SD. Measurements and Main Results: We identified a total of 26 articles, including 7 studies analyzing variability under the same conditions, 10 studies analyzing variability with repeat testing over time under different conditions, and 19 studies reporting individual sources of variability. Most data were on QuantiFERON (only three studies on T-SPOT.TB). A considerable number of conversions and reversions were seen around the manufacturer-recommended cut-point. The estimated range of variability of IFN-γ response in QuantiFERON under identical conditions was ±0.47 IU/ml (coefficient of variation, 13%) and ±0.26 IU/ml (30%) for individuals with an initial IFN-γ response in the borderline range (0.25–0.80 IU/ml). The estimated range of variability in noncontrolled settings was substantially larger (±1.4 IU/ml; 60%). Blood volume inoculated into QuantiFERON tubes and preanalytic delay were identified as key sources of variability. Conclusions: This systematic review shows substantial variability with repeat IFN-γ release assays testing even under identical conditions, suggesting that reversions and conversions around the existing cut-point should be interpreted with caution. PMID:25188809

Assessing the Risk of Progression From Asymptomatic Left Ventricular Dysfunction to Overt Heart Failure: A Systematic Overview and Meta-Analysis.

PubMed

Echouffo-Tcheugui, Justin B; Erqou, Sebhat; Butler, Javed; Yancy, Clyde W; Fonarow, Gregg C

2016-04-01

This study sought to provide estimates of the risk of progression to overt heart failure (HF) from systolic or diastolic asymptomatic left ventricular dysfunction through a systematic review and meta-analysis. Precise population-based estimates on the progression from asymptomatic left ventricular dysfunction (or stage B HF) to clinical HF (stage C HF) remain limited, despite its prognostic and clinical implications. Pre-emptive intervention with neurohormonal modulation may attenuate disease progression. MEDLINE and EMBASE were systematically searched (until March 2015). Cohort studies reporting on the progression from asymptomatic left ventricular systolic dysfunction (ALVSD) or asymptomatic left ventricular diastolic dysfunction (ALVDD) to overt HF were included. Effect estimates (prevalence, incidence, and relative risk) were pooled using a random-effects model meta-analysis, separately for systolic and diastolic dysfunction, with heterogeneity assessed with the I(2) statistic. Thirteen reports based on 11 distinct studies of progression of ALVSD were included in the meta-analysis assessing a total of 25,369 participants followed for 7.9 years on average. The absolute risks of progression to HF were 8.4 per 100 person-years (95% confidence interval [CI]: 4.0 to 12.8 per 100 person-years) for those with ALVSD, 2.8 per 100 person-years (95% CI: 1.9 to 3.7 per 100 person-years) for those with ALVDD, and 1.04 per 100 person-years (95% CI: 0.0 to 2.2 per 100 person-years) without any ventricular dysfunction evident. The combined maximally adjusted relative risk of HF for ALVSD was 4.6 (95% CI: 2.2 to 9.8), and that of ALVDD was 1.7 (95% CI: 1.3 to 2.2). ALVSD and ALVDD are each associated with a substantial risk for incident HF indicating an imperative to develop effective intervention at these stages. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Why we should talk about compliance with assisted reproductive technologies (ART): a systematic review and meta-analysis of ART compliance rates

PubMed Central

Gameiro, S.; Verhaak, C.M.; Kremer, J.A.M.; Boivin, J.

2013-01-01

BACKGROUND The goal of this systematic review and meta-analysis was to estimate the rate of compliance with assisted reproductive technologies (ART) and examine its relationship with treatment success rates. METHODS Six databases were systematically searched from 1978 to December 2011. Studies were included if they reported data on patient progression through three consecutive standard ART cycles. Compliance was estimated for the first three ART cycles (typical ART Regimen Compliance, TARC) and after the first and the second failed cycles (CAF1, CAF2). Treatment success rates for all patients who started ART and for those who fully complied with the three ART cycles were estimated. RESULTS Ten studies with data for 14 810 patients were included. TARC was 78.2% [95% confidence interval (CI) 68.8–85.3%], CAF1 was 81.8% (73.3–88.1%) and CAF2 was 75.3% (68.2–81.2%). The overall success rate was 42.7% (32.6–53.6%) for all patients starting ART and 57.9% (49.4–65.9%) for those who complied with three ART cycles. Compliance rates did not vary according to study quality, but TARC was higher for studies that reported data on doctor-censored patients versus those that did not (84.2% 95% CI 75.5–90.2 versus 70.6% 95% CI 58.3–80.5, P = 0.043). Analysis of funnel plots and the Egger test indicated publication bias for CAF1. CONCLUSIONS Findings from this meta-analysis should reassure clinics and patients that most patients are able to comply with three cycles of ART. Compliers could increase their chances of success by as much as 15%. A more detailed assessment of compliance requires monitoring long-term treatment trajectories through the creation of national registries. PMID:23178304

Systematic review with dose-response meta-analyses between vitamin B-12 intake and European Micronutrient Recommendations Aligned's prioritized biomarkers of vitamin B-12 including randomized controlled trials and observational studies in adults and elderly persons.

PubMed

Dullemeijer, Carla; Souverein, Olga W; Doets, Esmée L; van der Voet, Hilko; van Wijngaarden, Janneke P; de Boer, Waldo J; Plada, Maria; Dhonukshe-Rutten, Rosalie A M; In 't Veld, Paulette H; Cavelaars, Adrienne E J M; de Groot, Lisette C P G M; van 't Veer, Pieter

2013-02-01

Many randomized controlled trials (RCTs) and observational studies have provided information on the association between vitamin B-12 intake and biomarkers. The use of these data to estimate dose-response relations provides a useful means to summarize the body of evidence. We systematically reviewed studies that investigated vitamin B-12 intake and biomarkers of vitamin B-12 status and estimated dose-response relations with the use of a meta-analysis. This systematic review included all RCTs, prospective cohort studies, nested case-control studies, and cross-sectional studies in healthy adult populations published through January 2010 that supplied or measured dietary vitamin B-12 intake and measured vitamin B-12 status as serum or plasma vitamin B-12, methylmalonic acid (MMA), or holotranscobalamin. We calculated an intake-status regression coefficient ( ) for each individual study and calculated the overall pooled and SE ( ) by using random-effects meta-analysis on a double-log scale. The meta-analysis of observational studies showed a weaker slope of dose-response relations than the meta-analysis of RCTs. The pooled dose-response relation of all studies between vitamin B-12 intake and status indicated that a doubling of the vitamin B-12 intake increased vitamin B-12 concentrations by 11% (95% CI: 9.4%, 12.5%). This increase was larger for studies in elderly persons (13%) than in studies in adults (8%). The dose-response relation between vitamin B-12 intake and MMA concentrations indicated a decrease in MMA of 7% (95% CI: -10%, -4%) for every doubling of the vitamin B-12 intake. The assessment of risk of bias within individual studies and across studies indicated risk that was unlikely to seriously alter these results. The obtained dose-response estimate between vitamin B-12 intake and status provides complementary evidence to underpin recommendations for a vitamin B-12 intake of populations.

Systematic review on the recurrence of postoperative nausea and vomiting after a first episode in the recovery room – implications for the treatment of PONV and related clinical trials

PubMed Central

Eberhart, Leopold HJ; Frank, Silke; Lange, Henning; Morin, Astrid M; Scherag, André; Wulf, Hinnerk; Kranke, Peter

2006-01-01

Background Despite the presence of a plethora of publications on the prevention of postoperative nausea and vomiting (PONV) only little is known how to treat established symptoms. Besides the high effort of performing these efficacy trials (much more patients must give their consent than are actually included in a study) and ethical concerns, little is known about the rate of re-occurring PONV/vomiting after placebo. As a consequence investigators will have difficulties defining a clinically relevant effect for the new treatment which is crucial for any planning. A quantitative systematic review was performed in order to provide more reliable estimates of the incidence of re-occurring PONV/vomiting after placebo and to help investigators defining a clinically relevant treatment effect. Methods A systematic search of the literature was performed using an extended search strategy of a previous review. Data on the recurrence of PONV (any nausea or emetic symptom) and vomiting (retching or vomiting) was extracted from published reports treating PONV with placebo and unpublished results from two observational trials where no treatment was given. A nonlinear random effects model was used to calculate estimates of the recurrence of symptoms and their 95%-confidence intervals (95%-CI). Results A total of 29 trials (including the unpublished data) were eligible for the calculations. Depending on the length of observation after administering placebo or no treatment the recurrence rate of PONV was between 65% (95%-CI: 53%...75%) and 84% (95%-CI: 73%...91%) and that of vomiting was between 65% (95%-CI: 44%...81%) and 78% (95%-CI: 59%...90%). Conclusion Almost all trials showed a considerable and consistently high rate of recurrence of emetic symptoms after placebo highlighting the need for a consequent antiemetic treatment. Future (placebo) controlled efficacy trials may use the presented empirical estimates for defining clinically relevant effects and for statistical power considerations. PMID:17166262

Quotation accuracy in medical journal articles-a systematic review and meta-analysis.

PubMed

Jergas, Hannah; Baethge, Christopher

2015-01-01

Background. Quotations and references are an indispensable element of scientific communication. They should support what authors claim or provide important background information for readers. Studies indicate, however, that quotations not serving their purpose-quotation errors-may be prevalent. Methods. We carried out a systematic review, meta-analysis and meta-regression of quotation errors, taking account of differences between studies in error ascertainment. Results. Out of 559 studies screened we included 28 in the main analysis, and estimated major, minor and total quotation error rates of 11,9%, 95% CI [8.4, 16.6] 11.5% [8.3, 15.7], and 25.4% [19.5, 32.4]. While heterogeneity was substantial, even the lowest estimate of total quotation errors was considerable (6.7%). Indirect references accounted for less than one sixth of all quotation problems. The findings remained robust in a number of sensitivity and subgroup analyses (including risk of bias analysis) and in meta-regression. There was no indication of publication bias. Conclusions. Readers of medical journal articles should be aware of the fact that quotation errors are common. Measures against quotation errors include spot checks by editors and reviewers, correct placement of citations in the text, and declarations by authors that they have checked cited material. Future research should elucidate if and to what degree quotation errors are detrimental to scientific progress.

Quotation accuracy in medical journal articles—a systematic review and meta-analysis

PubMed Central

Jergas, Hannah

2015-01-01

Background. Quotations and references are an indispensable element of scientific communication. They should support what authors claim or provide important background information for readers. Studies indicate, however, that quotations not serving their purpose—quotation errors—may be prevalent. Methods. We carried out a systematic review, meta-analysis and meta-regression of quotation errors, taking account of differences between studies in error ascertainment. Results. Out of 559 studies screened we included 28 in the main analysis, and estimated major, minor and total quotation error rates of 11,9%, 95% CI [8.4, 16.6] 11.5% [8.3, 15.7], and 25.4% [19.5, 32.4]. While heterogeneity was substantial, even the lowest estimate of total quotation errors was considerable (6.7%). Indirect references accounted for less than one sixth of all quotation problems. The findings remained robust in a number of sensitivity and subgroup analyses (including risk of bias analysis) and in meta-regression. There was no indication of publication bias. Conclusions. Readers of medical journal articles should be aware of the fact that quotation errors are common. Measures against quotation errors include spot checks by editors and reviewers, correct placement of citations in the text, and declarations by authors that they have checked cited material. Future research should elucidate if and to what degree quotation errors are detrimental to scientific progress. PMID:26528420

Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis

PubMed Central

Cheungpasitporn, Wisit; Thongprayoon, Charat; Mao, Michael A; Kittanamongkolchai, Wonngarm; Jaffer Sathick, Insara J; Dhondup, Tsering; Erickson, Stephen B

2016-01-01

AIM To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients. METHODS A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones. RESULTS Twenty one studies with 64416 kidney transplant patients were included in the analyses to assess the incidence of kidney stones after kidney transplantation. The estimated incidence of kidney stones was 1.0% (95%CI: 0.6%-1.4%). The mean duration to diagnosis of kidney stones after kidney transplantation was 28 ± 22 mo. The mean age of patients with kidney stones was 42 ± 7 years. Within reported studies, approximately 50% of kidney transplant recipients with kidney stones were males. 67% of kidney stones were calcium-based stones (30% mixed CaOx/CaP, 27%CaOx and 10%CaP), followed by struvite stones (20%) and uric acid stones (13%). CONCLUSION The estimated incidence of kidney stones in patients after kidney transplantation is 1.0%. Although calcium based stones are the most common kidney stones after transplantation, struvite stones (also known as “infection stones”) are not uncommon in kidney transplant recipients. These findings may impact the prevention and clinical management of kidney stones after kidney transplantation. PMID:28058231

The impact of Spitzer infrared data on stellar mass estimates - and a revised galaxy stellar mass function at 0 < z < 5

NASA Astrophysics Data System (ADS)

Elsner, F.; Feulner, G.; Hopp, U.

2008-01-01

Aims:We estimate stellar masses of galaxies in the high redshift universe with the intention of determining the influence of newly available Spitzer/IRAC infrared data on the analysis. Based on the results, we probe the mass assembly history of the universe. Methods: We use the GOODS-MUSIC catalog, which provides multiband photometry from the U-filter to the 8 μm Spitzer band for almost 15 000 galaxies with either spectroscopic (for ≈7% of the sample) or photometric redshifts, and apply a standard model fitting technique to estimate stellar masses. We than repeat our calculations with fixed photometric redshifts excluding Spitzer photometry and directly compare the outcomes to look for systematic deviations. Finally we use our results to compute stellar mass functions and mass densities up to redshift z = 5. Results: We find that stellar masses tend to be overestimated on average if further constraining Spitzer data are not included into the analysis. Whilst this trend is small up to intermediate redshifts z ⪉ 2.5 and falls within the typical error in mass, the deviation increases strongly for higher redshifts and reaches a maximum of a factor of three at redshift z ≈ 3.5. Thus, up to intermediate redshifts, results for stellar mass density are in good agreement with values taken from literature calculated without additional Spitzer photometry. At higher redshifts, however, we find a systematic trend towards lower mass densities if Spitzer/IRAC data are included.

Solid rocket motor cost model

NASA Technical Reports Server (NTRS)

Harney, A. G.; Raphael, L.; Warren, S.; Yakura, J. K.

1972-01-01

A systematic and standardized procedure for estimating life cycle costs of solid rocket motor booster configurations. The model consists of clearly defined cost categories and appropriate cost equations in which cost is related to program and hardware parameters. Cost estimating relationships are generally based on analogous experience. In this model the experience drawn on is from estimates prepared by the study contractors. Contractors' estimates are derived by means of engineering estimates for some predetermined level of detail of the SRM hardware and program functions of the system life cycle. This method is frequently referred to as bottom-up. A parametric cost analysis is a useful technique when rapid estimates are required. This is particularly true during the planning stages of a system when hardware designs and program definition are conceptual and constantly changing as the selection process, which includes cost comparisons or trade-offs, is performed. The use of cost estimating relationships also facilitates the performance of cost sensitivity studies in which relative and comparable cost comparisons are significant.

Inclusion of quasi-experimental studies in systematic reviews of health systems research.

PubMed

Rockers, Peter C; Røttingen, John-Arne; Shemilt, Ian; Tugwell, Peter; Bärnighausen, Till

2015-04-01

Systematic reviews of health systems research commonly limit studies for evidence synthesis to randomized controlled trials. However, well-conducted quasi-experimental studies can provide strong evidence for causal inference. With this article, we aim to stimulate and inform discussions on including quasi-experiments in systematic reviews of health systems research. We define quasi-experimental studies as those that estimate causal effect sizes using exogenous variation in the exposure of interest that is not directly controlled by the researcher. We incorporate this definition into a non-hierarchical three-class taxonomy of study designs - experiments, quasi-experiments, and non-experiments. Based on a review of practice in three disciplines related to health systems research (epidemiology, economics, and political science), we discuss five commonly used study designs that fit our definition of quasi-experiments: natural experiments, instrumental variable analyses, regression discontinuity analyses, interrupted times series studies, and difference studies including controlled before-and-after designs, difference-in-difference designs and fixed effects analyses of panel data. We further review current practices regarding quasi-experimental studies in three non-health fields that utilize systematic reviews (education, development, and environment studies) to inform the design of approaches for synthesizing quasi-experimental evidence in health systems research. Ultimately, the aim of any review is practical: to provide useful information for policymakers, practitioners, and researchers. Future work should focus on building a consensus among users and producers of systematic reviews regarding the inclusion of quasi-experiments. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Complexities and Perplexities: A Critical Appraisal of the Evidence for Soil-Transmitted Helminth Infection-Related Morbidity

PubMed Central

Nery, Susana V.; Doi, Suhail A.; Gray, Darren J.; Soares Magalhães, Ricardo J.; McCarthy, James S.; Traub, Rebecca J.; Andrews, Ross M.; Clements, Archie C. A.

2016-01-01

Background: Soil-transmitted helminths (STH) have acute and chronic manifestations, and can result in lifetime morbidity. Disease burden is difficult to quantify, yet quantitative evidence is required to justify large-scale deworming programmes. A recent Cochrane systematic review, which influences Global Burden of Disease (GBD) estimates for STH, has again called into question the evidence for deworming benefit on morbidity due to STH. In this narrative review, we investigate in detail what the shortfalls in evidence are. Methodology/Principal Findings: We systematically reviewed recent literature that used direct measures to investigate morbidity from STH and we critically appraised systematic reviews, particularly the most recent Cochrane systematic review investigating deworming impact on morbidity. We included six systematic reviews and meta-analyses, 36 literature reviews, 44 experimental or observational studies, and five case series. We highlight where evidence is insufficient and where research needs to be directed to strengthen morbidity evidence, ideally to prove benefits of deworming. Conclusions/Significance: Overall, the Cochrane systematic review and recent studies indicate major shortfalls in evidence for direct morbidity. However, it is questionable whether the systematic review methodology should be applied to STH due to heterogeneity of the prevalence of different species in each setting. Urgent investment in studies powered to detect direct morbidity effects due to STH is required. PMID:27196100

Quantum Chemical Approach to Estimating the Thermodynamics of Metabolic Reactions

PubMed Central

Jinich, Adrian; Rappoport, Dmitrij; Dunn, Ian; Sanchez-Lengeling, Benjamin; Olivares-Amaya, Roberto; Noor, Elad; Even, Arren Bar; Aspuru-Guzik, Alán

2014-01-01

Thermodynamics plays an increasingly important role in modeling and engineering metabolism. We present the first nonempirical computational method for estimating standard Gibbs reaction energies of metabolic reactions based on quantum chemistry, which can help fill in the gaps in the existing thermodynamic data. When applied to a test set of reactions from core metabolism, the quantum chemical approach is comparable in accuracy to group contribution methods for isomerization and group transfer reactions and for reactions not including multiply charged anions. The errors in standard Gibbs reaction energy estimates are correlated with the charges of the participating molecules. The quantum chemical approach is amenable to systematic improvements and holds potential for providing thermodynamic data for all of metabolism. PMID:25387603

The direct cost of epilepsy in the United States: A systematic review of estimates.

PubMed

Begley, Charles E; Durgin, Tracy L

2015-09-01

To develop estimates of the direct cost of epilepsy in the United States for the general epilepsy population and sub-populations by systematically comparing similarities and differences in types of estimates and estimation methods from recently published studies. Papers published since 1995 were identified by systematic literature search. Information on types of estimates, study designs, data sources, types of epilepsy, and estimation methods was extracted from each study. Annual per person cost estimates from methodologically similar studies were identified, converted to 2013 U.S. dollars, and compared. From 4,104 publications discovered in the literature search, 21 were selected for review. Three were added that were published after the search. Eighteen were identified that reported estimates of average annual direct costs for the general epilepsy population in the United States. For general epilepsy populations (comprising all clinically defined subgroups), total direct healthcare costs per person ranged from $10,192 to $47,862 and epilepsy-specific costs ranged from $1,022 to $19,749. Four recent studies using claims data from large general populations yielded relatively similar epilepsy-specific annual cost estimates ranging from $8,412 to $11,354. Although more difficult to compare, studies examining direct cost differences for epilepsy sub-populations indicated a consistent pattern of markedly higher costs for those with uncontrolled or refractory epilepsy, and for those with comorbidities. This systematic review found that various approaches have been used to estimate the direct costs of epilepsy in the United States. However, recent studies using large claims databases and similar methods allow estimation of the direct cost burden of epilepsy for the general disease population, and show that it is greater for some patient subgroups. Additional research is needed to further understand the broader economic burden of epilepsy and how it varies across subpopulations. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Human body mass estimation: a comparison of "morphometric" and "mechanical" methods.

PubMed

Auerbach, Benjamin M; Ruff, Christopher B

2004-12-01

In the past, body mass was reconstructed from hominin skeletal remains using both "mechanical" methods which rely on the support of body mass by weight-bearing skeletal elements, and "morphometric" methods which reconstruct body mass through direct assessment of body size and shape. A previous comparison of two such techniques, using femoral head breadth (mechanical) and stature and bi-iliac breadth (morphometric), indicated a good general correspondence between them (Ruff et al. [1997] Nature 387:173-176). However, the two techniques were never systematically compared across a large group of modern humans of diverse body form. This study incorporates skeletal measures taken from 1,173 Holocene adult individuals, representing diverse geographic origins, body sizes, and body shapes. Femoral head breadth, bi-iliac breadth (after pelvic rearticulation), and long bone lengths were measured on each individual. Statures were estimated from long bone lengths using appropriate reference samples. Body masses were calculated using three available femoral head breadth (FH) formulae and the stature/bi-iliac breadth (STBIB) formula, and compared. All methods yielded similar results. Correlations between FH estimates and STBIB estimates are 0.74-0.81. Slight differences in results between the three FH estimates can be attributed to sampling differences in the original reference samples, and in particular, the body-size ranges included in those samples. There is no evidence for systematic differences in results due to differences in body proportions. Since the STBIB method was validated on other samples, and the FH methods produced similar estimates, this argues that either may be applied to skeletal remains with some confidence. 2004 Wiley-Liss, Inc.

Men who have sex with men in India: a systematic review of the literature.

PubMed

Setia, Maninder Singh; Brassard, Paul; Jerajani, Hemangi R; Bharat, Shalini; Gogate, Alka; Kumta, Sameer; Row-Kavi, Ashok; Anand, Vivek; Boivin, Jean-François

2008-01-01

This study systematically reviews the existing literature on sexually transmitted infections (STIs) including human immunodeficiency virus (HIV) infection in the men who have sex with men (MSM) in India. After a comprehensive literature search of Medline (1950-June 2008), Embase (1980-June 2008), and the Cochrane Library (1950-June 2008), 12 published studies met the inclusion criteria. The link between sexual identity and sexual behavior is a complex phenomenon strongly embedded in a very specific context in India. MSM in India are an important risk group for acquiring STIs/HIV and effective culturally sensitive prevention programs should be designed for them. The combined estimate of HIV prevalence in the MSM population in India calculated from 5 included studies was 16.5% (95% confidence intervals: 11% to 22%). The review also identifies the lacunae in existing literature and provides future directions for research in the MSM community in India.

Diabetes and Hypertension Prevalence in Homeless Adults in the United States: A Systematic Review and Meta-Analysis

PubMed Central

Meurer, Linda N.; Plumb, Ellen J.; Jackson, Jeffrey L.

2015-01-01

We estimated hypertension and diabetes prevalence among US homeless adults compared with the general population, and investigated prevalence trends. We systematically searched 5 databases for published studies (1980–2014) that included hypertension or diabetes prevalence for US homeless adults, pooled disease prevalence, and explored heterogeneity sources. We used the National Health Interview Survey for comparison. We included data from 97 366 homeless adults. The pooled prevalence of self-reported hypertension was 27.0% (95% confidence interval = 23.8%, 29.9%; n = 43 studies) and of diabetes was 8.0% (95% confidence interval = 6.8%, 9.2%; n = 39 studies). We found no difference in hypertension or diabetes prevalence between the homeless and general population. Additional health care and housing resources are needed to meet the significant, growing burden of chronic disease in the homeless population. PMID:25521899

Evolution of basic equations for nearshore wave field

PubMed Central

ISOBE, Masahiko

2013-01-01

In this paper, a systematic, overall view of theories for periodic waves of permanent form, such as Stokes and cnoidal waves, is described first with their validity ranges. To deal with random waves, a method for estimating directional spectra is given. Then, various wave equations are introduced according to the assumptions included in their derivations. The mild-slope equation is derived for combined refraction and diffraction of linear periodic waves. Various parabolic approximations and time-dependent forms are proposed to include randomness and nonlinearity of waves as well as to simplify numerical calculation. Boussinesq equations are the equations developed for calculating nonlinear wave transformations in shallow water. Nonlinear mild-slope equations are derived as a set of wave equations to predict transformation of nonlinear random waves in the nearshore region. Finally, wave equations are classified systematically for a clear theoretical understanding and appropriate selection for specific applications. PMID:23318680

Impact of statin adherence on cardiovascular disease and mortality outcomes: a systematic review

PubMed Central

De Vera, Mary A; Bhole, Vidula; Burns, Lindsay C; Lacaille, Diane

2014-01-01

Aims While suboptimal adherence to statin medication has been quantified in real-world patient settings, a better understanding of its impact is needed, particularly with respect to distinct problems of medication taking. Our aim was to synthesize current evidence on the impacts of statin adherence, discontinuation and persistence on cardiovascular disease and mortality outcomes. Methods We conducted a systematic review of peer-reviewed studies using a mapped search of Medline, Embase and International Pharmaceutical Abstracts databases. Observational studies that met the following criteria were included: defined patient population; statin adherence exposure; defined study outcome [i.e. cardiovascular disease (CVD), mortality]; and reporting of statin-specific results. Results Overall, 28 studies were included, with 19 studies evaluating outcomes associated with statin adherence, six with statin discontinuation and three with statin persistence. Among adherence studies, the proportion of days covered was the most widely used measure, with the majority of studies reporting increased risk of CVD (statistically significant risk estimates ranging from 1.22 to 5.26) and mortality (statistically significant risk estimates ranging from 1.25 to 2.54) among non-adherent individuals. There was greater methodological variability in discontinuation and persistence studies. However, findings of increased CVD (statistically significant risk estimates ranging from 1.22 to 1.67) and mortality (statistically significant risk estimates ranging from 1.79 to 5.00) among nonpersistent individuals were also consistently reported. Conclusions Observational studies consistently report an increased risk of adverse outcomes associated with poor statin adherence. These findings have important implications for patients and physicians and emphasize the importance of monitoring and encouraging adherence to statin therapy. PMID:25364801

Systematic review and meta-analysis estimating association of cysticercosis and neurocysticercosis with epilepsy

PubMed Central

Debacq, Gabrielle; Garcia, Héctor H.; Boumediene, Farid; Marin, Benoit; Ngoungou, Edgard B.; Preux, Pierre-Marie

2017-01-01

Background We reviewed studies that analyzed cysticercosis (CC), neurocysticercosis (NCC) and epilepsy across Latin America, Asia and Sub-Saharan Africa, to estimate the odds ratio and etiologic fraction of epilepsy due to CC in tropical regions. Methodology We conducted a systematic review of the literature on cysticercosis and epilepsy in the tropics, collecting data from case-control and cross-sectional studies. Exposure criteria for CC included one or more of the following: serum ELISA or EITB positivity, presence of subcutaneous cysts (both not verified and unverified by histology), histology consistent with calcified cysts, and brain CT scan consistent with NCC. A common odds-ratio was then estimated using meta-analysis. Principal findings 37 studies from 23 countries were included (n = 24,646 subjects, 14,934 with epilepsy and 9,712 without epilepsy). Of these, 29 were case-control (14 matched). The association between CC and epilepsy was significant in 19 scientific articles. Odds ratios ranged from 0.2 to 25.4 (a posteriori power 4.5–100%) and the common odds ratio was 2.7 (95% CI 2.1–3.6, p <0.001). Three subgroup analyses performed gave odds ratios as: 2.2 (EITB-based studies), 3.2 (CT-based studies), 1.9 (neurologist-confirmed epilepsy; door-to-door survey and at least one matched control per case). Etiologic fraction was estimated to be 63% in the exposed group among the population. Significance Despite differences in findings, this meta-analysis suggests that cysticercosis is a significant contributor to late-onset epilepsy in tropical regions around the world, and its impact may vary depending on transmission intensity. PMID:28267746

Diagnostic performance of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry in blood bacterial infections: a systematic review and meta-analysis.

PubMed

Scott, Jamie S; Sterling, Sarah A; To, Harrison; Seals, Samantha R; Jones, Alan E

2016-07-01

Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has shown promise in decreasing time to identification of causative organisms compared to traditional methods; however, the utility of MALDI-TOF MS in a heterogeneous clinical setting is uncertain. To perform a systematic review on the operational performance of the Bruker MALDI-TOF MS system and evaluate published cut-off values compared to traditional blood cultures. A comprehensive literature search was performed. Studies were included if they performed direct MALDI-TOF MS analysis of blood culture specimens in human patients with suspected bacterial infections using the Bruker Biotyper software. Sensitivities and specificities of the combined studies were estimated using a hierarchical random effects linear model (REML) incorporating cut-off scores of ≥1.7 and ≥2.0. Fifty publications were identified, with 11 studies included after final review. The estimated sensitivity utilising a cut-off of ≥2.0 from the combined studies was 74.6% (95% CI = 67.9-89.3%), with an estimated specificity of 88.0% (95% CI = 74.8-94.7%). When assessing a cut-off of ≥1.7, the combined sensitivity increases to 92.8% (95% CI = 87.4-96.0%), but the estimated specificity decreased to 81.2% (95% CI = 61.9-96.6%). In this analysis, MALDI-TOF MS showed acceptable sensitivity and specificity in bacterial speciation with the current recommended cut-off point compared to blood cultures; however, lowering the cut-off point from ≥2.0 to ≥1.7 would increase the sensitivity of the test without significant detrimental effect on the specificity, which could improve clinician confidence in their results.

Beware of Kinked Frontiers: A Systematic Review of the Choice of Comparator Strategies in Cost-Effectiveness Analyses of Human Papillomavirus Testing in Cervical Screening.

PubMed

O'Mahony, James F; Naber, Steffie K; Normand, Charles; Sharp, Linda; O'Leary, John J; de Kok, Inge M C M

2015-12-01

To systematically review the choice of comparator strategies in cost-effectiveness analyses (CEAs) of human papillomavirus testing in cervical screening. The PubMed, Web of Knowledge, and Scopus databases were searched to identify eligible model-based CEAs of cervical screening programs using human papillomavirus testing. The eligible CEAs were reviewed to investigate what screening strategies were chosen for analysis and how this choice might have influenced estimates of the incremental cost-effectiveness ratio (ICER). Selected examples from the reviewed studies are presented to illustrate how the omission of relevant comparators might influence estimates of screening cost-effectiveness. The search identified 30 eligible CEAs. The omission of relevant comparator strategies appears likely in 18 studies. The ICER estimates in these cases are probably lower than would be estimated had more comparators been included. Five of the 30 studies restricted relevant comparator strategies to sensitivity analyses or other subanalyses not part of the principal base-case analysis. Such exclusion of relevant strategies from the base-case analysis can result in cost-ineffective strategies being identified as cost-effective. Many of the CEAs reviewed appear to include insufficient comparator strategies. In particular, they omit strategies with relatively long screening intervals. Omitting relevant comparators matters particularly if it leads to the underestimation of ICERs for strategies around the cost-effectiveness threshold because these strategies are the most policy relevant from the CEA perspective. Consequently, such CEAs may not be providing the best possible policy guidance and lead to the mistaken adoption of cost-ineffective screening strategies. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Hand-arm vibration and the risk of vascular and neurological diseases—A systematic review and meta-analysis

PubMed Central

Wahlström, Jens; Burström, Lage

2017-01-01

Background Increased occurrence of Raynaud’s phenomenon, neurosensory injury and carpal tunnel syndrome has been reported for more than 100 years in association with work with vibrating machines. The current risk prediction modelling (ISO-5349) for “Raynaud’s phenomenon” is based on a few studies published 70 to 40 years ago. There are no corresponding risk prediction models for neurosensory injury or carpal tunnel syndrome, nor any systematic reviews comprising a statistical synthesis (meta-analysis) of the evidence. Objectives Our aim was to provide a systematic review of the literature on the association between Raynaud’s phenomenon, neurosensory injuries and carpal tunnel syndrome and hand-arm vibration (HAV) exposure. Moreover the aim was to estimate the magnitude of such an association using meta-analysis. Methods This systematic review covers the scientific literature up to January 2016. The databases used for the literature search were PubMed and Science Direct. We found a total of 4,335 abstracts, which were read and whose validity was assessed according to pre-established criteria. 294 articles were examined in their entirety to determine whether each article met the inclusion criteria. The possible risk of bias was assessed for each article. 52 articles finally met the pre-established criteria for inclusion in the systematic review. Results The results show that workers who are exposed to HAV have an increased risk of vascular and neurological diseases compared to non-vibration exposed groups. The crude estimate of the risk increase is approximately 4–5 fold. The estimated effect size (odds ratio) is 6.9 for the studies of Raynaud’s phenomenon when including only the studies judged to have a low risk of bias. The corresponding risk of neurosensory injury is 7.4 and the equivalent of carpal tunnel syndrome is 2.9. Conclusion At equal exposures, neurosensory injury occurs with a 3-time factor shorter latency than Raynaud’s phenomenon. Which is why preventive measures should address this vibration health hazard with greater attention. PMID:28704466

Comparison of prevalence estimation of Mycobacterium avium subsp. paratuberculosis infection by sampling slaughtered cattle with macroscopic lesions vs. systematic sampling.

PubMed

Elze, J; Liebler-Tenorio, E; Ziller, M; Köhler, H

2013-07-01

The objective of this study was to identify the most reliable approach for prevalence estimation of Mycobacterium avium ssp. paratuberculosis (MAP) infection in clinically healthy slaughtered cattle. Sampling of macroscopically suspect tissue was compared to systematic sampling. Specimens of ileum, jejunum, mesenteric and caecal lymph nodes were examined for MAP infection using bacterial microscopy, culture, histopathology and immunohistochemistry. MAP was found most frequently in caecal lymph nodes, but sampling more tissues optimized the detection rate. Examination by culture was most efficient while combination with histopathology increased the detection rate slightly. MAP was detected in 49/50 animals with macroscopic lesions representing 1.35% of the slaughtered cattle examined. Of 150 systematically sampled macroscopically non-suspect cows, 28.7% were infected with MAP. This indicates that the majority of MAP-positive cattle are slaughtered without evidence of macroscopic lesions and before clinical signs occur. For reliable prevalence estimation of MAP infection in slaughtered cattle, systematic random sampling is essential.

Incorporation of habitat information in the development of indices of larval bluefin tuna (Thunnus thynnus) in the Western Mediterranean Sea (2001-2005 and 2012-2013)

NASA Astrophysics Data System (ADS)

Ingram, G. Walter; Alvarez-Berastegui, Diego; Reglero, Patricia; Balbín, Rosa; García, Alberto; Alemany, Francisco

2017-06-01

Fishery independent indices of bluefin tuna larvae in the Western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 and 2012 through 2013. Indices were developed using larval catch rates collected using two different types of bongo sampling, by first standardizing catch rates by gear/fishing-style and then employing a delta-lognormal modeling approach. The delta-lognormal models were developed three ways: 1) a basic larval index including the following covariates: time of day, a systematic geographic area variable, month and year; 2) a standard environmental larval index including the following covariates: mean water temperature over the mixed layer depth, mean salinity over the mixed layer depth, geostrophic velocity, time of day, a systematic geographic area variable, month and year; and 3) a habitat-adjusted larval index including the following covariates: a potential habitat variable, time of day, a systematic geographic area variable, month and year. Results indicated that all three model-types had similar precision in index values. However, the habitat-adjusted larval index demonstrated a high correlation with estimates of spawning stock biomass from the previous stock assessment model, and, therefore, is recommended as a tuning index in future stock assessment models.

Effects of after-school programs with at-risk youth on attendance and externalizing behaviors: a systematic review and meta-analysis.

PubMed

Kremer, Kristen P; Maynard, Brandy R; Polanin, Joshua R; Vaughn, Michael G; Sarteschi, Christine M

2015-03-01

The popularity, demand, and increased federal and private funding for after-school programs have resulted in a marked increase in after-school programs over the past two decades. After-school programs are used to prevent adverse outcomes, decrease risks, or improve functioning with at-risk youth in several areas, including academic achievement, crime and behavioral problems, socio-emotional functioning, and school engagement and attendance; however, the evidence of effects of after-school programs remains equivocal. This systematic review and meta-analysis, following Campbell Collaboration guidelines, examined the effects of after-school programs on externalizing behaviors and school attendance with at-risk students. A systematic search for published and unpublished literature resulted in the inclusion of 24 studies. A total of 64 effect sizes (16 for attendance outcomes; 49 for externalizing behavior outcomes) extracted from 31 reports were included in the meta-analysis using robust variance estimation to handle dependencies among effect sizes. Mean effects were small and non-significant for attendance and externalizing behaviors. A moderate to large amount of heterogeneity was present; however, no moderator variable tested explained the variance between studies. Significant methodological shortcomings were identified across the corpus of studies included in this review. Implications for practice, policy and research are discussed.

Effects of After-School Programs with At-Risk Youth on Attendance and Externalizing Behaviors: A Systematic Review and Meta-Analysis

PubMed Central

Maynard, Brandy R.; Polanin, Joshua R.; Vaughn, Michael G.; Sarteschi, Christine M.

2015-01-01

The popularity, demand, and increased federal and private funding for after-school programs have resulted in a marked increase in after-school programs over the past two decades. After-school programs are used to prevent adverse outcomes, decrease risks, or improve functioning with at-risk youth in several areas, including academic achievement, crime and behavioral problems, socio-emotional functioning, and school engagement and attendance; however, the evidence of effects of after-school programs remains equivocal. This systematic review and meta-analysis, following Campbell Collaboration guidelines, examined the effects of after-school programs on externalizing behaviors and school attendance with at-risk students. A systematic search for published and unpublished literature resulted in the inclusion of 24 studies. A total of 64 effect sizes (16 for attendance outcomes; 49 for externalizing behavior outcomes) extracted from 31 reports were included in the meta-analysis using robust variance estimation to handle dependencies among effect sizes. Mean effects were small and non-significant for attendance and externalizing behaviors. A moderate to large amount of heterogeneity was present; however, no moderator variable tested explained the variance between studies. Significant methodological shortcomings were identified across the corpus of studies included in this review. Implications for practice, policy and research are discussed. PMID:25416228

Network structure and travel time perception.

PubMed

Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

2013-01-01

The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time.

Estimating the Incidence of Symptomatic Rotavirus Infections: A Systematic Review and Meta-Analysis

PubMed Central

Bilcke, Joke; Van Damme, Pierre; Van Ranst, Marc; Hens, Niel; Aerts, Marc; Beutels, Philippe

2009-01-01

Background We conducted for the first time a systematic review, including a meta-analysis, of the incidence of symptomatic rotavirus (RV) infections, because (1) it was shown to be an influential factor in estimating the cost-effectiveness of RV vaccination, (2) multiple community-based studies assessed it prospectively, (3) previous studies indicated, inconclusively, it might be similar around the world. Methodology Pubmed (which includes Medline) was searched for surveys assessing prospectively symptomatic (diarrheal) episodes in a general population and situation, which also reported on the number of the episodes being tested RV+ and on the persons and the time period observed. A bias assessment tool was developed and used according to Cochrane guidelines by 4 researchers with different backgrounds. Heterogeneity was explored graphically and by comparing fits of study-homogenous ‘fixed effects’ and -heterogeneous ‘random effects’ models. Data were synthesized using these models. Sensitivity analysis for uncertainty regarding data abstraction, bias assessment and included studies was performed. Principal Findings Variability between the incidences obtained from 20 studies is unlikely to be due to study groups living in different environments (tropical versus temperate climate, slums versus middle-class suburban populations), nor due to the year the study was conducted (from 1967 to 2003). A random effects model was used to incorporate unexplained heterogeneity and resulted in a global incidence estimate of 0.31 [0.19; 0.50] symptomatic RV infections per personyear of observation for children below 2 years of age, and of 0.24 [0.17; 0.34] when excluding the extreme high value of 0.84 reported for Mayan Indians in Guatemala. Apart from the inclusion/exclusion of the latter study, results were robust. Conclusions/Significance Rather than assumptions based on an ad-hoc selection of one or two studies, these pooled estimates (together with the measure for variability between populations) should be used as an input in future cost-effectiveness analyses of RV vaccination. PMID:19557133

Suicide among agricultural, forestry, and fishery workers.

PubMed

Shiri, Rahman

2018-01-01

In their meta-analysis, Klingelschmidt and her associates (1) found that agricultural, forestry, and fishery workers are at 48% higher risk of suicide than the working-age population. Moreover, they found that the excess risk is even greater among Japanese agricultural workers than workers from other high-income countries. There are several concerns regarding this meta-analysis. It appears that the excess risk has been overestimated for these workers. Furthermore, the excess risk in Japan is not different than other high-income countries. First, in a systematic review, a literature search is comprehensive. A search of a single database is unlikely to identify most of relevant studies, and these types of reviews are not therefore considered as systematic reviews (2). In this review, a specialized database (-PsycINFO) or a European database (EMBASE or -Scopus) was not searched. Second, following the PRISMA guidelines, the critical appraisal of included studies (quality assessment) is a requirement for a systematic review. In a meta-analysis of observational studies, selection bias and confounding should be ruled out. Third, the reviewers did not correctly extract confidence intervals (CI) for the estimates of several studies such as Hassler 2004, Fleming 1999, and Fragar 2011. Moreover, some studies reported both the least- and maximally adjusted risk estimates. The reviewers, however, extracted age- or the least-adjusted risk estimate. A confounder-adjusted estimate is a more appropriate estimate of the true association. In some studies [eg, Kposowa (3) Agerbo (4)], the excess risk dropped by 52-71% after adjustment for confounders. As a sensitivity analysis, the reviewers could limit their meta-analysis to a subgroup of studies controlled for confounders. Fourth, the reviewers did not estimate an overall risk estimate for each study. They included the estimates of 2-6 subgroups for 22 studies in forest and funnel plots. A fixed-effect meta-analysis is a more appropriate model to combine the subgroups of a single study. Moreover, for the assessment of publication bias, it is not appropriate to include several subsamples of a single study in a funnel plot. Using estimates of subgroups can change a large study into several smaller studies. Fifth, some of the included studies compared agricultural, forestry, and fishery workers with a specific occupational group. The reviewers could calculate a risk estimate using all other occupational groups as a comparison group and exclude those studies that did not provide sufficient data for estimating such a risk estimate. In some studies, the excess risk for agricultural, forestry, and fishery workers disappears after comparing with other occupational groups [eg, adjusted risk ratios (RR) for Kposowa (3) = 1.02, 95% CI 0.41-2.54]. This is a main reason for observed higher excess risk in Japanese workers. Wada et al (5) compared Japanese agricultural workers with sales workers and Suzuki et al (6) compared Japanese agricultural, forestry, and fishery workers with production process and related workers. Using all other occupational groups as a reference group, age-adjusted RR dropped from 3.53 (95% CI 2.84-4.38) to 2.61 (95% CI 2.10-3.25) for Wada et al (5) and from 3.24 (CI 2.95-3.57, both sexes combined) to 1.31 (CI 1.27-1.35 age-adjusted OR after excluding unemployed people) for Suzuki et al (6). The pooled estimate of these two register-based studies was 1.33 (95% CI 1.29-1.37) using a fixed model and 1.83 (95% CI 0.93-3.60) using a random model. Sixth, most of the included studies used register data, which had little information on the background characteristics of the participants. A majority of these studies controlled the estimates for age and sex only. Moreover, in this review, prospective cohort studies did not support the observed association. A meta-analysis of 11 case-control and prospective cohort studies shows no significant excess risk of suicide for agricultural, forestry, and fishery workers (pooled estimate = 1.02, 95% CI 0.71-1.47 for 6 cohort studies and 1.13, 95% CI 0.92-1.39, I2 = 91% for 11 case control and cohort studies, combining maximally adjusted risk estimates and comparing agricultural, forestry, and fishery workers with all other occupational groups where possible). The excess risk found in this review (1) can thus largely be due to confounding. References 1. Klingelschmidt J, Milner A, Khireddine-Medouni I, Witt K, Alexopoulos EC, Toivanen S, LaMontagne AD, Chastang JF, Niedhammer I. Suicide among agricultural, forestry, and fishery workers: a systematic literature review and meta-analysis. Scand J Work Environ Health. 2018;44(1):3-15. https://doi.org/10.5271/sjweh.3682.  2. Puljak L. If there is only one author or only one database was searched, a study should not be called a systematic review. J Clin Epidemiol. 2017;91:4-5. https://doi.org/10.1016/j.jclinepi.2017.08.002.  3. Kposowa AJ. Suicide mortality in the United States: differentials by industrial and occupational groups. Am J Ind Med. 1999;36:645-52. https://doi.org/10.1002/(SICI)1097-0274(199912)36:63.0.CO;2-T. 4. Agerbo E, Gunnell D, Bonde JP, Mortensen PB, Nordentoft M. Suicide and occupation: the impact of socio-economic, demographic and psychiatric differences. Psychol Med. 2007;37:1131-40. https://doi.org/10.1017/S0033291707000487.  5. Wada K, Gilmour S. Inequality in mortality by occupation related to economic crisis from 1980 to 2010 among working-age Japanese males. Sci Rep. 2016;6:22255. https://doi.org/10.1038/srep22255. 6. Suzuki E, Kashima S, Kawachi I, Subramanian SV. Social and geographical inequalities in suicide in Japan from 1975 through 2005: a census-based longitudinal analysis. PLoS One. 2013;8:e63443. https://doi.org/10.1371/journal.pone.0063443.

Prevalence of treponema species detected in endodontic infections: systematic review and meta-regression analysis.

PubMed

Leite, Fábio R M; Nascimento, Gustavo G; Demarco, Flávio F; Gomes, Brenda P F A; Pucci, Cesar R; Martinho, Frederico C

2015-05-01

This systematic review and meta-regression analysis aimed to calculate a combined prevalence estimate and evaluate the prevalence of different Treponema species in primary and secondary endodontic infections, including symptomatic and asymptomatic cases. The MEDLINE/PubMed, Embase, Scielo, Web of Knowledge, and Scopus databases were searched without starting date restriction up to and including March 2014. Only reports in English were included. The selected literature was reviewed by 2 authors and classified as suitable or not to be included in this review. Lists were compared, and, in case of disagreements, decisions were made after a discussion based on inclusion and exclusion criteria. A pooled prevalence of Treponema species in endodontic infections was estimated. Additionally, a meta-regression analysis was performed. Among the 265 articles identified in the initial search, only 51 were included in the final analysis. The studies were classified into 2 different groups according to the type of endodontic infection and whether it was an exclusively primary/secondary study (n = 36) or a primary/secondary comparison (n = 15). The pooled prevalence of Treponema species was 41.5% (95% confidence interval, 35.9-47.0). In the multivariate model of meta-regression analysis, primary endodontic infections (P < .001), acute apical abscess, symptomatic apical periodontitis (P < .001), and concomitant presence of 2 or more species (P = .028) explained the heterogeneity regarding the prevalence rates of Treponema species. Our findings suggest that Treponema species are important pathogens involved in endodontic infections, particularly in cases of primary and acute infections. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Parameter estimation method that directly compares gravitational wave observations to numerical relativity

NASA Astrophysics Data System (ADS)

Lange, J.; O'Shaughnessy, R.; Boyle, M.; Calderón Bustillo, J.; Campanelli, M.; Chu, T.; Clark, J. A.; Demos, N.; Fong, H.; Healy, J.; Hemberger, D. A.; Hinder, I.; Jani, K.; Khamesra, B.; Kidder, L. E.; Kumar, P.; Laguna, P.; Lousto, C. O.; Lovelace, G.; Ossokine, S.; Pfeiffer, H.; Scheel, M. A.; Shoemaker, D. M.; Szilagyi, B.; Teukolsky, S.; Zlochower, Y.

2017-11-01

We present and assess a Bayesian method to interpret gravitational wave signals from binary black holes. Our method directly compares gravitational wave data to numerical relativity (NR) simulations. In this study, we present a detailed investigation of the systematic and statistical parameter estimation errors of this method. This procedure bypasses approximations used in semianalytical models for compact binary coalescence. In this work, we use the full posterior parameter distribution for only generic nonprecessing binaries, drawing inferences away from the set of NR simulations used, via interpolation of a single scalar quantity (the marginalized log likelihood, ln L ) evaluated by comparing data to nonprecessing binary black hole simulations. We also compare the data to generic simulations, and discuss the effectiveness of this procedure for generic sources. We specifically assess the impact of higher order modes, repeating our interpretation with both l ≤2 as well as l ≤3 harmonic modes. Using the l ≤3 higher modes, we gain more information from the signal and can better constrain the parameters of the gravitational wave signal. We assess and quantify several sources of systematic error that our procedure could introduce, including simulation resolution and duration; most are negligible. We show through examples that our method can recover the parameters for equal mass, zero spin, GW150914-like, and unequal mass, precessing spin sources. Our study of this new parameter estimation method demonstrates that we can quantify and understand the systematic and statistical error. This method allows us to use higher order modes from numerical relativity simulations to better constrain the black hole binary parameters.

Quantifying Errors in TRMM-Based Multi-Sensor QPE Products Over Land in Preparation for GPM

NASA Technical Reports Server (NTRS)

Peters-Lidard, Christa D.; Tian, Yudong

2011-01-01

Determining uncertainties in satellite-based multi-sensor quantitative precipitation estimates over land of fundamental importance to both data producers and hydro climatological applications. ,Evaluating TRMM-era products also lays the groundwork and sets the direction for algorithm and applications development for future missions including GPM. QPE uncertainties result mostly from the interplay of systematic errors and random errors. In this work, we will synthesize our recent results quantifying the error characteristics of satellite-based precipitation estimates. Both systematic errors and total uncertainties have been analyzed for six different TRMM-era precipitation products (3B42, 3B42RT, CMORPH, PERSIANN, NRL and GSMap). For systematic errors, we devised an error decomposition scheme to separate errors in precipitation estimates into three independent components, hit biases, missed precipitation and false precipitation. This decomposition scheme reveals hydroclimatologically-relevant error features and provides a better link to the error sources than conventional analysis, because in the latter these error components tend to cancel one another when aggregated or averaged in space or time. For the random errors, we calculated the measurement spread from the ensemble of these six quasi-independent products, and thus produced a global map of measurement uncertainties. The map yields a global view of the error characteristics and their regional and seasonal variations, reveals many undocumented error features over areas with no validation data available, and provides better guidance to global assimilation of satellite-based precipitation data. Insights gained from these results and how they could help with GPM will be highlighted.

Infectious risk of endovaginal and transrectal ultrasonography: systematic review and meta-analysis.

PubMed

Leroy, S

2013-02-01

Appropriate endovaginal/rectal ultrasound transducer disinfection has been an ongoing and vexed question in gynaecology, obstetrics and urology. However, the routine use of probe covers followed by low-level disinfection (wipes/spray) is usually applied between patients in some countries (e.g. France). To perform a systematic review and meta-analysis of the scientific literature in order to identify case reports of contamination following endovaginal/rectal probe use, and to estimate the infection prevalence related to the use of these probes in common daily practice. Systematic review and meta-analysis. From the 867 potentially eligible references, 32 articles were finally included. Very few cases with an established route of contamination had been reported. Indeed, apart from occurrence of outbreaks, it is difficult if not impossible to detect viral contamination through the use of endovaginal/rectal ultrasound probes. However, there was a pooled prevalence of 12.9% (95% confidence interval: 1.7-24.3) for pathogenic bacteria, and 1.0% (0.0-10.0) for frequently occurring virus (human papillomavirus, herpes simplex virus, and cytomegalovirus) for endovaginal/rectal probes, both after low-level disinfection. The pooled prevalence of infected patients after transrectal ultrasound and guided biopsies was estimated to be 3.1% (1.6-4.3). There appears to be a risk of transmitting bacterial or viral infections via endovaginal/rectal ultrasound transducer, and the present meta-analysis provides an estimate of this risk. Further research with sophisticated modelling is warranted to quantify the risk. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Comparison of intervention effects in split-mouth and parallel-arm randomized controlled trials: a meta-epidemiological study

PubMed Central

2014-01-01

Background Split-mouth randomized controlled trials (RCTs) are popular in oral health research. Meta-analyses frequently include trials of both split-mouth and parallel-arm designs to derive combined intervention effects. However, carry-over effects may induce bias in split- mouth RCTs. We aimed to assess whether intervention effect estimates differ between split- mouth and parallel-arm RCTs investigating the same questions. Methods We performed a meta-epidemiological study. We systematically reviewed meta- analyses including both split-mouth and parallel-arm RCTs with binary or continuous outcomes published up to February 2013. Two independent authors selected studies and extracted data. We used a two-step approach to quantify the differences between split-mouth and parallel-arm RCTs: for each meta-analysis. First, we derived ratios of odds ratios (ROR) for dichotomous data and differences in standardized mean differences (∆SMD) for continuous data; second, we pooled RORs or ∆SMDs across meta-analyses by random-effects meta-analysis models. Results We selected 18 systematic reviews, for 15 meta-analyses with binary outcomes (28 split-mouth and 28 parallel-arm RCTs) and 19 meta-analyses with continuous outcomes (28 split-mouth and 28 parallel-arm RCTs). Effect estimates did not differ between split-mouth and parallel-arm RCTs (mean ROR, 0.96, 95% confidence interval 0.52–1.80; mean ∆SMD, 0.08, -0.14–0.30). Conclusions Our study did not provide sufficient evidence for a difference in intervention effect estimates derived from split-mouth and parallel-arm RCTs. Authors should consider including split-mouth RCTs in their meta-analyses with suitable and appropriate analysis. PMID:24886043

Impact of Exposure Uncertainty on the Association between Perfluorooctanoate and Preeclampsia in the C8 Health Project Population.

PubMed

Avanasi, Raghavendhran; Shin, Hyeong-Moo; Vieira, Verónica M; Savitz, David A; Bartell, Scott M

2016-01-01

Uncertainty in exposure estimates from models can result in exposure measurement error and can potentially affect the validity of epidemiological studies. We recently used a suite of environmental models and an integrated exposure and pharmacokinetic model to estimate individual perfluorooctanoate (PFOA) serum concentrations and assess the association with preeclampsia from 1990 through 2006 for the C8 Health Project participants. The aims of the current study are to evaluate impact of uncertainty in estimated PFOA drinking-water concentrations on estimated serum concentrations and their reported epidemiological association with preeclampsia. For each individual public water district, we used Monte Carlo simulations to vary the year-by-year PFOA drinking-water concentration by randomly sampling from lognormal distributions for random error in the yearly public water district PFOA concentrations, systematic error specific to each water district, and global systematic error in the release assessment (using the estimated concentrations from the original fate and transport model as medians and a range of 2-, 5-, and 10-fold uncertainty). Uncertainty in PFOA water concentrations could cause major changes in estimated serum PFOA concentrations among participants. However, there is relatively little impact on the resulting epidemiological association in our simulations. The contribution of exposure uncertainty to the total uncertainty (including regression parameter variance) ranged from 5% to 31%, and bias was negligible. We found that correlated exposure uncertainty can substantially change estimated PFOA serum concentrations, but results in only minor impacts on the epidemiological association between PFOA and preeclampsia. Avanasi R, Shin HM, Vieira VM, Savitz DA, Bartell SM. 2016. Impact of exposure uncertainty on the association between perfluorooctanoate and preeclampsia in the C8 Health Project population. Environ Health Perspect 124:126-132; http://dx.doi.org/10.1289/ehp.1409044.

Urbanization and prevalence of type 2 diabetes in Southern Asia: A systematic analysis

PubMed Central

Cheema, Arsalan; Adeloye, Davies; Sidhu, Simrita; Sridhar, Devi; Chan, Kit Yee

2014-01-01

Background Diabetes mellitus is one of the diseases considered to be the main constituents of the global non–communicable disease (NCD) pandemic. Despite the large impact that NCDs are predicted to have, particularly in developing countries, estimates of disease burden are sparse and inconsistent. This systematic review transparently estimates prevalence of type 2 diabetes mellitus in Southern Asia, its association with urbanization and provides insight into the policy challenges facing the region. Methods The databases Medline and PubMed were searched for population–based studies providing estimates of diabetes prevalence in the Southern Asia region. Studies using WHO diagnostic criteria of fasting plasma glucose (FPG) ≥7.0mmol/L and/or 2h–plasma glucose (2hPG) ≥11.1mmol/L were included. Data from eligible studies was extracted into bubble graphs, and trend lines were applied to UNPD figures to estimate age–specific prevalence in the regional population. Estimates specific to sex, area of residency, and diagnostic method were compared and trends analysed. Results A total of 151 age–specific prevalence estimates were extracted from 39 studies. Diabetes prevalence was estimated to be 7.47% for 2005 and 7.60% for 2010. Prevalence was strongly associated with increased age, male gender and urban residency (P < 0.001). Conclusion Diabetes prevalence in Southern Asia is high and predicted to increase in the future as life expectancy rises and the region continues to urbanise. Countries in this region need to improve NCD surveillance and monitoring so policies can be informed with the best evidence. Programs for prevention need to be put in place, and health system capacity and access needs to be assessed and increased to deal with the predicted rise in NCD prevalence. PMID:24976963

Quantification of residual dose estimation error on log file-based patient dose calculation.

PubMed

Katsuta, Yoshiyuki; Kadoya, Noriyuki; Fujita, Yukio; Shimizu, Eiji; Matsunaga, Kenichi; Matsushita, Haruo; Majima, Kazuhiro; Jingu, Keiichi

2016-05-01

The log file-based patient dose estimation includes a residual dose estimation error caused by leaf miscalibration, which cannot be reflected on the estimated dose. The purpose of this study is to determine this residual dose estimation error. Modified log files for seven head-and-neck and prostate volumetric modulated arc therapy (VMAT) plans simulating leaf miscalibration were generated by shifting both leaf banks (systematic leaf gap errors: ±2.0, ±1.0, and ±0.5mm in opposite directions and systematic leaf shifts: ±1.0mm in the same direction) using MATLAB-based (MathWorks, Natick, MA) in-house software. The generated modified and non-modified log files were imported back into the treatment planning system and recalculated. Subsequently, the generalized equivalent uniform dose (gEUD) was quantified for the definition of the planning target volume (PTV) and organs at risks. For MLC leaves calibrated within ±0.5mm, the quantified residual dose estimation errors that obtained from the slope of the linear regression of gEUD changes between non- and modified log file doses per leaf gap are in head-and-neck plans 1.32±0.27% and 0.82±0.17Gy for PTV and spinal cord, respectively, and in prostate plans 1.22±0.36%, 0.95±0.14Gy, and 0.45±0.08Gy for PTV, rectum, and bladder, respectively. In this work, we determine the residual dose estimation errors for VMAT delivery using the log file-based patient dose calculation according to the MLC calibration accuracy. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Economic evaluation of HIV pre-exposure prophylaxis strategies: protocol for a methodological systematic review and quantitative synthesis.

PubMed

Thavorn, Kednapa; Kugathasan, Howsikan; Tan, Darrell H S; Moqueet, Nasheed; Baral, Stefan D; Skidmore, Becky; MacFadden, Derek; Simkin, Anna; Mishra, Sharmistha

2018-03-15

Pre-exposure prophylaxis (PrEP) with antiretrovirals is an efficacious and effective intervention to decrease the risk of HIV (human immunodeficiency virus) acquisition. Yet drug and delivery costs prohibit access in many jurisdictions. In the absence of guidelines for the synthesis of economic evaluations, we developed a protocol for a systematic review of economic evaluation studies for PrEP by drawing on best practices in systematic reviews and the conduct and reporting of economic evaluations. We aim to estimate the incremental cost per health outcome of PrEP compared with placebo, no PrEP, or other HIV prevention strategies; assess the methodological variability in, and quality of, economic evaluations of PrEP; estimate the incremental cost per health outcome of different PrEP implementation strategies; and quantify the potential sources of heterogeneity in outcomes. We will systematically search electronic databases (MEDLINE, Embase) and the gray literature. We will include economic evaluation studies that assess both costs and health outcomes of PrEP in HIV-uninfected individuals, without restricting language or year of publication. Two reviewers will independently screen studies using predefined inclusion criteria, extract data, and assess methodological quality using the Philips checklist, Second Panel on the Cost-effectiveness of Health and Medicines, and the International Society for Pharmacoeconomics and Outcomes Research recommendations. Outcomes of interest include incremental costs and outcomes in natural units or utilities, cost-effectiveness ratios, and net monetary benefit. We will perform descriptive and quantitative syntheses using sensitivity analyses of outcomes by population subgroups, HIV epidemic settings, study designs, baseline intervention contexts, key parameter inputs and assumptions, type of outcomes, economic perspectives, and willingness to pay values. Findings will guide future economic evaluation of PrEP strategies in terms of methodological and knowledge gaps, and will inform decisions on the efficient integration of PrEP into public health programs across epidemiologic and health system contexts. PROSPERO CRD42016038440 .

Sensitivity subgroup analysis based on single-center vs. multi-center trial status when interpreting meta-analyses pooled estimates: the logical way forward.

PubMed

Alexander, Paul E; Bonner, Ashley J; Agarwal, Arnav; Li, Shelly-Anne; Hariharan, Abishek; Izhar, Zain; Bhatnagar, Neera; Alba, Carolina; Akl, Elie A; Fei, Yutong; Guyatt, Gordon H; Beyene, Joseph

2016-06-01

Prior studies regarding whether single-center trial estimates are larger than multi-center are equivocal. We examined the extent to which single-center trials yield systematically larger effects than multi-center trials. We searched the 119 core clinical journals and the Cochrane Database of Systematic Reviews for meta-analyses (MAs) of randomized controlled trials (RCTs) published during 2012. In this meta-epidemiologic study, for binary variables, we computed the pooled ratio of ORs (RORs), and for continuous outcomes mean difference in standardized mean differences (SMDs), we conducted weighted random-effects meta-regression and random-effects MA modeling. Our primary analyses were restricted to MAs that included at least five RCTs and in which at least 25% of the studies used each of single trial center (SC) and more trial center (MC) designs. We identified 81 MAs for the odds ratio (OR) and 43 for the SMD outcome measures. Based on our analytic plan, our primary analysis (core) is based on 25 MAs/241 RCTs (binary outcome) and 18 MAs/173 RCTs (continuous outcome). Based on the core analysis, we found no difference in magnitude of effect between SC and MC for binary outcomes [RORs: 1.02; 95% confidence interval (CI): 0.83, 1.24; I(2) 20.2%]. Effect sizes were systematically larger for SC than MC for the continuous outcome measure (mean difference in SMDs: -0.13; 95% CI: -0.21, -0.05; I(2) 0%). Our results do not support prior findings of larger effects in SC than MC trials addressing binary outcomes but show a very similar small increase in effect in SC than MC trials addressing continuous outcomes. Authors of systematic reviews would be wise to include all trials irrespective of SC vs. MC design and address SC vs. MC status as a possible explanation of heterogeneity (and consider sensitivity analyses). Copyright © 2015 Elsevier Inc. All rights reserved.

Who perpetrates violence against children? A systematic analysis of age-specific and sex-specific data

PubMed Central

Devries, Karen; Knight, Louise; Petzold, Max; Merrill, Katherine G; Maxwell, Lauren; Williams, Abigail; Cappa, Claudia; Chan, Ko Ling; Garcia-Moreno, Claudia; Hollis, NaTasha; Kress, Howard; Peterman, Amber; Walsh, Sophie D; Kishor, Sunita; Guedes, Alessandra; Bott, Sarah; Butron Riveros, Betzabe C; Watts, Charlotte; Abrahams, Naeemah

2018-01-01

Objective The epidemiology of violence against children is likely to differ substantially by sex and age of the victim and the perpetrator. Thus far, investment in effective prevention strategies has been hindered by lack of clarity in the burden of childhood violence across these dimensions. We produced the first age-specific and sex-specific prevalence estimates by perpetrator type for physical, sexual and emotional violence against children globally. Design We used random effects meta-regression to estimate prevalence. Estimates were adjusted for relevant quality covariates, variation in definitions of violence and weighted by region-specific, age-specific and sex-specific population data to ensure estimates reflect country population structures. Data sources Secondary data from 600 population or school-based representative datasets and 43 publications obtained via systematic literature review, representing 13 830 estimates from 171 countries. Eligibility criteria for selecting studies Estimates for recent violence against children aged 0–19 were included. Results The most common perpetrators of physical and emotional violence for both boys and girls across a range of ages are household members, with prevalence often surpassing 50%, followed by student peers. Children reported experiencing more emotional than physical violence from both household members and students. The most common perpetrators of sexual violence against girls aged 15–19 years are intimate partners; however, few data on other perpetrators of sexual violence against children are systematically collected internationally. Few age-specific and sex-specific data are available on violence perpetration by schoolteachers; however, existing data indicate high prevalence of physical violence from teachers towards students. Data from other authority figures, strangers, siblings and other adults are limited, as are data on neglect of children. Conclusions Without further investment in data generation on violence exposure from multiple perpetrators for boys and girls of all ages, progress towards Sustainable Development Goals 4, 5 and 16 may be slow. Despite data gaps, evidence shows violence from household members, peers in school and for girls, from intimate partners, should be prioritised for prevention. Trial registration number PROSPERO 2015: CRD42015024315. PMID:29637183

Phobos laser ranging: Numerical Geodesy experiments for Martian system science

NASA Astrophysics Data System (ADS)

Dirkx, D.; Vermeersen, L. L. A.; Noomen, R.; Visser, P. N. A. M.

2014-09-01

Laser ranging is emerging as a technology for use over (inter)planetary distances, having the advantage of high (mm-cm) precision and accuracy and low mass and power consumption. We have performed numerical simulations to assess the science return in terms of geodetic observables of a hypothetical Phobos lander performing active two-way laser ranging with Earth-based stations. We focus our analysis on the estimation of Phobos and Mars gravitational, tidal and rotational parameters. We explicitly include systematic error sources in addition to uncorrelated random observation errors. This is achieved through the use of consider covariance parameters, specifically the ground station position and observation biases. Uncertainties for the consider parameters are set at 5 mm and at 1 mm for the Gaussian uncorrelated observation noise (for an observation integration time of 60 s). We perform the analysis for a mission duration up to 5 years. It is shown that a Phobos Laser Ranging (PLR) can contribute to a better understanding of the Martian system, opening the possibility for improved determination of a variety of physical parameters of Mars and Phobos. The simulations show that the mission concept is especially suited for estimating Mars tidal deformation parameters, estimating degree 2 Love numbers with absolute uncertainties at the 10-2 to 10-4 level after 1 and 4 years, respectively and providing separate estimates for the Martian quality factors at Sun and Phobos-forced frequencies. The estimation of Phobos libration amplitudes and gravity field coefficients provides an estimate of Phobos' relative equatorial and polar moments of inertia with an absolute uncertainty of 10-4 and 10-7, respectively, after 1 year. The observation of Phobos tidal deformation will be able to differentiate between a rubble pile and monolithic interior within 2 years. For all parameters, systematic errors have a much stronger influence (per unit uncertainty) than the uncorrelated Gaussian observation noise. This indicates the need for the inclusion of systematic errors in simulation studies and special attention to the mitigation of these errors in mission and system design.

Clinical and Molecular Epidemiology of Extended-Spectrum Beta-Lactamase-Producing Klebsiella spp.: A Systematic Review and Meta-Analyses

PubMed Central

Hendrik, Tirza C.; Voor in ‘t holt, Anne F.; Vos, Margreet C.

2015-01-01

Healthcare-related infections caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella spp. are of major concern. To control transmission, deep understanding of the transmission mechanisms is needed. This systematic review aimed to identify risk factors and sources, clonal relatedness using molecular techniques, and the most effective control strategies for ESBL-producing Klebsiella spp. A systematic search of PubMed, Embase, and Outbreak Database was performed. We identified 2771 articles from November 25th, 1960 until April 7th, 2014 of which 148 were included in the systematic review and 23 in a random-effects meta-analysis study. The random-effects meta-analyses showed that underlying disease or condition (odds ratio [OR] = 6.25; 95% confidence interval [CI] = 2.85 to 13.66) generated the highest pooled estimate. ESBL-producing Klebsiella spp. were spread through person-to-person contact and via sources in the environment; we identified both monoclonal and polyclonal presence. Multi-faceted interventions are needed to prevent transmission of ESBL-producing Klebsiella spp. PMID:26485570

The Natural History of Erectile Dysfunction After Prostatic Radiotherapy: A Systematic Review and Meta-Analysis.

PubMed

Gaither, Thomas W; Awad, Mohannad A; Osterberg, E Charles; Murphy, Gregory P; Allen, Isabel E; Chang, Albert; Rosen, Raymond C; Breyer, Benjamin N

2017-09-01

Erectile dysfunction (ED) after treatment for prostate cancer with radiotherapy (RT) is well known, and pooled estimates of ED after RT will provide more accurate patient education. To systematically evaluate the natural history of ED in men with previous erectile function after prostate RT and to determine clinical factors associated with ED. We performed a review of the PubMed and Medline, Embase, Cochrane Library, and Web of Science databases in April 2016 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Identified reports included a measurement of ED before and after prostate RT. Two hundred seventy-eight abstracts were screened and 105 publications met the criteria for inclusion. Only men with known erectile function before RT were included in the analysis. ED after RT of the prostate. In total, 17,057 men underwent brachytherapy (65%), 8,166 men underwent external-beam RT (31%), and 1,046 men underwent both (4%). Seven common instruments were used to measure ED, including 23 different cutoffs for ED. The Sexual Health Inventory for Men (SHIM) was used in 31 studies (30%). Pooled estimates of SHIM-confirmed ED (score <10-17) suggested the prevalence of ED after RT is 34% of men (95% CI = 0.29-0.39) at 1 year and 57% (95% CI = 0.53-0.61) at 5.5 years. Compared with brachytherapy, studies of the two types of radiation increased the proportion of new-onset ED found by 12.3% of studies (95% CI = 2.3-22.4). For every 10% who were lost to follow-up, the proportion of ED reported increased by 2.3% (95% CI = 0.03-4.7). ED is common regardless of RT modality and increases during each year of follow-up. Using the SHIM, ED is found in approximately 50% patients at 5 years. The strengths of this systematic review include strict inclusion criteria of studies that measured baseline erectile function, no evidence for large effect size bias, and a large number of studies, which allow for modeling techniques. However, all data included in this analysis were observational, which leaves the possibility that residual confounding factors increase the rates of ED. Definitions and measurements of ED after RT vary considerably in published series and could account for variability in the prevalence of reported ED. Loss to follow-up in studies could bias the results to overestimate ED. Gaither TW, Awad MA, Osterberg EC, et al. The Natural History of Erectile Dysfunction After Prostatic Radiotherapy: A Systematic Review and Meta-Analysis. J Sex Med 2017;14:1071-1078. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A critical appraisal of the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing interventions: a systematic review of reviews.

PubMed

Jin, Ying-Hui; Wang, Guo-Hao; Sun, Yi-Rong; Li, Qi; Zhao, Chen; Li, Ge; Si, Jin-Hua; Li, Yan; Lu, Cui; Shang, Hong-Cai

2016-11-14

To assess the methodology and quality of evidence of systematic reviews and meta-analyses of traditional Chinese medical nursing (TCMN) interventions in Chinese journals. These interventions include acupressure, massage, Tai Chi, Qi Gong, electroacupuncture and use of Chinese herbal medicines-for example, in enemas, foot massage and compressing the umbilicus. A systematic literature search for systematic reviews and meta-analyses of TCMN interventions was performed. Review characteristics were extracted. The methodological quality and the quality of the evidence were evaluated using the Assessment of Multiple Systematic Reviews (AMSTAR) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) approaches. We included 20 systematic reviews and meta-analyses, and a total of 11 TCMN interventions were assessed in the 20 reviews. The compliance with AMSTAR checklist items ranged from 4.5 to 8 and systematic reviews/meta-analyses were, on average, of medium methodological quality. The quality of the evidence we assessed ranged from very low to moderate; no high-quality evidence was found. The top two causes for downrating confidence in effect estimates among the 31 bodies of evidence assessed were the risk of bias and inconsistency. There is room for improvement in the methodological quality of systematic reviews/meta-analyses of TCMN interventions published in Chinese journals. Greater efforts should be devoted to ensuring a more comprehensive search strategy, clearer specification of the interventions of interest in the eligibility criteria and identification of meaningful outcomes for clinicians and patients (consumers). The overall quality of evidence among reviews remains suboptimal, which raise concerns about their roles in influencing clinical practice. Thus, the conclusions in reviews we assessed must be treated with caution and their roles in influencing clinical practice should be limited. A critical appraisal of systematic reviews/meta-analyses of TCMN interventions is particularly important to provide sound guidance for TCMN. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Tactical Defenses Against Systematic Variation in Wind Tunnel Testing

NASA Technical Reports Server (NTRS)

DeLoach, Richard

2002-01-01

This paper examines the role of unexplained systematic variation on the reproducibility of wind tunnel test results. Sample means and variances estimated in the presence of systematic variations are shown to be susceptible to bias errors that are generally non-reproducible functions of those variations. Unless certain precautions are taken to defend against the effects of systematic variation, it is shown that experimental results can be difficult to duplicate and of dubious value for predicting system response with the highest precision or accuracy that could otherwise be achieved. Results are reported from an experiment designed to estimate how frequently systematic variations are in play in a representative wind tunnel experiment. These results suggest that significant systematic variation occurs frequently enough to cast doubts on the common assumption that sample observations can be reliably assumed to be independent. The consequences of ignoring correlation among observations induced by systematic variation are considered in some detail. Experimental tactics are described that defend against systematic variation. The effectiveness of these tactics is illustrated through computational experiments and real wind tunnel experimental results. Some tutorial information describes how to analyze experimental results that have been obtained using such quality assurance tactics.

Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range.

PubMed

Wan, Xiang; Wang, Wenqian; Liu, Jiming; Tong, Tiejun

2014-12-19

In systematic reviews and meta-analysis, researchers often pool the results of the sample mean and standard deviation from a set of similar clinical trials. A number of the trials, however, reported the study using the median, the minimum and maximum values, and/or the first and third quartiles. Hence, in order to combine results, one may have to estimate the sample mean and standard deviation for such trials. In this paper, we propose to improve the existing literature in several directions. First, we show that the sample standard deviation estimation in Hozo et al.'s method (BMC Med Res Methodol 5:13, 2005) has some serious limitations and is always less satisfactory in practice. Inspired by this, we propose a new estimation method by incorporating the sample size. Second, we systematically study the sample mean and standard deviation estimation problem under several other interesting settings where the interquartile range is also available for the trials. We demonstrate the performance of the proposed methods through simulation studies for the three frequently encountered scenarios, respectively. For the first two scenarios, our method greatly improves existing methods and provides a nearly unbiased estimate of the true sample standard deviation for normal data and a slightly biased estimate for skewed data. For the third scenario, our method still performs very well for both normal data and skewed data. Furthermore, we compare the estimators of the sample mean and standard deviation under all three scenarios and present some suggestions on which scenario is preferred in real-world applications. In this paper, we discuss different approximation methods in the estimation of the sample mean and standard deviation and propose some new estimation methods to improve the existing literature. We conclude our work with a summary table (an Excel spread sheet including all formulas) that serves as a comprehensive guidance for performing meta-analysis in different situations.

Impacts of climate change on prioritizing conservation areas of hydrological ecosystem services

NASA Astrophysics Data System (ADS)

Lien, Wan Yu; Lin, Yu Pin

2015-04-01

Ecosystem services (ESs) including hydrological services play important roles in our daily life and provide a lot of benefits for human beings from ecological systems. The systems and their services may be threatened by climate change from global to local scales. We herein developed a systematic approach to assess the impacts of climate change on the hydrological ecosystem services, such as water yield, nutrient (nitrogen and phosphorous) retention, and soil retention in a watershed in Northern Taiwan. We first used an ecosystem service evaluation model, InVEST, to estimate the amount and spatial patterns of annual and monthly hydrological ecosystem services under historical weather data, and different climate change scenarios based on five GMSs. The monthly and annual spatiotemporal variations of the ESs were analyzed in this study. Finally, the multiple estimated ESs were considered as the protection conservation targets and regarded as the input data of the systematic conservation planning software, Zonation, to systematically prioritize reserve areas of the ESs under the climate change scenarios. The ES estimation results indicated that the increasing rainfall in wet season leads to the higher water yield and results in the higher sediment and nutrient export indirectly. The Zonation successfully fielded conservation priorities of the ESs. The conservation priorities of the ESs significantly varied spatially and monthly under the climate change scenarios. The ESs results also indicated that the areas where ESs values and conservation priorities with low resilience under climate change should be considered as high priority protected area to ensure the hydrological services in future. Our proposed approach is a novel systematic approach which can be applied to assess impacts of climate change on spatiotemporal variations of ESs as well as prioritize protected area of the ESs under various climate change scenarios. Keyword: climate change, ecosystem service, conservation planning, spatial analysis.

Early onset of magma ocean crystallization revealed by coupled 146,147Sm-142,143Nd systematics of Nulliak ultramafics (3.78 Ga, Labrador)

NASA Astrophysics Data System (ADS)

Morino, P.; Caro, G.; Reisberg, L. C.

2015-12-01

Early onset of magma ocean crystallization revealed by coupled 146,147Sm-142,143Nd systematics of Nulliak ultramafics (3.78 Ga, Labrador) Precillia Morino1, Guillaume Caro1, Laurie Reisberg 1 1CRPG-CNRS, Université de Lorraine, Nancy, France Coupled 146,147Sm-142,143Nd systematics provides constraints on the timing of magma ocean crystallization on Mars, the Moon and Vesta. Estimates for the Earth's mantle, however, are less accurate owing to the sparsity of Eoarchean mantle-derived rocks with undisturbed 147Sm-143Nd systematics. This study attempts to establish a coherent 142,143Nd dataset for the Eoarchean mantle using well-preserved ultramafic rocks from the Nulliak assemblage (Labrador). Samples include meta-dunites, -pyroxenites and -peridotites exhibiting only minor serpentinization and limited element mobility. The presence of "Barberton type" komatiitic compositions (low Al/Ti, HREE depletion) is suggestive of a deep mantle source. 146,147Sm-142,143Nd and 187Re-187Os analyses yield a crystallization age of 3.78±0.09 Ga with ɛ143Ndi=1.5±0.2 and ɛ142Nd=8.6±2 ppm. This 142,143Nd signature yields a model age of mantle differentiation of 4.43±0.05 Ga (assuming a BSE with chondritic Sm/Nd and ɛ142Nd=0). Superchondritic Sm/Nd compositions for the BSE would translate into older model ages. Irrespective of the choice of primitive mantle composition, Nulliak ultramafics provide differentiation ages 100 Ma older than those estimated from Akilia tonalites but remarkably similar to that estimated from the 2.7 Ga Theo's flow (Abitibi). If Nulliak ultramafics originated from deep melting of a hot plume, their model age could reflect the early onset of magma ocean crystallization in the lowermost mantle.

Advancement of Latent Trait Theory.

DTIC Science & Technology

1988-02-01

if I am the principal investigator, I find it practically impossible to include and systematize all the important findings and implications within a...methods are described in [1.21. Two important features of the principal investigator’s approach are the following. (1) It does not assume any specific...were described in the preceding chapter, the maximum likelihood estimate 0 of ability 0 , and also f of the transformed ability r play important roles

A systematic review and content analysis of bullying and cyber-bullying measurement strategies

PubMed Central

Vivolo-Kantor, Alana M.; Martell, Brandi N.; Holland, Kristin M.; Westby, Ruth

2015-01-01

Bullying has emerged as a behavior with deleterious effects on youth; however, prevalence estimates vary based on measurement strategies employed. We conducted a systematic review and content analysis of bullying measurement strategies to gain a better understanding of each strategy including behavioral content. Multiple online databases (i.e., PsychInfo, MedLine, ERIC) were searched to identify measurement strategies published between 1985 and 2012. Included measurement strategies assessed bullying behaviors, were administered to respondents with ages of 12 to 20, were administered in English, and included psychometric data. Each publication was coded independently by two study team members with a pre-set data extraction form, who subsequently met to discuss discrepancies. Forty-one measures were included in the review. A majority used differing terminology; student self-report as primary reporting method; and included verbal forms of bullying in item content. Eleven measures included a definition of bullying, and 13 used the term “bullying” in the measure. Very few definitions or measures captured components of bullying such as repetition, power imbalance, aggression, and intent to harm. Findings demonstrate general inconsistency in measurement strategies on a range of issues, thus, making comparing prevalence rates between measures difficult. PMID:26752229

Psychosocial Risk Factors and the Association With Carpal Tunnel Syndrome: A Systematic Review.

PubMed

Mansfield, Michael; Thacker, Michael; Sandford, Fiona

2017-10-01

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy of the upper limb. Research has shown that associative factors for CTS include occupational and biomechanical elements, gender, and age. To date, no systematic review has been undertaken to determine specifically whether there are any psychosocial risk factors in developing CTS. The objective is to determine whether psychosocial factors are associated with and/or predict the development of CTS. A systematic review was conducted including searches of PubMed (MEDLINE), EMBASE, and CINAHL from inception to May 30, 2017. Quantitative studies must have investigated a minimum of 1 or more psychosocial factors-cognitive, affective, behavioral, vocational, or interpersonal processes (eg, social support)-and include a point or risk estimate. One reviewer conducted the search and 2 reviewers independently assessed eligibility and completed methodological quality assessment using a modified Downs and Black checklist. Data were analyzed narratively. Six moderate- to high-quality studies were included in the final review. Five studies reported a positive association between psychosocial factors and CTS, where psychosocial factors were more in those who reported CTS. One study reported no positive or negative association with CTS development. Four studies reported a negative association between psychosocial factors and CTS, where psychosocial factors were less in those who reported CTS. There is limited evidence for a positive association between psychosocial factors and CTS. However, this was not a consistent finding across all included studies. Further research is indicated in standardizing CTS diagnostic criteria and investigating other working environments.

Evidence-based mapping of design heterogeneity prior to meta-analysis: a systematic review and evidence synthesis.

PubMed

Althuis, Michelle D; Weed, Douglas L; Frankenfeld, Cara L

2014-07-23

Assessment of design heterogeneity conducted prior to meta-analysis is infrequently reported; it is often presented post hoc to explain statistical heterogeneity. However, design heterogeneity determines the mix of included studies and how they are analyzed in a meta-analysis, which in turn can importantly influence the results. The goal of this work is to introduce ways to improve the assessment and reporting of design heterogeneity prior to statistical summarization of epidemiologic studies. In this paper, we use an assessment of sugar-sweetened beverages (SSB) and type 2 diabetes (T2D) as an example to show how a technique called 'evidence mapping' can be used to organize studies and evaluate design heterogeneity prior to meta-analysis.. Employing a systematic and reproducible approach, we evaluated the following elements across 11 selected cohort studies: variation in definitions of SSB, T2D, and co-variables, design features and population characteristics associated with specific definitions of SSB, and diversity in modeling strategies. Evidence mapping strategies effectively organized complex data and clearly depicted design heterogeneity. For example, across 11 studies of SSB and T2D, 7 measured diet only once (with 7 to 16 years of disease follow-up), 5 included primarily low SSB consumers, and 3 defined the study variable (SSB) as consumption of either sugar or artificially-sweetened beverages. This exercise also identified diversity in analysis strategies, such as adjustment for 11 to 17 co-variables and a large degree of fluctuation in SSB-T2D risk estimates depending on variables selected for multivariable models (2 to 95% change in the risk estimate from the age-adjusted model). Meta-analysis seeks to understand heterogeneity in addition to computing a summary risk estimate. This strategy effectively documents design heterogeneity, thus improving the practice of meta-analysis by aiding in: 1) protocol and analysis planning, 2) transparent reporting of differences in study designs, and 3) interpretation of pooled estimates. We recommend expanding the practice of meta-analysis reporting to include a table that summarizes design heterogeneity. This would provide readers with more evidence to interpret the summary risk estimates.

Evidence-based mapping of design heterogeneity prior to meta-analysis: a systematic review and evidence synthesis

PubMed Central

2014-01-01

Background Assessment of design heterogeneity conducted prior to meta-analysis is infrequently reported; it is often presented post hoc to explain statistical heterogeneity. However, design heterogeneity determines the mix of included studies and how they are analyzed in a meta-analysis, which in turn can importantly influence the results. The goal of this work is to introduce ways to improve the assessment and reporting of design heterogeneity prior to statistical summarization of epidemiologic studies. Methods In this paper, we use an assessment of sugar-sweetened beverages (SSB) and type 2 diabetes (T2D) as an example to show how a technique called ‘evidence mapping’ can be used to organize studies and evaluate design heterogeneity prior to meta-analysis.. Employing a systematic and reproducible approach, we evaluated the following elements across 11 selected cohort studies: variation in definitions of SSB, T2D, and co-variables, design features and population characteristics associated with specific definitions of SSB, and diversity in modeling strategies. Results Evidence mapping strategies effectively organized complex data and clearly depicted design heterogeneity. For example, across 11 studies of SSB and T2D, 7 measured diet only once (with 7 to 16 years of disease follow-up), 5 included primarily low SSB consumers, and 3 defined the study variable (SSB) as consumption of either sugar or artificially-sweetened beverages. This exercise also identified diversity in analysis strategies, such as adjustment for 11 to 17 co-variables and a large degree of fluctuation in SSB-T2D risk estimates depending on variables selected for multivariable models (2 to 95% change in the risk estimate from the age-adjusted model). Conclusions Meta-analysis seeks to understand heterogeneity in addition to computing a summary risk estimate. This strategy effectively documents design heterogeneity, thus improving the practice of meta-analysis by aiding in: 1) protocol and analysis planning, 2) transparent reporting of differences in study designs, and 3) interpretation of pooled estimates. We recommend expanding the practice of meta-analysis reporting to include a table that summarizes design heterogeneity. This would provide readers with more evidence to interpret the summary risk estimates. PMID:25055879

The Estimated Annual Cost of Uterine Leiomyomata in the United States

PubMed Central

CARDOZO, Eden R.; CLARK, Andrew D.; BANKS, Nicole K.; HENNE, Melinda B.; STEGMANN, Barbara J.; SEGARS, James H.

2011-01-01

Objective To estimate the total annual societal cost of uterine fibroids in the United States, based on direct and indirect costs, including associated obstetric complications. Study Design A systematic review of the literature was conducted to estimate the number of women seeking treatment for symptomatic fibroids annually, the costs of medical and surgical treatment, work lost and obstetric complications attributable to fibroids. Total annual costs were converted to 2010 U.S. dollars. A sensitivity analysis was performed. Results The estimated annual direct costs (surgery, hospital admissions, outpatient visits, medications) were $4.1 to $9.4 billion. Estimated lost work costs ranged from $1.55 to $17.2 billion annually. Obstetric outcomes attributed to fibroids resulted in a cost of $238 million to $7.76 billion annually. Uterine fibroids were estimated to cost the US $5.9 to $34.4 billion annually. Conclusions Obstetric complications associated with fibroids contributed significantly to their economic burden. Lost work costs may account for the largest proportion of societal costs due to fibroids. PMID:22244472

A Functional Varying-Coefficient Single-Index Model for Functional Response Data

PubMed Central

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2016-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. PMID:29200540

A Functional Varying-Coefficient Single-Index Model for Functional Response Data.

PubMed

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2017-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer's Disease Neuroimaging Initiative (ADNI) study.

Cost-Utility Analysis of Screening Strategies for Diabetic Retinopathy in Korea.

PubMed

Kim, Sang-Won; Kang, Gil-Won

2015-12-01

This study involved a cost-utility analysis of early diagnosis and treatment of diabetic retinopathy depending on the screening strategy used. The four screening strategies evaluated were no screening, opportunistic examination, systematic fundus photography, and systematic examination by an ophthalmologists. Each strategy was evaluated in 10,000 adults aged 40 yr with newly diagnosed diabetes mellitus (hypothetical cohort). The cost of each strategy was estimated in the perspective of both payer and health care system. The utility was estimated using quality-adjusted life years (QALY). Incremental Cost Effectiveness Ratio (ICER) for the different screening strategies was analyzed. After exclusion of the weakly dominating opportunistic strategy, the ICER of systematic photography was 57,716,867 and that of systematic examination by ophthalmologists was 419,989,046 from the perspective of the healthcare system. According to the results, the systematic strategy is preferable to the opportunistic strategy from the perspective of both a payer and a healthcare system. Although systematic examination by ophthalmologists may have higher utility than systematic photography, it is associated with higher cost. The systematic photography is the best strategy in terms of cost-utility. However systematic examination by ophthalmologists can also be a suitable policy alternative, if the incremental cost is socially acceptable.

A systematic review of neonatal treatment intensity scores and their potential application in low-resource setting hospitals for predicting mortality, morbidity and estimating resource use.

PubMed

Aluvaala, Jalemba; Collins, Gary S; Maina, Michuki; Berkley, James A; English, Mike

2017-12-07

Treatment intensity scores can predict mortality and estimate resource use. They may therefore be of interest for essential neonatal care in low resource settings where neonatal mortality remains high. We sought to systematically review neonatal treatment intensity scores to (1) assess the level of evidence on predictive performance in predicting clinical outcomes and estimating resource utilisation and (2) assess the applicability of the identified models to decision making for neonatal care in low resource settings. We conducted a systematic search of PubMed, EMBASE (OVID), CINAHL, Global Health Library (Global index, WHO) and Google Scholar to identify studies published up until 21 December 2016. Included were all articles that used treatments as predictors in neonatal models. Individual studies were appraised using the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies (CHARMS). In addition, Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used as a guiding framework to assess certainty in the evidence for predicting outcomes across studies. Three thousand two hundred forty-nine articles were screened, of which ten articles were included in the review. All of the studies were conducted in neonatal intensive care units with sample sizes ranging from 22 to 9978, with a median of 163. Two articles reported model development, while eight reported external application of existing models to new populations. Meta-analysis was not possible due heterogeneity in the conduct and reporting of the identified studies. Discrimination as assessed by area under receiver operating characteristic curve was reported for in-hospital mortality, median 0.84 (range 0.75-0.96, three studies), early adverse outcome and late adverse outcome (0.78 and 0.59, respectively, one study). Existing neonatal treatment intensity models show promise in predicting mortality and morbidity. There is however low certainty in the evidence on their performance in essential neonatal care in low resource settings as all studies had methodological limitations and were conducted in intensive care. The approach may however be developed further for low resource settings like Kenya because treatment data may be easier to obtain compared to measures of physiological status. PROSPERO CRD42016034205.

Systematic detection of long-term slow slip events along Hyuga-nada to central Shikoku, Nankai subduction zone, using GNSS data

NASA Astrophysics Data System (ADS)

Takagi, R.; Obara, K.; Uchida, N.

2017-12-01

Understanding slow earthquake activity improves our knowledge of slip behavior in brittle-ductile transition zone and subduction process including megathrust earthquakes. In order to understand overall picture of slow slip activity, it is important to make a comprehensive catalog of slow slip events (SSEs). Although short-term SSEs have been detected by GNSS and tilt meter records systematically, analysis of long-term slow slip events relies on individual slip inversions. We develop an algorism to systematically detect long-term SSEs and estimate source parameters of the SSEs using GNSS data. The algorism is similar to GRiD-MT (Tsuruoka et al., 2009), which is grid-based automatic determination of moment tensor solution. Instead of moment tensor fitting to long period seismic records, we estimate parameters of a single rectangle fault to fit GNSS displacement time series. First, we make a two dimensional grid covering possible location of SSE. Second, we estimate best-fit parameters (length, width, slip, and rake) of the rectangle fault at each grid point by an iterative damped least square method. Depth, strike, and dip are fixed on the plate boundary. Ramp function with duration of 300 days is used for expressing time evolution of the fault slip. Third, a grid maximizing variance reduction is selected as a candidate of long-term SSE. We also search onset of ramp function based on the grid search. We applied the method to GNSS data in southwest Japan to detect long-term SSEs in Nankai subduction zone. With current selection criteria, we found 13 events with Mw6.2-6.9 in Hyuga-nada, Bungo channel, and central Shikoku from 1998 to 2015, which include unreported events. Key finding is along strike migrations of long-term SSEs from Hyuga-nada to Bungo channel and from Bungo channel to central Shikoku. In particular, three successive events migrating northward in Hyuga-nada preceded the 2003 Bungo channel SSE, and one event in central Shikoku followed the 2003 SSE in Bungo channel. The space-time dimensions of the possible along-strike migration are about 300km in length and 6 years in time. Systematic detection with assumptions of various durations in the time evolution of SSE may improve the picture of SSE activity and possible interaction with neighboring SSEs.

A systematic review found that deviations from intention-to-treat are common in randomized trials and systematic reviews.

PubMed

Abraha, Iosief; Cozzolino, Francesco; Orso, Massimiliano; Marchesi, Mauro; Germani, Antonella; Lombardo, Guido; Eusebi, Paolo; De Florio, Rita; Luchetta, Maria Laura; Iorio, Alfonso; Montedori, Alessandro

2017-04-01

To describe the characteristics, and estimate the incidence, of trials included in systematic reviews deviating from the intention-to-treat (ITT) principle. A 5% random sample of reviews were selected (Medline 2006-2010). Trials from reviews were classified based on the ITT: (1) ITT trials (trials reporting standard ITT analyses); (2) modified ITT (mITT) trials (modified ITT; trials deviating from standard ITT); or (3) no ITT trials. Of 222 reviews, 81 (36%) included at least one mITT trial. Reviews with mITT trials were more likely to contain trials that used placebo, that investigated drugs, and that reported favorable results. The incidence of reviews with mITT trial ranged from 29% (17/58) to 48% (23/48). Of the 2,349 trials, 597 (25.4%) were classified as ITT trials, 323 (13.8%) as mITT trials, and 1,429 (60.8%) as no ITT trials. The mITT trials were more likely to have reported exclusions compared to studies classified as ITT trials and to have received funding. The reporting of the type of ITT may differ according to the clinical area and the type of intervention. Deviation from ITT in randomized controlled trials is a widespread phenomenon that significantly affects systematic reviews. Copyright © 2017 Elsevier Inc. All rights reserved.

Prevalence of PTSD and common mental disorders amongst ambulance personnel: a systematic review and meta-analysis.

PubMed

Petrie, Katherine; Milligan-Saville, Josie; Gayed, Aimée; Deady, Mark; Phelps, Andrea; Dell, Lisa; Forbes, David; Bryant, Richard A; Calvo, Rafael A; Glozier, Nicholas; Harvey, Samuel B

2018-06-05

There is increasing concern regarding the mental health impact of first responder work, with some reports suggesting ambulance personnel may be at particularly high risk. Through this systematic review and meta-analysis we aimed to determine the prevalence of mental health conditions among ambulance personnel worldwide. A systematic search and screening process was conducted to identify studies for inclusion in the review. To be eligible, studies had to report original quantitative data on the prevalence of at least one of the following mental health outcome(s) of interest (PTSD, depression, anxiety, general psychological distress) for ambulance personnel samples. Quality of the studies was assessed using a validated methodological rating tool. Random effects modelling was used to estimate pooled prevalence, as well as subgroup analyses and meta-regressions for five variables implicated in heterogeneity. In total, 941 articles were identified across all sources, with 95 full-text articles screened to confirm eligibility. Of these, 27 studies were included in the systematic review, reporting on a total of 30,878 ambulance personnel. A total of 18 studies provided necessary quantitative information and were retained for entry in the meta-analysis. The results demonstrated estimated prevalence rates of 11% for PTSD, 15% for depression, 15% for anxiety, and 27% for general psychological distress amongst ambulance personnel, with date of data collection a significant influence upon observed heterogeneity. Ambulance personnel worldwide have a prevalence of PTSD considerably higher than rates seen in the general population, although there is some evidence that rates of PTSD may have decreased over recent decades.

Determination of the influence of dispersion pattern of pesticide-resistant individuals on the reliability of resistance estimates using different sampling plans.

PubMed

Shah, R; Worner, S P; Chapman, R B

2012-10-01

Pesticide resistance monitoring includes resistance detection and subsequent documentation/ measurement. Resistance detection would require at least one (≥1) resistant individual(s) to be present in a sample to initiate management strategies. Resistance documentation, on the other hand, would attempt to get an estimate of the entire population (≥90%) of the resistant individuals. A computer simulation model was used to compare the efficiency of simple random and systematic sampling plans to detect resistant individuals and to document their frequencies when the resistant individuals were randomly or patchily distributed. A patchy dispersion pattern of resistant individuals influenced the sampling efficiency of systematic sampling plans while the efficiency of random sampling was independent of such patchiness. When resistant individuals were randomly distributed, sample sizes required to detect at least one resistant individual (resistance detection) with a probability of 0.95 were 300 (1%) and 50 (10% and 20%); whereas, when resistant individuals were patchily distributed, using systematic sampling, sample sizes required for such detection were 6000 (1%), 600 (10%) and 300 (20%). Sample sizes of 900 and 400 would be required to detect ≥90% of resistant individuals (resistance documentation) with a probability of 0.95 when resistant individuals were randomly dispersed and present at a frequency of 10% and 20%, respectively; whereas, when resistant individuals were patchily distributed, using systematic sampling, a sample size of 3000 and 1500, respectively, was necessary. Small sample sizes either underestimated or overestimated the resistance frequency. A simple random sampling plan is, therefore, recommended for insecticide resistance detection and subsequent documentation.

Community-Based Prevalence of Genital Human Papilloma Virus (HPV) Infection: a Systematic Review and Meta-Analysis

PubMed Central

Sabeena, Sasidharanpillai; Bhat, Parvati V; Kamath, Veena; Bhat, Shashikala K; Nair, Sreekumaran; N, Ravishankar; Chandrabharani, Kiran; Arunkumar, Govindakarnavar

2017-01-01

Introduction: Cervical cancer probably represents the best-studied human cancer caused by a viral infection and the causal association of this preventable cancer with human papilloma virus (HPV) is well established. Worldwide there is a scarcity of data regarding HPV prevalence with vast differences existing among populations. Objective: The aim of this meta-analysis was to determine the community-based HPV prevalence estimates among asymptomatic women from urban and rural set ups and in participants of cancer screening clinics. Study design: Systematic review and meta-analysis. Methods: PubMed-Medline, CINAHL, Scopus, and Google scholar were systematically searched for studies providing prevalence data for HPV infection among asymptomatic women between 1986 and 2016. Results: The final analysis included 32 studies comprising a population of 224,320 asymptomatic women. The overall pooled HPV prevalence was 11% (95% confidence interval (CI), 9%-12%). The pooled HPV prevalence of 11% (95% CI, 9%-11%) was observed among women attending cervical cancer screening clinics. The pooled HPV prevalences were 10% (95% CI 8%-12%) and 11% (95% CI 4%-18%) from urban and rural areas respectively, indicating higher infection rates among the rural women with the least access to cancer screening and cancer care. Conclusion: The prevalence rates in this systematic quantitative review provide a reliable estimate of the burden of HPV infection among asymptomatic women from developed as well as developing nations. Rural women and women attending cervical cancer screening programmes feature higher genital HPV prevalences compared to their urban counterparts. PMID:28240509

Community-Based Prevalence of Genital Human Papilloma Virus (HPV) Infection: a Systematic Review and Meta-Analysis

PubMed

Sabeena, Sasidharanpillai; Bhat, Parvati V; Kamath, Veena; Bhat, Shashikala K; Nair, Sreekumaran; n, Ravishankar; Chandrabharani, Kiran; Arunkumar, Govindakarnavar

2017-01-01

Introduction: Cervical cancer probably represents the best-studied human cancer caused by a viral infection and the causal association of this preventable cancer with human papilloma virus (HPV) is well established. Worldwide there is a scarcity of data regarding HPV prevalence with vast differences existing among populations. Objective: The aim of this meta-analysis was to determine the community-based HPV prevalence estimates among asymptomatic women from urban and rural set ups and in participants of cancer screening clinics. Study design: Systematic review and meta-analysis. Methods: PubMed-Medline, CINAHL, Scopus, and Google scholar were systematically searched for studies providing prevalence data for HPV infection among asymptomatic women between 1986 and 2016. Results: The final analysis included 32 studies comprising a population of 224,320 asymptomatic women. The overall pooled HPV prevalence was 11% (95% confidence interval (CI), 9%-12%). The pooled HPV prevalence of 11% (95% CI, 9%-11%) was observed among women attending cervical cancer screening clinics. The pooled HPV prevalences were 10% (95% CI 8%-12%) and 11% (95% CI 4%-18%) from urban and rural areas respectively, indicating higher infection rates among the rural women with the least access to cancer screening and cancer care. Conclusion: The prevalence rates in this systematic quantitative review provide a reliable estimate of the burden of HPV infection among asymptomatic women from developed as well as developing nations. Rural women and women attending cervical cancer screening programmes feature higher genital HPV prevalences compared to their urban counterparts. Creative Commons Attribution License

Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized.

PubMed

Saleh, Ahlam A; Ratajeski, Melissa A; Bertolet, Marnie

To identify estimates of time taken to search grey literature in support of health sciences systematic reviews and to identify searcher or systematic review characteristics that may impact resource selection or time spent searching. A survey was electronically distributed to searchers embarking on a new systematic review. Characteristics of the searcher and systematic review were collected along with time spent searching and what resources were searched. Time and resources were tabulated and resources were categorized as grey or non-grey. Data was analyzed using Kruskal-Wallis tests. Out of 81 original respondents, 21% followed through with completion of the surveys in their entirety. The median time spent searching all resources was 471 minutes, and of those a median of 85 minutes were spent searching grey literature. The median number of resources used in a systematic review search was four and the median number of grey literature sources searched was two. The amount of time spent searching was influenced by whether the systematic review was grant funded. Additionally, the number of resources searched was impacted by institution type and whether systematic review training was received. This study characterized the amount of time for conducting systematic review searches including searching the grey literature, in addition to the number and types of resources used. This may aid searchers in planning their time, along with providing benchmark information for future studies. This paper contributes by quantifying current grey literature search patterns and associating them with searcher and review characteristics. Further discussion and research into the search approach for grey literature in support of systematic reviews is encouraged.

Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized

PubMed Central

Saleh, Ahlam A.; Ratajeski, Melissa A.; Bertolet, Marnie

2015-01-01

Objective To identify estimates of time taken to search grey literature in support of health sciences systematic reviews and to identify searcher or systematic review characteristics that may impact resource selection or time spent searching. Methods A survey was electronically distributed to searchers embarking on a new systematic review. Characteristics of the searcher and systematic review were collected along with time spent searching and what resources were searched. Time and resources were tabulated and resources were categorized as grey or non-grey. Data was analyzed using Kruskal-Wallis tests. Results Out of 81 original respondents, 21% followed through with completion of the surveys in their entirety. The median time spent searching all resources was 471 minutes, and of those a median of 85 minutes were spent searching grey literature. The median number of resources used in a systematic review search was four and the median number of grey literature sources searched was two. The amount of time spent searching was influenced by whether the systematic review was grant funded. Additionally, the number of resources searched was impacted by institution type and whether systematic review training was received. Conclusions This study characterized the amount of time for conducting systematic review searches including searching the grey literature, in addition to the number and types of resources used. This may aid searchers in planning their time, along with providing benchmark information for future studies. This paper contributes by quantifying current grey literature search patterns and associating them with searcher and review characteristics. Further discussion and research into the search approach for grey literature in support of systematic reviews is encouraged. PMID:25914722

How much is the cost of multiple sclerosis--systematic literature review.

PubMed

Kolasa, Katarzyna

2013-01-01

In Poland, a data on MS costs is lacking. The systematic review of cost of illness studies was conducted to estimate the average annual cost of MS patient and its breakdown. The PubMed database was searched for relevant literature. Following search criteria were used: "multiple sclerosis", "costs", "cost of illness" and "disease burden". Articles written in English including total costs published 2002-2012 were included. In total 17 studies were classified. The costs were re-calculated into USD Purchasing Power Parity (PPP). The available approach from the literature was used for the cost breakdown presentation. The average patient was 47 years old with EDSS equals 4 and 13 years from the date of diagnosis. The average annual cost was 41 133 US$ PPP. The direct costs did not exceed 70% of total costs in any study. The pharmaceutical expenses were one of the most important contributors to the direct costs. Only 40% of patients were active on the labor market what translated into the loss of productivity and consequently an increase in total costs. The preformed systematic review revealed that multiple sclerosis imposes a huge economic burden on the healthcare system and society. It happens due to productivity loss and caregiver burden.

Effectiveness of wearable defibrillators: systematic review and quality of evidence.

PubMed

Uyei, Jennifer; Braithwaite, R Scott

2014-04-01

The objectives of this systematic literature review were to identify all published literature on wearable defibrillators, assess the wearable defibrillator's efficacy and effectiveness in general and among specific patient groups, including post-myocardial infarction, post coronary artery bypass grafting or percutaneous coronary intervention, non-ischemic cardiomyopathy, and ischemic cardiomyopathy, and to evaluate the quality of evidence. The search and synthesis was informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and the quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation and the Newcastle Ottawa Scale. A total of thirty-six articles and conference abstracts from thirty-three studies were included in the review. It appears that wearable defibrillator use compared with no defibrillator use reduces the chance of ventricular tachycardia and ventricular fibrillation (VT/VF) associated deaths by an absolute risk reduction of approximately 1 percent, achieved by averting approximately 4/5th of all VT/VF associated deaths. The quality of evidence was low to very low quality, such that our confidence in the reported estimates is weak. To validate beneficial results, further investigation using robust study designs conducted by independent researchers is warranted.

Breastfeeding and intelligence: a systematic review and meta-analysis.

PubMed

Horta, Bernardo L; Loret de Mola, Christian; Victora, Cesar G

2015-12-01

This study was aimed at systematically reviewing evidence of the association between breastfeeding and performance in intelligence tests. Two independent searches were carried out using Medline, LILACS, SCIELO and Web of Science. Studies restricted to infants and those where estimates were not adjusted for stimulation or interaction at home were excluded. Fixed- and random-effects models were used to pool the effect estimates, and a random-effects regression was used to assess potential sources of heterogeneity. We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model, breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression, none of the study characteristics explained the heterogeneity among the studies. Breastfeeding is related to improved performance in intelligence tests. A positive effect of breastfeeding on cognition was also observed in a randomised trial. This suggests that the association is causal. ©2015 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.

Evaluation and Application of Satellite-Based Latent Heating Profile Estimation Methods

NASA Technical Reports Server (NTRS)

Olson, William S.; Grecu, Mircea; Yang, Song; Tao, Wei-Kuo

2004-01-01

In recent years, methods for estimating atmospheric latent heating vertical structure from both passive and active microwave remote sensing have matured to the point where quantitative evaluation of these methods is the next logical step. Two approaches for heating algorithm evaluation are proposed: First, application of heating algorithms to synthetic data, based upon cloud-resolving model simulations, can be used to test the internal consistency of heating estimates in the absence of systematic errors in physical assumptions. Second, comparisons of satellite-retrieved vertical heating structures to independent ground-based estimates, such as rawinsonde-derived analyses of heating, provide an additional test. The two approaches are complementary, since systematic errors in heating indicated by the second approach may be confirmed by the first. A passive microwave and combined passive/active microwave heating retrieval algorithm are evaluated using the described approaches. In general, the passive microwave algorithm heating profile estimates are subject to biases due to the limited vertical heating structure information contained in the passive microwave observations. These biases may be partly overcome by including more environment-specific a priori information into the algorithm s database of candidate solution profiles. The combined passive/active microwave algorithm utilizes the much higher-resolution vertical structure information provided by spaceborne radar data to produce less biased estimates; however, the global spatio-temporal sampling by spaceborne radar is limited. In the present study, the passive/active microwave algorithm is used to construct a more physically-consistent and environment-specific set of candidate solution profiles for the passive microwave algorithm and to help evaluate errors in the passive algorithm s heating estimates. Although satellite estimates of latent heating are based upon instantaneous, footprint- scale data, suppression of random errors requires averaging to at least half-degree resolution. Analysis of mesoscale and larger space-time scale phenomena based upon passive and passive/active microwave heating estimates from TRMM, SSMI, and AMSR data will be presented at the conference.

An analysis of empirical estimates of sexual aggression victimization and perpetration.

PubMed

Spitzberg, B H

1999-01-01

Estimates of prevalence for several categories of sexual coercion, including rape and attempted rape, were statistically aggregated across 120 studies, involving over 100,000 subjects. According to the data, almost 13% of women and over 3% of men have been raped, and almost 5% of men claim to have perpetrated rape. In contrast, about 25% of women and men claim to have been sexually coerced and to have perpetrated sexual coercion. In general, the mediating variables examined--population type, decade, date of publication, and type of operationalization--were not consistently related to rates of victimization or perpetration. Nevertheless, the extensive variation among study estimates strongly suggests the possibility of systematic sources of variation that have yet to be identified. Further analyses are called for to disentangle such sources.

Conducting systematic reviews of economic evaluations.

PubMed

Gomersall, Judith Streak; Jadotte, Yuri Tertilus; Xue, Yifan; Lockwood, Suzi; Riddle, Dru; Preda, Alin

2015-09-01

In 2012, a working group was established to review and enhance the Joanna Briggs Institute (JBI) guidance for conducting systematic review of evidence from economic evaluations addressing a question(s) about health intervention cost-effectiveness. The objective is to present the outcomes of the working group. The group conducted three activities to inform the new guidance: review of literature on the utility/futility of systematic reviews of economic evaluations and consideration of its implications for updating the existing methodology; assessment of the critical appraisal tool in the existing guidance against criteria that promotes validity in economic evaluation research and two other commonly used tools; and a workshop. The debate in the literature on the limitations/value of systematic review of economic evidence cautions that systematic reviews of economic evaluation evidence are unlikely to generate one size fits all answers to questions about the cost-effectiveness of interventions and their comparators. Informed by this finding, the working group adjusted the framing of the objectives definition in the existing JBI methodology. The shift is away from defining the objective as to determine one cost-effectiveness measure toward summarizing study estimates of cost-effectiveness and informed by consideration of the included study characteristics (patient, setting, intervention component, etc.), identifying conditions conducive to lowering costs and maximizing health benefits. The existing critical appraisal tool was included in the new guidance. The new guidance includes the recommendation that a tool designed specifically for the purpose of appraising model-based studies be used together with the generic appraisal tool for economic evaluations assessment to evaluate model-based evaluations. The guidance produced by the group offers reviewers guidance for each step of the systematic review process, which are the same steps followed in JBI reviews of other types of evidence. The updated JBI guidance will be useful for researchers wanting to synthesize evidence about economic questions, either as stand-alone reviews or part of comprehensive or mixed method evidence reviews. Although the updated methodology produced by the work of the working group has improved the JBI guidance for systematic reviews of economic evaluations, there are areas where further work is required. These include adjusting the critical appraisal tool to separate out questions addressing intervention cost and effectiveness measurement; providing more explicit guidance for assessing generalizability of findings; and offering a more robust method for evidence synthesis that facilitates achieving the more ambitious review objectives.

Illness burden and physical outcomes associated with collaborative care in patients with comorbid depressive disorder in chronic medical conditions: A systematic review and meta-analysis.

PubMed

van Eck van der Sluijs, Jonna F; Castelijns, Hilde; Eijsbroek, Vera; Rijnders, Cees A Th; van Marwijk, Harm W J; van der Feltz-Cornelis, Christina M

Collaborative care (CC) improves depressive symptoms in people with comorbid depressive disorder in chronic medical conditions, but its effect on physical symptoms has not yet systematically been reviewed. This study aims to do so. Systematic review and meta-analysis was conducted using PubMed, the Cochrane Library, and the European and US Clinical Trial Registers. Eligible studies included randomized controlled trials (RCTs) of CC compared to care as usual (CAU), in primary care and general hospital setting, reporting on physical and depressive symptoms as outcomes. Overall treatment effects were estimated for illness burden, physical outcomes and depression, respectively. Twenty RCTs were included, with N=4774 patients. The overall effect size of CC versus CAU for illness burden was OR 1.64 (95%CI 1.47;1.83), d=0.27 (95%CI 0.21;0.33). Best physical outcomes in CC were found for hypertension with comorbiddepression. Overall, depression outcomes were better for CC than for CAU. Moderator analyses did not yield statistically significant differences. CC is more effective than CAU in terms of illness burden, physical outcomes and depression, in patients with comorbid depression in chronic medical conditions. More research covering multiple medical conditions is needed. The protocol for this systematic review and meta-analysis has been registered at the International Prospective Register of Systematic Reviews (PROSPERO) on February 19th 2016: http://www.crd.york.ac.uk/PROSPERO/DisplayPDF.php?ID=CRD42016035553. Copyright © 2017 Elsevier Inc. All rights reserved.

Network Structure and Travel Time Perception

PubMed Central

Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

2013-01-01

The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time. PMID:24204932

Multilevel models for estimating incremental net benefits in multinational studies.

PubMed

Grieve, Richard; Nixon, Richard; Thompson, Simon G; Cairns, John

2007-08-01

Multilevel models (MLMs) have been recommended for estimating incremental net benefits (INBs) in multicentre cost-effectiveness analysis (CEA). However, these models have assumed that the INBs are exchangeable and that there is a common variance across all centres. This paper examines the plausibility of these assumptions by comparing various MLMs for estimating the mean INB in a multinational CEA. The results showed that the MLMs that assumed the INBs were exchangeable and had a common variance led to incorrect inferences. The MLMs that included covariates to allow for systematic differences across the centres, and estimated different variances in each centre, made more plausible assumptions, fitted the data better and led to more appropriate inferences. We conclude that the validity of assumptions underlying MLMs used in CEA need to be critically evaluated before reliable conclusions can be drawn. Copyright 2006 John Wiley & Sons, Ltd.

Population prevalence and distribution of ankle pain and symptomatic radiographic ankle osteoarthritis in community dwelling older adults: A systematic review and cross-sectional study

PubMed Central

Murray, Charlotte; Rathod, Trishna; Bowen, Catherine J.; Menz, Hylton B.; Roddy, Edward

2018-01-01

Objectives To identify by systematic review published prevalence estimates of radiographic ankle osteoarthritis (OA) and to subsequently estimate the prevalence of ankle pain and symptomatic, radiographic ankle OA within community-dwelling older adults from North Staffordshire, UK. Methods Electronic databases were searched using terms for ankle, osteoarthritis and radiography. Data regarding population, radiographic methods, definitions and prevalence estimates of ankle OA were extracted from papers meeting predetermined selection criteria. Adults aged ≥50 years and registered with four general practices in North Staffordshire were mailed a health questionnaire. Ankle pain in the previous month was determined using a foot and ankle pain manikin. Respondents reporting pain in or around the foot in the last 12 months were invited to attend a research clinic where weight-bearing, antero-posterior and lateral ankle radiographs were obtained and scored for OA using a standardised atlas. Prevalence estimates for ankle pain and symptomatic, radiographic ankle OA were calculated using multiple imputation and weighted logistic regression, and stratified by age, gender and socioeconomic status. Results Eighteen studies were included in the systematic review. The methods of radiographic classification of ankle OA were poorly reported and showed heterogeneity. No true general population prevalence estimates of radiographic ankle OA were found, estimates in select sporting and medical community-dwelling populations ranged from 0.0–97.1%. 5109 participants responded to the health survey questionnaire (adjusted response 56%). Radiographs were obtained in 557 participants. The prevalence of ankle pain was 11.7% (10.8,12.6) and symptomatic, radiographic ankle OA grade≥2 was 3.4% (2.3, 4.5) (grade≥1: 8.8% (7.9,9.8); grade = 3: 1.9% (1.0,2.7). Prevalence was higher in females, younger adults (50–64 years) and those with routine/manual occupations. Conclusion No general population prevalence estimates of radiographic ankle OA were identified in the published literature. Our prevalence study found that ankle pain was common in community-dwelling older adults, whereas moderate to severe symptomatic, radiographic ankle OA occurred less frequently. Further investigations of the prevalence of ankle OA using more sensitive imaging modalities are warranted. PMID:29708977

Impact of the galactic acceleration on the terrestrial reference frame and the scale factor in VLBI

NASA Astrophysics Data System (ADS)

Krásná, Hana; Titov, Oleg

2017-04-01

The relative motion of the solar system barycentre around the galactic centre can also be described as an acceleration of the solar system directed towards the centre of the Galaxy. So far, this effect has been omitted in the a priori modelling of the Very Long Baseline Interferometry (VLBI) observable. Therefore, it results in a systematic dipole proper motion (Secular Aberration Drift, SAD) of extragalactic radio sources building the celestial reference frame with a theoretical maximum magnitude of 5-7 microarcsec/year. In this work, we present our estimation of the SAD vector obtained within a global adjustment of the VLBI measurements (1979.0 - 2016.5) using the software VieVS. We focus on the influence of the observed radio sources with the maximum SAD effect on the terrestrial reference frame. We show that the scale factor from the VLBI measurements estimated for each source individually discloses a clear systematic aligned with the direction to the Galactic centre-anticentre. Therefore, the radio sources located near Galactic anticentre may cause a strong systematic effect, especially, in early VLBI years. For instance, radio source 0552+398 causes a difference up to 1 mm in the estimated baseline length. Furthermore, we discuss the scale factor estimated for each radio source after removal of the SAD systematic.

Outcomes following severe hand foot and mouth disease: A systematic review and meta-analysis.

PubMed

Jones, Eben; Pillay, Timesh D; Liu, Fengfeng; Luo, Li; Bazo-Alvarez, Juan Carlos; Yuan, Chen; Zhao, Shanlu; Chen, Qi; Li, Yu; Liao, Qiaohong; Yu, Hongjie; Rogier van Doorn, H; Sabanathan, Saraswathy

2018-04-20

Hand, foot and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) is associated with acute neurological disease in children. This study aimed to estimate the burden of long-term sequelae and death following severe HFMD. This systematic review and meta-analysis pooled all reports from English and Chinese databases including MEDLINE and Wangfang on outbreaks of clinically diagnosed HFMD and/or laboratory-confirmed EV-A71 with at least 7 days' follow-up published between 1st January 1966 and 19th October 2015. Two independent reviewers assessed the literature. We used a random effects meta-analysis to estimate cumulative incidence of neurological sequelae or death. Studies were assessed for methodological and reporting quality. PROSPERO registration number: 10.15124/CRD42015021981. 43 studies were included in the review, and 599 children from 9 studies were included in the primary analysis. Estimated cumulative incidence of death or neurological sequelae at maximum follow up was 19.8% (95% CI:10.2%, 31.3%). Heterogeneity (Iˆ2) was 88.57%, partly accounted for by year of data collection and reporting quality of studies. Incidence by acute disease severity was 0.00% (0.00, 0.00) for grade IIa; 17.0% (7.9, 28.2) for grade IIb/III; 81.6% (65.1, 94.5) for grade IV (p = 0.00) disease. HFMD with neurological involvement is associated with a substantial burden of long-term neurological sequelae. Grade of acute disease severity was a strong predictor of outcome. Strengths of this study include its bilingual approach and clinical applicability. Future prospective and interventional studies must use rigorous methodology to assess long-term outcomes in survivors. There was no specific funding for this study. See below for researcher funding. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Peak-flow frequency estimates based on data through water year 2001 for selected streamflow-gaging stations in South Dakota

USGS Publications Warehouse

Sando, Steven K.; Driscoll, Daniel G.; Parrett, Charles

2008-01-01

Numerous users, including the South Dakota Department of Transportation, have continuing needs for peak-flow information for the design of highway infrastructure and many other purposes. This report documents results from a cooperative study between the South Dakota Department of Transportation and the U.S. Geological Survey to provide an update of peak-flow frequency estimates for South Dakota. Estimates of peak-flow magnitudes for 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals are reported for 272 streamflow-gaging stations, which include most gaging stations in South Dakota with 10 or more years of systematic peak-flow records through water year 2001. Recommended procedures described in Bulletin 17B were used as primary guidelines for developing peak-flow frequency estimates. The computer program PEAKFQ developed by the U.S. Geological Survey was used to run the frequency analyses. Flood frequencies for all stations were initially analyzed by using standard Bulletin 17B default procedures for fitting the log-Pearson III distribution. The resulting preliminary frequency curves were then plotted on a log-probability scale, and fits of the curves with systematic data were evaluated. In many cases, results of the default Bulletin 17B analyses were determined to be satisfactory. In other cases, however, the results could be improved by using various alternative procedures for frequency analysis. Alternative procedures for some stations included adjustments to skew coefficients or use of user-defined low-outlier criteria. Peak-flow records for many gaging stations are strongly influenced by low- or zero-flow values. This situation often results in a frequency curve that plots substantially above the systematic record data points at the upper end of the frequency curve. Adjustments to low-outlier criteria reduced the influence of very small peak flows and generally focused the analyses on the upper parts of the frequency curves (10- to 500-year recurrence intervals). The most common alternative procedures involved several different methods to extend systematic records, which was done primarily to address biases resulting from nonrepresentative climatic conditions during several specific periods of record and to reduce inconsistencies among multiple gaging stations along common stream channels with different periods of record. In some cases, records for proximal stations could be combined directly. In other cases, the two-station comparison procedure recommended in Bulletin 17B was used to adjust the mean and standard deviation of the logs of the systematic data for a target station on the basis of correlation with concurrent records from a nearby long-term index station. In some other cases, a 'mixed-station procedure' was used to adjust the log-distributional parameters for a target station, on the basis of correlation with one or more index stations, for the purpose of fitting the log-Pearson III distribution. Historical adjustment procedures were applied to peak-flow frequency analyses for 17 South Dakota gaging stations. A historical adjustment period extending back to 1881 (121 years) was used for 12 gaging stations in the James and Big Sioux River Basins, and various other adjustment periods were used for additional stations. Large peak flows that occurred in 1969 and 1997 accounted for 13 of the 17 historical adjustments. Other years for which historical peak flows were used include 1957, 1962, 1992, and 2001. A regional mixed-population analysis was developed to address complications associated with many high outliers for the Black Hills region. This analysis included definition of two populations of flood events. The population of flood events that composes the main body of peak flows for a given station is considered the 'ordinary-peaks population,' and the population of unusually large peak flows that plot substantially above the main body of peak flows on log-probability scale is co

Comparative evidence on harms in pediatric randomized clinical trials from less developed versus more developed countries is limited.

PubMed

Tedesco, Dario; Farid-Kapadia, Mufiza; Offringa, Martin; Bhutta, Zulfiqar A; Maldonado, Yvonne; Ioannidis, John P A; Contopoulos-Ioannidis, Despina G

2018-03-01

Evaluate comparative harm rates from medical interventions in pediatric randomized clinical trials (RCTs) from more developed (MDCs) and less developed countries (LDCs). Meta-epidemiologic empirical evaluation of Cochrane Database of Systematic Reviews (June 2014) meta-analyses reporting clinically important harm-outcomes (severe adverse events [AEs], discontinuations due to AEs, any AE, and mortality) that included at least one pediatric RCT from MDCs and at least one from LDCs. We estimated relative odds ratios (RORs) for each harm, within each meta-analysis, between RCTs from MDCs and LDCs and calculated random-effects-summary-RORs (sRORs) for each harm across multiple meta-analyses. Only 1% (26/2,363) of meta-analyses with clinically important harm-outcomes in the entire Cochrane Database of Systematic Reviews included pediatric RCTs both from MDCs and LDCs. We analyzed 26 meta-analyses with 244 data sets from pediatric RCTs, 116 from MDCs and 128 from LDCs (64 and 66 unique RCTs respectively). The summary ROR was 0.92 (95% confidence intervals: 0.78-1.08) for severe AEs; 1.13 (0.54-2.34) for discontinuations due to AEs; 1.10 (0.77-1.59) for any AE; and 0.99 (0.61-1.61) for mortality and for the all-harms-combined-end point 0.96 (0.83-1.10). Differences of ROR-point-estimates ≥2-fold between MDCs and LDCs were identified in 35% of meta-analyses. We found no major systematic differences in harm rates in pediatric trials between MDCs and LDCs, but data on harms in children were overall very limited. Copyright © 2017 Elsevier Inc. All rights reserved.

Empirical evidence of the importance of comparative studies of diagnostic test accuracy.

PubMed

Takwoingi, Yemisi; Leeflang, Mariska M G; Deeks, Jonathan J

2013-04-02

Systematic reviews that "compare" the accuracy of 2 or more tests often include different sets of studies for each test. To investigate the availability of direct comparative studies of test accuracy and to assess whether summary estimates of accuracy differ between meta-analyses of noncomparative and comparative studies. Systematic reviews in any language from the Database of Abstracts of Reviews of Effects and the Cochrane Database of Systematic Reviews from 1994 to October 2012. 1 of 2 assessors selected reviews that evaluated at least 2 tests and identified meta-analyses that included both noncomparative studies and comparative studies. 1 of 3 assessors extracted data about review and study characteristics and test performance. 248 reviews compared test accuracy; of the 6915 studies, 2113 (31%) were comparative. Thirty-six reviews (with 52 meta-analyses) had adequate studies to compare results of noncomparative and comparative studies by using a hierarchical summary receiver-operating characteristic meta-regression model for each test comparison. In 10 meta-analyses, noncomparative studies ranked tests in the opposite order of comparative studies. A total of 25 meta-analyses showed more than a 2-fold discrepancy in the relative diagnostic odds ratio between noncomparative and comparative studies. Differences in accuracy estimates between noncomparative and comparative studies were greater than expected by chance (P < 0.001). A paucity of comparative studies limited exploration of direction in bias. Evidence derived from noncomparative studies often differs from that derived from comparative studies. Robustly designed studies in which all patients receive all tests or are randomly assigned to receive one or other of the tests should be more routinely undertaken and are preferred for evidence to guide test selection. National Institute for Health Research (United Kingdom).

Smoking as a risk factor for stroke in women compared with men: a systematic review and meta-analysis of 81 cohorts, including 3,980,359 individuals and 42,401 strokes.

PubMed

Peters, Sanne A E; Huxley, Rachel R; Woodward, Mark

2013-10-01

It is currently unknown whether the excess risk of stroke by smoking is the same for women and men. We performed a systematic review and meta-analysis to estimate the effect of smoking on stroke in women compared with men. PubMed MEDLINE was systematically searched for prospective population-based cohort studies published between January 1, 1966, and January 26, 2013. Studies that presented sex-specific estimates of the relative risk of stroke comparing current smoking with nonsmoking and its associated variability were selected. The sex-specific relative risks and their ratio (RRR), comparing women with men, were pooled using random-effects meta-analysis with inverse variance weighting. Similarly, the RRR for former versus never smoking was pooled. Data from 81 prospective cohort studies that included 3,980,359 individuals and 42,401 strokes were available. Smoking was an independent risk factor for stroke in both sexes. Overall, the pooled multiple-adjusted RRR indicated a similar risk of stroke associated with smoking in women compared with men (RRR, 1.06 [95% confidence interval, 0.99-1.13]). In a regional analysis, there was evidence of a more harmful effect of smoking in women than in men in Western (RRR, 1.10 [1.02-1.18)] but not in Asian (RRR, 0.97 [0.87-1.09]) populations. Compared with never-smokers, the beneficial effects of quitting smoking among former smokers on stroke risk were similar between the sexes (RRR, 1.10 [0.99-1.22]). Compared with nonsmokers, the excess risk of stroke is at least as great among women who smoke compared with men who smoke.

Rapid On-Site Evaluation of Fine-Needle Aspiration by Non-Cytopathologists: A Systematic Review and Meta-Analysis of Diagnostic Accuracy Studies for Adequacy Assessment.

PubMed

Pearson, Lauren; Factor, Rachel E; White, Sandra K; Walker, Brandon S; Layfield, Lester J; Schmidt, Robert L

2018-06-06

Rapid on-site evaluation (ROSE) has been shown to improve adequacy rates and reduce needle passes. ROSE is often performed by cytopathologists who have limited availability and may be costlier than alternatives. Several recent studies examined the use of alternative evaluators (AEs) for ROSE. A summary of this information could help inform guidelines regarding the use of AEs. The objective was to assess the accuracy of AEs compared to cytopathologists in assessing the adequacy of specimens during ROSE. This was a systematic review and meta-analysis. Reporting and study quality were assessed using the STARD guidelines and QUADAS-2. All steps were performed independently by two evaluators. Summary estimates were obtained using the hierarchal method in Stata v14. Heterogeneity was evaluated using Higgins' I2 statistic. The systematic review identified 13 studies that were included in the meta-analysis. Summary estimates of sensitivity and specificity for AEs were 97% (95% CI: 92-99%) and 83% (95% CI: 68-92%). There was wide variation in accuracy statistics between studies (I2 = 0.99). AEs sometimes have accuracy that is close to cytopathologists. However, there is wide variability between studies, so it is not possible to provide a broad guideline regarding the use of AEs. © 2018 S. Karger AG, Basel.

Systematic co-operation between employer, occupational health service and social insurance office: a 6-year follow-up of vocational rehabilitation for people on sick-leave, including economic benefits.

PubMed

Kärrholm, Jenny; Ekholm, Karolina; Ekholm, Jan; Bergroth, Alf; Ekholm, Kristina Schüldt

2008-08-01

To evaluate the effects of systematic co-operation among municipal employees on the number of sick-leave days per month and the type of benefit granted by the Social Insurance Office. A further aim was to evaluate the economic consequences for society. A 6-year follow-up study with a matched-pairs design. Days on sick-leave were calculated for each subject one year before the intervention started and yearly for the following 6-year period. Statistical mixed-model analysis was used. The economic benefit of the intervention was estimated as the increased production stemming from fewer days on sick-leave. Sixty-four employees on long-term sick-leave were individually matched with controls from another Social Insurance Office in a county with a socioeconomic structure similar to that of the study group. The study group had 5.7 fewer days on sick-leave per month and person over the 6-year period (p=0.003). The estimated average economic benefit of the intervention was euro36,600 per person over the 6-year period. In conclusion, those who received systematic co-operation in vocational rehabilitation had fewer days on sick-leave than their "treatment-as-usual" peers. This effect persisted over 6 years, generating substantial net economic gains for society.

Welding, longitudinal lung function decline and chronic respiratory symptoms: a systematic review of cohort studies.

PubMed

Szram, Joanna; Schofield, Susie J; Cosgrove, Martin P; Cullinan, Paul

2013-11-01

While the acute respiratory risks of welding are well characterised, more chronic effects, including those on lung function, are less clear. We carried out a systematic review of published longitudinal studies of lung function decline in welders. Original cohort studies documenting two or more sequential measurements of lung function were reviewed. Meta-analysis was carried out on studies with suitable data on forced expiratory volume in 1 s (FEV1). Seven studies were included; their quality (measured on the Newcastle-Ottawa scale) was good, although exposure assessment was limited and the studies showed significant heterogeneity. Five had data suitable for meta-analysis; the pooled estimate of the difference in FEV1 decline between welders and nonwelders was -9.0 mL · year(-1) (95% CI -22.5-4.5; p=0.193). The pooled estimates of difference in annual FEV1 decline between welders and referents who smoked was -13.7 mL · year(-1) (95% CI -33.6-6.3; p=0.179). For welders and referents who did not smoke the estimated difference was -3.8 mL · year(-1) (95% CI -20.2-12.6; p=0.650). Symptom prevalence data were mainly narrative; smoking appeared to have the greatest effect on symptom evolution. Collectively, available longitudinal data on decline of lung function in welders and respiratory symptoms suggest a greater effect in those who smoke, supporting a focus on smoking cessation as well as control of fume exposure in this trade. Further prospective studies are required to confirm these findings.

The effect of giving global coronary risk information to adults: a systematic review.

PubMed

Sheridan, Stacey L; Viera, Anthony J; Krantz, Mori J; Ice, Christa L; Steinman, Lesley E; Peters, Karen E; Kopin, Laurie A; Lungelow, Danielle

2010-02-08

Global coronary heart disease (CHD) risk estimation (ie, a quantitative estimate of a patient's chances of CHD calculated by combining risk factors in an empirical equation) is recommended as a starting point for primary prevention efforts in all US adults. Whether it improves outcomes is currently unknown. To assess the effect of providing global CHD risk information to adults, we performed a systematic evidence review. We searched MEDLINE for the years 1980 to 2008, Psych Info, CINAHL, and the Cochrane Database and included English-language articles that met prespecified inclusion criteria. Two reviewers independently reviewed titles, abstracts, and articles for inclusion and assessed study quality. We identified 20 articles, reporting on 18 unique fair or good quality studies (including 14 randomized controlled studies). These showed that global CHD risk information alone or with accompanying education increased the accuracy of perceived risk and probably increased intent to start therapy. Studies with repeated risk information or risk information and repeated doses of counseling showed small significant reductions in predicted CHD risk (absolute differences, -0.2% to -2% over 10 years in studies using risk estimates derived from Framingham equations). Studies providing global risk information at only 1 point in time seemed ineffective. Global CHD risk information seems to improve the accuracy of risk perception and may increase intent to initiate CHD prevention among individuals at moderate to high risk. The effect of global risk presentation on more distal outcomes is less clear and seems to be related to the intensity of accompanying interventions.

Evidence for a Sizable Age Spread among Galaxies from the Ultraviolet-Upturn Phenomenon in Early-type Systems

NASA Astrophysics Data System (ADS)

Park, Jang-Hyun; Lee, Young-Wook

1997-02-01

The suggestion of Lee that the age spread among galaxies is responsible for the systematic variation of the ultraviolet upturn among early-type systems is examined here with detailed population synthesis models. Our models differ from previous ones by including (1) the effect of metallicity spreads and (2) detailed modeling of the variations in H-R diagram morphology (including the helium-burning phase) with age and metallicity. Our models suggest that the far-UV radiation of these systems is dominated by a minority population of metal-poor, hot horizontal-branch (HB) stars and their post-HB progeny, with some contribution from metal-rich post-asymptotic giant branch stars, while the optical radiation is dominated by a metal-rich population. The systematic variation of the UV upturn depends on the contribution from metal-poor, hot HB stars and their post-HB progeny, which in turn depends on the ages of old stellar populations in galaxies. Our result implies a prolonged epoch of galaxy formation, in the sense that more massive galaxies (in denser environments) formed first. With the assumption that the UV-upturn phenomenon is solely due to the age variations among galaxies, we estimate the difference in age between the giant elliptical galaxies and the spiral bulges of the Local Group to be ~3 Gyr. This suggests that the best estimate for the lower limit of the age of the universe is ~19 Gyr, which of course would be in conflict with the current estimate of H0, together with the standard cosmological models with zero cosmological constant.

Rethinking the Heterosexual Infectivity of HIV-1: A Systematic Review and Meta-analysis

PubMed Central

Powers, Kimberly A.; Poole, Charles; Pettifor, Audrey E.; Cohen, Myron S.

2009-01-01

Background Studies of cumulative HIV incidence suggest that co-factors such as genital ulcer disease (GUD), HIV disease stage, and circumcision influence HIV transmission; however, the heterosexual infectivity of HIV-1 is commonly cited as a fixed value (∼0·001, or 1 transmission per thousand contacts). We sought to estimate transmission co-factor effects on the heterosexual infectivity of HIV-1 and to quantify the extent to which study methods have affected infectivity estimates. Methods We conducted a systematic search (through April 2008) of PubMed, Web of Science, and relevant bibliographies to identify articles estimating the heterosexual infectivity of HIV-1. We used meta-regression and stratified random-effects meta-analysis to assess differences in infectivity by co-factors and study methods. Findings Infectivity estimates were extremely heterogeneous, ranging from zero transmissions after more than 100 penile-vaginal contacts in some sero-discordant couples to one transmission for every 3·1 episodes of heterosexual anal intercourse. Estimates were only weakly associated with study methods. Infectivity differences (95% confidence intervals), expressed as number of transmissions per 1000 contacts, were 8 (0-16) comparing uncircumcised to circumcised male susceptibles, 6 (3-9) comparing susceptible individuals with and without GUD, 2 (1-3) comparing late-stage to mid-stage index cases, and 3 (0-5) comparing early-stage to mid-stage index cases. Interpretation A single value for the heterosexual infectivity of HIV-1 fails to reflect the variation associated with important co-factors. The commonly cited value of ∼0·001 was estimated among stable couples with low prevalences of high-risk co-factors, and represents a lower bound. Co-factor effects are important to include in epidemic models, policy considerations, and prevention messages. PMID:18684670

Frequency of data extraction errors and methods to increase data extraction quality: a methodological review.

PubMed

Mathes, Tim; Klaßen, Pauline; Pieper, Dawid

2017-11-28

Our objective was to assess the frequency of data extraction errors and its potential impact on results in systematic reviews. Furthermore, we evaluated the effect of different extraction methods, reviewer characteristics and reviewer training on error rates and results. We performed a systematic review of methodological literature in PubMed, Cochrane methodological registry, and by manual searches (12/2016). Studies were selected by two reviewers independently. Data were extracted in standardized tables by one reviewer and verified by a second. The analysis included six studies; four studies on extraction error frequency, one study comparing different reviewer extraction methods and two studies comparing different reviewer characteristics. We did not find a study on reviewer training. There was a high rate of extraction errors (up to 50%). Errors often had an influence on effect estimates. Different data extraction methods and reviewer characteristics had moderate effect on extraction error rates and effect estimates. The evidence base for established standards of data extraction seems weak despite the high prevalence of extraction errors. More comparative studies are needed to get deeper insights into the influence of different extraction methods.

Estimated prevalence of halitosis: a systematic review and meta-regression analysis.

PubMed

Silva, Manuela F; Leite, Fábio R M; Ferreira, Larissa B; Pola, Natália M; Scannapieco, Frank A; Demarco, Flávio F; Nascimento, Gustavo G

2018-01-01

This study aims to conduct a systematic review to determine the prevalence of halitosis in adolescents and adults. Electronic searches were performed using four different databases without restrictions: PubMed, Scopus, Web of Science, and SciELO. Population-based observational studies that provided data about the prevalence of halitosis in adolescents and adults were included. Additionally, meta-analyses, meta-regression, and sensitivity analyses were conducted to synthesize the evidence. A total of 584 articles were initially found and considered for title and abstract evaluation. Thirteen articles met inclusion criteria. The combined prevalence of halitosis was found to be 31.8% (95% CI 24.6-39.0%). Methodological aspects such as the year of publication and the socioeconomic status of the country where the study was conducted seemed to influence the prevalence of halitosis. Our results demonstrated that the estimated prevalence of halitosis was 31.8%, with high heterogeneity between studies. The results suggest a worldwide trend towards a rise in halitosis prevalence. Given the high prevalence of halitosis and its complex etiology, dental professionals should be aware of their roles in halitosis prevention and treatment.

Effect of Risk of Bias on the Effect Size of Meta-Analytic Estimates in Randomized Controlled Trials in Periodontology and Implant Dentistry.

PubMed

Faggion, Clovis Mariano; Wu, Yun-Chun; Scheidgen, Moritz; Tu, Yu-Kang

2015-01-01

Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association.

Inconsistency between direct and indirect comparisons of competing interventions: meta-epidemiological study.

PubMed

Song, Fujian; Xiong, Tengbin; Parekh-Bhurke, Sheetal; Loke, Yoon K; Sutton, Alex J; Eastwood, Alison J; Holland, Richard; Chen, Yen-Fu; Glenny, Anne-Marie; Deeks, Jonathan J; Altman, Doug G

2011-08-16

To investigate the agreement between direct and indirect comparisons of competing healthcare interventions. Meta-epidemiological study based on sample of meta-analyses of randomised controlled trials. Data sources Cochrane Database of Systematic Reviews and PubMed. Inclusion criteria Systematic reviews that provided sufficient data for both direct comparison and independent indirect comparisons of two interventions on the basis of a common comparator and in which the odds ratio could be used as the outcome statistic. Inconsistency measured by the difference in the log odds ratio between the direct and indirect methods. The study included 112 independent trial networks (including 1552 trials with 478,775 patients in total) that allowed both direct and indirect comparison of two interventions. Indirect comparison had already been explicitly done in only 13 of the 85 Cochrane reviews included. The inconsistency between the direct and indirect comparison was statistically significant in 16 cases (14%, 95% confidence interval 9% to 22%). The statistically significant inconsistency was associated with fewer trials, subjectively assessed outcomes, and statistically significant effects of treatment in either direct or indirect comparisons. Owing to considerable inconsistency, many (14/39) of the statistically significant effects by direct comparison became non-significant when the direct and indirect estimates were combined. Significant inconsistency between direct and indirect comparisons may be more prevalent than previously observed. Direct and indirect estimates should be combined in mixed treatment comparisons only after adequate assessment of the consistency of the evidence.

Inconsistency between direct and indirect comparisons of competing interventions: meta-epidemiological study

PubMed Central

Xiong, Tengbin; Parekh-Bhurke, Sheetal; Loke, Yoon K; Sutton, Alex J; Eastwood, Alison J; Holland, Richard; Chen, Yen-Fu; Glenny, Anne-Marie; Deeks, Jonathan J; Altman, Doug G

2011-01-01

Objective To investigate the agreement between direct and indirect comparisons of competing healthcare interventions. Design Meta-epidemiological study based on sample of meta-analyses of randomised controlled trials. Data sources Cochrane Database of Systematic Reviews and PubMed. Inclusion criteria Systematic reviews that provided sufficient data for both direct comparison and independent indirect comparisons of two interventions on the basis of a common comparator and in which the odds ratio could be used as the outcome statistic. Main outcome measure Inconsistency measured by the difference in the log odds ratio between the direct and indirect methods. Results The study included 112 independent trial networks (including 1552 trials with 478 775 patients in total) that allowed both direct and indirect comparison of two interventions. Indirect comparison had already been explicitly done in only 13 of the 85 Cochrane reviews included. The inconsistency between the direct and indirect comparison was statistically significant in 16 cases (14%, 95% confidence interval 9% to 22%). The statistically significant inconsistency was associated with fewer trials, subjectively assessed outcomes, and statistically significant effects of treatment in either direct or indirect comparisons. Owing to considerable inconsistency, many (14/39) of the statistically significant effects by direct comparison became non-significant when the direct and indirect estimates were combined. Conclusions Significant inconsistency between direct and indirect comparisons may be more prevalent than previously observed. Direct and indirect estimates should be combined in mixed treatment comparisons only after adequate assessment of the consistency of the evidence. PMID:21846695

An evaluation of multipass electrofishing for estimating the abundance of stream-dwelling salmonids

Treesearch

James T. Peterson; Russell F. Thurow; John W. Guzevich

2004-01-01

Failure to estimate capture efficiency, defined as the probability of capturing individual fish, can introduce a systematic error or bias into estimates of fish abundance. We evaluated the efficacy of multipass electrofishing removal methods for estimating fish abundance by comparing estimates of capture efficiency from multipass removal estimates to capture...

Multiple Flux Footprints, Flux Divergences and Boundary Layer Mixing Ratios: Studies of Ecosystem-Atmosphere CO2 Exchange Using the WLEF Tall Tower.

NASA Astrophysics Data System (ADS)

Davis, K. J.; Bakwin, P. S.; Yi, C.; Cook, B. D.; Wang, W.; Denning, A. S.; Teclaw, R.; Isebrands, J. G.

2001-05-01

Long-term, tower-based measurements using the eddy-covariance method have revealed a wealth of detail about the temporal dynamics of netecosystem-atmosphere exchange (NEE) of CO2. The data also provide a measure of the annual net CO2 exchange. The area represented by these flux measurements, however, is limited, and doubts remain about possible systematic errors that may bias the annual net exchange measurements. Flux and mixing ratio measurements conducted at the WLEF tall tower as part of the Chequamegon Ecosystem-Atmosphere Study (ChEAS) allow for unique assessment of the uncertainties in NEE of CO2. The synergy between flux and mixing ratio observations shows the potential for comparing inverse and eddy-covariance methods of estimating NEE of CO2. Such comparisons may strengthen confidence in both results and begin to bridge the huge gap in spatial scales (at least 3 orders of magnitude) between continental or hemispheric scale inverse studies and kilometer-scale eddy covariance flux measurements. Data from WLEF and Willow Creek, another ChEAS tower, are used to estimate random and systematic errors in NEE of CO2. Random uncertainty in seasonal exchange rates and the annual integrated NEE, including both turbulent sampling errors and variability in enviromental conditions, is small. Systematic errors are identified by examining changes in flux as a function of atmospheric stability and wind direction, and by comparing the multiple level flux measurements on the WLEF tower. Nighttime drainage is modest but evident. Systematic horizontal advection occurs during the morning turbulence transition. The potential total systematic error appears to be larger than random uncertainty, but still modest. The total systematic error, however, is difficult to assess. It appears that the WLEF region ecosystems were a small net sink of CO2 in 1997. It is clear that the summer uptake rate at WLEF is much smaller than that at most deciduous forest sites, including the nearby Willow Creek site. The WLEF tower also allows us to study the potential for monitoring continental CO2 mixing ratios from tower sites. Despite concerns about the proximity to ecosystem sources and sinks, it is clear that boundary layer CO2 mixing ratios can be monitored using typical surface layer towers. Seasonal and annual land-ocean mixing ratio gradients are readily detectable, providing the motivation for a flux-tower based mixing ratio observation network that could greatly improve the accuracy of inversion-based estimates of NEE of CO2, and enable inversions to be applied on smaller temporal and spatial scales. Results from the WLEF tower illustrate the degree to which local flux measurements represent interannual, seasonal and synoptic CO2 mixing ratio trends. This coherence between fluxes and mixing ratios serves to "regionalize" the eddy-covariance based local NEE observations.

A systematic review and synthesis of the strengths and limitations of measuring malaria mortality through verbal autopsy.

PubMed

Herrera, Samantha; Enuameh, Yeetey; Adjei, George; Ae-Ngibise, Kenneth Ayuurebobi; Asante, Kwaku Poku; Sankoh, Osman; Owusu-Agyei, Seth; Yé, Yazoume

2017-10-23

Lack of valid and reliable data on malaria deaths continues to be a problem that plagues the global health community. To address this gap, the verbal autopsy (VA) method was developed to ascertain cause of death at the population level. Despite the adoption and wide use of VA, there are many recognized limitations of VA tools and methods, especially for measuring malaria mortality. This study synthesizes the strengths and limitations of existing VA tools and methods for measuring malaria mortality (MM) in low- and middle-income countries through a systematic literature review. The authors searched PubMed, Cochrane Library, Popline, WHOLIS, Google Scholar, and INDEPTH Network Health and Demographic Surveillance System sites' websites from 1 January 1990 to 15 January 2016 for articles and reports on MM measurement through VA. article presented results from a VA study where malaria was a cause of death; article discussed limitations/challenges related to measurement of MM through VA. Two authors independently searched the databases and websites and conducted a synthesis of articles using a standard matrix. The authors identified 828 publications; 88 were included in the final review. Most publications were VA studies; others were systematic reviews discussing VA tools or methods; editorials or commentaries; and studies using VA data to develop MM estimates. The main limitation were low sensitivity and specificity of VA tools for measuring MM. Other limitations included lack of standardized VA tools and methods, lack of a 'true' gold standard to assess accuracy of VA malaria mortality. Existing VA tools and methods for measuring MM have limitations. Given the need for data to measure progress toward the World Health Organization's Global Technical Strategy for Malaria 2016-2030 goals, the malaria community should define strategies for improving MM estimates, including exploring whether VA tools and methods could be further improved. Longer term strategies should focus on improving countries' vital registration systems for more robust and timely cause of death data.

Statins use and risk of depression: a systematic review and meta-analysis.

PubMed

Parsaik, Ajay K; Singh, Balwinder; Murad, M Hassan; Singh, Kuljit; Mascarenhas, Soniya S; Williams, Mark D; Lapid, Maria I; Richardson, Jarrett W; West, Colin P; Rummans, Teresa A

2014-05-01

Statin use has been associated with depression; however studies of the association between statin use and depression have yielded mixed results. To determine whether statin use is associated with depression and to evaluate the evidence supporting this association. Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, EMBASE, PsycInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus were searched through December 28, 2012. We included studies that evaluated exposure to statins, reported the development of depression, and relative risks or odds ratios (ORs) or provided data for their estimation. Two reviewers screened 981 abstracts independently using a standardized form, reviewed full text of 59 selected articles, and included 7 studies in this metaanalysis. Study design, statin exposure, development of depression, and study quality were extracted by 2 independent reviewers. A pooled OR with 95% confidence interval (CI) was estimated using the random-effects model and heterogeneity was assessed using Cochran's Q test and the I(2) statistic. Seven observational studies (4 cohort, 2 nested case-control, and 1 cross-sectional) from 5 countries enrolling 9187 patients were included. Statin users were 32% less likely to develop depression than nonusers (adjusted OR, 0.68; 95% CI, 0.52-0.89). Modest heterogeneity was observed between the studies (I(2)=55%, P=0.01), which could be accounted for by one study, exclusion of which removed the heterogeneity (P=0.40, I(2)=2%) and further strengthened the antidepressant effect of statin (adjusted OR, 0.63; 95% CI, 0.43-0.93). Heterogeneity could not be explained by study design or study population. The quality of supporting evidence was fair. This systematic review and meta-analysis suggests that statin use is associated with lower risk for depression. However, higher-quality studies are needed to confirm the magnitude of this association. Copyright © 2013 Elsevier B.V. All rights reserved.

Toxocariasis and Epilepsy: Systematic Review and Meta-Analysis

PubMed Central

Quattrocchi, Graziella; Nicoletti, Alessandra; Marin, Benoit; Bruno, Elisa; Druet-Cabanac, Michel; Preux, Pierre-Marie

2012-01-01

Objective Human toxocariasis is a zoonotic infection caused by the larval stages of Toxocara canis (T. canis) and less frequently Toxocara cati (T. cati). A relationship between toxocariasis and epilepsy has been hypothesized. We conducted a systematic review and a meta-analysis of available data to evaluate the strength of association between epilepsy and Toxocara spp. seropositivity and to propose some guidelines for future surveys. Data Sources Electronic databases, the database from the Institute of Neuroepidemiology and Tropical Neurology of the University of Limoges (http://www-ient.unilim.fr/) and the reference lists of all relevant papers and books were screened up to October 2011. Methods We performed a systematic review of literature on toxocariasis (the exposure) and epilepsy (the outcome). Two authors independently assessed eligibility and study quality and extracted data. A common odds ratio (OR) was estimated using a random-effects meta-analysis model of aggregated published data. Results Seven case-control studies met the inclusion criteria, for a total of 1867 participants (850 cases and 1017 controls). The percentage of seropositivity (presence of anti-Toxocara spp. antibodies) was higher among people with epilepsy (PWE) in all the included studies even if the association between epilepsy and Toxocara spp. seropositivity was statistically significant in only 4 studies, with crude ORs ranging 2.04–2.85. Another study bordered statistical significance, while in 2 of the included studies no significant association was found. A significant (p<0.001) common OR of 1.92 [95% confidence interval (CI) 1.50–2.44] was estimated. Similar results were found when meta-analysis was restricted to the studies considering an exclusively juvenile population and to surveys using Western Blot as confirmatory or diagnostic serological assay. Conclusion Our results support the existence of a positive association between Toxocara spp. seropositivity and epilepsy. Further studies, possibly including incident cases, should be performed to better investigate the relationship between toxocariasis and epilepsy. PMID:22905274

Framing the Salmonidae Family Phylogenetic Portrait: A More Complete Picture from Increased Taxon Sampling

PubMed Central

Crête-Lafrenière, Alexis; Weir, Laura K.; Bernatchez, Louis

2012-01-01

Considerable research efforts have focused on elucidating the systematic relationships among salmonid fishes; an understanding of these patterns of relatedness will inform conservation- and fisheries-related issues, as well as provide a framework for investigating evolutionary mechanisms in the group. However, uncertainties persist in current Salmonidae phylogenies due to biological and methodological factors, and a comprehensive phylogeny including most representatives of the family could provide insight into the causes of these difficulties. Here we increase taxon sampling by including nearly all described salmonid species (n = 63) to present a time-calibrated and more complete portrait of Salmonidae using a combination of molecular markers and analytical techniques. This strategy improved resolution by increasing the signal-to-noise ratio and helped discriminate methodological and systematic errors from sources of difficulty associated with biological processes. Our results highlight novel aspects of salmonid evolution. First, we call into question the widely-accepted evolutionary relationships among sub-families and suggest that Thymallinae, rather than Coregoninae, is the sister group to the remainder of Salmonidae. Second, we find that some groups in Salmonidae are older than previously thought and that the mitochondrial rate of molecular divergence varies markedly among genes and clades. We estimate the age of the family to be 59.1 MY (CI: 63.2-58.1 MY) old, which likely corresponds to the timing of whole genome duplication in salmonids. The average, albeit highly variable, mitochondrial rate of molecular divergence was estimated as ∼0.31%/MY (CI: 0.27–0.36%/MY). Finally, we suggest that some species require taxonomic revision, including two monotypic genera, Stenodus and Salvethymus. In addition, we resolve some relationships that have been notoriously difficult to discern and present a clearer picture of the evolution of the group. Our findings represent an important contribution to the systematics of Salmonidae, and provide a useful tool for addressing questions related to fundamental and applied evolutionary issues. PMID:23071608

Traffic-Related Air Pollution and Childhood Asthma: Recent Advances and Remaining Gaps in the Exposure Assessment Methods.

PubMed

Khreis, Haneen; Nieuwenhuijsen, Mark J

2017-03-17

Background : Current levels of traffic-related air pollution (TRAP) are associated with the development of childhood asthma, although some inconsistencies and heterogeneity remain. An important part of the uncertainty in studies of TRAP-associated asthma originates from uncertainties in the TRAP exposure assessment and assignment methods. In this work, we aim to systematically review the exposure assessment methods used in the epidemiology of TRAP and childhood asthma, highlight recent advances, remaining research gaps and make suggestions for further research. Methods : We systematically reviewed epidemiological studies published up until 8 September 2016 and available in Embase, Ovid MEDLINE (R), and "Transport database". We included studies which examined the association between children's exposure to TRAP metrics and their risk of "asthma" incidence or lifetime prevalence, from birth to the age of 18 years old. Results : We found 42 studies which examined the associations between TRAP and subsequent childhood asthma incidence or lifetime prevalence, published since 1999. Land-use regression modelling was the most commonly used method and nitrogen dioxide (NO₂) was the most commonly used pollutant in the exposure assessments. Most studies estimated TRAP exposure at the residential address and only a few considered the participants' mobility. TRAP exposure was mostly assessed at the birth year and only a few studies considered different and/or multiple exposure time windows. We recommend that further work is needed including e.g., the use of new exposure metrics such as the composition of particulate matter, oxidative potential and ultra-fine particles, improved modelling e.g., by combining different exposure assessment models, including mobility of the participants, and systematically investigating different exposure time windows. Conclusions : Although our previous meta-analysis found statistically significant associations for various TRAP exposures and subsequent childhood asthma, further refinement of the exposure assessment may improve the risk estimates, and shed light on critical exposure time windows, putative agents, underlying mechanisms and drivers of heterogeneity.

Is there a causal link between knee loading and knee osteoarthritis progression? A systematic review and meta-analysis of cohort studies and randomised trials

PubMed Central

Henriksen, Marius; Creaby, Mark W; Lund, Hans; Juhl, Carsten; Christensen, Robin

2014-01-01

Objective We performed a systematic review, meta-analysis and assessed the evidence supporting a causal link between knee joint loading during walking and structural knee osteoarthritis (OA) progression. Design Systematic review, meta-analysis and application of Bradford Hill's considerations on causation. Data sources We searched MEDLINE, Scopus, AMED, CINAHL and SportsDiscus for prospective cohort studies and randomised controlled trials (RCTs) from 1950 through October 2013. Study eligibility criteria We selected cohort studies and RCTs in which estimates of knee joint loading during walking were used to predict structural knee OA progression assessed by X-ray or MRI. Data analyses Meta-analysis was performed to estimate the combined OR for structural disease progression with higher baseline loading. The likelihood of a causal link between knee joint loading and OA progression was assessed from cohort studies using the Bradford Hill guidelines to derive a 0–4 causation score based on four criteria and examined for confirmation in RCTs. Results Of the 1078 potentially eligible articles, 5 prospective cohort studies were included. The studies included a total of 452 patients relating joint loading to disease progression over 12–72 months. There were very serious limitations associated with the methodological quality of the included studies. The combined OR for disease progression was 1.90 (95% CI 0.85 to 4.25; I2=77%) for each one-unit increment in baseline knee loading. The combined causation score was 0, indicating no causal association between knee loading and knee OA progression. No RCTs were found to confirm or refute the findings from the cohort studies. Conclusions There is very limited and low-quality evidence to support for a causal link between knee joint loading during walking and structural progression of knee OA. Trial registration number CRD42012003253 PMID:25031196

Is there a causal link between knee loading and knee osteoarthritis progression? A systematic review and meta-analysis of cohort studies and randomised trials.

PubMed

Henriksen, Marius; Creaby, Mark W; Lund, Hans; Juhl, Carsten; Christensen, Robin

2014-07-15

We performed a systematic review, meta-analysis and assessed the evidence supporting a causal link between knee joint loading during walking and structural knee osteoarthritis (OA) progression. Systematic review, meta-analysis and application of Bradford Hill's considerations on causation. We searched MEDLINE, Scopus, AMED, CINAHL and SportsDiscus for prospective cohort studies and randomised controlled trials (RCTs) from 1950 through October 2013. We selected cohort studies and RCTs in which estimates of knee joint loading during walking were used to predict structural knee OA progression assessed by X-ray or MRI. Meta-analysis was performed to estimate the combined OR for structural disease progression with higher baseline loading. The likelihood of a causal link between knee joint loading and OA progression was assessed from cohort studies using the Bradford Hill guidelines to derive a 0-4 causation score based on four criteria and examined for confirmation in RCTs. Of the 1078 potentially eligible articles, 5 prospective cohort studies were included. The studies included a total of 452 patients relating joint loading to disease progression over 12-72 months. There were very serious limitations associated with the methodological quality of the included studies. The combined OR for disease progression was 1.90 (95% CI 0.85 to 4.25; I(2)=77%) for each one-unit increment in baseline knee loading. The combined causation score was 0, indicating no causal association between knee loading and knee OA progression. No RCTs were found to confirm or refute the findings from the cohort studies. There is very limited and low-quality evidence to support for a causal link between knee joint loading during walking and structural progression of knee OA. CRD42012003253. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A Database of Historical Information on Landslides and Floods in Italy

NASA Astrophysics Data System (ADS)

Guzzetti, F.; Tonelli, G.

2003-04-01

For the past 12 years we have maintained and updated a database of historical information on landslides and floods in Italy, known as the National Research Council's AVI (Damaged Urban Areas) Project archive. The database was originally designed to respond to a specific request of the Minister of Civil Protection, and was aimed at helping the regional assessment of landslide and flood risk in Italy. The database was first constructed in 1991-92 to cover the period 1917 to 1990. Information of damaging landslide and flood event was collected by searching archives, by screening thousands of newspaper issues, by reviewing the existing technical and scientific literature on landslides and floods in Italy, and by interviewing landslide and flood experts. The database was then updated chiefly through the analysis of hundreds of newspaper articles, and it now covers systematically the period 1900 to 1998, and non-systematically the periods 1900 to 1916 and 1999 to 2002. Non systematic information on landslide and flood events older than 20th century is also present in the database. The database currently contains information on more than 32,000 landslide events occurred at more than 25,700 sites, and on more than 28,800 flood events occurred at more than 15,600 sites. After a brief outline of the history and evolution of the AVI Project archive, we present and discuss: (a) the present structure of the database, including the hardware and software solutions adopted to maintain, manage, use and disseminate the information stored in the database, (b) the type and amount of information stored in the database, including an estimate of its completeness, and (c) examples of recent applications of the database, including a web-based GIS systems to show the location of sites historically affected by landslides and floods, and an estimate of geo-hydrological (i.e., landslide and flood) risk in Italy based on the available historical information.

Prevalence of low back pain in emergency settings: a systematic review and meta-analysis.

PubMed

Edwards, Jordan; Hayden, Jill; Asbridge, Mark; Gregoire, Bruce; Magee, Kirk

2017-04-04

Low back pain may be having a significant impact on emergency departments around the world. Research suggests low back pain is one of the leading causes of emergency department visits. However, in the peer-reviewed literature, there has been limited focus on the prevalence and management of back pain in the emergency department setting. The aim of the systematic review was to synthesize evidence about the prevalence of low back pain in emergency settings and explore the impact of study characteristics including type of emergency setting and how the study defined low back pain. Studies were identified from PubMed and EMBASE, grey literature search, and other sources. We selected studies that presented prevalence data for adults presenting to an emergency setting with low back pain. Critical appraisal was conducted using a modified tool developed to assess prevalence studies. Meta-analyses and a meta-regression explored the influence of study-level characteristics on prevalence. We screened 1187 citations and included 21 studies, reported between 2000 and 2016 presenting prevalence data from 12 countries. The pooled prevalence estimate from studies of standard emergency settings was 4.39% (95% CI: 3.67-5.18). Prevalence estimates of the included studies ranged from 0.9% to 17.1% and varied with study definition of low back pain and the type of emergency setting. The overall quality of the evidence was judged to be moderate as there was limited generalizability and high heterogeneity in the results. This is the first systematic review to examine the prevalence of low back pain in emergency settings. Our results indicate that low back pain is consistently a top presenting complaint and that the prevalence of low back pain varies with definition of low back pain and emergency setting. Clinicians and policy decisions makers should be aware of the potential impact of low back pain in their emergency settings.

A systematic review of the survival and complication rates of inlay-retained fixed dental prostheses.

PubMed

Chen, Junyu; Cai, He; Suo, Lai; Xue, Yiyuan; Wang, Jian; Wan, Qianbing

2017-04-01

The aim of this systematic review was to investigate the survival and complication rates of inlay-retainer fixed dental prostheses (IRFDPs). A systematic search was conducted in the PubMed, EMBASE, and Cochrane Library databases in English and time filters (articles published from 1960) were used. Randomized controlled trails (RCTs), controlled clinical trials (CCTs) and prospective cohort studies on IRFDPs with a mean follow-up period of at least 2 years were included. Among 501 screened articles, one RCT and ten prospective cohort studies were included in this study. Of the included studies, information on failure and complications was independently extracted by two reviewers in duplicate. The failure and complication rates of IRFDPs were pooled with a random effect model and Poisson regression was applied to further investigate the influence of framework materials. The estimated 3- and 5-year survival rates of IRFDPs were 92.6% (95% CI: 85.8-97.6%) and 87.9% (95% CI: 77.4-96.1%), respectively. Debonding, fracture, dentine hypersensitivity and secondary caries were primary complications. The estimated 5-year rates of debonding, veneer fracture and secondary caries were 5.3%, 15.2% and 2.7%, respectively. Additionally, fiber-reinforced composite IRFDPs exhibited a lower incidence of debonding and caries with a higher rate of veneer fracture compared with metal-based and all-ceramic IRFDPs (p<0.05). Compared with conventional fixed dental prostheses (FDPs) and implant-supported single crowns (ISCs), IRFDPs exhibited an acceptable 3-year survival rate but higher complication rates of debonding and veneer fracture. IRFDPs can be recommended as viable short- or middle-term minimally invasive alternatives to short-span conventional FDPs and ISCs, while the clinical outcome of IRFDPs as long-term definitive restorations still calls for further research. The indications of IRFDPs should be strictly controlled and monitored. Copyright © 2017 Elsevier Ltd. All rights reserved.

Traffic-Related Air Pollution and Childhood Asthma: Recent Advances and Remaining Gaps in the Exposure Assessment Methods

PubMed Central

Khreis, Haneen; Nieuwenhuijsen, Mark J.

2017-01-01

Background: Current levels of traffic-related air pollution (TRAP) are associated with the development of childhood asthma, although some inconsistencies and heterogeneity remain. An important part of the uncertainty in studies of TRAP-associated asthma originates from uncertainties in the TRAP exposure assessment and assignment methods. In this work, we aim to systematically review the exposure assessment methods used in the epidemiology of TRAP and childhood asthma, highlight recent advances, remaining research gaps and make suggestions for further research. Methods: We systematically reviewed epidemiological studies published up until 8 September 2016 and available in Embase, Ovid MEDLINE (R), and “Transport database”. We included studies which examined the association between children’s exposure to TRAP metrics and their risk of “asthma” incidence or lifetime prevalence, from birth to the age of 18 years old. Results: We found 42 studies which examined the associations between TRAP and subsequent childhood asthma incidence or lifetime prevalence, published since 1999. Land-use regression modelling was the most commonly used method and nitrogen dioxide (NO2) was the most commonly used pollutant in the exposure assessments. Most studies estimated TRAP exposure at the residential address and only a few considered the participants’ mobility. TRAP exposure was mostly assessed at the birth year and only a few studies considered different and/or multiple exposure time windows. We recommend that further work is needed including e.g., the use of new exposure metrics such as the composition of particulate matter, oxidative potential and ultra-fine particles, improved modelling e.g., by combining different exposure assessment models, including mobility of the participants, and systematically investigating different exposure time windows. Conclusions: Although our previous meta-analysis found statistically significant associations for various TRAP exposures and subsequent childhood asthma, further refinement of the exposure assessment may improve the risk estimates, and shed light on critical exposure time windows, putative agents, underlying mechanisms and drivers of heterogeneity. PMID:28304360

Prevalence of psychotic disorders and its association with methodological issues. A systematic review and meta-analyses

PubMed Central

Martín, Carlos; Pastor, Loly

2018-01-01

Objectives The purpose of this study is to provide an updated systematic review to identify studies describing the prevalence of psychosis in order to explore methodological factors that could account for the variation in prevalence estimates. Methods Studies with original data related to the prevalence of psychosis (published between 1990 and 2015) were identified via searching electronic databases and reviewing manual citations. Prevalence estimates were sorted according to prevalence type (point, 12-months and lifetime). The independent association between key methodological variables and the mean effect of prevalence was examined (prevalence type, case-finding setting, method of confirming diagnosis, international classification of diseases, diagnosis category, and study quality) by meta-analytical techniques and random-effects meta-regression. Results Seventy-three primary studies were included, providing a total of 101 estimates of prevalence rates of psychosis. Across these studies, the pooled median point and 12-month prevalence for persons was 3.89 and 4.03 per 1000 respectively; and the median lifetime prevalence was 7.49 per 1000. The result of the random-effects meta-regression analysis revealed a significant effect for the prevalence type, with higher rates of lifetime prevalence than 12-month prevalence (p<0.001). Studies conducted in the general population presented higher prevalence rates than those carried out in populations attended in health/social services (p = 0.006). Compared to the diagnosis of schizophrenia only, prevalence rates were higher in the probable psychotic disorder (p = 0.022) and non-affective psychosis (p = 0.009). Finally, a higher study quality is associated with a lower estimated prevalence of psychotic disorders (p<0.001). Conclusions This systematic review provides a comprehensive comparison of methodologies used in studies of the prevalence of psychosis, which can provide insightful information for future epidemiological studies in adopting the most relevant methodological approach. PMID:29649252

Effects of female genital cutting on physical health outcomes: a systematic review and meta-analysis

PubMed Central

Berg, Rigmor C; Underland, Vigdis; Odgaard-Jensen, Jan; Fretheim, Atle; Vist, Gunn E

2014-01-01

Objective Worldwide, an estimated 125 million girls and women live with female genital mutilation/cutting (FGM/C). We aimed to systematically review the evidence for physical health risks associated with FGM/C. Design We searched 15 databases to identify studies (up to January 2012). Selection criteria were empirical studies reporting physical health outcomes from FGM/C, affecting females with any type of FGM/C, irrespective of ethnicity, nationality and age. Two review authors independently screened titles and abstracts, applied eligibility criteria, assessed methodological study quality and extracted full-text data. To derive overall risk estimates, we combined data from included studies using the Mantel-Haenszel method for unadjusted dichotomous data and the generic inverse-variance method for adjusted data. Outcomes that were sufficiently similar across studies and reasonably resistant to biases were aggregated in meta-analyses. We applied the instrument Grading of Recommendations Assessment, Development and Evaluation to assess the extent to which we have confidence in the effect estimates. Results Our search returned 5109 results, of which 185 studies (3.17 million women) satisfied the inclusion criteria. The risks of systematic and random errors were variable and we focused on key outcomes from the 57 studies with the best available evidence. The most common immediate complications were excessive bleeding, urine retention and genital tissue swelling. The most valid and statistically significant associations for the physical health sequelae of FGM/C were seen on urinary tract infections (unadjusted RR=3.01), bacterial vaginosis (adjusted OR (AOR)=1.68), dyspareunia (RR=1.53), prolonged labour (AOR=1.49), caesarean section (AOR=1.60), and difficult delivery (AOR=1.88). Conclusions While the precise estimation of the frequency and risk of immediate, gynaecological, sexual and obstetric complications is not possible, the results weigh against the continuation of FGM/C and support the diagnosis and management of girls and women suffering the physical risks of FGM/C. Trial registration number This study is registered with PROSPERO, number CRD42012003321. PMID:25416059

Prevalence of Prenatal Alcohol Exposure in the State of Texas as Assessed by Phosphatidylethanol in Newborn Dried Blood Spot Specimens.

PubMed

Bakhireva, Ludmila N; Sharkis, Janet; Shrestha, Shikhar; Miranda-Sohrabji, Tristan J; Williams, Sonnie; Miranda, Rajesh C

2017-05-01

While 2 to 5% of school-aged children in the United States are estimated to be affected by fetal alcohol spectrum disorders (FASD), the prevalence of prenatal alcohol exposure (PAE) might be substantially underreported. Our objective was to systematically estimate the prevalence of PAE in Texas by measuring a direct ethanol metabolite, phosphatidylethanol (PEth), in 1,000 infant residual dried blood spots (irDBSs) in the Texas Newborn Screening Repository. All public health regions (PHRs) were represented proportional to their 2014 birth rate (~0.25% of total births). A cross-sectional study design (unit of observation: individual irDBS cards/infants) with additional ecologic subanalysis (unit of observation: aggregate measures for each Texas PHR) was utilized. The study used PEth-irDBS to estimate the prevalence of PAE within 1 month before delivery for the state of Texas and each Texas PHR. The ecologic subanalysis compared different geographical regions' aggregate prevalence of PAE with (i) retail liquor licenses, (ii) median household income by PHR, and (iii) prevalence of birth outcomes commonly associated with FASD. The sample included an equal number of males and females; 47.8% non-Hispanic White, 40.8% Hispanic, 6.6% African American, and 4.8% Asian infants. In the entire sample, 8.4% of irDBSs were positive for PEth (>20 ng/ml) indicative of PAE within approximately 1 month before delivery. Large regional differences were observed with mostly urban, high median-income regions demonstrating the highest prevalence. Results of this first systematic statewide PAE prevalence study demonstrate that PAE might be more prevalent than previously thought. Active case ascertainment efforts for FASD coupled with systematic objective assessment of PAE should expand to the national level to better estimate public health needs required to provide adequate services for children affected by PAE. Copyright © 2017 by the Research Society on Alcoholism.

Family-based interventions for substance misuse: a systematic review of systematic reviews--protocol.

PubMed

Akram, Yasmin; Copello, Alex; Moore, David

2014-08-15

Worldwide, there are an estimated 15 million individuals with drug use disorders and over five times as many with alcohol use disorders (WHO 1:2, 2005). Most individuals with substance misuse have families who are affected. Initial scoping searches identified an expanse of broad and disparate studies and reviews on the family interventions for substance misuse. This systematic review of systematic reviews aims to bring together the expanse of research on the effectiveness of family-based interventions in substance misuse.Initial scoping searches identified an expanse of broad and disparate studies and reviews on the family interventions for substance misuse. This systematic review of systematic reviews aims to bring together the expanse of research on the effectiveness of family-based interventions in substance misuse. Extensive electronic and manual searches will be undertaken. Screening, data extraction and quality assessment will be undertaken by two reviewers with disagreements resolved through discussion.The inclusion criteria will be that the study is a systematically undertaken review, the population is individuals with substance misuse problems and the interventions include a family-focused component. Reviews that focus on prevention rather than treatment will be excluded. The reviews will be assessed for quality and relevance. The evidence from included systematic reviews will be mapped by focus of intervention (promoting engagement of user into treatment/joint involvement in treatment of user/treating family member in own right) for both adults and adolescents for drug and/or alcohol misusers to allow assessment of the density of available evidence. The higher-quality, up-to-date evidence for each domain will be identified and described, and conclusions will be drawn with limitations of the evidence highlighted. This systematic review of systematic reviews will be an efficient and robust way of looking at the current state of the evidence in the field of family-based interventions for substance misuse. It will evaluate all the available systematic-review-level literature to report on the effectiveness of family-based psychological interventions in improving substance-related outcomes and improving health and wellbeing of substance misusers and/or their families. This will inform future treatment policies and commissioning decisions.In addition, it will identify areas of poor quality, inconsistency and gaps in the evidence base for family-based psychological interventions in substance misuse with respect to secondary evidence in order to inform future research. PROSPERO CRD42014006834.

The application of quantitative methods for identifying and exploring the presence of bias in systematic reviews: PDE-5 inhibitors for erectile dysfunction.

PubMed

Bekkering, G E; Abou-Setta, A M; Kleijnen, J

2008-01-01

A systematic review of PDE-5 inhibitors for erectile dysfunction was performed to evaluate the utility of quantitative methods for identifying and exploring the influence of bias and study quality on pooled outcomes from meta-analyses. We included 123 randomized controlled trials (RCTs). Methodological quality was poorly reported. All three drugs appeared highly effective. Indirect adjusted analyses showed no differences between the three drugs. Funnel plots and statistical tests showed no evidence of small-study effects for sildenafil whereas there was evidence of such bias for tadalafil and vardenafil. Adjustment for missing studies using trim and fill techniques did not alter the pooled estimates substantially. The exclusion of previous sildenafil nonresponders was associated with larger treatment effects for tadalafil. This investigation was hampered by poor reporting of methodological quality, a low number of studies, heterogeneity and large effect sizes. Despite such limitations, a comprehensive assessment of biases should be a routine in systematic reviews.

Accurate Magnetometer/Gyroscope Attitudes Using a Filter with Correlated Sensor Noise

NASA Technical Reports Server (NTRS)

Sedlak, J.; Hashmall, J.

1997-01-01

Magnetometers and gyroscopes have been shown to provide very accurate attitudes for a variety of spacecraft. These results have been obtained, however, using a batch-least-squares algorithm and long periods of data. For use in onboard applications, attitudes are best determined using sequential estimators such as the Kalman filter. When a filter is used to determine attitudes using magnetometer and gyroscope data for input, the resulting accuracy is limited by both the sensor accuracies and errors inherent in the Earth magnetic field model. The Kalman filter accounts for the random component by modeling the magnetometer and gyroscope errors as white noise processes. However, even when these tuning parameters are physically realistic, the rate biases (included in the state vector) have been found to show systematic oscillations. These are attributed to the field model errors. If the gyroscope noise is sufficiently small, the tuned filter 'memory' will be long compared to the orbital period. In this case, the variations in the rate bias induced by field model errors are substantially reduced. Mistuning the filter to have a short memory time leads to strongly oscillating rate biases and increased attitude errors. To reduce the effect of the magnetic field model errors, these errors are estimated within the filter and used to correct the reference model. An exponentially-correlated noise model is used to represent the filter estimate of the systematic error. Results from several test cases using in-flight data from the Compton Gamma Ray Observatory are presented. These tests emphasize magnetometer errors, but the method is generally applicable to any sensor subject to a combination of random and systematic noise.

Prevalence of attention deficit/hyperactivity disorder among children and adolescents in China: a systematic review and meta-analysis.

PubMed

Wang, Tingting; Liu, Kaihua; Li, Zhanzhan; Xu, Yang; Liu, Yuan; Shi, Wenpei; Chen, Lizhang

2017-01-19

Attention deficit/hyperactivity disorder (ADHD), the most common childhood neurobehavioural disorder, can produce a series of negative effects on children, adolescents, and even adults as well as place a serious economic burden on families and society. However, the prevalence of ADHD is not well understood in China. The goal of this study was to estimate the pooled prevalence of ADHD among children and adolescents in China using a systematic review and meta-analysis. A systematic literature search was conducted in PubMed, Web of Science, MEDLINE, CNKI, Wanfang, Weipu and CBM databases, and relevant articles published from inception to March 1, 2016, that provided the prevalence of ADHD among children and adolescents in China were reviewed. The risk of bias in individual studies was assessed using the Risk of Bias Tool for prevalence studies. Pooled-prevalence estimates were calculated with a random-effects model. Sources of heterogeneity were explored using subgroup analyses. Sixty-seven studies with a total of 275,502 individuals were included in this study. The overall pooled-prevalence of ADHD among children and adolescents in China was 6.26% (95% CI: 5.36-7.22%) with significant heterogeneity (I 2  = 99.0%, P < 0.001). The subgroup analyses showed that, the variables "geographic location" and "source of information" partially explained of the heterogeneity in this study (P < 0.05). The prevalence of ADHD-I was the highest of the subtypes, followed by ADHD-HI and ADHD-C. The prevalence of ADHD among children and adolescents in China is generally consistent with the worldwide prevalence and shows that ADHD affects quite a large number of people under 18 years old. However, a nationwide study is needed to provide more accurate estimations.

Impact of Rhinitis on Work Productivity: A Systematic Review.

PubMed

Vandenplas, Olivier; Vinnikov, Denis; Blanc, Paul D; Agache, Ioana; Bachert, Claus; Bewick, Michael; Cardell, Lars-Olaf; Cullinan, Paul; Demoly, Pascal; Descatha, Alexis; Fonseca, Joao; Haahtela, Tari; Hellings, Peter W; Jamart, Jacques; Jantunen, Juha; Kalayci, Ömer; Price, David; Samolinski, Boleslaw; Sastre, Joaquin; Tian, Longxiu; Valero, Antonio L; Zhang, Xinyi; Bousquet, Jean

2017-10-07

Allergic rhinitis (AR) is increasingly acknowledged as having a substantial socioeconomic impact associated with impaired work productivity, although available information remains fragmented. This systematic review summarizes recently available information to provide a quantitative estimate of the burden of AR on work productivity including lost work time (ie, absenteeism) and reduced performance while working (ie, presenteeism). A Medline search retrieved original studies from 2005 to 2015 pertaining to the impact of AR on work productivity. A pooled analysis of results was carried out with studies reporting data collected through the validated Work Productivity and Activity Impairment (WPAI) questionnaire. The search identified 19 observational surveys and 9 interventional studies. Six studies reported economic evaluations. Pooled analysis of WPAI-based studies found an estimated 3.6% (95% confidence interval [CI], 2.4; 4.8%) missed work time and 35.9% (95% CI, 29.7; 42.1%) had impairment in at-work performance due to AR. Economic evaluations indicated that indirect costs associated with lost work productivity are the principal contributor to the total AR costs and result mainly from impaired presenteeism. The severity of AR symptoms was the most consistent disease-related factor associated with a greater impact of AR on work productivity, although ocular symptoms and sleep disturbances may independently affect work productivity. Overall, the pharmacologic treatment of AR showed a beneficial effect on work productivity. This systematic review provides summary estimates of the magnitude of work productivity impairment due to AR and identifies its main determinant factors. This information may help guide both clinicians and health policy makers. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The Significance of an Excess in a Counting Experiment: Assessing the Impact of Systematic Uncertainties and the Case with a Gaussian Background

NASA Astrophysics Data System (ADS)

Vianello, Giacomo

2018-05-01

Several experiments in high-energy physics and astrophysics can be treated as on/off measurements, where an observation potentially containing a new source or effect (“on” measurement) is contrasted with a background-only observation free of the effect (“off” measurement). In counting experiments, the significance of the new source or effect can be estimated with a widely used formula from Li & Ma, which assumes that both measurements are Poisson random variables. In this paper we study three other cases: (i) the ideal case where the background measurement has no uncertainty, which can be used to study the maximum sensitivity that an instrument can achieve, (ii) the case where the background estimate b in the off measurement has an additional systematic uncertainty, and (iii) the case where b is a Gaussian random variable instead of a Poisson random variable. The latter case applies when b comes from a model fitted on archival or ancillary data, or from the interpolation of a function fitted on data surrounding the candidate new source/effect. Practitioners typically use a formula that is only valid when b is large and when its uncertainty is very small, while we derive a general formula that can be applied in all regimes. We also develop simple methods that can be used to assess how much an estimate of significance is sensitive to systematic uncertainties on the efficiency or on the background. Examples of applications include the detection of short gamma-ray bursts and of new X-ray or γ-ray sources. All the techniques presented in this paper are made available in a Python code that is ready to use.

The diagnostic accuracy of screening questionnaires for the identification of adults with epilepsy: a systematic review.

PubMed

Keezer, Mark R; Bouma, Hanni K; Wolfson, Christina

2014-11-01

To describe the diagnostic accuracy of screening questionnaires to identify epilepsy in adults, we performed a systematic review of diagnostic studies that assessed the sensitivity and specificity of such screening questionnaires as compared to a physician's clinical assessment. We searched Ovid MEDLINE (1946 to present) and Ovid EMBASE (1947 to present) for studies that estimated the sensitivity and specificity of nonphysician administered screening questionnaires for adults with epilepsy. Both telephone and in-person administered questionnaires were included, whether applied to population or hospital/clinic-based cohorts. The risk of bias was assessed using the Quality Assessment of Diagnostic Studies-2 (QUADAS-2) tool. Our initial search strategy resulted in 917 records. We found nine studies eligible for inclusion. The estimated sensitivity and specificity of the questionnaires used to identify persons with a lifetime history of epilepsy ranged from 81.5% to 100% and 65.6% to 99.2%, respectively. The sensitivity and specificity of these questionnaires in identifying persons with active epilepsy ranged from 48.6% to 100% and 73.9% to 99.9%, respectively. Overall we found a high risk of bias in patient selection and study flow in the majority of studies. We identified nine validation studies of epilepsy screening questionnaires, summarized their study characteristics, presented their results, and performed a rigorous quality assessment. This review serves as a basis for future studies by providing a systematic review of existing work. Future research addressing previous limitations will ultimately allow us to more accurately estimate the burden and risk of epilepsy in the general population. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Colorectal cancer association with metabolic syndrome and its components: a systematic review with meta-analysis.

PubMed

Esposito, Katherine; Chiodini, Paolo; Capuano, Annalisa; Bellastella, Giuseppe; Maiorino, Maria Ida; Rafaniello, Concetta; Panagiotakos, Demosthenes B; Giugliano, Dario

2013-12-01

We performed a systematic review and meta-analysis of the empirical evidence on the association of metabolic syndrome and its components with colorectal cancer incidence and mortality. A systematic literature search of multiple electronic databases was conducted and complemented by cross-referencing to identify studies published before 31 October 2012. Every included study was to report risk estimates with 95 % confidence intervals for the association between metabolic syndrome and colorectal cancer (incidence or mortality). Core items of identified studies were independently extracted by two reviewers, and results were summarized by standard methods of meta-analysis. We identified 17 studies, which reported on 49 data sets with 11,462 cancer cases. Metabolic syndrome was associated with an increased risk of colorectal cancer incidence and mortality in both men (RR: 1.33, 95 % CI 1.18-1.50, and 1.36, 1.25-1.48, respectively) and women (RR: 1.41, 1.18-1.70, and 1.16, 1.03-1.30, respectively). The risk estimates changed little depending on type of study (cohort vs non cohort), populations (US, Europe, Asia), cancer site (colon and rectum), or definition of the syndrome. The risk estimates for any single factor of the syndrome were significant for higher values of BMI/waist (RR: 1.19, 95 % CI 1.10-1.28), dysglycemia (RR: 1.29, 1.11-1.49), and higher blood pressure (RR: 1.09, 1.01-1.18). Dysglycemia and/or higher BMI/waist explained most of the risk associated with metabolic syndrome. Metabolic syndrome is associated with an increased risk of colorectal cancer incidence and mortality in both sexes. The risk conveyed by the full syndrome is not superior to the sum of its parts.

Diagnostic accuracy of ultrasonography, MRI and MR arthrography in the characterisation of rotator cuff disorders: a systematic review and meta-analysis

PubMed Central

Roy, Jean-Sébastien; Braën, Caroline; Leblond, Jean; Desmeules, François; Dionne, Clermont E; MacDermid, Joy C; Bureau, Nathalie J; Frémont, Pierre

2015-01-01

Background Different diagnostic imaging modalities, such as ultrasonography (US), MRI, MR arthrography (MRA) are commonly used for the characterisation of rotator cuff (RC) disorders. Since the most recent systematic reviews on medical imaging, multiple diagnostic studies have been published, most using more advanced technological characteristics. The first objective was to perform a meta-analysis on the diagnostic accuracy of medical imaging for characterisation of RC disorders. Since US is used at the point of care in environments such as sports medicine, a secondary analysis assessed accuracy by radiologists and non-radiologists. Methods A systematic search in three databases was conducted. Two raters performed data extraction and evaluation of risk of bias independently, and agreement was achieved by consensus. Hierarchical summary receiver-operating characteristic package was used to calculate pooled estimates of included diagnostic studies. Results Diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears was high with overall estimates of sensitivity and specificity over 0.90. As for partial RC tears and tendinopathy, overall estimates of specificity were also high (>0.90), while sensitivity was lower (0.67–0.83). Diagnostic accuracy of US was similar whether a trained radiologist, sonographer or orthopaedist performed it. Conclusions Our results show the diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears. Since full thickness tear constitutes a key consideration for surgical repair, this is an important characteristic when selecting an imaging modality for RC disorder. When considering accuracy, cost, and safety, US is the best option. PMID:25677796

Chest ultrasonography for the emergency diagnosis of traumatic pneumothorax and haemothorax: A systematic review and meta-analysis.

PubMed

Staub, Leonardo Jönck; Biscaro, Roberta Rodolfo Mazzali; Kaszubowski, Erikson; Maurici, Rosemeri

2018-03-01

To assess the accuracy of the chest ultrasonography for the emergency diagnosis of traumatic pneumothorax and haemothorax in adults. Systematic review and meta-analysis. PubMed, EMBASE, Scopus, Web of Science and LILACS (up to 2016) were systematically searched for prospective studies on the diagnostic accuracy of ultrasonography for pneumothorax and haemothorax in adult trauma patients. The references of other systematic reviews and the included studies were checked for further articles. The characteristics and results of the studies were extracted using a standardised form, and their methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Primary analysis was performed considering each hemithorax as an independent unit, while secondary analysis considered each patient. The global diagnostic accuracy of the chest ultrasonography was estimated using the Rutter-Gatsonis hierarchical summary ROC method. Moreover, Reitsma's bivariate model was used to estimate the sensitivity, specificity, positive likelihood ratio (LR + ) and negative likelihood ratio (LR-) of each sonographic sign. This review was previously registered (PROSPERO CRD42016048085). Nineteen studies were included in the review, 17 assessing pneumothorax and 5 assessing haemothorax. The reference standard was always chest tomography, alone or in parallel with chest radiography and observation of the chest tube. The overall methodological quality of the studies was low. The diagnostic accuracy of chest ultrasonography had an area under the curve (AUC) of 0.979 for pneumothorax (Fig). The absence of lung sliding and comet-tail artefacts was the most reported sonographic sign of pneumothorax, with a sensitivity of 0.81 (95% confidence interval [95%CI], 0.71-0.88), specificity of 0.98 (95%CI, 0.97-0.99), LR+ of 67.9 (95%CI, 26.3-148) and LR- of 0.18 (95%CI, 0.11-0.29). An echo-poor or anechoic area in the pleural space was the only sonographic sign for haemothorax, with a sensitivity of 0.60 (95%CI, 0.31-0.86), specificity of 0.98 (95%CI, 0.94-0.99), LR+ of 37.5 (95%CI, 5.26-207.5), LR- of 0.40 (95%CI, 0.17-0.72) and AUC of 0.953. Notwithstanding the limitations of the included studies, this systematic review and meta-analysis suggested that chest ultrasonography is an accurate tool for the diagnostic assessment of traumatic pneumothorax and haemothorax in adults. Copyright © 2018 Elsevier Ltd. All rights reserved.

Shift work, long working hours and preterm birth: a systematic review and meta-analysis.

PubMed

van Melick, M J G J; van Beukering, M D M; Mol, B W; Frings-Dresen, M H W; Hulshof, C T J

2014-11-01

Specific physical activities or working conditions are suspected for increasing the risk of preterm birth (PTB). The aim of this meta-analysis is to review and summarize the pre-existing evidence on the effect of shift work or long working hours on the risk of PTB. We conducted a systematic search in MEDLINE and EMBASE (1990-2013) for observational and intervention studies with original data. We only included articles that met our specific criteria for language, exposure, outcome, data collection and original data that were of at least of moderate quality. The data of the included studies were pooled. Eight high-quality studies and eight moderate-quality studies were included in the meta-analysis. In these studies, no clear or statistically significant relationship between shift work and PTB was found. The summary estimate OR for performing shift work during pregnancy and the risk of PTB were 1.04 (95% CI 0.90-1.20). For long working hours during pregnancy, the summary estimate OR was 1.25 (95% CI 1.01-1.54), indicating a marginally statistically significant relationship but an only slightly elevated risk. Although in many of the included studies a positive association between long working hours and PTB was seen this did reach only marginal statistical significance. In the studies included in this review, working in shifts or in night shifts during pregnancy was not significantly associated with an increased risk for PTB. For both risk factors, due to the lack of high-quality studies focusing on the risks per trimester, in particular the third trimester, a firm conclusion about an association cannot be stated.

Extracting galactic structure parameters from multivariated density estimation

NASA Technical Reports Server (NTRS)

Chen, B.; Creze, M.; Robin, A.; Bienayme, O.

1992-01-01

Multivariate statistical analysis, including includes cluster analysis (unsupervised classification), discriminant analysis (supervised classification) and principle component analysis (dimensionlity reduction method), and nonparameter density estimation have been successfully used to search for meaningful associations in the 5-dimensional space of observables between observed points and the sets of simulated points generated from a synthetic approach of galaxy modelling. These methodologies can be applied as the new tools to obtain information about hidden structure otherwise unrecognizable, and place important constraints on the space distribution of various stellar populations in the Milky Way. In this paper, we concentrate on illustrating how to use nonparameter density estimation to substitute for the true densities in both of the simulating sample and real sample in the five-dimensional space. In order to fit model predicted densities to reality, we derive a set of equations which include n lines (where n is the total number of observed points) and m (where m: the numbers of predefined groups) unknown parameters. A least-square estimation will allow us to determine the density law of different groups and components in the Galaxy. The output from our software, which can be used in many research fields, will also give out the systematic error between the model and the observation by a Bayes rule.

Interventions for non-metastatic squamous cell carcinoma of the skin: systematic review and pooled analysis of observational studies.

PubMed

Lansbury, Louise; Bath-Hextall, Fiona; Perkins, William; Stanton, Wendy; Leonardi-Bee, Jo

2013-11-04

To assess the effects of treatments for non-metastatic invasive squamous cell carcinoma (SCC) of the skin using evidence from observational studies, given the paucity of evidence from randomised controlled trials. Systematic review of observational studies. Medline, Embase, to December 2012. Observational studies of interventions for primary, non-metastatic, invasive, SCC of the skin that reported recurrence during follow-up, quality of life, initial response to treatment, adverse events, cosmetic appearance, or death from disease. Studies were excluded if data for primary cutaneous SCC was not separable from other data. Data were extracted independently by two reviewers. Meta-analysis was performed where appropriate using a random effects model to estimate the pooled proportion of an event with 95% confidence intervals. 118 publications were included, covering seven treatment modalities. Pooled estimates of recurrence of SCCs were lowest after cryotherapy (0.8% (95% confidence interval 0.1% to 2%)) and curettage and electrodesiccation (1.7% (0.5% to 3.4%)), but most treated SCCs were small, low risk lesions. After Mohs micrographic surgery, the pooled estimate of local recurrence during variable follow-up periods from 10 studies was 3.0% (2.2% to 3.9%), which was non-significantly lower than the pooled average local recurrence of 5.4% (2.5% to 9.1%) after standard surgical excision (12 studies), and 6.4% (3.0% to 11.0%) after external radiotherapy (7 studies). After an apparently successful initial response of SCCs to photodynamic therapy, pooled average recurrence of 26.4% (12.3% to 43.7%; 8 studies) was significantly higher than other treatments. Evidence was limited for laser treatment (1 study) and for topical and systemic treatments (mostly single case reports or small non-comparative series with limited follow-up). Many observational studies have looked at different treatment modalities for SCC, but the evidence base for the effectiveness of these interventions is poor. Comparison of outcomes after different treatments should be interpreted cautiously owing to biases inherent in the types of study included, and lack of direct comparisons to enable the estimation of relative treatment effect. Further evidence is needed to develop a prognostic model and stratify individuals at high risk of developing SCC, to improve the evidence base for this common cancer and to optimise clinical management. International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42011001450.

Systematic parameter estimation in data-rich environments for cell signalling dynamics

PubMed Central

Nim, Tri Hieu; Luo, Le; Clément, Marie-Véronique; White, Jacob K.; Tucker-Kellogg, Lisa

2013-01-01

Motivation: Computational models of biological signalling networks, based on ordinary differential equations (ODEs), have generated many insights into cellular dynamics, but the model-building process typically requires estimating rate parameters based on experimentally observed concentrations. New proteomic methods can measure concentrations for all molecular species in a pathway; this creates a new opportunity to decompose the optimization of rate parameters. Results: In contrast with conventional parameter estimation methods that minimize the disagreement between simulated and observed concentrations, the SPEDRE method fits spline curves through observed concentration points, estimates derivatives and then matches the derivatives to the production and consumption of each species. This reformulation of the problem permits an extreme decomposition of the high-dimensional optimization into a product of low-dimensional factors, each factor enforcing the equality of one ODE at one time slice. Coarsely discretized solutions to the factors can be computed systematically. Then the discrete solutions are combined using loopy belief propagation, and refined using local optimization. SPEDRE has unique asymptotic behaviour with runtime polynomial in the number of molecules and timepoints, but exponential in the degree of the biochemical network. SPEDRE performance is comparatively evaluated on a novel model of Akt activation dynamics including redox-mediated inactivation of PTEN (phosphatase and tensin homologue). Availability and implementation: Web service, software and supplementary information are available at www.LtkLab.org/SPEDRE Supplementary information: Supplementary data are available at Bioinformatics online. Contact: LisaTK@nus.edu.sg PMID:23426255

Estimating the prevalence of heterozygous familial hypercholesterolaemia: a systematic review and meta-analysis

PubMed Central

Akioyamen, Leo E; Genest, Jacques; Shan, Shubham D; Reel, Rachel L; Albaum, Jordan M; Chu, Anna; Tu, Jack V

2017-01-01

Objectives Heterozygous familial hypercholesterolaemia (FH) confers a significant risk for premature cardiovascular disease (CVD). However, the estimated prevalence of FH varies substantially among studies. We aimed to provide a summary estimate of FH prevalence in the general population and assess variations in frequency across different sociodemographic characteristics. Setting, participants and outcome measures We searched MEDLINE, EMBASE, Global Health, the Cochrane Library, PsycINFO and PubMed for peer-reviewed literature using validated strategies. Results were limited to studies published in English between January 1990 and January 2017. Studies were eligible if they determined FH prevalence using clinical criteria or DNA-based analyses. We determined a pooled point prevalence of FH in adults and children and assessed the variation of the pooled frequency by age, sex, geographical location, diagnostic method, study quality and year of publication. Estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were investigated through subgroups, meta-regression and sensitivity analyses. Results The pooled prevalence of FH from 19 studies including 2 458 456 unique individuals was 0.40% (95% CI 0.29% to 0.52%) which corresponds to a frequency of 1 in 250 individuals. FH prevalence was found to vary by age and geographical location but not by any other covariates. Results were consistent in sensitivity analyses. Conclusions Our systematic review suggests that FH is a common disorder, affecting 1 in 250 individuals. These findings underscore the need for early detection and management to decrease CVD risk. PMID:28864697

Prevalence of and factors associated with burnout among health care professionals in Arab countries: a systematic review.

PubMed

Elbarazi, I; Loney, T; Yousef, S; Elias, A

2017-07-17

Burnout among healthcare professionals is one of the key challenges affecting health care practice and quality of care. This systematic review aims to (1) estimate the prevalence of burnout among health care professionals (HCP) in Arab countries; and (2) explore individual and work-related factors associated with burnout in this population. Multiple electronic databases were searched for studies published in English or Arabic from January 1980 to November 2014 assessing burnout (using the Maslach Burnout Inventory; MBI) amongst health care professionals (HCP) in Arab countries. Nineteen studies (N = 4108; 49.3% females) conducted on HCP in Bahrain, Egypt, Jordan, Lebanon, Palestine, Saudi Arabia and Yemen were included in this review. There was a wide range of prevalence estimates for the three MBI subscales, high Emotional Exhaustion (20.0-81.0%), high Depersonalization (9.2-80.0%), and low Personal Accomplishment (13.3-85.8%). Gender, nationality, service duration, working hours, and shift patterns were all significantly associated with burnout. Within the constraints of the study and the range of quality papers available, our review revealed moderate-to-high estimates of self-reported burnout among HCP in Arab countries that are similar to prevalence estimates in non-Arabic speaking westernized developed countries. In order to develop culturally appropriate interventions, further research using longitudinal designs is needed to confirm the risk factors for burnout in specific HCP settings and specialties in Arab countries.

The mortality rate of electroconvulsive therapy: a systematic review and pooled analysis.

PubMed

Tørring, N; Sanghani, S N; Petrides, G; Kellner, C H; Østergaard, S D

2017-05-01

Electroconvulsive therapy (ECT) remains underutilized because of fears of cognitive and medical risks, including the risk of death. In this study, we aimed to assess the mortality rate of ECT by means of a systematic review and pooled analysis. The study was conducted in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The ECT-related mortality rate was calculated as the total number of ECT-related deaths reported in the included studies divided by the total number of ECT treatments. Fifteen studies with data from 32 countries reporting on a total of 766 180 ECT treatments met the inclusion criteria. Sixteen cases of ECT-related death were reported in the included studies yielding an ECT-related mortality rate of 2.1 per 100 000 treatments (95% CI: 1.2-3.4). In the nine studies that were published after 2001 (covering 414 747 treatments), there was only one reported ECT-related death. The ECT-related mortality rate was estimated at 2.1 per 100 000 treatments. In comparison, a recent analysis of the mortality of general anesthesia in relation to surgical procedures reported a mortality rate of 3.4 per 100 000. Our findings document that death caused by ECT is an extremely rare event. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strategy Developed for Selecting Optimal Sensors for Monitoring Engine Health

NASA Technical Reports Server (NTRS)

2004-01-01

Sensor indications during rocket engine operation are the primary means of assessing engine performance and health. Effective selection and location of sensors in the operating engine environment enables accurate real-time condition monitoring and rapid engine controller response to mitigate critical fault conditions. These capabilities are crucial to ensure crew safety and mission success. Effective sensor selection also facilitates postflight condition assessment, which contributes to efficient engine maintenance and reduced operating costs. Under the Next Generation Launch Technology program, the NASA Glenn Research Center, in partnership with Rocketdyne Propulsion and Power, has developed a model-based procedure for systematically selecting an optimal sensor suite for assessing rocket engine system health. This optimization process is termed the systematic sensor selection strategy. Engine health management (EHM) systems generally employ multiple diagnostic procedures including data validation, anomaly detection, fault-isolation, and information fusion. The effectiveness of each diagnostic component is affected by the quality, availability, and compatibility of sensor data. Therefore systematic sensor selection is an enabling technology for EHM. Information in three categories is required by the systematic sensor selection strategy. The first category consists of targeted engine fault information; including the description and estimated risk-reduction factor for each identified fault. Risk-reduction factors are used to define and rank the potential merit of timely fault diagnoses. The second category is composed of candidate sensor information; including type, location, and estimated variance in normal operation. The final category includes the definition of fault scenarios characteristic of each targeted engine fault. These scenarios are defined in terms of engine model hardware parameters. Values of these parameters define engine simulations that generate expected sensor values for targeted fault scenarios. Taken together, this information provides an efficient condensation of the engineering experience and engine flow physics needed for sensor selection. The systematic sensor selection strategy is composed of three primary algorithms. The core of the selection process is a genetic algorithm that iteratively improves a defined quality measure of selected sensor suites. A merit algorithm is employed to compute the quality measure for each test sensor suite presented by the selection process. The quality measure is based on the fidelity of fault detection and the level of fault source discrimination provided by the test sensor suite. An inverse engine model, whose function is to derive hardware performance parameters from sensor data, is an integral part of the merit algorithm. The final component is a statistical evaluation algorithm that characterizes the impact of interference effects, such as control-induced sensor variation and sensor noise, on the probability of fault detection and isolation for optimal and near-optimal sensor suites.

Small-Area Estimation of Spatial Access to Care and Its Implications for Policy.

PubMed

Gentili, Monica; Isett, Kim; Serban, Nicoleta; Swann, Julie

2015-10-01

Local or small-area estimates to capture emerging trends across large geographic regions are critical in identifying and addressing community-level health interventions. However, they are often unavailable due to lack of analytic capabilities in compiling and integrating extensive datasets and complementing them with the knowledge about variations in state-level health policies. This study introduces a modeling approach for small-area estimation of spatial access to pediatric primary care that is data "rich" and mathematically rigorous, integrating data and health policy in a systematic way. We illustrate the sensitivity of the model to policy decision making across large geographic regions by performing a systematic comparison of the estimates at the census tract and county levels for Georgia and California. Our results show the proposed approach is able to overcome limitations of other existing models by capturing patient and provider preferences and by incorporating possible changes in health policies. The primary finding is systematic underestimation of spatial access, and inaccurate estimates of disparities across population and across geography at the county level with respect to those at the census tract level with implications on where to focus and which type of interventions to consider.

Particulate air pollution and panel studies in children: a systematic review

PubMed Central

Ward, D; Ayres, J

2004-01-01

Aims: To systematically review the results of such studies in children, estimate summary measures of effect, and investigate potential sources of heterogeneity. Methods: Studies were identified by searching electronic databases to June 2002, including those where outcomes and particulate level measurements were made at least daily for ⩾8 weeks, and analysed using an appropriate regression model. Study results were compared using forest plots, and fixed and random effects summary effect estimates obtained. Publication bias was considered using a funnel plot. Results: Twenty two studies were identified, all except two reporting PM10 (24 hour mean) >50 µg.m-3. Reported effects of PM10 on PEF were widely spread and smaller than those for PM2.5 (fixed effects summary: -0.012 v -0.063 l.min-1 per µg.m-3 rise). A similar pattern was evident for symptoms. Random effects models produced larger estimates. Overall, in between-study comparisons, panels of children with diagnosed asthma or pre-existing respiratory symptoms appeared less affected by PM10 levels than those without, and effect estimates were larger where studies were conducted in higher ozone conditions. Larger PM10 effect estimates were obtained from studies using generalised estimating equations to model autocorrelation and where results were derived by pooling subject specific regression coefficients. A funnel plot of PM10 results for PEF was markedly asymmetrical. Conclusions: The majority of identified studies indicate an adverse effect of particulate air pollution that is greater for PM2.5 than PM10. However, results show considerable heterogeneity and there is evidence consistent with publication bias, so limited confidence may be placed on summary estimates of effect. The possibility of interaction between particle and ozone effects merits further investigation, as does variability due to analytical differences that alter the interpretation of final estimates. PMID:15031404

Iraq War mortality estimates: a systematic review.

PubMed

Tapp, Christine; Burkle, Frederick M; Wilson, Kumanan; Takaro, Tim; Guyatt, Gordon H; Amad, Hani; Mills, Edward J

2008-03-07

In March 2003, the United States invaded Iraq. The subsequent number, rates, and causes of mortality in Iraq resulting from the war remain unclear, despite intense international attention. Understanding mortality estimates from modern warfare, where the majority of casualties are civilian, is of critical importance for public health and protection afforded under international humanitarian law. We aimed to review the studies, reports and counts on Iraqi deaths since the start of the war and assessed their methodological quality and results. We performed a systematic search of 15 electronic databases from inception to January 2008. In addition, we conducted a non-structured search of 3 other databases, reviewed study reference lists and contacted subject matter experts. We included studies that provided estimates of Iraqi deaths based on primary research over a reported period of time since the invasion. We excluded studies that summarized mortality estimates and combined non-fatal injuries and also studies of specific sub-populations, e.g. under-5 mortality. We calculated crude and cause-specific mortality rates attributable to violence and average deaths per day for each study, where not already provided. Thirteen studies met the eligibility criteria. The studies used a wide range of methodologies, varying from sentinel-data collection to population-based surveys. Studies assessed as the highest quality, those using population-based methods, yielded the highest estimates. Average deaths per day ranged from 48 to 759. The cause-specific mortality rates attributable to violence ranged from 0.64 to 10.25 per 1,000 per year. Our review indicates that, despite varying estimates, the mortality burden of the war and its sequelae on Iraq is large. The use of established epidemiological methods is rare. This review illustrates the pressing need to promote sound epidemiologic approaches to determining mortality estimates and to establish guidelines for policy-makers, the media and the public on how to interpret these estimates.

A Bayesian Machine Learning Model for Estimating Building Occupancy from Open Source Data

DOE PAGES

Stewart, Robert N.; Urban, Marie L.; Duchscherer, Samantha E.; ...

2016-01-01

Understanding building occupancy is critical to a wide array of applications including natural hazards loss analysis, green building technologies, and population distribution modeling. Due to the expense of directly monitoring buildings, scientists rely in addition on a wide and disparate array of ancillary and open source information including subject matter expertise, survey data, and remote sensing information. These data are fused using data harmonization methods which refer to a loose collection of formal and informal techniques for fusing data together to create viable content for building occupancy estimation. In this paper, we add to the current state of the artmore » by introducing the Population Data Tables (PDT), a Bayesian based informatics system for systematically arranging data and harmonization techniques into a consistent, transparent, knowledge learning framework that retains in the final estimation uncertainty emerging from data, expert judgment, and model parameterization. PDT probabilistically estimates ambient occupancy in units of people/1000ft2 for over 50 building types at the national and sub-national level with the goal of providing global coverage. The challenge of global coverage led to the development of an interdisciplinary geospatial informatics system tool that provides the framework for capturing, storing, and managing open source data, handling subject matter expertise, carrying out Bayesian analytics as well as visualizing and exporting occupancy estimation results. We present the PDT project, situate the work within the larger community, and report on the progress of this multi-year project.Understanding building occupancy is critical to a wide array of applications including natural hazards loss analysis, green building technologies, and population distribution modeling. Due to the expense of directly monitoring buildings, scientists rely in addition on a wide and disparate array of ancillary and open source information including subject matter expertise, survey data, and remote sensing information. These data are fused using data harmonization methods which refer to a loose collection of formal and informal techniques for fusing data together to create viable content for building occupancy estimation. In this paper, we add to the current state of the art by introducing the Population Data Tables (PDT), a Bayesian model and informatics system for systematically arranging data and harmonization techniques into a consistent, transparent, knowledge learning framework that retains in the final estimation uncertainty emerging from data, expert judgment, and model parameterization. PDT probabilistically estimates ambient occupancy in units of people/1000 ft 2 for over 50 building types at the national and sub-national level with the goal of providing global coverage. The challenge of global coverage led to the development of an interdisciplinary geospatial informatics system tool that provides the framework for capturing, storing, and managing open source data, handling subject matter expertise, carrying out Bayesian analytics as well as visualizing and exporting occupancy estimation results. We present the PDT project, situate the work within the larger community, and report on the progress of this multi-year project.« less

Risk factors for persistent problems following acute whiplash injury: update of a systematic review and meta-analysis.

PubMed

Walton, David M; Macdermid, Joy C; Giorgianni, Anthony A; Mascarenhas, Joanna C; West, Stephen C; Zammit, Caroline A

2013-02-01

Systematic review and meta-analysis. To update a previous review and meta-analysis on risk factors for persistent problems following whiplash secondary to a motor vehicle accident. Prognosis in whiplash-associated disorder (WAD) has become an active area of research, perhaps owing to the difficulty of treating chronic problems. A previously published review and meta-analysis of prognostic factors included primary sources up to May 2007. Since that time, more research has become available, and an update to that original review is warranted. A systematic search of international databases was conducted, with rigorous inclusion criteria focusing on studies published between May 2007 and May 2012. Articles were scored, and data were extracted and pooled to estimate the odds ratio for any factor that had at least 3 independent data points in the literature. Four new cohorts (n = 1121) were identified. In combination with findings of a previous review, 12 variables were found to be significant predictors of poor outcome following whiplash, 9 of which were new (n = 2) or revised (n = 7) as a result of additional data. The significant variables included high baseline pain intensity (greater than 5.5/10), report of headache at inception, less than postsecondary education, no seatbelt in use during the accident, report of low back pain at inception, high Neck Disability Index score (greater than 14.5/50), preinjury neck pain, report of neck pain at inception (regardless of intensity), high catastrophizing, female sex, WAD grade 2 or 3, and WAD grade 3 alone. Those variables robust to publication bias included high pain intensity, female sex, report of headache at inception, less than postsecondary education, high Neck Disability Index score, and WAD grade 2 or 3. Three existing variables (preaccident history of headache, rear-end collision, older age) and 1 additional novel variable (collision severity) were refined or added in this updated review but showed no significant predictive value. This review identified 2 additional prognostic factors and refined the estimates of 7 previously identified factors, bringing the total number of significant predictors across the 2 reviews to 12. These factors can be easily identified in a clinical setting to provide estimates of prognosis following whiplash.

Instruments evaluating the quality of the clinical learning environment in nursing education: A systematic review of psychometric properties.

PubMed

Mansutti, Irene; Saiani, Luisa; Grassetti, Luca; Palese, Alvisa

2017-03-01

The clinical learning environment is fundamental to nursing education paths, capable of affecting learning processes and outcomes. Several instruments have been developed in nursing education, aimed at evaluating the quality of the clinical learning environments; however, no systematic review of the psychometric properties and methodological quality of these studies has been performed to date. The aims of the study were: 1) to identify validated instruments evaluating the clinical learning environments in nursing education; 2) to evaluate critically the methodological quality of the psychometric property estimation used; and 3) to compare psychometric properties across the instruments available. A systematic review of the literature (using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines) and an evaluation of the methodological quality of psychometric properties (using the COnsensus-based Standards for the selection of health Measurement INstruments guidelines). The Medline and CINAHL databases were searched. Eligible studies were those that satisfied the following criteria: a) validation studies of instruments evaluating the quality of clinical learning environments; b) in nursing education; c) published in English or Italian; d) before April 2016. The included studies were evaluated for the methodological quality of the psychometric properties measured and then compared in terms of both the psychometric properties and the methodological quality of the processes used. The search strategy yielded a total of 26 studies and eight clinical learning environment evaluation instruments. A variety of psychometric properties have been estimated for each instrument, with differing qualities in the methodology used. Concept and construct validity were poorly assessed in terms of their significance and rarely judged by the target population (nursing students). Some properties were rarely considered (e.g., reliability, measurement error, criterion validity), whereas others were frequently estimated, but using different coefficients and statistical analyses (e.g., internal consistency, structural validity), thus rendering comparison across instruments difficult. Moreover, the methodological quality adopted in the property assessments was poor or fair in most studies, compromising the goodness of the psychometric values estimated. Clinical learning placements represent the key strategies in educating the future nursing workforce: instruments evaluating the quality of the settings, as well as their capacity to promote significant learning, are strongly recommended. Studies estimating psychometric properties, using an increased quality of research methodologies are needed in order to support nursing educators in the process of clinical placements accreditation and quality improvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Global hydrocephalus epidemiology and incidence: systematic review and meta-analysis.

PubMed

Dewan, Michael C; Rattani, Abbas; Mekary, Rania; Glancz, Laurence J; Yunusa, Ismaeel; Baticulon, Ronnie E; Fieggen, Graham; Wellons, John C; Park, Kee B; Warf, Benjamin C

2018-04-27

OBJECTIVE Hydrocephalus is one of the most common brain disorders, yet a reliable assessment of the global burden of disease is lacking. The authors sought a reliable estimate of the prevalence and annual incidence of hydrocephalus worldwide. METHODS The authors performed a systematic literature review and meta-analysis to estimate the incidence of congenital hydrocephalus by WHO region and World Bank income level using the MEDLINE/PubMed and Cochrane Database of Systematic Reviews databases. A global estimate of pediatric hydrocephalus was obtained by adding acquired forms of childhood hydrocephalus to the baseline congenital figures using neural tube defect (NTD) registry data and known proportions of posthemorrhagic and postinfectious cases. Adult forms of hydrocephalus were also examined qualitatively. RESULTS Seventy-eight articles were included from the systematic review, representative of all WHO regions and each income level. The pooled incidence of congenital hydrocephalus was highest in Africa and Latin America (145 and 316 per 100,000 births, respectively) and lowest in the United States/Canada (68 per 100,000 births) (p for interaction < 0.1). The incidence was higher in low- and middle-income countries (123 per 100,000 births; 95% CI 98-152 births) than in high-income countries (79 per 100,000 births; 95% CI 68-90 births) (p for interaction < 0.01). While likely representing an underestimate, this model predicts that each year, nearly 400,000 new cases of pediatric hydrocephalus will develop worldwide. The greatest burden of disease falls on the African, Latin American, and Southeast Asian regions, accounting for three-quarters of the total volume of new cases. The high crude birth rate, greater proportion of patients with postinfectious etiology, and higher incidence of NTDs all contribute to a case volume in low- and middle-income countries that outweighs that in high-income countries by more than 20-fold. Global estimates of adult and other forms of acquired hydrocephalus are lacking. CONCLUSIONS For the first time in a global model, the annual incidence of pediatric hydrocephalus is estimated. Low- and middle-income countries incur the greatest burden of disease, particularly those within the African and Latin American regions. Reliable incidence and burden figures for adult forms of hydrocephalus are absent in the literature and warrant specific investigation. A global effort to address hydrocephalus in regions with the greatest demand is imperative to reduce disease incidence, morbidity, mortality, and disparities of access to treatment.

Accurate determinations of alpha(s) from realistic lattice QCD.

PubMed

Mason, Q; Trottier, H D; Davies, C T H; Foley, K; Gray, A; Lepage, G P; Nobes, M; Shigemitsu, J

2005-07-29

We obtain a new value for the QCD coupling constant by combining lattice QCD simulations with experimental data for hadron masses. Our lattice analysis is the first to (1) include vacuum polarization effects from all three light-quark flavors (using MILC configurations), (2) include third-order terms in perturbation theory, (3) systematically estimate fourth and higher-order terms, (4) use an unambiguous lattice spacing, and (5) use an [symbol: see text](a2)-accurate QCD action. We use 28 different (but related) short-distance quantities to obtain alpha((5)/(MS))(M(Z)) = 0.1170(12).

Evidence-Based Systematic Review: Effects of Oral Motor Interventions on Feeding and Swallowing in Preterm Infants

ERIC Educational Resources Information Center

Arvedson, Joan; Clark, Heather; Lazarus, Cathy; Schooling, Tracy; Frymark, Tobi

2010-01-01

Purpose: To conduct an evidence-based systematic review and provide an estimate of the effects of oral motor interventions (OMIs) on feeding/swallowing outcomes (both physiological and functional) and pulmonary health in preterm infants. Method: A systematic search of the literature published from 1960 to 2007 was conducted. Articles meeting the…

The Epidemiology and Associated Phenomenology of Formal Thought Disorder: A Systematic Review

PubMed Central

Roche, Eric; Creed, Lisa; MacMahon, Donagh; Brennan, Daria; Clarke, Mary

2015-01-01

Background: Authors of the Diagnostic and Statistical Manual, Fifth Edition (DSM-V) have recommended to “integrate dimensions into clinical practice.” The epidemiology and associated phenomenology of formal thought disorder (FTD) have been described but not reviewed. We aimed to carry out a systematic review of FTD to this end. Methods: A systematic review of FTD literature, from 1978 to 2013, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 881 abstracts were reviewed and 120 articles met inclusion criteria; articles describing FTD factor structure (n = 15), prevalence and longitudinal course (n = 41), role in diagnosis (n = 22), associated clinical variables (n = 56), and influence on outcome (n = 35) were included. Prevalence estimates for FTD in psychosis range from 5% to 91%. Dividing FTD into domains, by factor analysis, can accurately identify 91% of psychotic diagnoses. FTD is associated with increased clinical severity. Poorer outcomes are predicted by negative thought disorder, more so than the typical construct of “disorganized speech.” Conclusion: FTD is a common symptom of psychosis and may be considered a marker of illness severity. Detailed dimensional assessment of FTD can clarify diagnosis and may help predict prognosis. PMID:25180313

Systematic Identification of Preferred Orbits for Magnetospheric Missions. 1; Single Satellites

NASA Technical Reports Server (NTRS)

Stern, David P.

2000-01-01

This is a systematic attempt to identify and assess near-equatorial, high-eccentricity orbits best suited for studying the Earth's magnetosphere, in particular its most dynamic part, the plasma sheet of the magnetotail. The study was motivated by the design needs of a multi-spacecraft "constellation" mission, stressing low cost, minimal active control and economic launch strategies, and both quantitative and qualitative aspects were investigated. On one hand, by collecting hourly samples throughout the year, accurate estimates were obtained of the coverage of different regions, and of the frequency and duration of long eclipses. On the other hand, an intuitive understanding was developed of the factors which determine the merits of the mission, including long-range factors due to perturbations by the Moon, Sun and the Earth's equatorial bulge.

A Systematic Review of the Correlates of Violence Against Sex Workers

PubMed Central

Deering, Kathleen N.; Amin, Avni; Shoveller, Jean; Nesbitt, Ariel; Garcia-Moreno, Claudia; Duff, Putu; Argento, Elena; Shannon, Kate

2014-01-01

We conducted a systematic review in June 2012 (updated September 2013) to examine the prevalence and factors shaping sexual or physical violence against sex workers globally. We identified 1536 (update = 340) unique articles. We included 28 studies, with 14 more contributing to violence prevalence estimates. Lifetime prevalence of any or combined workplace violence ranged from 45% to 75% and over the past year, 32% to 55%. Growing research links contextual factors with violence against sex workers, alongside known interpersonal and individual risks. This high burden of violence against sex workers globally and large gaps in epidemiological data support the need for research and structural interventions to better document and respond to the contextual factors shaping this violence. Measurement and methodological innovation, in partnership with sex work communities, are critical. PMID:24625169

Prevalence of scoliosis among primary and middle school students in Mainland China: a systematic review and meta-analysis.

PubMed

Zhang, Hongqi; Guo, Chaofeng; Tang, Mingxing; Liu, Shaohua; Li, Jinsong; Guo, Qiang; Chen, Lizhang; Zhu, Yong; Zhao, Shushan

2015-01-01

Systematic review and meta-analysis of published prevalence of scoliosis among primary and middle school students in Mainland China. To evaluate the prevalence of scoliosis among primary and middle school students in Mainland China. There is substantial uncertainty regarding the prevalence of scoliosis in Mainland China among the primary and middle school students. We conducted a systematic review aiming to describe the prevalence of scoliosis in Mainland China. We systematically reviewed the published epidemiological studies or reports on the prevalence of scoliosis in Chinese cities. Scopus, PubMed, WanFang Database, CNKI, China National Science and Technology Digital Library, and WeiPu Database were searched for studies reporting a prevalence estimate for scoliosis in primary and middle school students. Meta-analyses were performed to estimate the pooled prevalence of scoliosis by STATA 12.0. Subgroup analyses were conducted according to the sex, age, and geographical area. A total of 38 articles, including 697,043 patients, were eligible for inclusion in this review. Meta-analyses revealed the prevalence of scoliosis to be 1.02% (95% [confidence interval] CI, 0.85-1.18) among the primary and middle school students in Mainland China. The female to male ratio was 1.54 (95% CI, 1.35-1.74; P < 0.001). According to the subgroup analysis by different ages, the prevalence of scoliosis increased from 0.73% (95% CI, 0.55-0.90) to 1.14% (95% CI, 0.86-1.42). Meta-analyses showed that the prevalence of scoliosis in Mainland China was 1.02% among the primary and middle school students. The prevalence of scoliosis in females was higher than in males and the ratio was 1.54. As they grew older, the prevalence of scoliosis increased in the students.

Prevalence of transactive response DNA-binding protein 43 (TDP-43) proteinopathy in cognitively normal older adults: systematic review and meta-analysis.

PubMed

Nascimento, C; Di Lorenzo Alho, A T; Bazan Conceição Amaral, C; Leite, R E P; Nitrini, R; Jacob-Filho, W; Pasqualucci, C A; Hokkanen, S R K; Hunter, S; Keage, H; Kovacs, G G; Grinberg, L T; Suemoto, C K

2018-04-01

To perform a systematic review and meta-analysis on the prevalence of transactive response DNA-binding protein 43 (TDP-43) proteinopathy in cognitively normal older adults. We systematically reviewed and performed a meta-analysis on the prevalence of TDP-43 proteinopathy in older adults with normal cognition, evaluated by the Mini-Mental State Examination or the Clinical Dementia Rating. We estimated the overall prevalence of TDP-43 using random-effect models, and stratified by age, sex, sample size, study quality, antibody used to assess TDP-43 aggregates, analysed brain regions, Braak stage, Consortium to Establish a Registry for Alzheimer's Disease score, hippocampal sclerosis and geographic location. A total of 505 articles were identified in the systematic review, and 7 were included in the meta-analysis with 1196 cognitively normal older adults. We found an overall prevalence of TDP-43 proteinopathy of 24%. Prevalence of TDP-43 proteinopathy varied widely across geographic location (North America: 37%, Asia: 29%, Europe: 14%, and Latin America: 11%). Estimated prevalence of TDP-43 proteinopathy also varied according to study quality (quality score >7: 22% vs. quality score <7: 42%), antibody used to assess TDP-43 proteinopathy (native: 18% vs. hyperphosphorylated: 24%) and presence of hippocampal sclerosis (without 24% vs. with hippocampal sclerosis: 48%). Other stratified analyses by age, sex, analysed brain regions, sample size and severity of AD neuropathology showed similar pooled TDP-43 prevalence. Different methodology to access TDP-43, and also differences in lifestyle and genetic factors across different populations could explain our results. Standardization of TDP-43 measurement, and future studies about the impact of genetic and lifestyle characteristics on the development of neurodegenerative diseases are needed. © 2017 British Neuropathological Society.

Effects of complex interventions in ‘skin cancer prevention and treatment’: protocol for a mixed-method systematic review with qualitative comparative analysis

PubMed Central

Breitbart, Eckhard; Köberlein-Neu, Juliane

2017-01-01

Introduction Occurring from ultraviolet radiation combined with impairing ozone levels, uncritical sun exposure and use of tanning beds an increasing number of people are affected by different types of skin cancer. But preventive interventions like skin cancer screening are still missing the evidence for effectiveness and therefore are criticised. Fundamental for an appropriate course of action is to approach the defined parameters as measures for effectiveness critically. A prerequisite should be the critical application of used parameter that are defined as measures for effectiveness. This research seeks to establish, through the available literature, the effects and conditions that prove the effectiveness of prevention strategies in skin cancer. Method and analysis A mixed-method approach is employed to combine quantitative to qualitative methods and answer what effects can display effectiveness considering time horizon, perspective and organisational level and what are essential and sufficient conditions to prove effectiveness and cost-effectiveness in skin cancer prevention strategies. A systematic review will be performed to spot studies from any design and assess the data quantitatively and qualitatively. Included studies from each key question will be summarised by characteristics like population, intervention, comparison, outcomes, study design, endpoints, effect estimator and so on. Beside statistical relevancies for a systematic review the qualitative method of qualitative comparative analysis (QCA) will be performed. The estimated outcomes from this review and QCA are the accomplishment and absence of effects that are appropriate for application in effectiveness assessments and further cost-effectiveness assessment. Ethics and dissemination Formal ethical approval is not required as primary data will not be collected. Trial registration number International Prospective Register for Systematic Reviews number CRD42017053859. PMID:28877950

Risk of relapse after natalizumab withdrawal

PubMed Central

Vukusic, Sandra; Casey, Romain; Debard, Nadine; Stankoff, Bruno; Mrejen, Serge; Uhry, Zoe; Van Ganse, Eric; Castot, Anne; Clanet, Michel; Lubetzki, Catherine; Confavreux, Christian

2016-01-01

Objective: To assess disease activity within 12 months after natalizumab (NZ) discontinuation in a large French postmarketing cohort. Methods: In France, patients exposed at least once to NZ were included in the TYSEDMUS observational and multicenter cohort, part of the French NZ Risk Management Plan. Clinical disease activity during the year following NZ discontinuation was assessed in this cohort. Time to first relapse after NZ stop was analyzed using Kaplan-Meier method and potentially associated factors were studied using a multivariate Cox model. Results: Out of the 4,055 patients with multiple sclerosis (MS) included in TYSEDMUS, 1,253 discontinued NZ and 715 of them had relevant data for our study. The probability of relapse within the year after NZ stop was estimated at 45% (95% confidence interval 0.41–0.49). Conclusions: This large and systematic survey of patients with MS after NZ withdrawal allows quantifying the risk of increased disease activity following treatment discontinuation. This study provides large-scale, multicenter, systematic data after NZ cessation in real-life settings. PMID:27844037

Mortality in adults with hypopituitarism: a systematic review and meta-analysis.

PubMed

Jasim, Sina; Alahdab, Fares; Ahmed, Ahmed T; Tamhane, Shrikant; Prokop, Larry J; Nippoldt, Todd B; Murad, M Hassan

2017-04-01

Hypopituitarism is a rare disorder with significant morbidity. To study the evidence on the association of premature mortality and hypopituitarism. A comprehensive search of multiple databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus was conducted through August, 2015. Eligible studies that evaluated patients with hypopituitarism and reported mortality estimates were selected following a predefined protocol. Reviewers, independently and in duplicate, extracted data and assessed the risk of bias. We included 12 studies (published 1996-2015) that reported on 23,515 patients. Compared to the general population, hypopituitarism was associated with an overall excess mortality (weighted SMR of 1.55; 95 % CI 1.14-2.11), I 2  = 97.8 %, P = 0.000. Risk factors for increased mortality included younger age at diagnosis, female gender, diagnosis of craniopharyngioma, radiation therapy, transcranial surgery, diabetes insipidus and hypogonadism. Hypopituitarism may be associated with premature mortality in adults. Risk is particularly higher in women and those diagnosed at a younger age.

Contribution made by biomarkers of status to an FP6 Network of Excellence, EURopean micronutrient RECommendations Aligned (EURRECA).

PubMed

Fairweather-Tait, Susan J

2011-08-01

Dietary reference values for micronutrients vary considerably among countries, and harmonization is needed to facilitate nutrition policy and public health strategies at the European and global levels. The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence is developing generic instruments for systematically deriving and updating micronutrient reference values and dietary recommendations. These include best practice guidelines, interlinked web pages, online databases, and decision trees. Journal supplements have been published on micronutrient intakes and status, and an ongoing activity of EURRECA is the completion of systematic reviews on associations between intakes, status, and various health outcomes for priority micronutrients (ie, iron, zinc, folate, vitamin B-12, and iodine), which were selected by using a triage technique. Future activities include meta-analyses to identify dose-response relations and the variability, factorial estimates of requirements, bioavailability from whole diets, effects of genotype, and modeling techniques for addressing dietary recommendations for combinations of nutrients with common health endpoints.

Directional variance adjustment: bias reduction in covariance matrices based on factor analysis with an application to portfolio optimization.

PubMed

Bartz, Daniel; Hatrick, Kerr; Hesse, Christian W; Müller, Klaus-Robert; Lemm, Steven

2013-01-01

Robust and reliable covariance estimates play a decisive role in financial and many other applications. An important class of estimators is based on factor models. Here, we show by extensive Monte Carlo simulations that covariance matrices derived from the statistical Factor Analysis model exhibit a systematic error, which is similar to the well-known systematic error of the spectrum of the sample covariance matrix. Moreover, we introduce the Directional Variance Adjustment (DVA) algorithm, which diminishes the systematic error. In a thorough empirical study for the US, European, and Hong Kong stock market we show that our proposed method leads to improved portfolio allocation.

Directional Variance Adjustment: Bias Reduction in Covariance Matrices Based on Factor Analysis with an Application to Portfolio Optimization

PubMed Central

Bartz, Daniel; Hatrick, Kerr; Hesse, Christian W.; Müller, Klaus-Robert; Lemm, Steven

2013-01-01

Robust and reliable covariance estimates play a decisive role in financial and many other applications. An important class of estimators is based on factor models. Here, we show by extensive Monte Carlo simulations that covariance matrices derived from the statistical Factor Analysis model exhibit a systematic error, which is similar to the well-known systematic error of the spectrum of the sample covariance matrix. Moreover, we introduce the Directional Variance Adjustment (DVA) algorithm, which diminishes the systematic error. In a thorough empirical study for the US, European, and Hong Kong stock market we show that our proposed method leads to improved portfolio allocation. PMID:23844016

Errors in the estimation method for the rejection of vibrations in adaptive optics systems

NASA Astrophysics Data System (ADS)

Kania, Dariusz

2017-06-01

In recent years the problem of the mechanical vibrations impact in adaptive optics (AO) systems has been renewed. These signals are damped sinusoidal signals and have deleterious effect on the system. One of software solutions to reject the vibrations is an adaptive method called AVC (Adaptive Vibration Cancellation) where the procedure has three steps: estimation of perturbation parameters, estimation of the frequency response of the plant, update the reference signal to reject/minimalize the vibration. In the first step a very important problem is the estimation method. A very accurate and fast (below 10 ms) estimation method of these three parameters has been presented in several publications in recent years. The method is based on using the spectrum interpolation and MSD time windows and it can be used to estimate multifrequency signals. In this paper the estimation method is used in the AVC method to increase the system performance. There are several parameters that affect the accuracy of obtained results, e.g. CiR - number of signal periods in a measurement window, N - number of samples in the FFT procedure, H - time window order, SNR, b - number of ADC bits, γ - damping ratio of the tested signal. Systematic errors increase when N, CiR, H decrease and when γ increases. The value for systematic error is approximately 10^-10 Hz/Hz for N = 2048 and CiR = 0.1. This paper presents equations that can used to estimate maximum systematic errors for given values of H, CiR and N before the start of the estimation process.

Knowledge transfer to clinicians and consumers by the Cochrane Musculoskeletal Group.

PubMed

Santesso, Nancy; Maxwell, Lara; Tugwell, Peter S; Wells, George A; O'connor, Annette M; Judd, Maria; Buchbinder, Rachelle

2006-11-01

The Cochrane Musculoskeletal Group (CMSG) is one of 50 groups of the Cochrane Collaboration that prepares, maintains, and disseminates systematic reviews of treatments for musculoskeletal diseases. Once systematic reviews are completed, the next challenge is presenting the results in useful formats to be integrated into the healthcare decisions of clinicians and consumers. The CMSG recommends 3 methods to aid knowledge translation and exchange between clinicians and patients: produce clinical relevance tables, create graphical displays using face figures, and write consumer summaries and patient decision aids. Accordingly, CMSG has developed specific guidelines to help researchers and authors convert the pooled estimates of metaanalyses in the systematic reviews to user-friendly numbers. First, clinical relevance tables are developed that include absolute and relative benefits or harms and the numbers needed to treat. Next, the numbers from the clinical relevance tables are presented graphically using faces. The faces represent a group of 100 people and are shaded according to how many people out of 100 benefited or were harmed by the interventions. The user-friendly numbers are also included in short summaries and decision aids written for patients. The different levels of detail in the summaries and decision aids provide patients with tools to prepare them to discuss treatment options with their clinicians. Methods to improve the effects and usability of systematic reviews by providing results in more clinically relevant formats are essential. Both clinicians and consumers can use these products to use evidence-based information in individual and shared decision-making.

Hypertension and the risk of endometrial cancer: a systematic review and meta-analysis of case-control and cohort studies.

PubMed

Aune, Dagfinn; Sen, Abhijit; Vatten, Lars J

2017-04-07

A history of hypertension has been associated with increased risk of endometrial cancer in several studies, but the results have not been consistent. We conducted a systematic review and meta-analysis of case-control and cohort studies to clarify the association between hypertension and endometrial cancer risk. PubMed and Embase databases were searched up to 27 th of February 2016. Prospective and case-control studies which reported adjusted relative risk estimates and 95% confidence intervals of endometrial cancer associated with a hypertension diagnosis were included. Summary relative risks were estimated using a random effects model. Nineteen case-control studies and 6 cohort studies were included. The summary RR was 1.61 (95% CI: 1.41-1.85, I 2  = 86%) for all studies, 1.73 (95% CI: 1.45-2.06, I 2  = 89%) for case-control studies and 1.32 (95% CI: 1.12-1.56, I 2  = 47%) for cohort studies. The association between hypertension and endometrial cancer was weaker, but still significant, among studies with adjustment for smoking, BMI, oral contraceptive use, and parity, compared to studies without such adjustment. This meta-analysis suggest an increased risk of endometrial cancer among patients with hypertension, however, further studies with more comprehensive adjustments for confounders are warranted to clarify the association.

Prevalence of asymptomatic Zika virus infection: a systematic review.

PubMed

Haby, Michelle M; Pinart, Mariona; Elias, Vanessa; Reveiz, Ludovic

2018-06-01

To conduct a systematic review to estimate the prevalence of asymptomatic Zika virus infection in the general population and in specific population groups. We searched PubMed®, Embase® and LILACS online databases from inception to 26 January 2018. We included observational epidemiological studies where laboratory testing was used to confirm positive exposure of participants to Zika virus and in which Zika virus symptom status was also recorded. We excluded studies in which having symptoms of Zika virus was a criterion for inclusion. The main outcome assessed was percentage of all Zika virus-positive participants who were asymptomatic. We used a quality-effects approach and the double arcsine transformation for the meta-analysis. We assessed 753 studies for inclusion, of which 23 were included in the meta-analysis, totalling 11 305 Zika virus-positive participants. The high degree of heterogeneity in the studies ( I 2  = 99%) suggests that the pooled prevalence of asymptomatic Zika virus-positive participants was probably not a robust estimate. Analysis based on subgroups of the population (general population, returned travellers, blood donors, adults with Guillain-Barré syndrome, pregnant women and babies with microcephaly) was not able to explain the heterogeneity. Funnel and Doi plots showed major asymmetry, suggesting selection bias or true heterogeneity. Better-quality research is needed, using standardized methods, to determine the true prevalence of asymptomatic Zika virus and whether it varies between populations or over time.

Measurement of predictive validity in violence risk assessment studies: a second-order systematic review.

PubMed

Singh, Jay P; Desmarais, Sarah L; Van Dorn, Richard A

2013-01-01

The objective of the present review was to examine how predictive validity is analyzed and reported in studies of instruments used to assess violence risk. We reviewed 47 predictive validity studies published between 1990 and 2011 of 25 instruments that were included in two recent systematic reviews. Although all studies reported receiver operating characteristic curve analyses and the area under the curve (AUC) performance indicator, this methodology was defined inconsistently and findings often were misinterpreted. In addition, there was between-study variation in benchmarks used to determine whether AUCs were small, moderate, or large in magnitude. Though virtually all of the included instruments were designed to produce categorical estimates of risk - through the use of either actuarial risk bins or structured professional judgments - only a minority of studies calculated performance indicators for these categorical estimates. In addition to AUCs, other performance indicators, such as correlation coefficients, were reported in 60% of studies, but were infrequently defined or interpreted. An investigation of sources of heterogeneity did not reveal significant variation in reporting practices as a function of risk assessment approach (actuarial vs. structured professional judgment), study authorship, geographic location, type of journal (general vs. specialized audience), sample size, or year of publication. Findings suggest a need for standardization of predictive validity reporting to improve comparison across studies and instruments. Copyright © 2013 John Wiley & Sons, Ltd.

Summary of long-baseline systematics session at CETUP*2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherdack, Daniel; Worcester, Elizabeth

2015-10-15

A session studying systematics in long-baseline neutrino oscillation physics was held July 14-18, 2014 as part of CETUP* 2014. Systematic effects from flux normalization and modeling, modeling of cross sections and nuclear interactions, and far detector effects were addressed. Experts presented the capabilities of existing and planned tools. A program of study to determine estimates of and requirements for the size of these effects was designed. This document summarizes the results of the CETUP* systematics workshop and the current status of systematic uncertainty studies in long-baseline neutrino oscillation measurements.

Valuation Diagramming and Accounting of Transactive Energy Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makhmalbaf, Atefe; Hammerstrom, Donald J.; Huang, Qiuhua

Transactive energy (TE) systems support both economic and technical objectives of a power system including efficiency and reliability. TE systems utilize value-driven mechanisms to coordinate and balance responsive supply and demand in the power system. Economic performance of TE systems cannot be assessed without estimating their value. Estimating the potential value of transactive energy systems requires a systematic valuation methodology that can capture value exchanges among different stakeholders (i.e., actors) and ultimately estimate impact of one TE design and compare it against another one. Such a methodology can help decision makers choose the alternative that results in preferred outcomes. Thismore » paper presents a valuation methodology developed to assess value of TE systems. A TE use-case example is discussed, and metrics identified in the valuation process are quantified using a TE simulation program.« less

CosmoSIS: Modular cosmological parameter estimation

DOE PAGES

Zuntz, J.; Paterno, M.; Jennings, E.; ...

2015-06-09

Cosmological parameter estimation is entering a new era. Large collaborations need to coordinate high-stakes analyses using multiple methods; furthermore such analyses have grown in complexity due to sophisticated models of cosmology and systematic uncertainties. In this paper we argue that modularity is the key to addressing these challenges: calculations should be broken up into interchangeable modular units with inputs and outputs clearly defined. Here we present a new framework for cosmological parameter estimation, CosmoSIS, designed to connect together, share, and advance development of inference tools across the community. We describe the modules already available in CosmoSIS, including CAMB, Planck, cosmicmore » shear calculations, and a suite of samplers. Lastly, we illustrate it using demonstration code that you can run out-of-the-box with the installer available at http://bitbucket.org/joezuntz/cosmosis« less

Prevalence and patterns of congenital heart diseases in Africa: a systematic review and meta-analysis protocol.

PubMed

Tankeu, Aurel T; Bigna, Jean Joel R; Nansseu, Jobert Richie N; Aminde, Leopold Ndemnge; Danwang, Celestin; Temgoua, Mazou N; Noubiap, Jean Jacques N

2017-02-14

Congenital heart diseases (CHD) are common causes of cardiovascular morbidity and mortality among young children and adolescents living in Africa. Accurate epidemiological data are needed in order to evaluate and improve preventive strategies. This review aims to determine the prevalence of CHD and their main patterns in Africa. This systematic review and meta-analysis will include cross-sectional, case-control and cohort studies of populations residing inside African countries, which have reported the prevalence of CHD, confirmed by an echocardiographic examination and/or describing different patterns of these abnormalities in Africa. Relevant abstracts published without language restriction from 1 January 1986 to 31 December 2016 will be searched in PubMed, Exerpta Medica Database and online African journals as well as references of included articles and relevant reviews. Two review authors will independently screen, select studies, extract data and assess the risk of bias in each study. The study-specific estimates will be pooled through a random-effects meta-analysis model to obtain an overall summary estimate of the prevalence of CHD across studies. Clinical and statistical heterogeneity will be assessed, and we will pool studies judged to be clinically homogeneous. On the other hand, statistical heterogeneity will be evaluated by the χ2 test on Cochrane's Q statistic. Funnel-plots analysis and Egger's test will be used to detect publication bias. Results will be presented by geographic region (central, eastern, northern, southern and western Africa). The current study will be based on published data, and thus ethical approval is not required. This systematic review and meta-analysis is expected to serve as a base which could help in estimating and evaluating the burden of these abnormalities on the African continent. The final report of this study will be published in a peer-reviewed journal. PROSPERO CRD42016052880. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

High-Accuracy Decoupling Estimation of the Systematic Coordinate Errors of an INS and Intensified High Dynamic Star Tracker Based on the Constrained Least Squares Method

PubMed Central

Jiang, Jie; Yu, Wenbo; Zhang, Guangjun

2017-01-01

Navigation accuracy is one of the key performance indicators of an inertial navigation system (INS). Requirements for an accuracy assessment of an INS in a real work environment are exceedingly urgent because of enormous differences between real work and laboratory test environments. An attitude accuracy assessment of an INS based on the intensified high dynamic star tracker (IHDST) is particularly suitable for a real complex dynamic environment. However, the coupled systematic coordinate errors of an INS and the IHDST severely decrease the attitude assessment accuracy of an INS. Given that, a high-accuracy decoupling estimation method of the above systematic coordinate errors based on the constrained least squares (CLS) method is proposed in this paper. The reference frame of the IHDST is firstly converted to be consistent with that of the INS because their reference frames are completely different. Thereafter, the decoupling estimation model of the systematic coordinate errors is established and the CLS-based optimization method is utilized to estimate errors accurately. After compensating for error, the attitude accuracy of an INS can be assessed based on IHDST accurately. Both simulated experiments and real flight experiments of aircraft are conducted, and the experimental results demonstrate that the proposed method is effective and shows excellent performance for the attitude accuracy assessment of an INS in a real work environment. PMID:28991179

Adherence to Mediterranean Diet Reduces Incident Frailty Risk: Systematic Review and Meta-Analysis.

PubMed

Kojima, Gotaro; Avgerinou, Christina; Iliffe, Steve; Walters, Kate

2018-04-01

To conduct a systematic review of the literature on prospective cohort studies examining associations between adherence to a Mediterranean diet and incident frailty and to perform a meta-analysis to synthesize the pooled risk estimates. Systematic review and meta-analysis. Embase, MEDLINE, CINAHL, PsycINFO, and Cochrane Library were systematically searched on September 14, 2017. We reviewed references of included studies and relevant review papers and performed forward citation tracking for additional studies. Corresponding authors were contacted for additional data necessary for a meta-analysis. Community-dwelling older adults (mean age ≥60). Incident frailty risk according to adherence to a Mediterranean diet. Two reviewers independently screened the title, abstract, and full text to ascertain the eligibility of 125 studies that the systematic search of the literature identified, and four studies were included (5,789 older people with mean follow-up of 3.9 years). Two reviewers extracted data from the studies independently. All four studies provided adjusted odds ratios (ORs) of incident frailty risk according to three Mediterranean diet score (MDS) groups (0-3, 4-5, and 6-9). Greater adherence to a Mediterranean diet was associated with significantly lower incident frailty risk (pooled OR = 0.62, 95% CI = 0.47-0.82, P = .001 for MDS 4-5; pooled OR = 0.44, 95% CI = 0.31-0.64, P < .001 for MDS 6-9) than poorer adherence (MDS 0-3). Neither significant heterogeneity (I 2  = 0-16%, P = .30) nor evidence of publication bias was observed. Greater adherence to a Mediterranean diet is associated with significantly lower risk of incident frailty in community-dwelling older people. Future studies should confirm these findings and evaluate whether adherence to a Mediterranean diet can reduce the risk of frailty, including in non-Mediterranean populations. © 2018, Copyright the Authors Journal compilation © 2018, The American Geriatrics Society.

Alcohol Consumption and the Physical Availability of Take-Away Alcohol: Systematic Reviews and Meta-Analyses of the Days and Hours of Sale and Outlet Density.

PubMed

Sherk, Adam; Stockwell, Tim; Chikritzhs, Tanya; Andréasson, Sven; Angus, Colin; Gripenberg, Johanna; Holder, Harold; Holmes, John; Mäkelä, Pia; Mills, Megan; Norström, Thor; Ramstedt, Mats; Woods, Jonathan

2018-01-01

Systematic reviews and meta-analyses were completed studying the effect of changes in the physical availability of take-away alcohol on per capita alcohol consumption. Previous reviews examining this topic have not focused on off-premise outlets where take-away alcohol is sold and have not completed meta-analyses. Systematic reviews were conducted separately for policies affecting the temporal availability (days and hours of sale) and spatial availability (outlet density) of take-away alcohol. Studies were included up to December 2015. Quality criteria were used to select articles that studied the effect of changes in these policies on alcohol consumption with a focus on natural experiments. Random-effects meta-analyses were applied to produce the estimated effect of an additional day of sale on total and beverage-specific consumption. Separate systematic reviews identified seven studies regarding days and hours of sale and four studies regarding density. The majority of articles included in these systematic reviews, for days/hours of sale (7/7) and outlet density (3/4), concluded that restricting the physical availability of take-away alcohol reduces per capita alcohol consumption. Meta-analyses studying the effect of adding one additional day of sale found that this was associated with per capita consumption increases of 3.4% (95% CI [2.7, 4.1]) for total alcohol, 5.3% (95% CI [3.2, 7.4]) for beer, 2.6% (95% CI [1.8, 3.5]) for wine, and 2.6% (95% CI [2.1, 3.2]) for spirits. The small number of included studies regarding hours of sale and density precluded meta-analysis. The results of this study suggest that decreasing the physical availability of take-away alcohol will decrease per capita consumption. As decreasing per capita consumption has been shown to reduce alcohol-related harm, restricting the physical availability of take-away alcohol would be expected to result in improvements to public health.

NatHER: protocol for systematic evaluation of trends in survival among patients with HER2-positive advanced breast cancer.

PubMed

Korner, Eli J; Morris, Anne; Allen, Isabel Elaine; Hurvitz, Sara; Beattie, Mary S; Kalesan, Bindu

2015-10-01

Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) is an aggressive form of breast cancer and is historically associated with poor outcomes compared with HER2-negative MBC. Since 1998, four drugs have been globally approved for the targeted treatment of HER2-positive MBC. Additional advances in patient care-such as improved breast cancer screening, HER2 testing, and supportive care-have also occurred. The objective of this systematic review and meta-analysis is to determine whether there has been a cumulative change in survival over time in patients with HER2-positive advanced breast cancer based on results from interventional clinical trials (ICTs) and observational studies and to compare outcomes across these types of studies. A systematic search of Medline, EMBASE, and the Cochrane Central Register of Controlled Trials will be performed. Two investigators will independently assess each abstract for inclusion. English language reports of ICTs and observational studies that include patients with HER2-positive advanced breast cancer from 1987 onwards will be considered. The primary outcome of interest is overall survival; secondary outcomes include progression-free survival and safety. Data on clinical outcomes, as well as on study design, study population, treatment/intervention, methodological quality, and outcomes, will be extracted using a structured codebook developed by the authors for this study. Standard and cumulative random effects meta-analysis will be performed to derive pooled risk estimates, both overall and by study design, controlling for covariates such as aggregate demographic and clinical characteristics of patients, treatment/intervention, and study characteristics. Heterogeneity of studies will be evaluated using the I(2) statistic. Differences in risk estimates by quality characteristics will be performed using meta-regression. This study will evaluate current and evolving trends in survival associated with HER2-positive advanced breast cancer over nearly 30 years and will build upon prior, less comprehensive, systematic analyses. This information is important to patients, healthcare providers, and researchers, particularly in the advanced disease setting, in which new therapies have been recently approved. Including observational studies allows us to evaluate real-world effectiveness; useful information will be gained by comparing findings from observational studies with those from ICTs. PROSPERO CRD42014014345.

The effect of oral rehydration solution and recommended home fluids on diarrhoea mortality

PubMed Central

Munos, Melinda K.; Walker, Christa L Fischer; Black, Robert E

2010-01-01

Background Most diarrhoeal deaths can be prevented through the prevention and treatment of dehydration. Oral rehydration solution (ORS) and recommended home fluids (RHFs) have been recommended since 1970s and 1980s to prevent and treat diarrhoeal dehydration. We sought to estimate the effects of these interventions on diarrhoea mortality in children aged <5 years. Methods We conducted a systematic review to identify studies evaluating the efficacy and effectiveness of ORS and RHFs and abstracted study characteristics and outcome measures into standardized tables. We categorized the evidence by intervention and outcome, conducted meta-analyses for all outcomes with two or more data points and graded the quality of the evidence supporting each outcome. The CHERG Rules for Evidence Review were used to estimate the effectiveness of ORS and RHFs against diarrhoea mortality. Results We identified 205 papers for abstraction, of which 157 were included in the meta-analyses of ORS outcomes and 12 were included in the meta-analyses of RHF outcomes. We estimated that ORS may prevent 93% of diarrhoea deaths. Conclusions ORS is effective against diarrhoea mortality in home, community and facility settings; however, there is insufficient evidence to estimate the effectiveness of RHFs against diarrhoea mortality. PMID:20348131

Complex systematic review - Perioperative antibiotics in conjunction with dental implant placement.

PubMed

Lund, Bodil; Hultin, Margareta; Tranaeus, Sofia; Naimi-Akbar, Aron; Klinge, Björn

2015-09-01

The aim of this study was to revisit the available scientific literature regarding perioperative antibiotics in conjunction with implant placement by combining the recommended methods for systematic reviews and complex systematic reviews. A search of Medline (OVID), The Cochrane Library (Wiley), EMBASE, PubMed and Health technology assessment (HTA) organizations was performed, in addition to a complementary hand-search. Selected systematic reviews and primary studies were assessed using GRADE and AMSTAR, respectively. A meta-analysis was performed. The literature search identified 846 papers of which 10 primary studies and seven systematic reviews were included. Quality assessment of the systematic reviews revealed two studies of moderate risk of bias and five with high risk of bias. The two systematic reviews of moderate risk of bias stated divergent numbers needed to treat (NNT) to prevent one patient from implant failure. Four of the primary studies comparing antibiotic prophylaxis with placebo were estimated to be of low, or moderate, risk of bias and subjected to meta-analysis. The NNT was 50 (pooled RR 0.39, 95% CI 0.18, 0.84; P = 0.02). None of these four studies individually show a statistical significant benefit of antibiotic prophylaxis. Furthermore, narrative analysis of the studies eligible for meta-analysis reveals clinical heterogeneity regarding intervention and smoking. Antibiotic prophylaxis in conjunction with implant placement reduced the risk for implant loss by 2%. However, the sub-analysis of the primary studies suggests that there is no benefit of antibiotic prophylaxis in uncomplicated implant surgery in healthy patient. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Applicability and feasibility of systematic review for performing evidence-based risk assessment in food and feed safety.

PubMed

Aiassa, E; Higgins, J P T; Frampton, G K; Greiner, M; Afonso, A; Amzal, B; Deeks, J; Dorne, J-L; Glanville, J; Lövei, G L; Nienstedt, K; O'connor, A M; Pullin, A S; Rajić, A; Verloo, D

2015-01-01

Food and feed safety risk assessment uses multi-parameter models to evaluate the likelihood of adverse events associated with exposure to hazards in human health, plant health, animal health, animal welfare, and the environment. Systematic review and meta-analysis are established methods for answering questions in health care, and can be implemented to minimize biases in food and feed safety risk assessment. However, no methodological frameworks exist for refining risk assessment multi-parameter models into questions suitable for systematic review, and use of meta-analysis to estimate all parameters required by a risk model may not be always feasible. This paper describes novel approaches for determining question suitability and for prioritizing questions for systematic review in this area. Risk assessment questions that aim to estimate a parameter are likely to be suitable for systematic review. Such questions can be structured by their "key elements" [e.g., for intervention questions, the population(s), intervention(s), comparator(s), and outcome(s)]. Prioritization of questions to be addressed by systematic review relies on the likely impact and related uncertainty of individual parameters in the risk model. This approach to planning and prioritizing systematic review seems to have useful implications for producing evidence-based food and feed safety risk assessment.

Where's the evidence? a systematic review of economic analyses of residential aged care infrastructure.

PubMed

Easton, Tiffany; Milte, Rachel; Crotty, Maria; Ratcliffe, Julie

2017-03-21

Residential care infrastructure, in terms of the characteristics of the organisation (such as proprietary status, size, and location) and the physical environment, have been found to directly influence resident outcomes. This review aimed to summarise the existing literature of economic evaluations of residential care infrastructure. A systematic review of English language articles using AgeLine, CINAHL, Econlit, Informit (databases in Health; Business and Law; Social Sciences), Medline, ProQuest, Scopus, and Web of Science with retrieval up to 14 December 2015. The search strategy combined terms relating to nursing homes, economics, and older people. Full economic evaluations, partial economic evaluations, and randomised trials reporting more limited economic information, such as estimates of resource use or costs of interventions were included. Data was extracted using predefined data fields and synthesized in a narrative summary to address the stated review objective. Fourteen studies containing an economic component were identified. None of the identified studies attempted to systematically link costs and outcomes in the form of a cost-benefit, cost-effectiveness, or cost-utility analysis. There was a wide variation in approaches taken for valuing the outcomes associated with differential residential care infrastructures: 8 studies utilized various clinical outcomes as proxies for the quality of care provided, and 2 focused on resident outcomes including agitation, quality of life, and the quality of care interactions. Only 2 studies included residents living with dementia. Robust economic evidence is needed to inform aged care facility design. Future research should focus on identifying appropriate and meaningful outcome measures that can be used at a service planning level, as well as the broader health benefits and cost-saving potential of different organisational and environmental characteristics in residential care. International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42015015977 .

Preoperative identification of a suspicious adnexal mass: a systematic review and meta-analysis.

PubMed

Dodge, Jason E; Covens, Allan L; Lacchetti, Christina; Elit, Laurie M; Le, Tien; Devries-Aboud, Michaela; Fung-Kee-Fung, Michael

2012-07-01

To systematically review the existing literature in order to determine the optimal strategy for preoperative identification of the adnexal mass suspicious for ovarian cancer. A review of all systematic reviews and guidelines published between 1999 and 2009 was conducted as a first step. After the identification of a 2004 AHRQ systematic review on the topic, searches of MEDLINE for studies published since 2004 was also conducted to update and supplement the evidentiary base. A bivariate, random-effects meta-regression model was used to produce summary estimates of sensitivity and specificity and to plot summary ROC curves with 95% confidence regions. Four meta-analyses and 53 primary studies were included in this review. The diagnostic performance of each technology was compared and contrasted based on the summary data on sensitivity and specificity obtained from the meta-analysis. Results suggest that 3D ultrasonography has both a higher sensitivity and specificity when compared to 2D ultrasound. Established morphological scoring systems also performed with respectable sensitivity and specificity, each with equivalent diagnostic competence. Explicit scoring systems did not perform as well as other diagnostic testing methods. Assessment of an adnexal mass by colour Doppler technology was neither as sensitive nor as specific as simple ultrasonography. Of the three imaging modalities considered, MRI appeared to perform the best, although results were not statistically different from CT. PET did not perform as well as either MRI or CT. The measurement of the CA-125 tumour marker appears to be less reliable than do other available assessment methods. The best available evidence was collected and included in this rigorous systematic review and meta-analysis. The abundant evidentiary base provided the context and direction for the diagnosis of early-staged ovarian cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies

PubMed Central

Katagiri, Ryoko; Yuan, Xiaoyi; Kobayashi, Satomi; Sasaki, Satoshi

2017-01-01

Background Although several reports concerning the association of iodine excess and thyroid disease have appeared, no systematic review of the association between iodine excess intake and thyroid diseases, especially hyperthyroidism and hypothyroidism, has yet been reported. Method We conducted a systematic search of Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials databases, Ichushi-Web and CiNii database for intervention trials and observational studies. Search terms were constructed from related words for excess AND iodine intake or excretion AND thyroid hormones or diseases AND study designs. After considering the qualitative heterogeneity among studies, a meta-analysis was conducted and odds ratios and 95% confidence intervals (CI) were estimated in random-effects models. A protocol was registered with PROSPERO (No. CRD42015028081). Results 50 articles were included, including three intervention trials, six case-control studies, six follow-up studies and 35 cross-sectional studies. Three cross-sectional studies in adults included in meta-analysis. Odds ratio of overt and subclinical hypothyroidism between excess and adequate populations were 2.78 (CI:1.47 to 5.27) and 2.03 (CI:1.58 to 2.62) in adults, respectively. Source of excess iodine status was mainly iodized salt or water in included studies. Conclusion Although universal salt iodization has improved goiter rates, chronic exposure to excess iodine from water or poorly monitored salt are risk factors for hypothyroidism in free-living populations. Monitoring of both iodine concentration in salt as well as the iodine concentration in local drinking water are essential to preventing thyroid diseases. Hypothyroidism should be also carefully monitored in areas with excess iodine. Because of the low quality and limited number of included studies, further evidence and review are required. PMID:28282437

Monte-Carlo-based phase retardation estimator for polarization sensitive optical coherence tomography

NASA Astrophysics Data System (ADS)

Duan, Lian; Makita, Shuichi; Yamanari, Masahiro; Lim, Yiheng; Yasuno, Yoshiaki

2011-08-01

A Monte-Carlo-based phase retardation estimator is developed to correct the systematic error in phase retardation measurement by polarization sensitive optical coherence tomography (PS-OCT). Recent research has revealed that the phase retardation measured by PS-OCT has a distribution that is neither symmetric nor centered at the true value. Hence, a standard mean estimator gives us erroneous estimations of phase retardation, and it degrades the performance of PS-OCT for quantitative assessment. In this paper, the noise property in phase retardation is investigated in detail by Monte-Carlo simulation and experiments. A distribution transform function is designed to eliminate the systematic error by using the result of the Monte-Carlo simulation. This distribution transformation is followed by a mean estimator. This process provides a significantly better estimation of phase retardation than a standard mean estimator. This method is validated both by numerical simulations and experiments. The application of this method to in vitro and in vivo biological samples is also demonstrated.

Global, regional, and national levels and causes of maternal mortality during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

PubMed

Kassebaum, Nicholas J; Bertozzi-Villa, Amelia; Coggeshall, Megan S; Shackelford, Katya A; Steiner, Caitlyn; Heuton, Kyle R; Gonzalez-Medina, Diego; Barber, Ryan; Huynh, Chantal; Dicker, Daniel; Templin, Tara; Wolock, Timothy M; Ozgoren, Ayse Abbasoglu; Abd-Allah, Foad; Abera, Semaw Ferede; Abubakar, Ibrahim; Achoki, Tom; Adelekan, Ademola; Ademi, Zanfina; Adou, Arsène Kouablan; Adsuar, José C; Agardh, Emilie E; Akena, Dickens; Alasfoor, Deena; Alemu, Zewdie Aderaw; Alfonso-Cristancho, Rafael; Alhabib, Samia; Ali, Raghib; Al Kahbouri, Mazin J; Alla, François; Allen, Peter J; AlMazroa, Mohammad A; Alsharif, Ubai; Alvarez, Elena; Alvis-Guzmán, Nelson; Amankwaa, Adansi A; Amare, Azmeraw T; Amini, Hassan; Ammar, Walid; Antonio, Carl A T; Anwari, Palwasha; Arnlöv, Johan; Arsenijevic, Valentina S Arsic; Artaman, Ali; Asad, Majed Masoud; Asghar, Rana J; Assadi, Reza; Atkins, Lydia S; Badawi, Alaa; Balakrishnan, Kalpana; Basu, Arindam; Basu, Sanjay; Beardsley, Justin; Bedi, Neeraj; Bekele, Tolesa; Bell, Michelle L; Bernabe, Eduardo; Beyene, Tariku J; Bhutta, Zulfiqar; Bin Abdulhak, Aref; Blore, Jed D; Basara, Berrak Bora; Bose, Dipan; Breitborde, Nicholas; Cárdenas, Rosario; Castañeda-Orjuela, Carlos A; Castro, Ruben Estanislao; Catalá-López, Ferrán; Cavlin, Alanur; Chang, Jung-Chen; Che, Xuan; Christophi, Costas A; Chugh, Sumeet S; Cirillo, Massimo; Colquhoun, Samantha M; Cooper, Leslie Trumbull; Cooper, Cyrus; da Costa Leite, Iuri; Dandona, Lalit; Dandona, Rakhi; Davis, Adrian; Dayama, Anand; Degenhardt, Louisa; De Leo, Diego; del Pozo-Cruz, Borja; Deribe, Kebede; Dessalegn, Muluken; deVeber, Gabrielle A; Dharmaratne, Samath D; Dilmen, Uğur; Ding, Eric L; Dorrington, Rob E; Driscoll, Tim R; Ermakov, Sergei Petrovich; Esteghamati, Alireza; Faraon, Emerito Jose A; Farzadfar, Farshad; Felicio, Manuela Mendonca; Fereshtehnejad, Seyed-Mohammad; de Lima, Graça Maria Ferreira; Forouzanfar, Mohammad H; França, Elisabeth B; Gaffikin, Lynne; Gambashidze, Ketevan; Gankpé, Fortuné Gbètoho; Garcia, Ana C; Geleijnse, Johanna M; Gibney, Katherine B; Giroud, Maurice; Glaser, Elizabeth L; Goginashvili, Ketevan; Gona, Philimon; González-Castell, Dinorah; Goto, Atsushi; Gouda, Hebe N; Gugnani, Harish Chander; Gupta, Rahul; Gupta, Rajeev; Hafezi-Nejad, Nima; Hamadeh, Randah Ribhi; Hammami, Mouhanad; Hankey, Graeme J; Harb, Hilda L; Havmoeller, Rasmus; Hay, Simon I; Pi, Ileana B Heredia; Hoek, Hans W; Hosgood, H Dean; Hoy, Damian G; Husseini, Abdullatif; Idrisov, Bulat T; Innos, Kaire; Inoue, Manami; Jacobsen, Kathryn H; Jahangir, Eiman; Jee, Sun Ha; Jensen, Paul N; Jha, Vivekanand; Jiang, Guohong; Jonas, Jost B; Juel, Knud; Kabagambe, Edmond Kato; Kan, Haidong; Karam, Nadim E; Karch, André; Karema, Corine Kakizi; Kaul, Anil; Kawakami, Norito; Kazanjan, Konstantin; Kazi, Dhruv S; Kemp, Andrew H; Kengne, Andre Pascal; Kereselidze, Maia; Khader, Yousef Saleh; Khalifa, Shams Eldin Ali Hassan; Khan, Ejaz Ahmed; Khang, Young-Ho; Knibbs, Luke; Kokubo, Yoshihiro; Kosen, Soewarta; Defo, Barthelemy Kuate; Kulkarni, Chanda; Kulkarni, Veena S; Kumar, G Anil; Kumar, Kaushalendra; Kumar, Ravi B; Kwan, Gene; Lai, Taavi; Lalloo, Ratilal; Lam, Hilton; Lansingh, Van C; Larsson, Anders; Lee, Jong-Tae; Leigh, James; Leinsalu, Mall; Leung, Ricky; Li, Xiaohong; Li, Yichong; Li, Yongmei; Liang, Juan; Liang, Xiaofeng; Lim, Stephen S; Lin, Hsien-Ho; Lipshultz, Steven E; Liu, Shiwei; Liu, Yang; Lloyd, Belinda K; London, Stephanie J; Lotufo, Paulo A; Ma, Jixiang; Ma, Stefan; Machado, Vasco Manuel Pedro; Mainoo, Nana Kwaku; Majdan, Marek; Mapoma, Christopher Chabila; Marcenes, Wagner; Marzan, Melvin Barrientos; Mason-Jones, Amanda J; Mehndiratta, Man Mohan; Mejia-Rodriguez, Fabiola; Memish, Ziad A; Mendoza, Walter; Miller, Ted R; Mills, Edward J; Mokdad, Ali H; Mola, Glen Liddell; Monasta, Lorenzo; de la Cruz Monis, Jonathan; Hernandez, Julio Cesar Montañez; Moore, Ami R; Moradi-Lakeh, Maziar; Mori, Rintaro; Mueller, Ulrich O; Mukaigawara, Mitsuru; Naheed, Aliya; Naidoo, Kovin S; Nand, Devina; Nangia, Vinay; Nash, Denis; Nejjari, Chakib; Nelson, Robert G; Neupane, Sudan Prasad; Newton, Charles R; Ng, Marie; Nieuwenhuijsen, Mark J; Nisar, Muhammad Imran; Nolte, Sandra; Norheim, Ole F; Nyakarahuka, Luke; Oh, In-Hwan; Ohkubo, Takayoshi; Olusanya, Bolajoko O; Omer, Saad B; Opio, John Nelson; Orisakwe, Orish Ebere; Pandian, Jeyaraj D; Papachristou, Christina; Park, Jae-Hyun; Caicedo, Angel J Paternina; Patten, Scott B; Paul, Vinod K; Pavlin, Boris Igor; Pearce, Neil; Pereira, David M; Pesudovs, Konrad; Petzold, Max; Poenaru, Dan; Polanczyk, Guilherme V; Polinder, Suzanne; Pope, Dan; Pourmalek, Farshad; Qato, Dima; Quistberg, D Alex; Rafay, Anwar; Rahimi, Kazem; Rahimi-Movaghar, Vafa; ur Rahman, Sajjad; Raju, Murugesan; Rana, Saleem M; Refaat, Amany; Ronfani, Luca; Roy, Nobhojit; Pimienta, Tania Georgina Sánchez; Sahraian, Mohammad Ali; Salomon, Joshua A; Sampson, Uchechukwu; Santos, Itamar S; Sawhney, Monika; Sayinzoga, Felix; Schneider, Ione J C; Schumacher, Austin; Schwebel, David C; Seedat, Soraya; Sepanlou, Sadaf G; Servan-Mori, Edson E; Shakh-Nazarova, Marina; Sheikhbahaei, Sara; Shibuya, Kenji; Shin, Hwashin Hyun; Shiue, Ivy; Sigfusdottir, Inga Dora; Silberberg, Donald H; Silva, Andrea P; Singh, Jasvinder A; Skirbekk, Vegard; Sliwa, Karen; Soshnikov, Sergey S; Sposato, Luciano A; Sreeramareddy, Chandrashekhar T; Stroumpoulis, Konstantinos; Sturua, Lela; Sykes, Bryan L; Tabb, Karen M; Talongwa, Roberto Tchio; Tan, Feng; Teixeira, Carolina Maria; Tenkorang, Eric Yeboah; Terkawi, Abdullah Sulieman; Thorne-Lyman, Andrew L; Tirschwell, David L; Towbin, Jeffrey A; Tran, Bach X; Tsilimbaris, Miltiadis; Uchendu, Uche S; Ukwaja, Kingsley N; Undurraga, Eduardo A; Uzun, Selen Begüm; Vallely, Andrew J; van Gool, Coen H; Vasankari, Tommi J; Vavilala, Monica S; Venketasubramanian, N; Villalpando, Salvador; Violante, Francesco S; Vlassov, Vasiliy Victorovich; Vos, Theo; Waller, Stephen; Wang, Haidong; Wang, Linhong; Wang, XiaoRong; Wang, Yanping; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G; Westerman, Ronny; Wilkinson, James D; Woldeyohannes, Solomon Meseret; Wong, John Q; Wordofa, Muluemebet Abera; Xu, Gelin; Yang, Yang C; Yano, Yuichiro; Yentur, Gokalp Kadri; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Younis, Mustafa Z; Yu, Chuanhua; Jin, Kim Yun; El Sayed Zaki, Maysaa; Zhao, Yong; Zheng, Yingfeng; Zhou, Maigeng; Zhu, Jun; Zou, Xiao Nong; Lopez, Alan D; Naghavi, Mohsen; Murray, Christopher J L; Lozano, Rafael

2014-09-13

The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100,000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery. We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013. We estimated the number of pregnancy-related deaths caused by HIV on the basis of a systematic review of the relative risk of dying during pregnancy for HIV-positive women compared with HIV-negative women. We also estimated the fraction of these deaths aggravated by pregnancy on the basis of a systematic review. To estimate the numbers of maternal deaths due to nine different causes, we identified 61 sources from a systematic review and 943 site-years of vital registration data. We also did a systematic review of reports about the timing of maternal death, identifying 142 sources to use in our analysis. We developed estimates for each country for 1990-2013 using Bayesian meta-regression. We estimated 95% uncertainty intervals (UIs) for all values. 292,982 (95% UI 261,017-327,792) maternal deaths occurred in 2013, compared with 376,034 (343,483-407,574) in 1990. The global annual rate of change in the MMR was -0·3% (-1·1 to 0·6) from 1990 to 2003, and -2·7% (-3·9 to -1·5) from 2003 to 2013, with evidence of continued acceleration. MMRs reduced consistently in south, east, and southeast Asia between 1990 and 2013, but maternal deaths increased in much of sub-Saharan Africa during the 1990s. 2070 (1290-2866) maternal deaths were related to HIV in 2013, 0·4% (0·2-0·6) of the global total. MMR was highest in the oldest age groups in both 1990 and 2013. In 2013, most deaths occurred intrapartum or postpartum. Causes varied by region and between 1990 and 2013. We recorded substantial variation in the MMR by country in 2013, from 956·8 (685·1-1262·8) in South Sudan to 2·4 (1·6-3·6) in Iceland. Global rates of change suggest that only 16 countries will achieve the MDG 5 target by 2015. Accelerated reductions since the Millennium Declaration in 2000 coincide with increased development assistance for maternal, newborn, and child health. Setting of targets and associated interventions for after 2015 will need careful consideration of regions that are making slow progress, such as west and central Africa. Bill & Melinda Gates Foundation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Global, regional, and national levels and causes of maternal mortality during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

PubMed Central

Kassebaum, Nicholas J; Bertozzi-Villa, Amelia; Coggeshall, Megan S; Shackelford, Katya A; Steiner, Caitlyn; Heuton, Kyle R; Gonzalez-Medina, Diego; Barber, Ryan; Huynh, Chantal; Dicker, Daniel; Templin, Tara; Wolock, Timothy M; Ozgoren, Ayse Abbasoglu; Abd-Allah, Foad; Abera, Semaw Ferede; Abubakar, Ibrahim; Achoki, Tom; Adelekan, Ademola; Ademi, Zanfina; Adou, Arsène Kouablan; Adsuar, José C; Agardh, Emilie E; Akena, Dickens; Alasfoor, Deena; Alemu, Zewdie Aderaw; Alfonso-Cristancho, Rafael; Alhabib, Samia; Ali, Raghib; Al Kahbouri, Mazin J; Alla, François; Allen, Peter J; AlMazroa, Mohammad A; Alsharif, Ubai; Alvarez, Elena; Alvis-Guzmán, Nelson; Amankwaa, Adansi A; Amare, Azmeraw T; Amini, Hassan; Ammar, Walid; Antonio, Carl A T; Anwari, Palwasha; Ärnlöv, Johan; Arsenijevic, Valentina S Arsic; Artaman, Ali; Asad, Majed Masoud; Asghar, Rana J; Assadi, Reza; Atkins, Lydia S; Badawi, Alaa; Balakrishnan, Kalpana; Basu, Arindam; Basu, Sanjay; Beardsley, Justin; Bedi, Neeraj; Bekele, Tolesa; Bell, Michelle L; Bernabe, Eduardo; Beyene, Tariku J; Bhutta, Zulfiqar; Abdulhak, Aref Bin; Blore, Jed D; Basara, Berrak Bora; Bose, Dipan; Breitborde, Nicholas; Cárdenas, Rosario; Castañeda-Orjuela, Carlos A; Castro, Ruben Estanislao; Catalá-López, Ferrán; Cavlin, Alanur; Chang, Jung-Chen; Che, Xuan; Christophi, Costas A; Chugh, Sumeet S; Cirillo, Massimo; Colquhoun, Samantha M; Cooper, Leslie Trumbull; Cooper, Cyrus; da Costa Leite, Iuri; Dandona, Lalit; Dandona, Rakhi; Davis, Adrian; Dayama, Anand; Degenhardt, Louisa; De Leo, Diego; del Pozo-Cruz, Borja; Deribe, Kebede; Dessalegn, Muluken; deVeber, Gabrielle A; Dharmaratne, Samath D; Dilmen, Uğur; Ding, Eric L; Dorrington, Rob E; Driscoll, Tim R; Ermakov, Sergei Petrovich; Esteghamati, Alireza; Faraon, Emerito Jose A; Farzadfar, Farshad; Felicio, Manuela Mendonca; Fereshtehnejad, Seyed-Mohammad; de Lima, Graça Maria Ferreira; Forouzanfar, Mohammad H; França, Elisabeth B; Gaffikin, Lynne; Gambashidze, Ketevan; Gankpé, Fortuné Gbètoho; Garcia, Ana C; Geleijnse, Johanna M; Gibney, Katherine B; Giroud, Maurice; Glaser, Elizabeth L; Goginashvili, Ketevan; Gona, Philimon; González-Castell, Dinorah; Goto, Atsushi; Gouda, Hebe N; Gugnani, Harish Chander; Gupta, Rahul; Gupta, Rajeev; Hafezi-Nejad, Nima; Hamadeh, Randah Ribhi; Hammami, Mouhanad; Hankey, Graeme J; Harb, Hilda L; Havmoeller, Rasmus; Hay, Simon I; Heredia Pi, Ileana B; Hoek, Hans W; Hosgood, H Dean; Hoy, Damian G; Husseini, Abdullatif; Idrisov, Bulat T; Innos, Kaire; Inoue, Manami; Jacobsen, Kathryn H; Jahangir, Eiman; Jee, Sun Ha; Jensen, Paul N; Jha, Vivekanand; Jiang, Guohong; Jonas, Jost B; Juel, Knud; Kabagambe, Edmond Kato; Kan, Haidong; Karam, Nadim E; Karch, André; Karema, Corine Kakizi; Kaul, Anil; Kawakami, Norito; Kazanjan, Konstantin; Kazi, Dhruv S; Kemp, Andrew H; Kengne, Andre Pascal; Kereselidze, Maia; Khader, Yousef Saleh; Khalifa, Shams Eldin Ali Hassan; Khan, Ejaz Ahmed; Khang, Young-Ho; Knibbs, Luke; Kokubo, Yoshihiro; Kosen, Soewarta; Defo, Barthelemy Kuate; Kulkarni, Chanda; Kulkarni, Veena S; Kumar, G Anil; Kumar, Kaushalendra; Kumar, Ravi B; Kwan, Gene; Lai, Taavi; Lalloo, Ratilal; Lam, Hilton; Lansingh, Van C; Larsson, Anders; Lee, Jong-Tae; Leigh, James; Leinsalu, Mall; Leung, Ricky; Li, Xiaohong; Li, Yichong; Li, Yongmei; Liang, Juan; Liang, Xiaofeng; Lim, Stephen S; Lin, Hsien-Ho; Lipshultz, Steven E; Liu, Shiwei; Liu, Yang; Lloyd, Belinda K; London, Stephanie J; Lotufo, Paulo A; Ma, Jixiang; Ma, Stefan; Machado, Vasco Manuel Pedro; Mainoo, Nana Kwaku; Majdan, Marek; Mapoma, Christopher Chabila; Marcenes, Wagner; Marzan, Melvin Barrientos; Mason-Jones, Amanda J; Mehndiratta, Man Mohan; Mejia-Rodriguez, Fabiola; Memish, Ziad A; Mendoza, Walter; Miller, Ted R; Mills, Edward J; Mokdad, Ali H; Mola, Glen Liddell; Monasta, Lorenzo; de la Cruz Monis, Jonathan; Hernandez, Julio Cesar Montañez; Moore, Ami R; Moradi-Lakeh, Maziar; Mori, Rintaro; Mueller, Ulrich O; Mukaigawara, Mitsuru; Naheed, Aliya; Naidoo, Kovin S; Nand, Devina; Nangia, Vinay; Nash, Denis; Nejjari, Chakib; Nelson, Robert G; Neupane, Sudan Prasad; Newton, Charles R; Ng, Marie; Nieuwenhuijsen, Mark J; Nisar, Muhammad Imran; Nolte, Sandra; Norheim, Ole F; Nyakarahuka, Luke; Oh, In-Hwan; Ohkubo, Takayoshi; Olusanya, Bolajoko O; Omer, Saad B; Opio, John Nelson; Orisakwe, Orish Ebere; Pandian, Jeyaraj D; Papachristou, Christina; Park, Jae-Hyun; Caicedo, Angel J Paternina; Patten, Scott B; Paul, Vinod K; Pavlin, Boris Igor; Pearce, Neil; Pereira, David M; Pesudovs, Konrad; Petzold, Max; Poenaru, Dan; Polanczyk, Guilherme V; Polinder, Suzanne; Pope, Dan; Pourmalek, Farshad; Qato, Dima; Quistberg, D Alex; Rafay, Anwar; Rahimi, Kazem; Rahimi-Movaghar, Vafa; Rahman, Sajjad ur; Raju, Murugesan; Rana, Saleem M; Refaat, Amany; Ronfani, Luca; Roy, Nobhojit; Sánchez Pimienta, Tania Georgina; Sahraian, Mohammad Ali; Salomon, Joshua A; Sampson, Uchechukwu; Santos, Itamar S; Sawhney, Monika; Sayinzoga, Felix; Schneider, Ione J C; Schumacher, Austin; Schwebel, David C; Seedat, Soraya; Sepanlou, Sadaf G; Servan-Mori, Edson E; Shakh-Nazarova, Marina; Sheikhbahaei, Sara; Shibuya, Kenji; Shin, Hwashin Hyun; Shiue, Ivy; Sigfusdottir, Inga Dora; Silberberg, Donald H; Silva, Andrea P; Singh, Jasvinder A; Skirbekk, Vegard; Sliwa, Karen; Soshnikov, Sergey S; Sposato, Luciano A; Sreeramareddy, Chandrashekhar T; Stroumpoulis, Konstantinos; Sturua, Lela; Sykes, Bryan L; Tabb, Karen M; Talongwa, Roberto Tchio; Tan, Feng; Teixeira, Carolina Maria; Tenkorang, Eric Yeboah; Terkawi, Abdullah Sulieman; Thorne-Lyman, Andrew L; Tirschwell, David L; Towbin, Jeffrey A; Tran, Bach X; Tsilimbaris, Miltiadis; Uchendu, Uche S; Ukwaja, Kingsley N; Undurraga, Eduardo A; Uzun, Selen Begüm; Vallely, Andrew J; van Gool, Coen H; Vasankari, Tommi J; Vavilala, Monica S; Venketasubramanian, N; Villalpando, Salvador; Violante, Francesco S; Vlassov, Vasiliy Victorovich; Vos, Theo; Waller, Stephen; Wang, Haidong; Wang, Linhong; Wang, XiaoRong; Wang, Yanping; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G; Westerman, Ronny; Wilkinson, James D; Woldeyohannes, Solomon Meseret; Wong, John Q; Wordofa, Muluemebet Abera; Xu, Gelin; Yang, Yang C; Yano, Yuichiro; Yentur, Gokalp Kadri; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Younis, Mustafa Z; Yu, Chuanhua; Jin, Kim Yun; El SayedZaki, Maysaa; Zhao, Yong; Zheng, Yingfeng; Zhou, Maigeng; Zhu, Jun; Zou, Xiao Nong; Lopez, Alan D; Naghavi, Mohsen; Murray, Christopher J L; Lozano, Rafael

2014-01-01

Summary Background The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100 000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery. Methods We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013. We estimated the number of pregnancy-related deaths caused by HIV on the basis of a systematic review of the relative risk of dying during pregnancy for HIV-positive women compared with HIV-negative women. We also estimated the fraction of these deaths aggravated by pregnancy on the basis of a systematic review. To estimate the numbers of maternal deaths due to nine different causes, we identified 61 sources from a systematic review and 943 site-years of vital registration data. We also did a systematic review of reports about the timing of maternal death, identifying 142 sources to use in our analysis. We developed estimates for each country for 1990–2013 using Bayesian meta-regression. We estimated 95% uncertainty intervals (UIs) for all values. Findings 292 982 (95% UI 261 017–327 792) maternal deaths occurred in 2013, compared with 376 034 (343 483–407 574) in 1990. The global annual rate of change in the MMR was −0·3% (−1·1 to 0·6) from 1990 to 2003, and −2·7% (−3·9 to −1·5) from 2003 to 2013, with evidence of continued acceleration. MMRs reduced consistently in south, east, and southeast Asia between 1990 and 2013, but maternal deaths increased in much of sub-Saharan Africa during the 1990s. 2070 (1290–2866) maternal deaths were related to HIV in 2013, 0·4% (0·2–0·6) of the global total. MMR was highest in the oldest age groups in both 1990 and 2013. In 2013, most deaths occurred intrapartum or postpartum. Causes varied by region and between 1990 and 2013. We recorded substantial variation in the MMR by country in 2013, from 956·8 (685·1–1262·8) in South Sudan to 2·4 (1·6–3·6) in Iceland. Interpretation Global rates of change suggest that only 16 countries will achieve the MDG 5 target by 2015. Accelerated reductions since the Millennium Declaration in 2000 coincide with increased development assistance for maternal, newborn, and child health. Setting of targets and associated interventions for after 2015 will need careful consideration of regions that are making slow progress, such as west and central Africa. Funding Bill & Melinda Gates Foundation. PMID:24797575

A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If themore » detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.« less

A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

DOE PAGES

Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

2017-06-13

An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If themore » detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.« less

Bile leakage test in liver resection: A systematic review and meta-analysis

PubMed Central

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-01-01

AIM: To assess systematically the safety and efficacy of bile leakage test in liver resection. METHODS : Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. RESULTS: Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I2 = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. CONCLUSION: The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. PMID:24363535

Bile leakage test in liver resection: a systematic review and meta-analysis.

PubMed

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-12-07

To assess systematically the safety and efficacy of bile leakage test in liver resection. Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I (2) = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. © 2013 Baishideng Publishing Group Co., Limited. All rights reserved.

Confidence in outcome estimates from systematic reviews used in informed consent.

PubMed

Fritz, Robert; Bauer, Janet G; Spackman, Sue S; Bains, Amanjyot K; Jetton-Rangel, Jeanette

2016-12-01

Evidence-based dentistry now guides informed consent in which clinicians are obliged to provide patients with the most current, best evidence, or best estimates of outcomes, of regimens, therapies, treatments, procedures, materials, and equipment or devices when developing personal oral health care, treatment plans. Yet, clinicians require that the estimates provided from systematic reviews be verified to their validity, reliability, and contextualized as to performance competency so that clinicians may have confidence in explaining outcomes to patients in clinical practice. The purpose of this paper was to describe types of informed estimates from which clinicians may have confidence in their capacity to assist patients in competent decision-making, one of the most important concepts of informed consent. Using systematic review methodology, researchers provide clinicians with valid best estimates of outcomes regarding a subject of interest from best evidence. Best evidence is verified through critical appraisals using acceptable sampling methodology either by scoring instruments (Timmer analysis) or checklist (grade), a Cochrane Collaboration standard that allows transparency in open reviews. These valid best estimates are then tested for reliability using large databases. Finally, valid and reliable best estimates are assessed for meaning using quantification of margins and uncertainties. Through manufacturer and researcher specifications, quantification of margins and uncertainties develops a performance competency continuum by which valid, reliable best estimates may be contextualized for their performance competency: at a lowest margin performance competency (structural failure), high margin performance competency (estimated true value of success), or clinically determined critical values (clinical failure). Informed consent may be achieved when clinicians are confident of their ability to provide useful and accurate best estimates of outcomes regarding regimens, therapies, treatments, and equipment or devices to patients in their clinical practices and when developing personal, oral health care, treatment plans. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Risk of Bias on the Effect Size of Meta-Analytic Estimates in Randomized Controlled Trials in Periodontology and Implant Dentistry

PubMed Central

Faggion, Clovis Mariano; Wu, Yun-Chun; Scheidgen, Moritz; Tu, Yu-Kang

2015-01-01

Background Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. Objective The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. Methods A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Results Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. Conclusion In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association. PMID:26422698

Using the Violence Risk Scale-Sexual Offense version in sexual violence risk assessments: Updated risk categories and recidivism estimates from a multisite sample of treated sexual offenders.

PubMed

Olver, Mark E; Mundt, James C; Thornton, David; Beggs Christofferson, Sarah M; Kingston, Drew A; Sowden, Justina N; Nicholaichuk, Terry P; Gordon, Audrey; Wong, Stephen C P

2018-04-30

The present study sought to develop updated risk categories and recidivism estimates for the Violence Risk Scale-Sexual Offense version (VRS-SO; Wong, Olver, Nicholaichuk, & Gordon, 2003-2017), a sexual offender risk assessment and treatment planning tool. The overarching purpose was to increase the clarity and accuracy of communicating risk assessment information that includes a systematic incorporation of new information (i.e., change) to modify risk estimates. Four treated samples of sexual offenders with VRS-SO pretreatment, posttreatment, and Static-99R ratings were combined with a minimum follow-up period of 10-years postrelease (N = 913). Logistic regression was used to model 5- and 10-year sexual and violent (including sexual) recidivism estimates across 6 different regression models employing specific risk and change score information from the VRS-SO and/or Static-99R. A rationale is presented for clinical applications of select models and the necessity of controlling for baseline risk when utilizing change information across repeated assessments. Information concerning relative risk (percentiles) and absolute risk (recidivism estimates) is integrated with common risk assessment language guidelines to generate new risk categories for the VRS-SO. Guidelines for model selection and forensic clinical application of the risk estimates are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Untreated maternal syphilis and adverse outcomes of pregnancy: a systematic review and meta-analysis

PubMed Central

Kamb, Mary L; Newman, Lori M; Mark, Jennifer; Broutet, Nathalie; Hawkes, Sarah J

2013-01-01

Abstract Objective To perform a systematic review and meta-analysis of reported estimates of adverse pregnancy outcomes among untreated women with syphilis and women without syphilis. Methods PubMed, EMBASE and Cochrane Libraries were searched for literature assessing adverse pregnancy outcomes among untreated women with seroreactivity for Treponema pallidum infection and non-seroreactive women. Adverse pregnancy outcomes were fetal loss or stillbirth, neonatal death, prematurity or low birth weight, clinical evidence of syphilis and infant death. Random-effects meta-analyses were used to calculate pooled estimates of adverse pregnancy outcomes and, where appropriate, heterogeneity was explored in group-specific analyses. Findings Of the 3258 citations identified, only six, all case-control studies, were included in the analysis. Pooled estimates showed that among untreated pregnant women with syphilis, fetal loss and stillbirth were 21% more frequent, neonatal deaths were 9.3% more frequent and prematurity or low birth weight were 5.8% more frequent than among women without syphilis. Of the infants of mothers with untreated syphilis, 15% had clinical evidence of congenital syphilis. The single study that estimated infant death showed a 10% higher frequency among infants of mothers with syphilis. Substantial heterogeneity was found across studies in the estimates of all adverse outcomes for both women with syphilis (66.5% [95% confidence interval, CI: 58.0–74.1]; I2 = 91.8%; P < 0.001) and women without syphilis (14.3% [95% CI: 11.8–17.2]; I2 = 95.9%; P < 0.001). Conclusion Untreated maternal syphilis is associated with adverse pregnancy outcomes. These findings can inform policy decisions on resource allocation for the detection of syphilis and its timely treatment in pregnant women. PMID:23476094

Prevalence of neuropathic pain in knee or hip osteoarthritis: A systematic review and meta-analysis.

PubMed

French, Helen P; Smart, Keith M; Doyle, Frank

2017-08-01

Discordance between radiographic and pain severity in osteoarthritis (OA) has led researchers to investigate other pain mechanisms, including neuropathic pain. Accurate identification of any neuropathic pain in hip or knee OA is important for appropriate management, but neuropathic pain prevalence is unknown. We aimed to obtain an overall prevalence estimate by systematically reviewing and meta-analysing the prevalence of neuropathic pain in people with hip or knee OA. Observational studies which measured neuropathic pain in people aged 18 years and older with hip or knee OA were considered for inclusion. Electronic databases were searched up to February 2016. Two reviewers independently identified eligible studies and assessed methodological quality. Prevalence estimates and 95% confidence intervals were calculated using random effects meta-analytic techniques. Nine studies met the inclusion criteria. Study samples were from general population, hospital and community settings and all used self-report questionnaires to determine neuropathic pain. The overall prevalence estimate was 23% (95% CI: 10-39%), with considerable heterogeneity (I 2 = 97.9%, p < 0.001). This estimate was largely unchanged with subgroup analyses based on index joint, questionnaire type, setting and consideration of other potential causes of neuropathic pain. However, the estimate for two studies that excluded other potential causes of neuropathic pain was substantially higher (32%, 95% CI: 29-35%). Neuropathic pain prevalence in people with knee or hip OA is considerable at 23%, and may be higher after other potential causes of neuropathic pain are excluded. Concerns regarding the validity of neuropathic pain questionnaires, selection bias, methodological quality and study heterogeneity suggest caution with interpretation of these findings. Prevalence studies using standardised criteria for neuropathic pain are required. Copyright © 2017 Elsevier Inc. All rights reserved.

Estimating Volume, Biomass, and Carbon in Hedmark County, Norway Using a Profiling LiDAR

NASA Technical Reports Server (NTRS)

Nelson, Ross; Naesset, Erik; Gobakken, T.; Gregoire, T.; Stahl, G.

2009-01-01

A profiling airborne LiDAR is used to estimate the forest resources of Hedmark County, Norway, a 27390 square kilometer area in southeastern Norway on the Swedish border. One hundred five profiling flight lines totaling 9166 km were flown over the entire county; east-west. The lines, spaced 3 km apart north-south, duplicate the systematic pattern of the Norwegian Forest Inventory (NFI) ground plot arrangement, enabling the profiler to transit 1290 circular, 250 square meter fixed-area NFI ground plots while collecting the systematic LiDAR sample. Seven hundred sixty-three plots of the 1290 plots were overflown within 17.8 m of plot center. Laser measurements of canopy height and crown density are extracted along fixed-length, 17.8 m segments closest to the center of the ground plot and related to basal area, timber volume and above- and belowground dry biomass. Linear, nonstratified equations that estimate ground-measured total aboveground dry biomass report an R(sup 2) = 0.63, with an regression RMSE = 35.2 t/ha. Nonstratified model results for the other biomass components, volume, and basal area are similar, with R(sup 2) values for all models ranging from 0.58 (belowground biomass, RMSE = 8.6 t/ha) to 0.63. Consistently, the most useful single profiling LiDAR variable is quadratic mean canopy height, h (sup bar)(sub qa). Two-variable models typically include h (sup bar)(sub qa) or mean canopy height, h(sup bar)(sub a), with a canopy density or a canopy height standard deviation measure. Stratification by productivity class did not improve the nonstratified models, nor did stratification by pine/spruce/hardwood. County-wide profiling LiDAR estimates are reported, by land cover type, and compared to NFI estimates.

Large Uncertainty in Estimating pCO2 From Carbonate Equilibria in Lakes

NASA Astrophysics Data System (ADS)

Golub, Malgorzata; Desai, Ankur R.; McKinley, Galen A.; Remucal, Christina K.; Stanley, Emily H.

2017-11-01

Most estimates of carbon dioxide (CO2) evasion from freshwaters rely on calculating partial pressure of aquatic CO2 (pCO2) from two out of three CO2-related parameters using carbonate equilibria. However, the pCO2 uncertainty has not been systematically evaluated across multiple lake types and equilibria. We quantified random errors in pH, dissolved inorganic carbon, alkalinity, and temperature from the North Temperate Lakes Long-Term Ecological Research site in four lake groups across a broad gradient of chemical composition. These errors were propagated onto pCO2 calculated from three carbonate equilibria, and for overlapping observations, compared against uncertainties in directly measured pCO2. The empirical random errors in CO2-related parameters were mostly below 2% of their median values. Resulting random pCO2 errors ranged from ±3.7% to ±31.5% of the median depending on alkalinity group and choice of input parameter pairs. Temperature uncertainty had a negligible effect on pCO2. When compared with direct pCO2 measurements, all parameter combinations produced biased pCO2 estimates with less than one third of total uncertainty explained by random pCO2 errors, indicating that systematic uncertainty dominates over random error. Multidecadal trend of pCO2 was difficult to reconstruct from uncertain historical observations of CO2-related parameters. Given poor precision and accuracy of pCO2 estimates derived from virtually any combination of two CO2-related parameters, we recommend direct pCO2 measurements where possible. To achieve consistently robust estimates of CO2 emissions from freshwater components of terrestrial carbon balances, future efforts should focus on improving accuracy and precision of CO2-related parameters (including direct pCO2) measurements and associated pCO2 calculations.

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers.

PubMed

Lenters, Virissa; Basinas, Ioannis; Beane-Freeman, Laura; Boffetta, Paolo; Checkoway, Harvey; Coggon, David; Portengen, Lützen; Sim, Malcolm; Wouters, Inge M; Heederik, Dick; Vermeulen, Roel

2010-04-01

To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins. Risk estimates were extracted from studies published before 2009 that met predefined quality criteria, including 8 cohort, 1 case-cohort, and 2 case-control studies of cotton textile industry workers, and 15 cohort and 2 case-control studies of agricultural workers. Summary risk estimates were calculated using random effects meta-analyses. Potential sources of heterogeneity were explored through subgroup analyses. The summary risk of lung cancer was 0.72 (95% CI, 0.57-0.90) for textile workers and 0.62 (0.52-0.75) for agricultural workers. The relative risk of lung cancer was below 1.0 for most subgroups defined according to sex, study design, outcome, smoking adjustment, and geographic area. Two studies provided quantitative estimates of endotoxin exposure and both studies tended to support a dose-dependent protective effect of endotoxins on lung cancer risk. Despite several limitations, this meta-analysis based on high-quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer.

Gauging Metallicity of Diffuse Gas under an Uncertain Ionizing Radiation Field

NASA Astrophysics Data System (ADS)

Chen, Hsiao-Wen; Johnson, Sean D.; Zahedy, Fakhri S.; Rauch, Michael; Mulchaey, John S.

2017-06-01

Gas metallicity is a key quantity used to determine the physical conditions of gaseous clouds in a wide range of astronomical environments, including interstellar and intergalactic space. In particular, considerable effort in circumgalactic medium (CGM) studies focuses on metallicity measurements because gas metallicity serves as a critical discriminator for whether the observed heavy ions in the CGM originate in chemically enriched outflows or in more chemically pristine gas accreted from the intergalactic medium. However, because the gas is ionized, a necessary first step in determining CGM metallicity is to constrain the ionization state of the gas which, in addition to gas density, depends on the ultraviolet background radiation field (UVB). While it is generally acknowledged that both the intensity and spectral slope of the UVB are uncertain, the impact of an uncertain spectral slope has not been properly addressed in the literature. This Letter shows that adopting a different spectral slope can result in an order of magnitude difference in the inferred CGM metallicity. Specifically, a harder UVB spectrum leads to a higher estimated gas metallicity for a given set of observed ionic column densities. Therefore, such systematic uncertainties must be folded into the error budget for metallicity estimates of ionized gas. An initial study shows that empirical diagnostics are available for discriminating between hard and soft ionizing spectra. Applying these diagnostics helps reduce the systematic uncertainties in CGM metallicity estimates.

Gauging Metallicity of Diffuse Gas under an Uncertain Ionizing Radiation Field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Hsiao-Wen; Zahedy, Fakhri S.; Johnson, Sean D.

Gas metallicity is a key quantity used to determine the physical conditions of gaseous clouds in a wide range of astronomical environments, including interstellar and intergalactic space. In particular, considerable effort in circumgalactic medium (CGM) studies focuses on metallicity measurements because gas metallicity serves as a critical discriminator for whether the observed heavy ions in the CGM originate in chemically enriched outflows or in more chemically pristine gas accreted from the intergalactic medium. However, because the gas is ionized, a necessary first step in determining CGM metallicity is to constrain the ionization state of the gas which, in addition tomore » gas density, depends on the ultraviolet background radiation field (UVB). While it is generally acknowledged that both the intensity and spectral slope of the UVB are uncertain, the impact of an uncertain spectral slope has not been properly addressed in the literature. This Letter shows that adopting a different spectral slope can result in an order of magnitude difference in the inferred CGM metallicity. Specifically, a harder UVB spectrum leads to a higher estimated gas metallicity for a given set of observed ionic column densities. Therefore, such systematic uncertainties must be folded into the error budget for metallicity estimates of ionized gas. An initial study shows that empirical diagnostics are available for discriminating between hard and soft ionizing spectra. Applying these diagnostics helps reduce the systematic uncertainties in CGM metallicity estimates.« less

Systematic Review and Meta-Analysis of Antimicrobial Treatment Effect Estimation in Complicated Urinary Tract Infection

PubMed Central

Li, Gang; Mitrani-Gold, Fanny S.; Kurtinecz, Milena; Wetherington, Jeffrey; Tomayko, John F.; Mundy, Linda M.

2013-01-01

Noninferiority trial design and analyses are commonly used to establish the effectiveness of a new antimicrobial drug for treatment of serious infections such as complicated urinary tract infection (cUTI). A systematic review and meta-analysis were conducted to estimate the treatment effects of three potential active comparator drugs for the design of a noninferiority trial. The systematic review identified no placebo trials of cUTI, four clinical trials of cUTI with uncomplicated urinary tract infection as a proxy for placebo, and nine trials with reports of treatment effect estimates for doripenem, levofloxacin, or imipenem-cilastatin. In the meta-analysis, the primary efficacy endpoint of interest was the microbiological eradication rate at the test-of-cure visit in the microbiological intent-to-treat population. The estimated eradication rates and corresponding 95% confidence intervals (CI) were 31.8% (26.5% to 37.2%) for placebo, 81% (77.7% to 84.2%) for doripenem, 79% (75.9% to 82.2%) for levofloxacin, and 80.5% (71.9% to 89.1%) for imipenem-cilastatin. The treatment effect estimates were 40.5% for doripenem, 38.7% for levofloxacin, 34.7% for imipenem-cilastatin, and 40.8% overall. These treatment effect estimates can be used to inform the design and analysis of future noninferiority trials in cUTI study populations. PMID:23939900

Income and child mortality in developing countries: a systematic review and meta-analysis.

PubMed

O'Hare, Bernadette; Makuta, Innocent; Chiwaula, Levison; Bar-Zeev, Naor

2013-10-01

We aimed to quantify the relationship between national income and infant and under-five mortality in developing countries. We conducted a systematic literature search of studies that examined the relationship between income and child mortality (infant and/or under-five mortality) and meta-analysed their results. Developing countries. Child mortality (infant and /or under-five mortality). The systematic literature search identified 24 studies, which produced 38 estimates that examined the impact of income on the mortality rates. Using meta-analysis, we produced pooled estimates of the relationship between income and mortality. The pooled estimate of the relationship between income and infant mortality before adjusting for covariates is -0.95 (95% CI -1.34 to -0.57) and that for under-five mortality is -0.45 (95% CI -0.79 to -0.11). After adjusting for covariates, pooled estimate of the relationship between income and infant mortality is -0.33 (-0.39 to -0.26) while the estimate for under-five mortality is -0.28 (-0.37 to -0.19). If a country has an infant mortality of 50 per 1000 live births and the gross domestic product per capita purchasing power parity increases by 10%, the infant mortality will decrease to 45 per 1000 live births. Income is an important determinant of child survival and this work provides a pooled estimate for the relationship.

Prevalence of Bovine Tuberculosis in India: A systematic review and meta-analysis.

PubMed

Srinivasan, Sreenidhi; Easterling, Laurel; Rimal, Bipin; Niu, Xiaoyue Maggie; Conlan, Andrew J K; Dudas, Patrick; Kapur, Vivek

2018-06-08

Bovine tuberculosis (bTB) is a chronic disease of cattle that impacts productivity and represents a major public health threat. Despite the considerable economic costs and zoonotic risk consequences associated with the disease, accurate estimates of bTB prevalence are lacking in many countries, including India, where national control programmes are not yet implemented and the disease is considered endemic. To address this critical knowledge gap, we performed a systematic review of the literature and a meta-analysis to estimate bTB prevalence in cattle in India and provide a foundation for the future formulation of rational disease control strategies and the accurate assessment of economic and health impact risks. The literature search was performed in accordance with PRISMA guidelines and identified 285 cross-sectional studies on bTB in cattle in India across four electronic databases and handpicked publications. Of these, 44 articles were included, contributing a total of 82,419 cows and buffaloes across 18 states and one union territory in India. Based on a random-effects (RE) meta-regression model, the analysis revealed a pooled prevalence estimate of 7.3% (95% CI: 5.6, 9.5), indicating that there may be an estimated 21.8 million (95% CI: 16.6, 28.4) infected cattle in India-a population greater than the total number of dairy cows in the United States. The analyses further suggest that production system, species, breed, study location, diagnostic technique, sample size and study period are likely moderators of bTB prevalence in India and need to be considered when developing future disease surveillance and control programmes. Taken together with the projected increase in intensification of dairy production and the subsequent increase in the likelihood of zoonotic transmission, the results of our study suggest that attempts to eliminate tuberculosis from humans will require simultaneous consideration of bTB control in cattle population in countries such as India. © 2018 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

The association of antidepressant drug usage with cognitive impairment or dementia, including Alzheimer disease: A systematic review and meta‐analysis

PubMed Central

Moraros, John; Nwankwo, Chijioke; Patten, Scott B.

2016-01-01

1 Objective To determine if antidepressant drug usage is associated with cognitive impairment or dementia, including Alzheimer disease (AD). 2 Method We conducted a systematic search of Medline, PubMed, PsycINFO, Web of Science, Embase, CINAHL, and the Cochrane Library. An initial screen by abstracts and titles was performed, and relevant full articles were then reviewed and assessed for their methodologic quality. Crude effect estimates were extracted from the included articles and a pooled estimate was obtained using a random effects model. 3 Results Five articles were selected from an initial pool of 4,123 articles. Use of antidepressant drugs was associated with a significant twofold increase in the odds of some form of cognitive impairment or dementia (OR = 2.17). Age was identified as a likely modifier of the association between antidepressant use and some form of cognitive impairment or AD/dementia. Studies that included participants with an average age equal to or greater than 65 years showed an increased odds of some form of cognitive impairment with antidepressant drug usage (OR = 1.65), whereas those with participants less than age 65 revealed an even stronger association (OR = 3.25). 4 Conclusions Antidepressant drug usage is associated with AD/dementia and this is particularly evident if usage begins before age 65. This association may arise due to confounding by depression or depression severity. However, biological mechanisms potentially linking antidepressant exposure to dementia have been described, so an etiological effect of antidepressants is possible. With this confirmation that an association exists, clarification of underlying etiologic pathways requires urgent attention. PMID:28029715

The association of antidepressant drug usage with cognitive impairment or dementia, including Alzheimer disease: A systematic review and meta-analysis.

PubMed

Moraros, John; Nwankwo, Chijioke; Patten, Scott B; Mousseau, Darrell D

2017-03-01

To determine if antidepressant drug usage is associated with cognitive impairment or dementia, including Alzheimer disease (AD). We conducted a systematic search of Medline, PubMed, PsycINFO, Web of Science, Embase, CINAHL, and the Cochrane Library. An initial screen by abstracts and titles was performed, and relevant full articles were then reviewed and assessed for their methodologic quality. Crude effect estimates were extracted from the included articles and a pooled estimate was obtained using a random effects model. Five articles were selected from an initial pool of 4,123 articles. Use of antidepressant drugs was associated with a significant twofold increase in the odds of some form of cognitive impairment or dementia (OR = 2.17). Age was identified as a likely modifier of the association between antidepressant use and some form of cognitive impairment or AD/dementia. Studies that included participants with an average age equal to or greater than 65 years showed an increased odds of some form of cognitive impairment with antidepressant drug usage (OR = 1.65), whereas those with participants less than age 65 revealed an even stronger association (OR = 3.25). Antidepressant drug usage is associated with AD/dementia and this is particularly evident if usage begins before age 65. This association may arise due to confounding by depression or depression severity. However, biological mechanisms potentially linking antidepressant exposure to dementia have been described, so an etiological effect of antidepressants is possible. With this confirmation that an association exists, clarification of underlying etiologic pathways requires urgent attention. © 2016 The Authors. Depression and Anxiety published by Wiley Periodicals, Inc.

[Systematic review of the validity of urine cultures collected by sterile perineal bags].

PubMed

Ochoa Sangrador, C; Pascual Terrazas, A

2016-02-01

The perineal adhesive bag is the most used method in our country for urine culture collection in infants, despite having a high risk of contamination and false-positive results. We aim to quantify both types of risks through a systematic review. Search updated in May 2014 in PUBMED, SCOPUS (includes EMBASE), IBECS; CINAHL, LILACS AND CUIDEN, without language or time limits. Percentages of contaminated urines, false positives, sensitivity and specificity (with respect to catheterization or bladder puncture) were recorded. A total of 21 studies of medium quality (7,659 samples) were selected. The pooled percentage of contaminated urines was 46.6% (15 studies; 6856 samples; 95% confidence interval [95% CI]: 35.6 to 57.8%; I(2): 97.3%). The pooled percentage of false positives was 61.1% (12 studies; 575 samples; 95% CI: 37.9 to 82.2%; I(2): 96.2%). Sensitivity (88%; 95% CI: 81-93%; I(2): 55.2%), and specificity (82%; 95% CI: 75-89%; I(2): 41.3%) were estimated in five studies, but without including contaminated urines. The perineal adhesive bag is not a valid enough method for urine culture collection, because almost half are contaminated and, if they are positive, two out of three are false. Although these estimates are imprecise, because of their great heterogeneity, they should be considered when choosing the method of urine collection. The estimates of sensitivity and specificity are not applicable because they do not take into account the risk of contamination. Copyright © 2015 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

Methodological quality of diagnostic accuracy studies on non-invasive coronary CT angiography: influence of QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) items on sensitivity and specificity.

PubMed

Schueler, Sabine; Walther, Stefan; Schuetz, Georg M; Schlattmann, Peter; Dewey, Marc

2013-06-01

To evaluate the methodological quality of diagnostic accuracy studies on coronary computed tomography (CT) angiography using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) tool. Each QUADAS item was individually defined to adapt it to the special requirements of studies on coronary CT angiography. Two independent investigators analysed 118 studies using 12 QUADAS items. Meta-regression and pooled analyses were performed to identify possible effects of methodological quality items on estimates of diagnostic accuracy. The overall methodological quality of coronary CT studies was merely moderate. They fulfilled a median of 7.5 out of 12 items. Only 9 of the 118 studies fulfilled more than 75 % of possible QUADAS items. One QUADAS item ("Uninterpretable Results") showed a significant influence (P = 0.02) on estimates of diagnostic accuracy with "no fulfilment" increasing specificity from 86 to 90 %. Furthermore, pooled analysis revealed that each QUADAS item that is not fulfilled has the potential to change estimates of diagnostic accuracy. The methodological quality of studies investigating the diagnostic accuracy of non-invasive coronary CT is only moderate and was found to affect the sensitivity and specificity. An improvement is highly desirable because good methodology is crucial for adequately assessing imaging technologies. • Good methodological quality is a basic requirement in diagnostic accuracy studies. • Most coronary CT angiography studies have only been of moderate design quality. • Weak methodological quality will affect the sensitivity and specificity. • No improvement in methodological quality was observed over time. • Authors should consider the QUADAS checklist when undertaking accuracy studies.

A systematic review of selected interventions for worksite health promotion. The assessment of health risks with feedback.

PubMed

Soler, Robin E; Leeks, Kimberly D; Razi, Sima; Hopkins, David P; Griffith, Matt; Aten, Adam; Chattopadhyay, Sajal K; Smith, Susan C; Habarta, Nancy; Goetzel, Ron Z; Pronk, Nicolaas P; Richling, Dennis E; Bauer, Deborah R; Buchanan, Leigh Ramsey; Florence, Curtis S; Koonin, Lisa; MacLean, Debbie; Rosenthal, Abby; Matson Koffman, Dyann; Grizzell, James V; Walker, Andrew M

2010-02-01

Many health behaviors and physiologic indicators can be used to estimate one's likelihood of illness or premature death. Methods have been developed to assess this risk, most notably the use of a health-risk assessment or biometric screening tool. This report provides recommendations on the effectiveness of interventions that use an Assessment of Health Risks with Feedback (AHRF) when used alone or as part of a broader worksite health promotion program to improve the health of employees. The Guide to Community Preventive Services' methods for systematic reviews were used to evaluate the effectiveness of AHRF when used alone and when used in combination with other intervention components. Effectiveness was assessed on the basis of changes in health behaviors and physiologic estimates, but was also informed by changes in risk estimates, healthcare service use, and worker productivity. The review team identified strong evidence of effectiveness of AHRF when used with health education with or without other intervention components for five outcomes. There is sufficient evidence of effectiveness for four additional outcomes assessed. There is insufficient evidence to determine effectiveness for others such as changes in body composition and fruit and vegetable intake. The team also found insufficient evidence to determine the effectiveness of AHRF when implemented alone. The results of these reviews indicate that AHRF is useful as a gateway intervention to a broader worksite health promotion program that includes health education lasting > or =1 hour or repeating multiple times during 1 year, and that may include an array of health promotion activities. These reviews form the basis of the recommendations by the Task Force on Community Preventive Services presented elsewhere in this supplement. Published by Elsevier Inc.

Risk of recurrence of Barrett's esophagus after successful endoscopic therapy

PubMed Central

Krishnamoorthi, Rajesh; Singh, Siddharth; Ragunathan, Karthik; Katzka, David A.; Wang, Kenneth K.; Iyer, Prasad G.

2016-01-01

Background and Aims Previous estimates of incidence of intestinal metaplasia (IM) recurrence after achieving complete remission of IM (CRIM) through endoscopic therapy of Barrett's esophagus (BE) have varied widely. We performed a systematic review and meta-analysis of studies to estimate an accurate recurrence risk after CRIM. Methods We performed a systematic search of multiple literature databases through June 2015 to identify studies reporting long-term follow-up after achieving CRIM through endoscopic therapy. Pooled incidence rate (IR) of recurrent IM, dysplastic BE, and high-grade dysplasia (HGD)/esophageal adenocarcinoma (EAC) per person-year of follow-up after CRIM was estimated. Factors associated with recurrence were also assessed. Results We identified 41 studies that reported 795 cases of recurrence in 4443 patients over 10,427 patient-years of follow-up. This included 21 radiofrequency ablation studies that reported 603 cases of IM recurrence in 3186 patients over 5741 patient-years of follow-up. Pooled IRs of recurrent IM, dysplastic BE, and HGD/EAC after radiofrequency ablation were 9.5% (95% CI, 6.7-12.3), 2.0% (95% CI, 1.3-2.7), and 1.2% (95% CI, .8-1.6) per patient-year, respectively. When all endoscopic modalities were included, pooled IRs of recurrent IM, dysplastic BE, and HGD/EAC were 7.1% (95% CI, 5.6-8.6), 1.3% (95% CI, .8-1.7), and .8% (95% CI, .5-1.1) per patient-year, respectively. Substantial heterogeneity was noted. Increasing age and BE length were predictive of recurrence; 97% of recurrences were treated endoscopically. Conclusions The incidence of recurrence after achieving CRIM through endoscopic therapy was substantial. A small minority of recurrences were dysplastic BE and HGD/EAC. Hence, continued surveillance after CRIM is imperative. Additional studies with long-term follow-up are needed. PMID:26902843

Association between exogenous testosterone and cardiovascular events: an overview of systematic reviews.

PubMed

Onasanya, Oluwadamilola; Iyer, Geetha; Lucas, Eleanor; Lin, Dora; Singh, Sonal; Alexander, G Caleb

2016-11-01

Given the conflicting evidence regarding the association between exogenous testosterone and cardiovascular events, we systematically assessed published systematic reviews for evidence of the association between exogenous testosterone and cardiovascular events. We searched PubMed, MEDLINE, Embase, Cochrane Collaboration Clinical Trials, ClinicalTrials.gov, and the US Food and Drug Administration website for systematic reviews of randomised controlled trials published up to July 19, 2016. Two independent reviewers screened 954 full texts from 29 335 abstracts to identify systematic reviews of randomised controlled trials in which the cardiovascular effects of exogenous testosterone on men aged 18 years or older were examined. We extracted data for study characteristics, analytic methods, and key findings, and applied the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist to assess methodological quality of each review. Our primary outcome measure was the direction and magnitude of association between exogenous testosterone and cardiovascular events. We identified seven reviews and meta-analyses, which had substantial clinical heterogeneity, differing statistical methods, and variable methodological quality and quality of data abstraction. AMSTAR scores ranged from 3 to 9 out of 11. Six systematic reviews that each included a meta-analysis showed no significant association between exogenous testosterone and cardiovascular events, with summary estimates ranging from 1·07 to 1·82 and imprecise confidence intervals. Two of these six meta-analyses showed increased risk in subgroup analyses of oral testosterone and men aged 65 years or older during their first treatment year. One meta-analysis showed a significant association between exogenous testosterone and cardiovascular events, in men aged 18 years or older generally, with a summary estimate of 1·54 (95% CI 1·09-2·18). Our optimal information size analysis showed that any randomised controlled trial aiming to detect a true difference in cardiovascular risk between treatment groups receiving exogenous testosterone and their controls (with a two-sided p value of 0·05 and a power of 80%) would require at least 17 664 participants in each trial group. Therefore, given the challenge of adequately powering clinical trials for rare outcomes, rigorous observational studies are needed to clarify the association between testosterone-replacement therapy and major adverse cardiovascular outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of left ventricular function and mass by MR imaging: a stereological study based on the systematic slice sampling procedure.

PubMed

Mazonakis, Michalis; Sahin, Bunyamin; Pagonidis, Konstantin; Damilakis, John

2011-06-01

The aim of this study was to combine the stereological technique with magnetic resonance (MR) imaging data for the volumetric and functional analysis of the left ventricle (LV). Cardiac MR examinations were performed in 13 consecutive subjects with known or suspected coronary artery disease. The end-diastolic volume (EDV), end-systolic volume, ejection fraction (EF), and mass were estimated by stereology using the entire slice set depicting LV and systematic sampling intensities of 1/2 and 1/3 that provided samples with every second and third slice, respectively. The repeatability of stereology was evaluated. Stereological assessments were compared with the reference values derived by manually tracing the endocardial and epicardial contours on MR images. Stereological EDV and EF estimations obtained by the 1/3 systematic sampling scheme were significantly different from those by manual delineation (P < .05). No difference was observed between the reference values and the LV parameters estimated by the entire slice set or a sampling intensity of 1/2 (P > .05). For these stereological approaches, a high correlation (r(2) = 0.80-0.93) and clinically acceptable limits of agreement were found with the reference method. Stereological estimations obtained by both sample sizes presented comparable coefficient of variation values of 2.9-5.8%. The mean time for stereological measurements on the entire slice set was 3.4 ± 0.6 minutes and it was reduced to 2.5 ± 0.5 minutes with the 1/2 systematic sampling scheme. Stereological analysis on systematic samples of MR slices generated by the 1/2 sampling intensity provided efficient and quick assessment of LV volumes, function, and mass. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

A method for inferring the rate of evolution of homologous characters that can potentially improve phylogenetic inference, resolve deep divergence and correct systematic biases.

PubMed

Cummins, Carla A; McInerney, James O

2011-12-01

Current phylogenetic methods attempt to account for evolutionary rate variation across characters in a matrix. This is generally achieved by the use of sophisticated evolutionary models, combined with dense sampling of large numbers of characters. However, systematic biases and superimposed substitutions make this task very difficult. Model adequacy can sometimes be achieved at the cost of adding large numbers of free parameters, with each parameter being optimized according to some criterion, resulting in increased computation times and large variances in the model estimates. In this study, we develop a simple approach that estimates the relative evolutionary rate of each homologous character. The method that we describe uses the similarity between characters as a proxy for evolutionary rate. In this article, we work on the premise that if the character-state distribution of a homologous character is similar to many other characters, then this character is likely to be relatively slowly evolving. If the character-state distribution of a homologous character is not similar to many or any of the rest of the characters in a data set, then it is likely to be the result of rapid evolution. We show that in some test cases, at least, the premise can hold and the inferences are robust. Importantly, the method does not use a "starting tree" to make the inference and therefore is tree independent. We demonstrate that this approach can work as well as a maximum likelihood (ML) approach, though the ML method needs to have a known phylogeny, or at least a very good estimate of that phylogeny. We then demonstrate some uses for this method of analysis, including the improvement in phylogeny reconstruction for both deep-level and recent relationships and overcoming systematic biases such as base composition bias. Furthermore, we compare this approach to two well-established methods for reweighting or removing characters. These other methods are tree-based and we show that they can be systematically biased. We feel this method can be useful for phylogeny reconstruction, understanding evolutionary rate variation, and for understanding selection variation on different characters.

Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density

PubMed Central

Edwards, D. L.; Saleh, A. A.; Greenspan, S. L.

2015-01-01

Summary We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90 % at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. Introduction The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density. Methods Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references. Results One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89 % (95%CI 82–96 %) and 41 % (95%CI 23–59 %), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88 % (95%CI 79–97 %) and 55 % (95%CI 42–68 %), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90 % but always with a trade-off of relatively low specificity. Conclusions Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90 % for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. PMID:25644147

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, Robert N.; Urban, Marie L.; Duchscherer, Samantha E.

Understanding building occupancy is critical to a wide array of applications including natural hazards loss analysis, green building technologies, and population distribution modeling. Due to the expense of directly monitoring buildings, scientists rely in addition on a wide and disparate array of ancillary and open source information including subject matter expertise, survey data, and remote sensing information. These data are fused using data harmonization methods which refer to a loose collection of formal and informal techniques for fusing data together to create viable content for building occupancy estimation. In this paper, we add to the current state of the artmore » by introducing the Population Data Tables (PDT), a Bayesian based informatics system for systematically arranging data and harmonization techniques into a consistent, transparent, knowledge learning framework that retains in the final estimation uncertainty emerging from data, expert judgment, and model parameterization. PDT probabilistically estimates ambient occupancy in units of people/1000ft2 for over 50 building types at the national and sub-national level with the goal of providing global coverage. The challenge of global coverage led to the development of an interdisciplinary geospatial informatics system tool that provides the framework for capturing, storing, and managing open source data, handling subject matter expertise, carrying out Bayesian analytics as well as visualizing and exporting occupancy estimation results. We present the PDT project, situate the work within the larger community, and report on the progress of this multi-year project.Understanding building occupancy is critical to a wide array of applications including natural hazards loss analysis, green building technologies, and population distribution modeling. Due to the expense of directly monitoring buildings, scientists rely in addition on a wide and disparate array of ancillary and open source information including subject matter expertise, survey data, and remote sensing information. These data are fused using data harmonization methods which refer to a loose collection of formal and informal techniques for fusing data together to create viable content for building occupancy estimation. In this paper, we add to the current state of the art by introducing the Population Data Tables (PDT), a Bayesian model and informatics system for systematically arranging data and harmonization techniques into a consistent, transparent, knowledge learning framework that retains in the final estimation uncertainty emerging from data, expert judgment, and model parameterization. PDT probabilistically estimates ambient occupancy in units of people/1000 ft 2 for over 50 building types at the national and sub-national level with the goal of providing global coverage. The challenge of global coverage led to the development of an interdisciplinary geospatial informatics system tool that provides the framework for capturing, storing, and managing open source data, handling subject matter expertise, carrying out Bayesian analytics as well as visualizing and exporting occupancy estimation results. We present the PDT project, situate the work within the larger community, and report on the progress of this multi-year project.« less

A systematic review and meta-analysis on herpes zoster and the risk of cardiac and cerebrovascular events

PubMed Central

Erskine, Nathaniel; Tran, Hoang; Levin, Leonard; Ulbricht, Christine; Fingeroth, Joyce; Kiefe, Catarina; Singh, Sonal

2017-01-01

Background Patients who develop herpes zoster or herpes zoster ophthalmicus may be at risk for cerebrovascular and cardiac complications. We systematically reviewed the published literature to determine the association between herpes zoster and its subtypes with the occurrence of cerebrovascular and cardiac events. Methods/Results Systematic searches of PubMed (MEDLINE), SCOPUS (Embase) and Google Scholar were performed in December 2016. Eligible studies were cohort, case-control, and self-controlled case-series examining the association between herpes zoster or subtypes of herpes zoster with the occurrence of cerebrovascular and cardiac events including stroke, transient ischemic attack, coronary heart disease, and myocardial infarction. Data on the occurrence of the examined events were abstracted. Odds ratios and their accompanying confidence intervals were estimated using random and fixed effects models with statistical heterogeneity estimated with the I2 statistic. Twelve studies examining 7.9 million patients up to 28 years after the onset of herpes zoster met our pre-defined eligibility criteria. Random and fixed effects meta-analyses showed that herpes zoster, type unspecified, and herpes zoster ophthalmicus were associated with a significantly increased risk of cerebrovascular events, without any evidence of statistical heterogeneity. Our meta-analysis also found a significantly increased risk of cardiac events associated with herpes zoster, type unspecified. Conclusions Our results are consistent with the accumulating body of evidence that herpes zoster and herpes zoster ophthalmicus are significantly associated with cerebrovascular and cardiovascular events. PMID:28749981

A systematic review and meta-analysis on herpes zoster and the risk of cardiac and cerebrovascular events.

PubMed

Erskine, Nathaniel; Tran, Hoang; Levin, Leonard; Ulbricht, Christine; Fingeroth, Joyce; Kiefe, Catarina; Goldberg, Robert J; Singh, Sonal

2017-01-01

Patients who develop herpes zoster or herpes zoster ophthalmicus may be at risk for cerebrovascular and cardiac complications. We systematically reviewed the published literature to determine the association between herpes zoster and its subtypes with the occurrence of cerebrovascular and cardiac events. Systematic searches of PubMed (MEDLINE), SCOPUS (Embase) and Google Scholar were performed in December 2016. Eligible studies were cohort, case-control, and self-controlled case-series examining the association between herpes zoster or subtypes of herpes zoster with the occurrence of cerebrovascular and cardiac events including stroke, transient ischemic attack, coronary heart disease, and myocardial infarction. Data on the occurrence of the examined events were abstracted. Odds ratios and their accompanying confidence intervals were estimated using random and fixed effects models with statistical heterogeneity estimated with the I2 statistic. Twelve studies examining 7.9 million patients up to 28 years after the onset of herpes zoster met our pre-defined eligibility criteria. Random and fixed effects meta-analyses showed that herpes zoster, type unspecified, and herpes zoster ophthalmicus were associated with a significantly increased risk of cerebrovascular events, without any evidence of statistical heterogeneity. Our meta-analysis also found a significantly increased risk of cardiac events associated with herpes zoster, type unspecified. Our results are consistent with the accumulating body of evidence that herpes zoster and herpes zoster ophthalmicus are significantly associated with cerebrovascular and cardiovascular events.

Systematic review and economic evaluation of Helicobacter pylori eradication treatment for non-ulcer dyspepsia

PubMed Central

Moayyedi, Paul; Soo, Shelly; Deeks, Jonathan; Forman, David; Mason, James; Innes, Michael; Delaney, Brendan

2000-01-01

Objectives To evaluate efficacy and cost effectiveness of Helicobacter pylori eradication treatment in patients with non-ulcer dyspepsia infected with H pylori. Design Systematic review of randomised controlled trials comparing H pylori eradication with placebo or another drug treatment. Results were incorporated into a Markov model comparing health service costs and benefits of H pylori eradication with antacid treatment over one year. Data sources Six electronic databases were searched for randomised controlled trials from January 1966 to May 2000. Experts in the field, pharmaceutical companies, and journals were contacted for information on any unpublished trials. Trial reports were reviewed according to predefined eligibility and quality criteria. Main outcome measures Relative risk reduction for remaining dyspeptic symptoms (the same or worse) at 3-12 months. Cost per dyspepsia-free month estimated from Markov model based on estimated relative risk reduction. Results Twelve trials were included in the systematic review, nine of which evaluated dyspepsia at 3-12 months in 2541 patients. H pylori eradication treatment was significantly superior to placebo in treating non-ulcer dyspepsia (relative risk reduction 9% (95% confidence interval 4% to 14%)), one case of dyspepsia being cured for every 15 people treated. H pylori eradication cost £56 per dyspepsia-free month during first year after treatment. Conclusion H pylori eradication may be cost effective treatment for non-ulcer dyspepsia in infected patients but further evidence is needed on decision makers' willingness to pay for relief of dyspepsia. PMID:10987767

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jennings, E.; Madigan, M.

Given the complexity of modern cosmological parameter inference where we arefaced with non-Gaussian data and noise, correlated systematics and multi-probecorrelated data sets, the Approximate Bayesian Computation (ABC) method is apromising alternative to traditional Markov Chain Monte Carlo approaches in thecase where the Likelihood is intractable or unknown. The ABC method is called"Likelihood free" as it avoids explicit evaluation of the Likelihood by using aforward model simulation of the data which can include systematics. Weintroduce astroABC, an open source ABC Sequential Monte Carlo (SMC) sampler forparameter estimation. A key challenge in astrophysics is the efficient use oflarge multi-probe datasets to constrainmore » high dimensional, possibly correlatedparameter spaces. With this in mind astroABC allows for massive parallelizationusing MPI, a framework that handles spawning of jobs across multiple nodes. Akey new feature of astroABC is the ability to create MPI groups with differentcommunicators, one for the sampler and several others for the forward modelsimulation, which speeds up sampling time considerably. For smaller jobs thePython multiprocessing option is also available. Other key features include: aSequential Monte Carlo sampler, a method for iteratively adapting tolerancelevels, local covariance estimate using scikit-learn's KDTree, modules forspecifying optimal covariance matrix for a component-wise or multivariatenormal perturbation kernel, output and restart files are backed up everyiteration, user defined metric and simulation methods, a module for specifyingheterogeneous parameter priors including non-standard prior PDFs, a module forspecifying a constant, linear, log or exponential tolerance level,well-documented examples and sample scripts. This code is hosted online athttps://github.com/EliseJ/astroABC« less

astroABC : An Approximate Bayesian Computation Sequential Monte Carlo sampler for cosmological parameter estimation

NASA Astrophysics Data System (ADS)

Jennings, E.; Madigan, M.

2017-04-01

Given the complexity of modern cosmological parameter inference where we are faced with non-Gaussian data and noise, correlated systematics and multi-probe correlated datasets,the Approximate Bayesian Computation (ABC) method is a promising alternative to traditional Markov Chain Monte Carlo approaches in the case where the Likelihood is intractable or unknown. The ABC method is called "Likelihood free" as it avoids explicit evaluation of the Likelihood by using a forward model simulation of the data which can include systematics. We introduce astroABC, an open source ABC Sequential Monte Carlo (SMC) sampler for parameter estimation. A key challenge in astrophysics is the efficient use of large multi-probe datasets to constrain high dimensional, possibly correlated parameter spaces. With this in mind astroABC allows for massive parallelization using MPI, a framework that handles spawning of processes across multiple nodes. A key new feature of astroABC is the ability to create MPI groups with different communicators, one for the sampler and several others for the forward model simulation, which speeds up sampling time considerably. For smaller jobs the Python multiprocessing option is also available. Other key features of this new sampler include: a Sequential Monte Carlo sampler; a method for iteratively adapting tolerance levels; local covariance estimate using scikit-learn's KDTree; modules for specifying optimal covariance matrix for a component-wise or multivariate normal perturbation kernel and a weighted covariance metric; restart files output frequently so an interrupted sampling run can be resumed at any iteration; output and restart files are backed up at every iteration; user defined distance metric and simulation methods; a module for specifying heterogeneous parameter priors including non-standard prior PDFs; a module for specifying a constant, linear, log or exponential tolerance level; well-documented examples and sample scripts. This code is hosted online at https://github.com/EliseJ/astroABC.

The incidence of human papillomavirus infection following treatment for cervical neoplasia: A systematic review

PubMed Central

Rositch, Anne F.; Soeters, Heidi M.; Offutt-Powell, Tabatha N.; Wheeler, Bradford S.; Taylor, Sylvia M.; Smith, Jennifer S.

2015-01-01

Objective To systematically review the published literature in order to estimate the incidence and describe the variability of human papillomavirus (HPV) infection in women following treatment for cervical neoplasia. Methods Several scientific literature databases (e.g. PubMed, ISI Web of Science) were searched through January 31, 2012. Eligible articles provided data on (i) baseline HPV infection status within 6 months prior to or at time of treatment (pre-treatment); and (ii) HPV test results for women's first visit after treatment occurring within 36 months (post-treatment). We abstracted and summarized the post-treatment incidence of newly detected HPV genotypes that were not present at pre-treatment, overall and stratified by study and other population characteristics. Results A total of 25 studies were included, reporting post-treatment HPV incidence in nearly 2000 women. Mean patient age ranged from 31 to 43 years (median 36). Most studies used cervical exfoliated cell specimens to test for HPV DNA (n = 20; 80%), using polymerase chain reaction (n = 21; 84%). Cervical neoplasia treatment included loop electrical excision procedure (n = 11; 44%); laser conization (n = 2; 8%); laser ablation, surgical conization, cryotherapy, alpha-interferon (n = 1; 4% each); or multiple treatment regimens (n = 8; 32%). Follow-up times post-treatment ranged from 1.5 to 36 months (median 6). More than half of studies (n = 17; 68%) estimated the incidence of any HPV type following treatment, while 7 (28%) focused specifically on high-risk (HR) HPV. HPV incidence after treatment varied widely, ranging from 0 to 47% (interquartile range: 0%-15%) in up to 3 years of follow-up after treatment. Lower HPV incidence was observed among studies that included relatively younger women, used laser conization, focused on HR-HPV rather than overall HPV infection, and had a lower proportion of recurrent cervical disease. Conclusions These modest summary incidence estimates from the published literature can guide clinicians, epidemiologists and health economists in developing best practices for post-treatment cervical cancer prevention. PMID:24412508

A Systematic Review of Mortality from Untreated Scrub Typhus (Orientia tsutsugamushi).

PubMed

Taylor, Andrew J; Paris, Daniel H; Newton, Paul N

2015-01-01

Scrub typhus, a bacterial infection caused by Orientia tsutsugamushi, is increasingly recognized as an important cause of fever in Asia, with an estimated one million infections occurring each year. Limited access to health care and the disease's non-specific symptoms mean that many patients are undiagnosed and untreated, but the mortality from untreated scrub typhus is unknown. This review systematically summarizes the literature on the untreated mortality from scrub typhus and disease outcomes. A literature search was performed to identify patient series containing untreated patients. Patients were included if they were symptomatic and had a clinical or laboratory diagnosis of scrub typhus and excluded if they were treated with antibiotics. The primary outcome was mortality from untreated scrub typhus and secondary outcomes were total days of fever, clinical symptoms, and laboratory results. A total of 76 studies containing 89 patient series and 19,644 patients were included in the final analysis. The median mortality of all patient series was 6.0% with a wide range (min-max) of 0-70%. Many studies used clinical diagnosis alone and had incomplete data on secondary outcomes. Mortality varied by location and increased with age and in patients with myocarditis, delirium, pneumonitis, or signs of hemorrhage, but not according to sex or the presence of an eschar or meningitis. Duration of fever was shown to be long (median 14.4 days Range (9-19)). Results show that the untreated mortality from scrub typhus appears lower than previously reported estimates. More data are required to clarify mortality according to location and host factors, clinical syndromes including myocarditis and central nervous system disease, and in vulnerable mother-child populations. Increased surveillance and improved access to diagnostic tests are required to accurately estimate the untreated mortality of scrub typhus. This information would facilitate reliable quantification of DALYs and guide empirical treatment strategies.

The current total economic burden of diabetes mellitus in the Netherlands.

PubMed

Peters, M L; Huisman, E L; Schoonen, M; Wolffenbuttel, B H R

2017-09-01

Insight into the total economic burden of diabetes mellitus (DM) is essential for decision makers and payers. Currently available estimates for the Netherlands only include part of the total burden or are no longer up-to-date. Therefore, this study aimed to determine the current total economic burden of DM and its complications in the Netherlands, by including all the relevant cost components. The study combined a systematic literature review to identify all relevant published information and a targeted review to identify relevant information in the grey literature. The identified evidence was then combined to estimate the current total economic burden. In 2016, there were an estimated 1.1 million DM patients in the Netherlands, of whom approximately 10% had type 1 and 90% had type 2 DM. The estimated current total economic burden of DM was € 6.8 billion in 2016. Healthcare costs (excluding costs of complications) were € 1.6 billion, direct costs of complications were € 1.3 billion and indirect costs due to productivity losses, welfare payments and complications were € 4.0 billion. DM and its complications pose a substantial economic burden to the Netherlands, which is expected to rise due to changing demographics and lifestyle. Indirect costs, such as welfare payments, accounted for a large portion of the current total economic burden of DM, while these cost components are often not included in cost estimations. Publicly available data for key cost drivers such as complications were scarce.

Complete Systematic Error Model of SSR for Sensor Registration in ATC Surveillance Networks

PubMed Central

Besada, Juan A.

2017-01-01

In this paper, a complete and rigorous mathematical model for secondary surveillance radar systematic errors (biases) is developed. The model takes into account the physical effects systematically affecting the measurement processes. The azimuth biases are calculated from the physical error of the antenna calibration and the errors of the angle determination dispositive. Distance bias is calculated from the delay of the signal produced by the refractivity index of the atmosphere, and from clock errors, while the altitude bias is calculated taking into account the atmosphere conditions (pressure and temperature). It will be shown, using simulated and real data, that adapting a classical bias estimation process to use the complete parametrized model results in improved accuracy in the bias estimation. PMID:28934157

Survey of Crop Losses in Response to Phytoparasitic Nematodes in the United States for 1994

PubMed Central

Koenning, S. R.; Overstreet, C.; Noling, J. W.; Donald, P. A.; Becker, J. O.; Fortnum, B. A.

1999-01-01

Previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. Reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the University of Georgia, the Beltwide Cotton Conference, and selected groups concerned with soybean. The Society of Nematologists Extension Committee contacted extension personnel in 49 U.S. states for information on estimated crop losses caused by plant-parasitic nematodes in major crops for the year 1994. Included in this paper are survey results from 35 states on various crops including corn, cotton, soybean, peanut, wheat, rice, sugarcane, sorghum, tobacco, numerous vegetable crops, fruit and nut crops, and golf greens. The data are reported systematically by state and include the estimated loss, hectarage of production, source of information, nematode species or taxon when available, and crop value. The major genera of phytoparasitic nematodes reported to cause crop losses were Heterodera, Hoplolaimus, Meloidogyne, Pratylenchus, Rotylenchulus, and Xiphinema. PMID:19270925

Survey of crop losses in response to phytoparasitic nematodes in the United States for 1994.

PubMed

Koenning, S R; Overstreet, C; Noling, J W; Donald, P A; Becker, J O; Fortnum, B A

1999-12-01

Previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. Reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the University of Georgia, the Beltwide Cotton Conference, and selected groups concerned with soybean. The Society of Nematologists Extension Committee contacted extension personnel in 49 U.S. states for information on estimated crop losses caused by plant-parasitic nematodes in major crops for the year 1994. Included in this paper are survey results from 35 states on various crops including corn, cotton, soybean, peanut, wheat, rice, sugarcane, sorghum, tobacco, numerous vegetable crops, fruit and nut crops, and golf greens. The data are reported systematically by state and include the estimated loss, hectarage of production, source of information, nematode species or taxon when available, and crop value. The major genera of phytoparasitic nematodes reported to cause crop losses were Heterodera, Hoplolaimus, Meloidogyne, Pratylenchus, Rotylenchulus, and Xiphinema.

A Systematic Review and Meta-Analysis of the Relationship Between Hospital Volume and the Outcomes of Percutaneous Coronary Intervention

PubMed Central

Lin, Xiaojun; Tao, Hongbing; Cai, Miao; Liao, Aihua; Cheng, Zhaohui; Lin, Haifeng

2016-01-01

Abstract Previous reviews have suggested that hospital volume is inversely related to in-hospital mortality. However, percutaneous coronary intervention (PCI) practices have changed substantially in recent years, and whether this relationship persists remains controversial. A systematic search was performed using PubMed, Embase, and the Cochrane Library to identify studies that describe the effect of hospital volume on the outcomes of PCI. Critical appraisals of the methodological quality and the risk of bias were conducted independently by 2 authors. Fourteen of 96 potentiality relevant articles were included in the analysis. Twelve of the articles described the relationship between hospital volume and mortality and included data regarding odds ratios (ORs); 3 studies described the relationship between hospital volume and long-term survival, and only 1 study included data regarding hazard ratios (HRs). A meta-analysis of postoperative mortality was performed using a random effects model, and the pooled effect estimate was significantly in favor of high volume providers (OR: 0.79; 95% confidence interval [CI], 0.72–0.86; P < 0.001). A systematic review of long-term survival was performed, and a trend toward better long-term survival in high volume hospitals was observed. This meta-analysis only included studies published after 2006 and revealed that postoperative mortality following PCI correlates significantly and inversely with hospital volume. However, the magnitude of the effect of volume on long-term survival is difficult to assess. Additional research is necessary to confirm our findings and to elucidate the mechanism underlying the volume–outcome relationship. PMID:26844508

Cost and Cost-Effectiveness of Donor Human Milk to Prevent Necrotizing Enterocolitis: Systematic Review.

PubMed

Buckle, Abigail; Taylor, Celia

2017-11-01

Necrotizing enterocolitis (NEC) is a costly gastrointestinal disorder that mainly affects preterm and low-birth-weight infants and can lead to considerable morbidity and mortality. Mother's own milk is protective against NEC but is not always available. In such cases, donor human milk has also been shown to be protective (although to a lesser extent) compared with formula milk, but it is more expensive. This systematic review aimed at evaluating the cost of donor milk, the cost of treating NEC, and the cost-effectiveness of exclusive donor milk versus formula milk feeding to reduce the short-term health and treatment costs of NEC. We systematically searched five relevant databases to find studies with verifiable costs or charges of donor milk and/or treatment of NEC and any economic evaluations comparing exclusive donor milk with exclusive formula milk feeding. All search results were double screened. Seven studies with verifiable donor milk costs and 17 with verifiable NEC treatment costs were included. The types of cost or charge included varied considerably across studies, so quantitative synthesis was not attempted. Estimates of the incremental length of stay associated with NEC were ∼18 days for medical NEC and 50 days for surgical NEC. Two studies claimed to report economic evaluations but did not do so in practice. It is likely that donor milk provides short-term cost savings by reducing the incidence of NEC. Future studies should provide more details on cost components included and a full economic evaluation, including long-term outcomes, should be undertaken.

The efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in people with abdominal and pelvic cancer: a systematic review and meta-analysis.

PubMed

Wang, Y-H; Yao, N; Wei, K-K; Jiang, L; Hanif, S; Wang, Z-X; Pei, C-X

2016-11-01

A systematic review and meta-analysis were designed to evaluate the efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in people with abdominal and pelvic cancer. We searched the Cochrane Library, PubMed, EMBASE and Web of Science up to November 2015. We also hand searched the citation lists of included studies and previously identified systematic reviews to identify further relevant trials. Odds ratio (OR) was used to compare efficacy, and the pooled OR was estimated using a random effects model; heterogeneity was assessed with Cochran's Q and the Higgins' I 2 -test. Two reviewers assessed trial quality and extracted data independently. Analysis and bias for each included study were performed using Review Manager 5.2. Nine randomized and placebo-controlled studies (N=1265 participants) were included for assessing efficacy, of which seven were about radiotherapy and two about chemotherapy. Probiotic groups were compared with control groups with respect to the the incidence of diarrhea, OR=0.47 (95% confidence interval 0.28-0.76; P=0.002). Eleven studies, including 1612 people (873 consuming probiotics and 739 not consuming probiotics), were used for the analysis of safety of probiotics. Of the 11 studies, seven studies had no adverse events (AEs) caused by probiotics, whereas four studies reported varying degrees of AEs in their treatment. Probiotics may have a beneficial effect in prevention of chemoradiotherapy-induced diarrhea generally, especially for Grade⩾2 diarrhea. Probiotics may rarely cause AEs.

HIV-Associated Cognitive Impairment in Perinatally Infected Children: A Meta-analysis.

PubMed

Phillips, Nicole; Amos, Taryn; Kuo, Caroline; Hoare, Jacqueline; Ipser, Jonathan; Thomas, Kevin G F; Stein, Dan J

2016-11-01

Research shows, conclusively, that perinatal HIV infection has negative effects on cognitive functioning of children and adolescents. However, the extent of these cognitive impairments is unknown. Current literature does not document specific cognitive domains most affected in HIV-infected children and adolescents. To systematically review and meta-analyze the degree of cognitive impairment, and the specific cognitive domains affected, in children and adolescents with perinatally acquired HIV infection. We systematically searched 5 electronic bibliographic databases, namely: PubMed, PsychINFO, Academic Search Premier, Scopus, and WorldCat, by using a search protocol specifically designed for this study. Studies were selected on the basis of set a priori eligibility criteria. Titles, abstracts, and full texts were assessed by 2 independent reviewers. Data from included studies were extracted into Microsoft Excel by 2 independent reviewers. Twenty-two studies were identified for inclusion in the systematic review and of this, 6 studies were included in the meta-analysis. Results from the meta-analysis indicated that working memory and executive function were the domains most affected by the HIV virus. Only 27% of the included studies were suitable to enter into the meta-analysis. There was significant geographic bias in published studies, with only 32% (7/22) of included studies from sub-Saharan Africa. The evidence supports an association between HIV infection in children and adolescents and cognitive impairment in the domains of working memory, executive function and processing speed, with effect size estimates also providing some support for deficits in visual memory and visual-spatial ability. Copyright © 2016 by the American Academy of Pediatrics.

Assessing the association between natural food folate intake and blood folate concentrations: a systematic review and Bayesian meta-analysis of trials and observational studies.

PubMed

Marchetta, Claire M; Devine, Owen J; Crider, Krista S; Tsang, Becky L; Cordero, Amy M; Qi, Yan Ping; Guo, Jing; Berry, Robert J; Rosenthal, Jorge; Mulinare, Joseph; Mersereau, Patricia; Hamner, Heather C

2015-04-10

Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992-3 2014) with both natural food folate intake alone and blood folate concentration among females aged 12-49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA) included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI): 4%, 9%) increase in red blood cell (RBC) folate concentration and a 7% (95% CrI: 1%, 12%) increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥ 450 μg dietary folate equivalents (DFE)/day could achieve the lower bound of an RBC folate concentration (~ 1050 nmol/L) associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births.

Toward a Framework for Systematic Error Modeling of NASA Spaceborne Radar with NOAA/NSSL Ground Radar-Based National Mosaic QPE

NASA Technical Reports Server (NTRS)

Kirstettier, Pierre-Emmanual; Honh, Y.; Gourley, J. J.; Chen, S.; Flamig, Z.; Zhang, J.; Howard, K.; Schwaller, M.; Petersen, W.; Amitai, E.

2011-01-01

Characterization of the error associated to satellite rainfall estimates is a necessary component of deterministic and probabilistic frameworks involving space-born passive and active microwave measurement") for applications ranging from water budget studies to forecasting natural hazards related to extreme rainfall events. We focus here on the error structure of NASA's Tropical Rainfall Measurement Mission (TRMM) Precipitation Radar (PR) quantitative precipitation estimation (QPE) at ground. The problem is addressed by comparison of PR QPEs with reference values derived from ground-based measurements using NOAA/NSSL ground radar-based National Mosaic and QPE system (NMQ/Q2). A preliminary investigation of this subject has been carried out at the PR estimation scale (instantaneous and 5 km) using a three-month data sample in the southern part of US. The primary contribution of this study is the presentation of the detailed steps required to derive trustworthy reference rainfall dataset from Q2 at the PR pixel resolution. It relics on a bias correction and a radar quality index, both of which provide a basis to filter out the less trustworthy Q2 values. Several aspects of PR errors arc revealed and quantified including sensitivity to the processing steps with the reference rainfall, comparisons of rainfall detectability and rainfall rate distributions, spatial representativeness of error, and separation of systematic biases and random errors. The methodology and framework developed herein applies more generally to rainfall rate estimates from other sensors onboard low-earth orbiting satellites such as microwave imagers and dual-wavelength radars such as with the Global Precipitation Measurement (GPM) mission.

Incidence of chronic atrophic gastritis: systematic review and meta-analysis of follow-up studies.

PubMed

Adamu, Mariam Abdullahi; Weck, Melanie Nicole; Gao, Lei; Brenner, Hermann

2010-07-01

Chronic atrophic gastritis (CAG) is an important precursor lesion of intestinal gastric cancer. As it is typically asymptomatic, epidemiological data on the incidence of CAG are sparse. We aimed to provide an overview of published data on CAG incidence (overall and according to risk factors) from follow-up studies. Articles with information on incidence of CAG published in English until 26th of July 2009 were identified through a systematic MEDLINE and EMBASE search. Data extracted include study characteristics and key findings regarding the incidence of CAG. A meta-analysis was performed on the association between Helicobacter pylori infection and CAG incidence. Overall, data on CAG incidence were available from 14 studies, in 7 studies incidence could be estimated according to H. pylori infection. Most studies were conducted in symptomatic or high risk populations and the maximum number of incident cases was 284. Incidence estimates ranged from 0 to 11% per year and were consistently below 1% in patients not infected with H. pylori. The highest incidence was observed in a special study conducted on ulcer patients treated by proximal gastric vagotomy. Rate ratios for the association between H. pylori infection and CAG incidence ranged from 2.4 to 7.6 with a summary estimate of 5.0 (95% confidence interval: 3.1-8.3). Incidence of CAG is very low in the absence of H. pylori infection. There is a need for more population-based studies to provide comparable estimates of incidence and the impact of risk factors in the development of CAG.

Systematic parameter estimation and sensitivity analysis using a multidimensional PEMFC model coupled with DAKOTA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chao Yang; Luo, Gang; Jiang, Fangming

2010-05-01

Current computational models for proton exchange membrane fuel cells (PEMFCs) include a large number of parameters such as boundary conditions, material properties, and numerous parameters used in sub-models for membrane transport, two-phase flow and electrochemistry. In order to successfully use a computational PEMFC model in design and optimization, it is important to identify critical parameters under a wide variety of operating conditions, such as relative humidity, current load, temperature, etc. Moreover, when experimental data is available in the form of polarization curves or local distribution of current and reactant/product species (e.g., O2, H2O concentrations), critical parameters can be estimated inmore » order to enable the model to better fit the data. Sensitivity analysis and parameter estimation are typically performed using manual adjustment of parameters, which is also common in parameter studies. We present work to demonstrate a systematic approach based on using a widely available toolkit developed at Sandia called DAKOTA that supports many kinds of design studies, such as sensitivity analysis as well as optimization and uncertainty quantification. In the present work, we couple a multidimensional PEMFC model (which is being developed, tested and later validated in a joint effort by a team from Penn State Univ. and Sandia National Laboratories) with DAKOTA through the mapping of model parameters to system responses. Using this interface, we demonstrate the efficiency of performing simple parameter studies as well as identifying critical parameters using sensitivity analysis. Finally, we show examples of optimization and parameter estimation using the automated capability in DAKOTA.« less

Exemplar-based human action pose correction.

PubMed

Shen, Wei; Deng, Ke; Bai, Xiang; Leyvand, Tommer; Guo, Baining; Tu, Zhuowen

2014-07-01

The launch of Xbox Kinect has built a very successful computer vision product and made a big impact on the gaming industry. This sheds lights onto a wide variety of potential applications related to action recognition. The accurate estimation of human poses from the depth image is universally a critical step. However, existing pose estimation systems exhibit failures when facing severe occlusion. In this paper, we propose an exemplar-based method to learn to correct the initially estimated poses. We learn an inhomogeneous systematic bias by leveraging the exemplar information within a specific human action domain. Furthermore, as an extension, we learn a conditional model by incorporation of pose tags to further increase the accuracy of pose correction. In the experiments, significant improvements on both joint-based skeleton correction and tag prediction are observed over the contemporary approaches, including what is delivered by the current Kinect system. Our experiments for the facial landmark correction also illustrate that our algorithm can improve the accuracy of other detection/estimation systems.

The economic impact of pig-associated parasitic zoonosis in Northern Lao PDR.

PubMed

Choudhury, Adnan Ali Khan; Conlan, James V; Racloz, Vanessa Nadine; Reid, Simon Andrew; Blacksell, Stuart D; Fenwick, Stanley G; Thompson, Andrew R C; Khamlome, Boualam; Vongxay, Khamphouth; Whittaker, Maxine

2013-03-01

The parasitic zoonoses human cysticercosis (Taenia solium), taeniasis (other Taenia species) and trichinellosis (Trichinella species) are endemic in the Lao People's Democratic Republic (Lao PDR). This study was designed to quantify the economic burden pig-associated zoonotic disease pose in Lao PDR. In particular, the analysis included estimation of the losses in the pork industry as well as losses due to human illness and lost productivity. A Markov-probability based decision-tree model was chosen to form the basis of the calculations to estimate the economic and public health impacts of taeniasis, trichinellosis and cysticercosis. Two different decision trees were run simultaneously on the model's human cohort. A third decision tree simulated the potential impacts on pig production. The human capital method was used to estimate productivity loss. The results found varied significantly depending on the rate of hospitalisation due to neurocysticerosis. This study is the first systematic estimate of the economic impact of pig-associated zoonotic diseases in Lao PDR that demonstrates the significance of the diseases in that country.

Estimating functional cognition in older adults using observational assessments of task performance in complex everyday activities: A systematic review and evaluation of measurement properties.

PubMed

Wesson, Jacqueline; Clemson, Lindy; Brodaty, Henry; Reppermund, Simone

2016-09-01

Functional cognition is a relatively new concept in assessment of older adults with mild cognitive impairment or dementia. Instruments need to be reliable and valid, hence we conducted a systematic review of observational assessments of task performance used to estimate functional cognition in this population. Two separate database searches were conducted: firstly to identify instruments; and secondly to identify studies reporting on the psychometric properties of the instruments. Studies were analysed using a published checklist and their quality reviewed according to specific published criteria. Clinical utility was reviewed and the information formulated into a best evidence synthesis. We found 21 instruments and included 58 studies reporting on measurement properties. The majority of studies were rated as being of fair methodological quality and the range of properties investigated was restricted. Most instruments had studies reporting on construct validity (hypothesis testing), none on content validity and there were few studies reporting on reliability. Overall the evidence on psychometric properties is lacking and there is an urgent need for further evaluation of instruments. Copyright © 2016 Elsevier Ltd. All rights reserved.

A systematic review of health economic models and utility estimation methods in schizophrenia.

PubMed

Németh, Bertalan; Fasseeh, Ahmad; Molnár, Anett; Bitter, István; Horváth, Margit; Kóczián, Kristóf; Götze, Árpád; Nagy, Balázs

2018-06-01

There is a growing need for economic evaluations describing the disease course, as well as the costs and clinical outcomes related to the treatment of schizophrenia. Areas covered: A systematic review on studies describing health economic models in schizophrenia and a targeted literature review on utility mapping algorithms in schizophrenia were carried out. Models found in the review were collated and assessed in detail according to their type and various other attributes. Fifty-nine studies were included in the review. Modeling techniques varied from simple decision trees to complex simulation models. The models used various clinical endpoints as value drivers, 47% of the models used quality-adjusted life years, and eight percent used disability-adjusted life years to measure benefits, while others applied various clinical outcomes. Most models considered patients switching between therapies, and therapeutic adherence, compliance or persistence. The targeted literature review identified four main approaches to map PANSS scores to utility values. Expert commentary: Health economic models developed for schizophrenia showed great variability, with simulation models becoming more frequently used in the last decade. Using PANSS scores as the basis of utility estimations is justifiable.

Prevalence of peptic ulcer in Iran: Systematic review and meta-analysis methods.

PubMed

Sayehmiri, Kourosh; Abangah, Ghobad; Kalvandi, Gholamreza; Tavan, Hamed; Aazami, Sanaz

2018-01-01

Peptic ulcer is a prevalent problem and symptoms include epigastria pain and heartburn. This study aimed at investigating the prevalence and causes of peptic ulcers in Iran using systematic review and meta-analysis. Eleven Iranian papers published from 2002 to 2016 are selected using valid keywords in the SID, Goggle scholar, PubMed and Elsevier databases. Results of studies pooled using random effects model in meta-analysis. The heterogeneity of the sample was checked using Q test and I 2 index. Total sample size in this study consist of 1335 individuals with peptic ulcer (121 samples per article). The prevalence of peptic ulcers was estimated 34% (95% CI= 0.25 - 0.43). The prevalence of peptic ulcers was 30% and 60% in woman and man respectively. The highest environmental factor (cigarette) has been addressed in 30% (95% CI= 0.23-0.37) of patients. The prevalence of Helicobacter pylori was estimated in 62% (95% CI= 0.49-0.75) of patients. The results of this study show that prevalence of peptic ulcers in Iran (34%) is higher that worldwide rate (6% to 15%). There was an increasing trend in the prevalence of peptic ulcer over a decade from 2002 to 2016.

Network meta-analysis in health psychology and behavioural medicine: a primer.

PubMed

Molloy, G J; Noone, C; Caldwell, D; Welton, N J; Newell, J

2018-04-05

Progress in the science and practice of health psychology depends on the systematic synthesis of quantitative psychological evidence. Meta-analyses of experimental studies have led to important advances in understanding health-related behaviour change interventions. Fundamental questions regarding such interventions have been systematically investigated through synthesising relevant experimental evidence using standard pairwise meta-analytic procedures that provide reliable estimates of the magnitude, homogeneity and potential biases in effects observed. However, these syntheses only provide information about whether particular types of interventions work better than a control condition or specific alternative approaches. To increase the impact of health psychology on health-related policy-making, evidence regarding the comparative efficacy of all relevant intervention approaches - which may include biomedical approaches - is necessary. With the development of network meta-analysis (NMA), such evidence can be synthesised, even when direct head-to-head trials do not exist. However, care must be taken in its application to ensure reliable estimates of the effect sizes between interventions are revealed. This review paper describes the potential importance of NMA to health psychology, how the technique works and important considerations for its appropriate application within health psychology.

The prevalence of vegetative and minimally conscious states: a systematic review and methodological appraisal.

PubMed

Pisa, Federica Edith; Biasutti, Emanuele; Drigo, Daniela; Barbone, Fabio

2014-01-01

To systematically review prevalence studies of vegetative state (VS) and minimally conscious state (MCS) in geographically defined populations, to appraise study methods and assess sources of heterogeneity. MEDLINE, EBM Reviews, and EMBASE databases were searched using key terms. Two reviewers independently identified pertinent articles and screened the references for additional studies. Studies measuring the prevalence of VS and/or MCS in a defined population were included, and information on characteristics, methods, and results was extracted. Heterogeneity was quantified through the statistic I. We identified 5 cross-sectional prevalence surveys of VS and 1 of MCS. Prevalence ranged from 0.2 cases per 100,000 inhabitants to 3.4 for VS and was 1.5 per 100,000 for MCS. Relevant heterogeneity (I = 99.0%) prevented us from calculating a summary estimate. The prevalence of trauma cases varied from 21.9% to 53.8%. Variability pertaining to diagnostic criteria, definition of case, and methods of ascertainment was found. In the few prevalence studies of VS and MCS that were identified, the estimates showed high variability and could not be pooled. Future studies should consider using comparable methods for the definition, ascertainment, and confirmation of cases.

A systematic review of validated methods for identifying pulmonary fibrosis and interstitial lung disease using administrative and claims data.

PubMed

Jones, Natalie; Schneider, Gary; Kachroo, Sumesh; Rotella, Philip; Avetisyan, Ruzan; Reynolds, Matthew W

2012-01-01

The Food and Drug Administration's Mini-Sentinel pilot program initially aimed to conduct active surveillance to refine safety signals that emerge for marketed medical products. A key facet of this surveillance is to develop and understand the validity of algorithms for identifying health outcomes of interest (HOIs) from administrative and claims data. This paper summarizes the process and findings of the algorithm review of pulmonary fibrosis and interstitial lung disease. PubMed and Iowa Drug Information Service Web searches were conducted to identify citations applicable to the pulmonary fibrosis/interstitial lung disease HOI. Level 1 abstract reviews and Level 2 full-text reviews were conducted to find articles using administrative and claims data to identify pulmonary fibrosis and interstitial lung disease, including validation estimates of the coding algorithms. Our search revealed a deficiency of literature focusing on pulmonary fibrosis and interstitial lung disease algorithms and validation estimates. Only five studies provided codes; none provided validation estimates. Because interstitial lung disease includes a broad spectrum of diseases, including pulmonary fibrosis, the scope of these studies varied, as did the corresponding diagnostic codes used. Research needs to be conducted on designing validation studies to test pulmonary fibrosis and interstitial lung disease algorithms and estimating their predictive power, sensitivity, and specificity. Copyright © 2012 John Wiley & Sons, Ltd.

Developing Risk Prediction Models for Postoperative Pancreatic Fistula: a Systematic Review of Methodology and Reporting Quality.

PubMed

Wen, Zhang; Guo, Ya; Xu, Banghao; Xiao, Kaiyin; Peng, Tao; Peng, Minhao

2016-04-01

Postoperative pancreatic fistula is still a major complication after pancreatic surgery, despite improvements of surgical technique and perioperative management. We sought to systematically review and critically access the conduct and reporting of methods used to develop risk prediction models for predicting postoperative pancreatic fistula. We conducted a systematic search of PubMed and EMBASE databases to identify articles published before January 1, 2015, which described the development of models to predict the risk of postoperative pancreatic fistula. We extracted information of developing a prediction model including study design, sample size and number of events, definition of postoperative pancreatic fistula, risk predictor selection, missing data, model-building strategies, and model performance. Seven studies of developing seven risk prediction models were included. In three studies (42 %), the number of events per variable was less than 10. The number of candidate risk predictors ranged from 9 to 32. Five studies (71 %) reported using univariate screening, which was not recommended in building a multivariate model, to reduce the number of risk predictors. Six risk prediction models (86 %) were developed by categorizing all continuous risk predictors. The treatment and handling of missing data were not mentioned in all studies. We found use of inappropriate methods that could endanger the development of model, including univariate pre-screening of variables, categorization of continuous risk predictors, and model validation. The use of inappropriate methods affects the reliability and the accuracy of the probability estimates of predicting postoperative pancreatic fistula.

The relationship between zinc intake and growth in children aged 1-8 years: a systematic review and meta-analysis.

PubMed

Stammers, A L; Lowe, N M; Medina, M W; Patel, S; Dykes, F; Pérez-Rodrigo, C; Serra-Majam, L; Nissensohn, M; Moran, V H

2015-02-01

It is estimated that zinc deficiency affects 17% of the world's population, and because of periods of rapid growth children are at an increased risk of deficiency, which may lead to stunting. This paper presents a systematic review and meta-analysis of the randomised controlled trials (RCTs) that assess zinc intake and growth in children aged 1-8 years. This review is part of a larger systematic review by the European Micronutrient Recommendations Aligned Network of Excellence that aims to harmonise the approach to setting micronutrient requirements for optimal health in European populations (www.eurreca.org). Searches were performed of literature published up to and including December 2013 using MEDLINE, Embase and the Cochrane Library databases. Included studies were RCTs in apparently healthy child populations aged from 1 to 8 years that supplied zinc supplements either as capsules or as part of a fortified meal. Pooled meta-analyses were performed when appropriate. Nine studies met the inclusion criteria. We found no significant effect of zinc supplementation of between 2 weeks and 12 months duration on weight gain, height for age, weight for age, length for age, weight for height (WHZ) or WHZ scores in children aged 1-8 years. Many of the children in the included studies were already stunted and may have been suffering from multiple micronutrient deficiencies, and therefore zinc supplementation alone may have only a limited effect on growth.

Surgical Versus Nonsurgical Treatment for Midshaft Clavicle Fractures in Patients Aged 16 Years and Older: A Systematic Review, Meta-analysis, and Comparison of Randomized Controlled Trials and Observational Studies.

PubMed

Smeeing, Diederik P J; van der Ven, Denise J C; Hietbrink, Falco; Timmers, Tim K; van Heijl, Mark; Kruyt, Moyo C; Groenwold, Rolf H H; van der Meijden, Olivier A J; Houwert, Roderick M

2017-07-01

There is no consensus on the choice of treatment of midshaft clavicle fractures (MCFs). The aims of this systematic review and meta-analysis were (1) to compare fracture healing disorders and functional outcomes of surgical versus nonsurgical treatment of MCFs and (2) to compare effect estimates obtained from randomized controlled trials (RCTs) and observational studies. Systematic review and meta-analysis. The PubMed/MEDLINE, Embase, CENTRAL, and CINAHL databases were searched for both RCTs and observational studies. Using the MINORS instrument, all included studies were assessed on their methodological quality. The primary outcome was a nonunion. Effects of surgical versus nonsurgical treatment were estimated using random-effects meta-analysis models. A total of 20 studies were included, of which 8 were RCTs and 12 were observational studies including 1760 patients. Results were similar across the different study designs. A meta-analysis of 19 studies revealed that nonunions were significantly less common after surgical treatment than after nonsurgical treatment (odds ratio [OR], 0.18 [95% CI, 0.10-0.33]). The risk of malunions did not differ between surgical and nonsurgical treatment (OR, 0.38 [95% CI, 0.12-1.19]). Both the long-term Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley scores favored surgical treatment (DASH: mean difference [MD], -2.04 [95% CI, -3.56 to -0.52]; Constant-Murley: MD, 3.23 [95% CI, 1.52 to 4.95]). No differences were observed regarding revision surgery (OR, 0.85 [95% CI, 0.42-1.73]). Including only high-quality studies, both the number of malunions and days to return to work show significant differences in favor of surgical treatment (malunions: OR, 0.26 [95% CI, 0.07 to 0.92]; return to work: MD, -8.64 [95% CI, -16.22 to -1.05]). This meta-analysis of high-quality studies showed that surgical treatment of MCFs results in fewer nonunions, fewer malunions, and an accelerated return to work compared with nonsurgical treatment. A meta-analysis of surgical treatments need not be restricted to randomized trials, provided that the included observational studies are of high quality.

Two-photon decay of the neutral pion in lattice QCD.

PubMed

Feng, Xu; Aoki, Sinya; Fukaya, Hidenori; Hashimoto, Shoji; Kaneko, Takashi; Noaki, Jun-Ichi; Shintani, Eigo

2012-11-02

We perform a nonperturbative calculation of the π(0) → γγ transition form factor and the associated decay width using lattice QCD. The amplitude for a two-photon final state, which is not an eigenstate of QCD, is extracted through a Euclidean time integral of the relevant three-point function. We utilize the all-to-all quark propagator technique to carry out this integration as well as to include the disconnected quark diagram contributions. The overlap fermion formulation is employed on the lattice to ensure exact chiral symmetry on the lattice. After examining various sources of systematic effects, except for a possible discretization effect, we obtain Γπ(0) → γγ = 7.83(31)(49) eV for the pion decay width, where the first error is statistical and the second is our estimate of the systematic error.

The HIV Care Cascade Before, During, and After Incarceration: A Systematic Review and Data Synthesis

PubMed Central

Iroh, Princess A.; Mayo, Helen

2015-01-01

We conducted a systematic literature review of the data on HIV testing, engagement in care, and treatment in incarcerated persons, and estimated the care cascade in this group. We identified 2706 titles in MEDLINE, EBSCO, and Cochrane Library databases for studies indexed to January 13, 2015, and included 92 for analysis. We summarized HIV testing results by type (blinded, opt-out, voluntary); reviewed studies on HIV care engagement, treatment, and virological suppression; and synthesized these results into an HIV care cascade before, during, and after incarceration. The HIV care cascade following diagnosis increased during incarceration and declined substantially after release, often to levels lower than before incarceration. Incarceration provides an opportunity to address HIV care in hard-to-reach individuals, though new interventions are needed to improve postrelease care continuity. PMID:25973818

Burden of typhoid fever in low-income and middle-income countries: a systematic, literature-based update with risk-factor adjustment.

PubMed

Mogasale, Vittal; Maskery, Brian; Ochiai, R Leon; Lee, Jung Seok; Mogasale, Vijayalaxmi V; Ramani, Enusa; Kim, Young Eun; Park, Jin Kyung; Wierzba, Thomas F

2014-10-01

No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk. We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confirmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates. The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9-14·7) cases with 129 000 (75 000-208 000) deaths. By comparison, the estimated risk-unadjusted burden was 20·6 million (17·5-24·2) cases and 223 000 (131 000-344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of differences between the current estimate and past estimates. The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk differences, it will allow assessment of the effect at the population level and will facilitate cost-effectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine. Copyright © 2014 Mogasale et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by .. All rights reserved.

Multiple effects of probiotics on different types of diabetes: a systematic review and meta-analysis of randomized, placebo-controlled trials.

PubMed

Wang, Xia; Juan, Qi-Fang; He, Yu-Wei; Zhuang, Li; Fang, Yuan-Yuan; Wang, Yong-Hong

2017-05-24

A systematic review and meta-analysis was designed to evaluate the effect of probiotics on diabetes and its associated risk factors. We systematically searched the Cochrane Library, PubMed, EMBASE and Web of Science to June 2016. We also hand-searched the citation lists of included studies and previously identified systematic reviews to identify further relevant trials. Our primary outcome variables included glucose, glycated hemoglobin (HbA1c) and insulin. The pooled standardized mean difference was used to compare the effect between the probiotics and controlled groups, and the pooled standardized mean difference effect size with a 95% confidence interval (CI) was estimated using a random-effect model. Heterogeneity was assessed with Cochran's Q and Higgins I2 tests. Two reviewers assessed trial quality and extracted data independently. The analysis and bias for each included study was performed and assessed using Review Manager 5.2. Eighteen randomized, placebo-controlled studies (n=1056 participants, 527 consuming probiotics, 529 not consuming probiotics) were included for analysis. Comparing the probiotics groups with the control groups, there were statistically significant pooled standardized mean differences on the reduction of glucose (-0.61, 95% CI -0.98, -0.24; p=0.001), insulin (-0.49, 95% CI -0.93, -0.04; p=0.03) and HbA1c (-0.39, 95% CI -0.60, -0.19%; p=0.0001). Subgroup analysis also indicated statistical significance on the reduction of low-density lipoprotein cholesterol (LDL-C) in non-type 2 diabetes (non-T2DM) mellitus patients with diabetes, for the pooled standardized mean difference was -0.29 (95% CI -0.54, -0.04; p=0.02). Probiotics may have beneficial effects on the reduction of glucose, insulin and HbA1c for diabetes, especially for T2DM mellitus patients.

The association between the use of proton pump inhibitors and the risk of hypomagnesemia: a systematic review and meta-analysis.

PubMed

Park, Chan Hyuk; Kim, Eun Hye; Roh, Yun Ho; Kim, Ha Yan; Lee, Sang Kil

2014-01-01

Although many case reports have described patients with proton pump inhibitor (PPI)-induced hypomagnesemia, the impact of PPI use on hypomagnesemia has not been fully clarified through comparative studies. We aimed to evaluate the association between the use of PPI and the risk of developing hypomagnesemia by conducting a systematic review with meta-analysis. We conducted a systematic search of MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "proton pump," "dexlansoprazole," "esomeprazole," "ilaprazole," "lansoprazole," "omeprazole," "pantoprazole," "rabeprazole," "hypomagnesemia," "hypomagnesaemia," and "magnesium." Studies were included if they evaluated the association between PPI use and hypomagnesemia and reported relative risks or odds ratios or provided data for their estimation. Pooled odds ratios with 95% confidence intervals were calculated using the random effects model. Statistical heterogeneity was assessed with Cochran's Q test and I2 statistics. Nine studies including 115,455 patients were analyzed. The median Newcastle-Ottawa quality score for the included studies was seven (range, 6-9). Among patients taking PPIs, the median proportion of patients with hypomagnesemia was 27.1% (range, 11.3-55.2%) across all included studies. Among patients not taking PPIs, the median proportion of patients with hypomagnesemia was 18.4% (range, 4.3-52.7%). On meta-analysis, pooled odds ratio for PPI use was found to be 1.775 (95% confidence interval 1.077-2.924). Significant heterogeneity was identified using Cochran's Q test (df = 7, P<0.001, I2 = 98.0%). PPI use may increase the risk of hypomagnesemia. However, significant heterogeneity among the included studies prevented us from reaching a definitive conclusion.

Towards SI-traceable radio occultation excess phase processing with integrated uncertainty estimation for climate applications

NASA Astrophysics Data System (ADS)

Innerkofler, Josef; Pock, Christian; Kirchengast, Gottfried; Schwaerz, Marc; Jaeggi, Adrian; Schwarz, Jakob

2016-04-01

The GNSS Radio Occultation (RO) measurement technique is highly valuable for climate monitoring of the atmosphere as it provides accurate and precise measurements in the troposphere and stratosphere regions with global coverage, long-term stability, and virtually all-weather capability. The novel Reference Occultation Processing System (rOPS), currently under development at the WEGC at University of Graz aims to process raw RO measurements into essential climate variables, such as temperature, pressure, and tropospheric water vapor, in a way which is SI-traceable to the universal time standard and which includes rigorous uncertainty propagation. As part of this rOPS climate-quality processing system, accurate atmospheric excess phase profiles with new approaches integrating uncertainty propagation are derived from the raw occultation tracking data and orbit data. Regarding the latter, highly accurate orbit positions and velocities of the GNSS transmitter satellites and the RO receiver satellites in low Earth orbit (LEO) need to be determined, in order to enable high accuracy of the excess phase profiles. Using several representative test days of GPS orbit data from the CODE and IGS archives, which are available at accuracies of about 3 cm (position) / 0.03 mm/s (velocity), and employing Bernese 5.2 and Napeos 3.3.1 software packages for the LEO orbit determination of the CHAMP, GRACE, and MetOp RO satellites, we achieved robust SI-traced LEO orbit uncertainty estimates of about 5 cm (position) / 0.05 mm/s (velocity) for the daily orbits, including estimates of systematic uncertainty bounds and of propagated random uncertainties. For COSMIC RO satellites, we found decreased accuracy estimates near 10-15 cm (position) / 0.1-0.15 mm/s (velocity), since the characteristics of the small COSMIC satellite platforms and antennas provide somewhat less favorable orbit determination conditions. We present the setup of how we (I) used the Bernese and Napeos package in mutual cross-check for this purpose, (II) integrated satellite laser-ranging validation of the estimated systematic uncertainty bounds, (III) expanded the Bernese 5.2 software for propagating random uncertainties from the GPS orbit data and LEO navigation tracking data input to the LEO data output. Preliminary excess phase results including propagated uncertainty estimates will also be shown. Except for disturbed space weather conditions, we expect a robust performance at millimeter level for the derived excess phases, which after large-scale processing of the RO data of many years can provide a new SI-traced fundamental climate data record.

A Role for MST Neurons in Heading Estimation

NASA Technical Reports Server (NTRS)

Stone, L. S.; Perrone, J. A.

1994-01-01

A template model of human visual self-motion perception, which uses neurophysiologically realistic "heading detectors", is consistent with numerous human psychophysical results including the failure of humans to estimate their heading (direction of forward translation) accurately under certain visual conditions. We tested the model detectors with stimuli used by others in single-unit studies. The detectors showed emergent properties similar to those of MST neurons: (1) Sensitivity to non-preferred flow; Each detector is tuned to a specific combination of flow components and its response is systematically reduced by the addition of nonpreferred flow, and (2) Position invariance; The detectors maintain their apparent preference for particular flow components over large regions of their receptive fields. It has been argued that this latter property is incompatible with MST playing a role in heading perception. The model however demonstrates how neurons with the above response properties could still support accurate heading estimation within extrastriate cortical maps.

Risk assessment of turbine rotor failure using probabilistic ultrasonic non-destructive evaluations

NASA Astrophysics Data System (ADS)

Guan, Xuefei; Zhang, Jingdan; Zhou, S. Kevin; Rasselkorde, El Mahjoub; Abbasi, Waheed A.

2014-02-01

The study presents a method and application of risk assessment methodology for turbine rotor fatigue failure using probabilistic ultrasonic nondestructive evaluations. A rigorous probabilistic modeling for ultrasonic flaw sizing is developed by incorporating the model-assisted probability of detection, and the probability density function (PDF) of the actual flaw size is derived. Two general scenarios, namely the ultrasonic inspection with an identified flaw indication and the ultrasonic inspection without flaw indication, are considered in the derivation. To perform estimations for fatigue reliability and remaining useful life, uncertainties from ultrasonic flaw sizing and fatigue model parameters are systematically included and quantified. The model parameter PDF is estimated using Bayesian parameter estimation and actual fatigue testing data. The overall method is demonstrated using a realistic application of steam turbine rotor, and the risk analysis under given safety criteria is provided to support maintenance planning.

Halitosis

PubMed Central

2008-01-01

Introduction Halitosis can be caused by oral disease, or by respiratory tract conditions such as sinusitis, tonsillitis, and bronchiectasis, but an estimated 40% of affected individuals have no underlying organic disease. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in people with physiological halitosis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2008 (Clinical evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found five systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: artificial saliva; cleaning, brushing, or scraping the tongue; diet modification; regular or single use of mouthwash; sugar-free chewing gums; and zinc toothpastes. PMID:19445739

Normalization Approaches for Removing Systematic Biases Associated with Mass Spectrometry and Label-Free Proteomics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Callister, Stephen J.; Barry, Richard C.; Adkins, Joshua N.

2006-02-01

Central tendency, linear regression, locally weighted regression, and quantile techniques were investigated for normalization of peptide abundance measurements obtained from high-throughput liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR MS). Arbitrary abundances of peptides were obtained from three sample sets, including a standard protein sample, two Deinococcus radiodurans samples taken from different growth phases, and two mouse striatum samples from control and methamphetamine-stressed mice (strain C57BL/6). The selected normalization techniques were evaluated in both the absence and presence of biological variability by estimating extraneous variability prior to and following normalization. Prior to normalization, replicate runs from each sample setmore » were observed to be statistically different, while following normalization replicate runs were no longer statistically different. Although all techniques reduced systematic bias, assigned ranks among the techniques revealed significant trends. For most LC-FTICR MS analyses, linear regression normalization ranked either first or second among the four techniques, suggesting that this technique was more generally suitable for reducing systematic biases.« less

Systematic review and meta-analysis in cardiac surgery: a primer.

PubMed

Yanagawa, Bobby; Tam, Derrick Y; Mazine, Amine; Tricco, Andrea C

2018-03-01

The purpose of this article is to review the strengths and weaknesses of systematic reviews and meta-analyses to inform our current understanding of cardiac surgery. A systematic review and meta-analysis of a focused topic can provide a quantitative estimate for the effect of a treatment intervention or exposure. In cardiac surgery, observational studies and small, single-center prospective trials provide most of the clinical outcomes that form the evidence base for patient management and guideline recommendations. As such, meta-analyses can be particularly valuable in synthesizing the literature for a particular focused surgical question. Since the year 2000, there are over 800 meta-analysis-related publications in our field. There are some limitations to this technique, including clinical, methodological and statistical heterogeneity, among other challenges. Despite these caveats, results of meta-analyses have been useful in forming treatment recommendations or in providing guidance in the design of future clinical trials. There is a growing number of meta-analyses in the field of cardiac surgery. Knowledge translation via meta-analyses will continue to guide and inform cardiac surgical practice and our practice guidelines.

Systematic feasibility analysis of a quantitative elasticity estimation for breast anatomy using supine/prone patient postures.

PubMed

Hasse, Katelyn; Neylon, John; Sheng, Ke; Santhanam, Anand P

2016-03-01

Breast elastography is a critical tool for improving the targeted radiotherapy treatment of breast tumors. Current breast radiotherapy imaging protocols only involve prone and supine CT scans. There is a lack of knowledge on the quantitative accuracy with which breast elasticity can be systematically measured using only prone and supine CT datasets. The purpose of this paper is to describe a quantitative elasticity estimation technique for breast anatomy using only these supine/prone patient postures. Using biomechanical, high-resolution breast geometry obtained from CT scans, a systematic assessment was performed in order to determine the feasibility of this methodology for clinically relevant elasticity distributions. A model-guided inverse analysis approach is presented in this paper. A graphics processing unit (GPU)-based linear elastic biomechanical model was employed as a forward model for the inverse analysis with the breast geometry in a prone position. The elasticity estimation was performed using a gradient-based iterative optimization scheme and a fast-simulated annealing (FSA) algorithm. Numerical studies were conducted to systematically analyze the feasibility of elasticity estimation. For simulating gravity-induced breast deformation, the breast geometry was anchored at its base, resembling the chest-wall/breast tissue interface. Ground-truth elasticity distributions were assigned to the model, representing tumor presence within breast tissue. Model geometry resolution was varied to estimate its influence on convergence of the system. A priori information was approximated and utilized to record the effect on time and accuracy of convergence. The role of the FSA process was also recorded. A novel error metric that combined elasticity and displacement error was used to quantify the systematic feasibility study. For the authors' purposes, convergence was set to be obtained when each voxel of tissue was within 1 mm of ground-truth deformation. The authors' analyses showed that a ∼97% model convergence was systematically observed with no-a priori information. Varying the model geometry resolution showed no significant accuracy improvements. The GPU-based forward model enabled the inverse analysis to be completed within 10-70 min. Using a priori information about the underlying anatomy, the computation time decreased by as much as 50%, while accuracy improved from 96.81% to 98.26%. The use of FSA was observed to allow the iterative estimation methodology to converge more precisely. By utilizing a forward iterative approach to solve the inverse elasticity problem, this work indicates the feasibility and potential of the fast reconstruction of breast tissue elasticity using supine/prone patient postures.

Rational decision-making in mental health: the role of systematic reviews.

PubMed

Gilbody, Simon M.; Petticrew, Mark

1999-09-01

BACKGROUND: "Systematic reviews" have come to be recognized as the most rigorous method of summarizing confusing and often contradictory primary research in a transparent and reproducible manner. Their greatest impact has been in the summarization of epidemiological literature - particularly that relating to clinical effectiveness. Systematic reviews also have a potential to inform rational decision-making in healthcare policy and to form a component of economic evaluation. AIMS OF THE STUDY: This article aims to introduce the rationale behind systematic reviews and, using examples from mental health, to introduce the strengths and limitations of systematic reviews, particularly in informing mental health policy and economic evaluation. METHODS: Examples are selected from recent controversies surrounding the introduction of new psychiatric drugs (anti-depressants and anti-schizophrenia drugs) and methods of delivering psychiatric care in the community (case management and assertive community treatment). The potential for systematic reviews to (i) produce best estimates of clinical efficacy and effectiveness, (ii) aid economic evaluation and policy decision-making and (iii) highlight gaps in the primary research knowledge base are discussed. Lastly examples are selected from outside mental health to show how systematic reviews have a potential to be explicitly used in economic and health policy evaluation. RESULTS: Systematic reviews produce the best estimates of clinical efficacy, which can form an important component of economic evaluation. Importantly, serious methodological flaws and areas of uncertainty in the primary research literature are identified within an explicit framework. Summary indices of clinical effectiveness can be produced, but it is difficult to produce such summary indices of cost effectiveness by pooling economic data from primary studies. Modelling is commonly used in economic and policy evaluation. Here, systematic reviews can provide the best estimates of effectiveness and, importantly, highlight areas of uncertainty that can be used in "sensitivity analysis". DISCUSSION: Systematic reviews are an important recent methodological advance, the potential for which has only begun to be realized in mental health. This use of systematic reviews is probably most advanced in producing critical summaries of clinical effectiveness data. Systematic reviews cannot produce valid and believable conclusions when the primary research literature is of poor quality. An important function of systematic reviews will be in highlighting this poor quality research which is of little use in mental health decision making. IMPLICATIONS FOR HEALTH PROVISION: Health care provision should be both clinically and cost effective. Systematic reviews are a key component in ensuring that this goal is achieved. IMPLICATIONS FOR HEALTH POLICIES: Systematic reviews have potential to inform health policy. Examples presented show that health policy is often made without due consideration of the research evidence. Systematic reviews can provide robust and believable answers, which can help inform rational decision-making. Importantly, systematic reviews can highlight the need for important primary research and can inform the design of this research such that it provides answers that will help in forming healthcare policy. IMPLICATIONS FOR FURTHER RESEARCH: Systematic reviews should precede costly (and often unnecessary) primary research. Many areas of health policy and practice have yet to be evaluated using systematic review methodology. Methods for the summarization of economic data are methodologically complex and deserve further research

Comparative analysis of whole mount processing and systematic sampling of radical prostatectomy specimens: pathological outcomes and risk of biochemical recurrence.

PubMed

Salem, Shady; Chang, Sam S; Clark, Peter E; Davis, Rodney; Herrell, S Duke; Kordan, Yakup; Wills, Marcia L; Shappell, Scott B; Baumgartner, Roxelyn; Phillips, Sharon; Smith, Joseph A; Cookson, Michael S; Barocas, Daniel A

2010-10-01

Whole mount processing is more resource intensive than routine systematic sampling of radical retropubic prostatectomy specimens. We compared whole mount and systematic sampling for detecting pathological outcomes, and compared the prognostic value of pathological findings across pathological methods. We included men (608 whole mount and 525 systematic sampling samples) with no prior treatment who underwent radical retropubic prostatectomy at Vanderbilt University Medical Center between January 2000 and June 2008. We used univariate and multivariate analysis to compare the pathological outcome detection rate between pathological methods. Kaplan-Meier curves and the log rank test were used to compare the prognostic value of pathological findings across pathological methods. There were no significant differences between the whole mount and the systematic sampling groups in detecting extraprostatic extension (25% vs 30%), positive surgical margins (31% vs 31%), pathological Gleason score less than 7 (49% vs 43%), 7 (39% vs 43%) or greater than 7 (12% vs 13%), seminal vesicle invasion (8% vs 10%) or lymph node involvement (3% vs 5%). Tumor volume was higher in the systematic sampling group and whole mount detected more multiple surgical margins (each p <0.01). There were no significant differences in the likelihood of biochemical recurrence between the pathological methods when patients were stratified by pathological outcome. Except for estimated tumor volume and multiple margins whole mount and systematic sampling yield similar pathological information. Each method stratifies patients into comparable risk groups for biochemical recurrence. Thus, while whole mount is more resource intensive, it does not appear to result in improved detection of clinically important pathological outcomes or prognostication. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Propagation of stage measurement uncertainties to streamflow time series

NASA Astrophysics Data System (ADS)

Horner, Ivan; Le Coz, Jérôme; Renard, Benjamin; Branger, Flora; McMillan, Hilary

2016-04-01

Streamflow uncertainties due to stage measurements errors are generally overlooked in the promising probabilistic approaches that have emerged in the last decade. We introduce an original error model for propagating stage uncertainties through a stage-discharge rating curve within a Bayesian probabilistic framework. The method takes into account both rating curve (parametric errors and structural errors) and stage uncertainty (systematic and non-systematic errors). Practical ways to estimate the different types of stage errors are also presented: (1) non-systematic errors due to instrument resolution and precision and non-stationary waves and (2) systematic errors due to gauge calibration against the staff gauge. The method is illustrated at a site where the rating-curve-derived streamflow can be compared with an accurate streamflow reference. The agreement between the two time series is overall satisfying. Moreover, the quantification of uncertainty is also satisfying since the streamflow reference is compatible with the streamflow uncertainty intervals derived from the rating curve and the stage uncertainties. Illustrations from other sites are also presented. Results are much contrasted depending on the site features. In some cases, streamflow uncertainty is mainly due to stage measurement errors. The results also show the importance of discriminating systematic and non-systematic stage errors, especially for long term flow averages. Perspectives for improving and validating the streamflow uncertainty estimates are eventually discussed.

[Criteria of estimation of state forensic-medical expert activity administration].

PubMed

Klevno, V A; Loban, I E

2008-01-01

Criteria of estimation of state forensic medical activity administration were systematized and their content was considered. New integral index of administration efficiency - index of technological efficiency - was developed and proved.

Statistical field estimators for multiscale simulations.

PubMed

Eapen, Jacob; Li, Ju; Yip, Sidney

2005-11-01

We present a systematic approach for generating smooth and accurate fields from particle simulation data using the notions of statistical inference. As an extension to a parametric representation based on the maximum likelihood technique previously developed for velocity and temperature fields, a nonparametric estimator based on the principle of maximum entropy is proposed for particle density and stress fields. Both estimators are applied to represent molecular dynamics data on shear-driven flow in an enclosure which exhibits a high degree of nonlinear characteristics. We show that the present density estimator is a significant improvement over ad hoc bin averaging and is also free of systematic boundary artifacts that appear in the method of smoothing kernel estimates. Similarly, the velocity fields generated by the maximum likelihood estimator do not show any edge effects that can be erroneously interpreted as slip at the wall. For low Reynolds numbers, the velocity fields and streamlines generated by the present estimator are benchmarked against Newtonian continuum calculations. For shear velocities that are a significant fraction of the thermal speed, we observe a form of shear localization that is induced by the confining boundary.

Estimating the incidence of breast cancer in Africa: a systematic review and meta-analysis.

PubMed

Adeloye, Davies; Sowunmi, Olaperi Y; Jacobs, Wura; David, Rotimi A; Adeosun, Adeyemi A; Amuta, Ann O; Misra, Sanjay; Gadanya, Muktar; Auta, Asa; Harhay, Michael O; Chan, Kit Yee

2018-06-01

Breast cancer is estimated to be the most common cancer worldwide. We sought to assemble publicly available data from Africa to provide estimates of the incidence of breast cancer on the continent. A systematic search of Medline, EMBASE, Global Health and African Journals Online (AJOL) was conducted. We included population- or hospital-based registry studies on breast cancer conducted in Africa, and providing estimates of the crude incidence of breast cancer among women. A random effects meta-analysis was employed to determine the pooled incidence of breast cancer across studies. The literature search returned 4648 records, with 41 studies conducted across 54 study sites in 22 African countries selected. We observed important variations in reported cancer incidence between population- and hospital-based cancer registries. The overall pooled crude incidence of breast cancer from population-based registries was 24.5 per 100 000 person years (95% confidence interval (CI) 20.1-28.9). The incidence in North Africa was higher at 29.3 per 100 000 (95% CI 20.0-38.7) than Sub-Saharan Africa (SSA) at 22.4 per 100 000 (95% CI 17.2-28.0). In hospital-based registries, the overall pooled crude incidence rate was estimated at 23.6 per 100 000 (95% CI 18.5-28.7). SSA and Northern Africa had relatively comparable rates at 24.0 per 100 000 (95% CI 17.5-30.4) and 23.2 per 100 000 (95% CI 6.6-39.7), respectively. Across both registries, incidence rates increased considerably between 2000 and 2015. The available evidence suggests a growing incidence of breast cancer in Africa. The representativeness of these estimates is uncertain due to the paucity of data in several countries and calendar years, as well as inconsistency in data collation and quality across existing cancer registries.

Estimating the incidence of breast cancer in Africa: a systematic review and meta-analysis

PubMed Central

Adeloye, Davies; Sowunmi, Olaperi Y.; Jacobs, Wura; David, Rotimi A; Adeosun, Adeyemi A; Amuta, Ann O.; Misra, Sanjay; Gadanya, Muktar; Auta, Asa; Harhay, Michael O; Chan, Kit Yee

2018-01-01

Background Breast cancer is estimated to be the most common cancer worldwide. We sought to assemble publicly available data from Africa to provide estimates of the incidence of breast cancer on the continent. Methods A systematic search of Medline, EMBASE, Global Health and African Journals Online (AJOL) was conducted. We included population- or hospital-based registry studies on breast cancer conducted in Africa, and providing estimates of the crude incidence of breast cancer among women. A random effects meta-analysis was employed to determine the pooled incidence of breast cancer across studies. Results The literature search returned 4648 records, with 41 studies conducted across 54 study sites in 22 African countries selected. We observed important variations in reported cancer incidence between population- and hospital-based cancer registries. The overall pooled crude incidence of breast cancer from population-based registries was 24.5 per 100 000 person years (95% confidence interval (CI) 20.1-28.9). The incidence in North Africa was higher at 29.3 per 100 000 (95% CI 20.0-38.7) than Sub-Saharan Africa (SSA) at 22.4 per 100 000 (95% CI 17.2-28.0). In hospital-based registries, the overall pooled crude incidence rate was estimated at 23.6 per 100 000 (95% CI 18.5-28.7). SSA and Northern Africa had relatively comparable rates at 24.0 per 100 000 (95% CI 17.5-30.4) and 23.2 per 100 000 (95% CI 6.6-39.7), respectively. Across both registries, incidence rates increased considerably between 2000 and 2015. Conclusions The available evidence suggests a growing incidence of breast cancer in Africa. The representativeness of these estimates is uncertain due to the paucity of data in several countries and calendar years, as well as inconsistency in data collation and quality across existing cancer registries. PMID:29740502

Reconciling geodetic and geological estimates of recent plate motion across the Southwest Indian Ridge

NASA Astrophysics Data System (ADS)

DeMets, C.; Calais, E.; Merkouriev, S.

2017-01-01

We use recently published, high-resolution reconstructions of the Southwest Indian Ridge to test whether a previously described systematic difference between Global Positioning System (GPS) and 3.16-Myr-average estimates of seafloor spreading rates between Antarctica and Africa is evidence for a recent slowdown in Southwest Indian Ridge seafloor spreading rates. Along the Nubia-Antarctic segment of the ridge, seafloor opening rates that are estimated with the new, high-resolution reconstructions and corrected for outward displacement agree well with geodetic rate estimates and reduce previously reported, highly significant non-closure of the Nubia-Antarctic-Sur plate circuit. The observations are inconsistent with a slowdown in spreading rates and instead indicate that Nubia-Antarctic plate motion has been steady since at least 5.2 Ma. Lwandle-Antarctic seafloor spreading rates that are estimated from the new high-resolution reconstructions differ insignificantly from a GPS estimate, thereby implying steady Lwandle-Antarctic plate motion since 5.2 Ma. Between the Somalia and Antarctic plates, the new Southwest Indian Ridge reconstructions eliminate roughly half of the systematic difference between the GPS and MORVEL spreading rate estimates.We interpret the available observations as evidence that Somalia-Antarctic spreading rates have been steady since at least 5.2 Ma and postulate that the remaining difference is attributable to random and/or systematic errors in the plate kinematic estimates and the combined effects of insufficient geodetic sampling of undeforming areas of the Somalia plate, glacial isostatic adjustment in Antarctica and transient deformation triggered by the 1998 Mw = 8.2 Antarctic earthquake, the 2004 Mw = 9.3 Sumatra earthquake, or possibly other large historic earthquakes.

Estimation of the spatiotemporal evolution of slow slip events in the Tokai region, central Japan, during 1994 - 2016 using GNSS data

NASA Astrophysics Data System (ADS)

Sakaue, H.; Nishimura, T.; Fukuda, J.; Kato, T.

2017-12-01

In the Tokai region, central Japan, the long-term slow slip events (L-SSEs) observed on the subducting Philippine Sea Plate (PSP) from 2000 to 2005 and since 2013. Moreover, many short-term slow slip events (S-SSEs) have been observed in the Tokai region since 1996. Sakaue et al. (2017) reported that the spatiotemporal evolution of an L-SSE and S-SSEs on the PSP beneath the Tokai region from 2013 to 2015. This study is probably the first case that migration of slip for S-SSE (Mw < 6.0) was estimated solely using GNSS data in southwest Japan.We, here, extend our analysis period to be from 1994 to 2016. The GIPSY-OASIS II software was used to estimate daily coordinates of GNSS stations operated by GSI and JUNCO (the Japanese University Consortium for GPS Research) in the Tokai region. It is well known that GNSS time series have many systematic signals that do not result from SSEs. These systematic signals include, for example, seasonal variations, cosiesmic and post-seismic deformation of the 2004 off Southeast Kii Peninsula eqrthquake and the 2011 Tohoku-oki earthquake (Mw. 9.0), crustal deformation of volcanic activity on Miyake-jima island and so on. After removing these systematic signals, we applied a modified Network Inversion Filter (NIF) [Fukuda et al., 2008]. The original NIF [Segall & Matthews, 1997] assumes a constant hyperparameter for the temporal smoothing of slip rates and thus often results in oversmoothing of slip rates. The modified NIF assumes a time-variable hyperparameter, so that changes in slip rates are effectively extracted from GNSS time series.The results indicate that not only the spatiotemporal evolutions of the 2000 Tokai L-SSE and the 2013 L-SSE but also the spatiotemporal evolution of S-SSEs are estimated. We will present a comparison of the spatiotemporal evolutions between the 2000 Tokai L-SSE and the 2013 L-SSE and possible dependence of the occurrence style of S-SSEs on the occurrence of the L-SSEs.

Surrogate gas prediction model as a proxy for Δ14C-based measurements of fossil fuel-CO2.

PubMed

Coakley, Kevin J; Miller, John B; Montzka, Stephen A; Sweeney, Colm; Miller, Ben R

2016-06-27

The measured 14 C: 12 C isotopic ratio of atmospheric CO 2 (and its associated derived Δ 14 C value) is an ideal tracer for determination of the fossil fuel derived CO 2 enhancement contributing to any atmospheric CO 2 measurement ( C ff ). Given enough such measurements, independent top-down estimation of US fossil fuel-CO 2 emissions should be possible. However, the number of Δ 14 C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ 14 C is therefore measured in just a small fraction of samples obtained by ask air sampling networks around the world. Here, we develop a Projection Pursuit Regression (PPR) model to predict C ff as a function of multiple surrogate gases acquired within the NOAA/ESRL Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF 6 , and halo- and hydrocarbons acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 through 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ 14 C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of uncertainties and potentially increase the number of C ff estimates by approximately a factor of three. Provided that these estimates are of comparable quality to Δ 14 C-based estimates, we expect an improved determination of fossil fuel-CO 2 emissions.

Global prevalence of visual impairment associated with myopic macular degeneration and temporal trends from 2000 through 2050: systematic review, meta-analysis and modelling.

PubMed

Fricke, Timothy R; Jong, Monica; Naidoo, Kovin S; Sankaridurg, Padmaja; Naduvilath, Thomas J; Ho, Suit May; Wong, Tien Yin; Resnikoff, Serge

2018-04-26

We used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050. The systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade. We included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%). The burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Interventions for non-metastatic squamous cell carcinoma of the skin: systematic review and pooled analysis of observational studies

PubMed Central

Bath-Hextall, Fiona; Perkins, William; Stanton, Wendy; Leonardi-Bee, Jo

2013-01-01

Objectives To assess the effects of treatments for non-metastatic invasive squamous cell carcinoma (SCC) of the skin using evidence from observational studies, given the paucity of evidence from randomised controlled trials. Design Systematic review of observational studies. Data sources Medline, Embase, to December 2012. Review methods Observational studies of interventions for primary, non-metastatic, invasive, SCC of the skin that reported recurrence during follow-up, quality of life, initial response to treatment, adverse events, cosmetic appearance, or death from disease. Studies were excluded if data for primary cutaneous SCC was not separable from other data. Data were extracted independently by two reviewers. Meta-analysis was performed where appropriate using a random effects model to estimate the pooled proportion of an event with 95% confidence intervals. Results 118 publications were included, covering seven treatment modalities. Pooled estimates of recurrence of SCCs were lowest after cryotherapy (0.8% (95% confidence interval 0.1% to 2%)) and curettage and electrodesiccation (1.7% (0.5% to 3.4%)), but most treated SCCs were small, low risk lesions. After Mohs micrographic surgery, the pooled estimate of local recurrence during variable follow-up periods from 10 studies was 3.0% (2.2% to 3.9%), which was non-significantly lower than the pooled average local recurrence of 5.4% (2.5% to 9.1%) after standard surgical excision (12 studies), and 6.4% (3.0% to 11.0%) after external radiotherapy (7 studies). After an apparently successful initial response of SCCs to photodynamic therapy, pooled average recurrence of 26.4% (12.3% to 43.7%; 8 studies) was significantly higher than other treatments. Evidence was limited for laser treatment (1 study) and for topical and systemic treatments (mostly single case reports or small non-comparative series with limited follow-up). Conclusions Many observational studies have looked at different treatment modalities for SCC, but the evidence base for the effectiveness of these interventions is poor. Comparison of outcomes after different treatments should be interpreted cautiously owing to biases inherent in the types of study included, and lack of direct comparisons to enable the estimation of relative treatment effect. Further evidence is needed to develop a prognostic model and stratify individuals at high risk of developing SCC, to improve the evidence base for this common cancer and to optimise clinical management. Protocol registration International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42011001450. PMID:24191270

Analyses of flood-flow frequency for selected gaging stations in South Dakota

USGS Publications Warehouse

Benson, R.D.; Hoffman, E.B.; Wipf, V.J.

1985-01-01

Analyses of flood flow frequency were made for 111 continuous-record gaging stations in South Dakota with 10 or more years of record. The analyses were developed using the log-Pearson Type III procedure recommended by the U.S. Water Resources Council. The procedure characterizes flood occurrence at a single site as a sequence of annual peak flows. The magnitudes of the annual peak flows are assumed to be independent random variables following a log-Pearson Type III probability distribution, which defines the probability that any single annual peak flow will exceed a specified discharge. By considering only annual peak flows, the flood-frequency analysis becomes the estimation of the log-Pearson annual-probability curve using the record of annual peak flows at the site. The recorded data are divided into two classes: systematic and historic. The systematic record includes all annual peak flows determined in the process of conducting a systematic gaging program at a site. In this program, the annual peak flow is determined for each and every year of the program. The systematic record is intended to constitute an unbiased and representative sample of the population of all possible annual peak flows at the site. In contrast to the systematic record, the historic record consists of annual peak flows that would not have been determined except for evidence indicating their unusual magnitude. Flood information acquired from historical sources almost invariably refers to floods of noteworthy, and hence extraordinary, size. Although historic records form a biased and unrepresentative sample, they can be used to supplement the systematic record. (Author 's abstract)

Testing the effectiveness of simplified search strategies for updating systematic reviews.

PubMed

Rice, Maureen; Ali, Muhammad Usman; Fitzpatrick-Lewis, Donna; Kenny, Meghan; Raina, Parminder; Sherifali, Diana

2017-08-01

The objective of the study was to test the overall effectiveness of a simplified search strategy (SSS) for updating systematic reviews. We identified nine systematic reviews undertaken by our research group for which both comprehensive and SSS updates were performed. Three relevant performance measures were estimated, that is, sensitivity, precision, and number needed to read (NNR). The update reference searches for all nine included systematic reviews identified a total of 55,099 citations that were screened resulting in final inclusion of 163 randomized controlled trials. As compared with reference search, the SSS resulted in 8,239 hits and had a median sensitivity of 83.3%, while precision and NNR were 4.5 times better. During analysis, we found that the SSS performed better for clinically focused topics, with a median sensitivity of 100% and precision and NNR 6 times better than for the reference searches. For broader topics, the sensitivity of the SSS was 80% while precision and NNR were 5.4 times better compared with reference search. SSS performed well for clinically focused topics and, with a median sensitivity of 100%, could be a viable alternative to a conventional comprehensive search strategy for updating this type of systematic reviews particularly considering the budget constraints and the volume of new literature being published. For broader topics, 80% sensitivity is likely to be considered too low for a systematic review update in most cases, although it might be acceptable if updating a scoping or rapid review. Copyright © 2017 Elsevier Inc. All rights reserved.

Network meta-analysis of multiple outcome measures accounting for borrowing of information across outcomes.

PubMed

Achana, Felix A; Cooper, Nicola J; Bujkiewicz, Sylwia; Hubbard, Stephanie J; Kendrick, Denise; Jones, David R; Sutton, Alex J

2014-07-21

Network meta-analysis (NMA) enables simultaneous comparison of multiple treatments while preserving randomisation. When summarising evidence to inform an economic evaluation, it is important that the analysis accurately reflects the dependency structure within the data, as correlations between outcomes may have implication for estimating the net benefit associated with treatment. A multivariate NMA offers a framework for evaluating multiple treatments across multiple outcome measures while accounting for the correlation structure between outcomes. The standard NMA model is extended to multiple outcome settings in two stages. In the first stage, information is borrowed across outcomes as well across studies through modelling the within-study and between-study correlation structure. In the second stage, we make use of the additional assumption that intervention effects are exchangeable between outcomes to predict effect estimates for all outcomes, including effect estimates on outcomes where evidence is either sparse or the treatment had not been considered by any one of the studies included in the analysis. We apply the methods to binary outcome data from a systematic review evaluating the effectiveness of nine home safety interventions on uptake of three poisoning prevention practices (safe storage of medicines, safe storage of other household products, and possession of poison centre control telephone number) in households with children. Analyses are conducted in WinBUGS using Markov Chain Monte Carlo (MCMC) simulations. Univariate and the first stage multivariate models produced broadly similar point estimates of intervention effects but the uncertainty around the multivariate estimates varied depending on the prior distribution specified for the between-study covariance structure. The second stage multivariate analyses produced more precise effect estimates while enabling intervention effects to be predicted for all outcomes, including intervention effects on outcomes not directly considered by the studies included in the analysis. Accounting for the dependency between outcomes in a multivariate meta-analysis may or may not improve the precision of effect estimates from a network meta-analysis compared to analysing each outcome separately.

Prevalence of asymptomatic Zika virus infection: a systematic review

PubMed Central

Pinart, Mariona; Elias, Vanessa; Reveiz, Ludovic

2018-01-01

Abstract Objective To conduct a systematic review to estimate the prevalence of asymptomatic Zika virus infection in the general population and in specific population groups. Methods We searched PubMed®, Embase® and LILACS online databases from inception to 26 January 2018. We included observational epidemiological studies where laboratory testing was used to confirm positive exposure of participants to Zika virus and in which Zika virus symptom status was also recorded. We excluded studies in which having symptoms of Zika virus was a criterion for inclusion. The main outcome assessed was percentage of all Zika virus-positive participants who were asymptomatic. We used a quality-effects approach and the double arcsine transformation for the meta-analysis. Findings We assessed 753 studies for inclusion, of which 23 were included in the meta-analysis, totalling 11 305 Zika virus-positive participants. The high degree of heterogeneity in the studies (I2 = 99%) suggests that the pooled prevalence of asymptomatic Zika virus-positive participants was probably not a robust estimate. Analysis based on subgroups of the population (general population, returned travellers, blood donors, adults with Guillain–Barré syndrome, pregnant women and babies with microcephaly) was not able to explain the heterogeneity. Funnel and Doi plots showed major asymmetry, suggesting selection bias or true heterogeneity. Conclusion Better-quality research is needed, using standardized methods, to determine the true prevalence of asymptomatic Zika virus and whether it varies between populations or over time. PMID:29904223

Systematic review on the financial return of worksite health promotion programmes aimed at improving nutrition and/or increasing physical activity.

PubMed

van Dongen, J M; Proper, K I; van Wier, M F; van der Beek, A J; Bongers, P M; van Mechelen, W; van Tulder, M W

2011-12-01

This systematic review summarizes the current evidence on the financial return of worksite health promotion programmes aimed at improving nutrition and/or increasing physical activity. Data on study characteristics and results were extracted from 18 studies published up to 14 January 2011. Two reviewers independently assessed the risk of bias of included studies. Three metrics were (re-)calculated per study: the net benefits, benefit cost ratio (BCR) and return on investment (ROI). Metrics were averaged, and a post hoc subgroup analysis was performed to compare financial return estimates between study designs. Four randomized controlled trials (RCTs), 13 non-randomized studies (NRSs) and one modelling study were included. Average financial return estimates in terms of absenteeism benefits (NRS: ROI 325%, BCR 4.25; RCT: ROI -49%, BCR 0.51), medical benefits (NRS: ROI 95%, BCR 1.95; RCT: ROI -112%, BCR -0.12) or both (NRS: ROI 387%, BCR 4.87; RCT: ROI -92%, BCR 0.08) were positive in NRSs, but negative in RCTs. Worksite health promotion programmes aimed at improving nutrition and/or increasing physical activity generate financial savings in terms of reduced absenteeism costs, medical costs or both according to NRSs, whereas they do not according to RCTs. Since these programmes are associated with additional types of benefits, conclusions about their overall profitability cannot be made. © 2011 The Authors. obesity reviews © 2011 International Association for the Study of Obesity.

Strong-lensing analysis of A2744 with MUSE and Hubble Frontier Fields images

NASA Astrophysics Data System (ADS)

Mahler, G.; Richard, J.; Clément, B.; Lagattuta, D.; Schmidt, K.; Patrício, V.; Soucail, G.; Bacon, R.; Pello, R.; Bouwens, R.; Maseda, M.; Martinez, J.; Carollo, M.; Inami, H.; Leclercq, F.; Wisotzki, L.

2018-01-01

We present an analysis of Multi Unit Spectroscopic Explorer (MUSE) observations obtained on the massive Frontier Fields (FFs) cluster A2744. This new data set covers the entire multiply imaged region around the cluster core. The combined catalogue consists of 514 spectroscopic redshifts (with 414 new identifications). We use this redshift information to perform a strong-lensing analysis revising multiple images previously found in the deep FF images, and add three new MUSE-detected multiply imaged systems with no obvious Hubble Space Telescope counterpart. The combined strong-lensing constraints include a total of 60 systems producing 188 images altogether, out of which 29 systems and 83 images are spectroscopically confirmed, making A2744 one of the most well-constrained clusters to date. Thanks to the large amount of spectroscopic redshifts, we model the influence of substructures at larger radii, using a parametrization including two cluster-scale components in the cluster core and several group scale in the outskirts. The resulting model accurately reproduces all the spectroscopic multiple systems, reaching an rms of 0.67 arcsec in the image plane. The large number of MUSE spectroscopic redshifts gives us a robust model, which we estimate reduces the systematic uncertainty on the 2D mass distribution by up to ∼2.5 times the statistical uncertainty in the cluster core. In addition, from a combination of the parametrization and the set of constraints, we estimate the relative systematic uncertainty to be up to 9 per cent at 200 kpc.

Does Infection Site Matter? A Systematic Review of Infection Site Mortality in Sepsis.

PubMed

Motzkus, Christine A; Luckmann, Roger

2017-09-01

Sepsis treatment protocols emphasize source control with empiric antibiotics and fluid resuscitation. Previous reviews have examined the impact of infection site and specific pathogens on mortality from sepsis; however, no recent review has addressed the infection site. This review focuses on the impact of infection site on hospital mortality among patients with sepsis. The PubMed database was searched for articles from 2001 to 2014. Studies were eligible if they included (1) one or more statistical models with hospital mortality as the outcome and considered infection site for inclusion in the model and (2) adult patients with sepsis, severe sepsis, or septic shock. Data abstracted included stage of sepsis, infection site, and raw and adjusted effect estimates. Nineteen studies were included. Infection sites most studied included respiratory (n = 19), abdominal (n = 19), genitourinary (n = 18), and skin and soft tissue infections (n = 11). Several studies found a statistically significant lower mortality risk for genitourinary infections on hospital mortality when compared to respiratory infections. Based on studies included in this review, the impact of infection site in patients with sepsis on hospital mortality could not be reliably estimated. Misclassification among infections and disease states remains a serious possibility in studies on this topic.

Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050.

PubMed

Holden, Brien A; Fricke, Timothy R; Wilson, David A; Jong, Monica; Naidoo, Kovin S; Sankaridurg, Padmaja; Wong, Tien Y; Naduvilath, Thomas J; Resnikoff, Serge

2016-05-01

Myopia is a common cause of vision loss, with uncorrected myopia the leading cause of distance vision impairment globally. Individual studies show variations in the prevalence of myopia and high myopia between regions and ethnic groups, and there continues to be uncertainty regarding increasing prevalence of myopia. Systematic review and meta-analysis. We performed a systematic review and meta-analysis of the prevalence of myopia and high myopia and estimated temporal trends from 2000 to 2050 using data published since 1995. The primary data were gathered into 5-year age groups from 0 to ≥100, in urban or rural populations in each country, standardized to definitions of myopia of -0.50 diopter (D) or less and of high myopia of -5.00 D or less, projected to the year 2010, then meta-analyzed within Global Burden of Disease (GBD) regions. Any urban or rural age group that lacked data in a GBD region took data from the most similar region. The prevalence data were combined with urbanization data and population data from United Nations Population Department (UNPD) to estimate the prevalence of myopia and high myopia in each country of the world. These estimates were combined with myopia change estimates over time derived from regression analysis of published evidence to project to each decade from 2000 through 2050. We included data from 145 studies covering 2.1 million participants. We estimated 1406 million people with myopia (22.9% of the world population; 95% confidence interval [CI], 932-1932 million [15.2%-31.5%]) and 163 million people with high myopia (2.7% of the world population; 95% CI, 86-387 million [1.4%-6.3%]) in 2000. We predict by 2050 there will be 4758 million people with myopia (49.8% of the world population; 3620-6056 million [95% CI, 43.4%-55.7%]) and 938 million people with high myopia (9.8% of the world population; 479-2104 million [95% CI, 5.7%-19.4%]). Myopia and high myopia estimates from 2000 to 2050 suggest significant increases in prevalences globally, with implications for planning services, including managing and preventing myopia-related ocular complications and vision loss among almost 1 billion people with high myopia. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and meta-analysis

PubMed Central

2014-01-01

Background Cognitive impairment, including dementia, is a major health concern with the increasing aging population. Preventive measures to delay cognitive decline are of utmost importance. Alzheimer’s disease (AD) is the most frequent cause of dementia, increasing in prevalence from <1% below the age of 60 years to >40% above 85 years of age. Methods We systematically reviewed selected modifiable factors such as education, smoking, alcohol, physical activity, caffeine, antioxidants, homocysteine (Hcy), n-3 fatty acids that were studied in relation to various cognitive health outcomes, including incident AD. We searched MEDLINE for published literature (January 1990 through October 2012), including cross-sectional and cohort studies (sample sizes > 300). Analyses compared study finding consistency across factors, study designs and study-level characteristics. Selecting studies of incident AD, our meta-analysis estimated pooled risk ratios (RR), population attributable risk percent (PAR%) and assessed publication bias. Results In total, 247 studies were retrieved for systematic review. Consistency analysis for each risk factor suggested positive findings ranging from ~38.9% for caffeine to ~89% for physical activity. Education also had a significantly higher propensity for “a positive finding” compared to caffeine, smoking and antioxidant-related studies. Meta-analysis of 31 studies with incident AD yielded pooled RR for low education (RR = 1.99; 95% CI: 1.30-3.04), high Hcy (RR = 1.93; 95% CI: 1.50-2.49), and current/ever smoking status (RR = 1.37; 95% CI: 1.23-1.52) while indicating protective effects of higher physical activity and n-3 fatty acids. Estimated PAR% were particularly high for physical activity (PAR% = 31.9; 95% CI: 22.7-41.2) and smoking (PAR%=31.09%; 95% CI: 17.9-44.3). Overall, no significant publication bias was found. Conclusions Higher Hcy levels, lower educational attainment, and decreased physical activity were particularly strong predictors of incident AD. Further studies are needed to support other potential modifiable protective factors, such as caffeine. PMID:24962204

Characteristics and effectiveness of diabetes self-management educational programs targeted to racial/ethnic minority groups: a systematic review, meta-analysis and meta-regression.

PubMed

Ricci-Cabello, Ignacio; Ruiz-Pérez, Isabel; Rojas-García, Antonio; Pastor, Guadalupe; Rodríguez-Barranco, Miguel; Gonçalves, Daniela C

2014-07-19

It is not clear to what extent educational programs aimed at promoting diabetes self-management in ethnic minority groups are effective. The aim of this work was to systematically review the effectiveness of educational programs to promote the self-management of racial/ethnic minority groups with type 2 diabetes, and to identify programs' characteristics associated with greater success. We undertook a systematic literature review. Specific searches were designed and implemented for Medline, EMBASE, CINAHL, ISI Web of Knowledge, Scirus, Current Contents and nine additional sources (from inception to October 2012). We included experimental and quasi-experimental studies assessing the impact of educational programs targeted to racial/ethnic minority groups with type 2 diabetes. We only included interventions conducted in countries members of the OECD. Two reviewers independently screened citations. Structured forms were used to extract information on intervention characteristics, effectiveness, and cost-effectiveness. When possible, we conducted random-effects meta-analyses using standardized mean differences to obtain aggregate estimates of effect size with 95% confidence intervals. Two reviewers independently extracted all the information and critically appraised the studies. We identified thirty-seven studies reporting on thirty-nine educational programs. Most of them were conducted in the US, with African American or Latino participants. Most programs obtained some benefits over standard care in improving diabetes knowledge, self-management behaviors and clinical outcomes. A meta-analysis of 20 randomized controlled trials (3,094 patients) indicated that the programs produced a reduction in glycated hemoglobin of -0.31% (95% CI -0.48% to -0.14%). Diabetes knowledge and self-management measures were too heterogeneous to pool. Meta-regressions showed larger reduction in glycated hemoglobin in individual and face to face delivered interventions, as well as in those involving peer educators, including cognitive reframing techniques, and a lower number of teaching methods. The long-term effects remain unknown and cost-effectiveness was rarely estimated. Diabetes self-management educational programs targeted to racial/ethnic minority groups can produce a positive effect on diabetes knowledge and on self-management behavior, ultimately improving glycemic control. Future programs should take into account the key characteristics identified in this review.

Spinal Manipulative Therapy for Adolescent Idiopathic Scoliosis: A Systematic Review.

PubMed

Théroux, Jean; Stomski, Norman; Losco, Christine Dominique; Khadra, Christelle; Labelle, Hubert; Le May, Sylvie

The purpose of this study was to perform a systematic review of clinical trials of spinal manipulative therapy for adolescent idiopathic scoliosis. Search strategies were developed for PubMed, CINHAL, and CENTRAL databases. Studies were included through June 2016 if they were prospective trials that evaluated spinal manipulative therapy (eg, chiropractic, osteopathic, physical therapy) for adolescent idiopathic scoliosis. Data were extracted and assessed by 2 independent reviewers. Cochrane risk of bias tools were used to assess the quality of the included studies. Data were reported qualitatively because heterogeneity prevented statistical pooling. Four studies satisfied the inclusion criteria and were critically appraised. The findings of the included studies indicated that spinal manipulative therapy might be effective for preventing curve progression or reducing Cobb angle. However, the lack of controls and small sample sizes precluded robust estimation of the interventions' effect sizes. There is currently insufficient evidence to establish whether spinal manipulative therapy may be beneficial for adolescent idiopathic scoliosis. The results of the included studies suggest that spinal manipulative therapy may be a promising treatment, but these studies were all at substantial risk of bias. Further high-quality studies are warranted to conclusively determine if spinal manipulative therapy may be effective in the management of adolescent idiopathic scoliosis. Copyright © 2017. Published by Elsevier Inc.

Reported Estimates of Adverse Pregnancy Outcomes among Women with and without Syphilis: A Systematic Review and Meta-Analysis

PubMed Central

Qin, Jiabi; Yang, Tubao; Xiao, Shuiyuan; Tan, Hongzhuan; Feng, Tiejian; Fu, Hanlin

2014-01-01

Background To estimate probability of adverse pregnancy outcomes (APOs) among women with and without syphilis through a systematic review of published literatures. Methodology/Principal Findings Chinese and English literatures were searched for studies assessing pregnancy outcomes in the presence of maternal syphilis through August 2013. The prevalence estimates were summarized and analyzed by meta-analysis. Fifty-four literatures involving 11398 syphilitic women and 43342 non-syphilitic women were included from 4187 records initially found. Among untreated mothers with syphilis, pooled estimates were 76.8% for all APOs, 36.0% for congenital syphilis, 23.2% for preterm, 23.4% for low birth weight, 26.4% for stillbirth or fetal loss, 14.9% for miscarriage and 16.2% for neonatal deaths. Among syphilitic mother receiving treatment only in the late trimester (>28 weeks), pooled estimates were 64.4% for APOs, 40.6% for congenital syphilis, 17.6% for preterm, 12.4% for low birth weight, and 21.3% for stillbirth or fetal loss. Among syphilitic mothers with high titers (≥1∶8), pooled estimates were 42.8% for all APOs, 25.8% for congenital syphilis, 15.1% for preterm, 9.4% for low birth weight, 14.6% for stillbirth or fetal loss and 16.0% for neonatal deaths. Among non-syphilitic mothers, the pooled estimates were 13.7% for all APOs, 7.2% for preterm birth, 4.5% for low birth weight, 3.7% for stillbirth or fetal loss, 2.3% for miscarriage and 2.0% for neonatal death. Begg's rank correlation test indicated little evidence of publication bias (P>0.10). Substantial heterogeneity was found across studies in the estimates of all adverse outcomes for both women with syphilis (I 2 = 93.9%; P<0.0001) and women without syphilis (I 2 = 94.8%; P<0.0001). Conclusions/Significance Syphilis continues to be an important cause of substantial perinatal morbidity and mortality, which reminds that policy-makers charged with resource allocation that the elimination of mother-to-child transmission of syphilis is a public health priority. PMID:25025232

Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

PubMed

Rossi, Carmine; Shrier, Ian; Marshall, Lee; Cnossen, Sonya; Schwartzman, Kevin; Klein, Marina B; Schwarzer, Guido; Greenaway, Chris

2012-01-01

International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV). We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2%) and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%). HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million) are estimated to be chronically infected with HBV. The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of international migrants can become an important component of HBV disease control efforts in immigrant-receiving countries.

Prevalence of tinnitus and hyperacusis in children and adolescents: a systematic review.

PubMed

Rosing, Susanne Nemholt; Schmidt, Jesper Hvass; Wedderkopp, Niels; Baguley, David M

2016-06-03

To systematically review studies of the epidemiology of tinnitus and hyperacusis in children and young people, in order to determine the methodological differences implicated in the variability of prevalence estimates and the influence of population characteristics on childhood tinnitus and hyperacusis. Articles were retrieved from PubMed, EMBASE and Scopus databases and from the relevant reference lists using the methods described in the study protocol, which has previously been published. Reporting Items for Systematic Review (PRISMA) guidelines were followed. Studies addressing childhood prevalence, for example, children and young people aged 5-19 years. 2 reviewers independently assessed the studies for eligibility, extracted data and assessed study consistency. Owing to the heterogeneity in the methodologies among the reported studies, only narrative synthesis of the results was carried out. Having identified 1032 publications, 131 articles were selected and 25 articles met the inclusion criteria and had sufficient methodological consistency to be included. Prevalence estimates of tinnitus range from 4.7% to 46% in the general paediatric population and among children with normal hearing, and from 23.5% to 62.2% of population of children with hearing loss. Reported prevalence ranged from 6% to 41.9% when children with hearing loss and normal hearing were both included. The prevalence of hyperacusis varied from 3.2% to 17.1%. Data on prevalence vary considerably according to the study design, study population and the research question posed. The age range of children studied was varied and a marked degree of variation between definitions (tinnitus, hyperacusis) and measures (severity, perception, annoyance) was observed. The lack of consistency among studies indicates the necessity of examining the epidemiology of tinnitus and hyperacusis in children and adolescents with a set of standardised criteria. CRD42014013456. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effect of Antihypertensive Medications on the Severity of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

PubMed Central

Khurshid, Kiran; Yabes, Jonathan; Weiss, Patricia M.; Dharia, Sushma; Brown, Lee; Unruh, Mark; Jhamb, Manisha

2016-01-01

Study Objectives: Obstructive sleep apnea (OSA) is an independent risk factor for hypertension (HTN). Increasing evidence from animal and human studies suggests that HTN exacerbates OSA. We performed a systematic review and meta-analysis of studies evaluating the effect of anti-hypertensive medications on the severity of OSA. Methods: A literature search of PubMed and Embase was done using search concepts of OSA, HTN, and drug classes used to treat HTN. Studies that reported changes in the severity of OSA objectively by using apnea-hypopnea index (AHI) or respiratory disturbance index (RDI) were included. Pooled mean difference estimates were calculated. Tests for heterogeneity, publication bias, and subgroup sensitivity analysis were conducted. Results: Of 27,376 studies screened, only 11 met inclusion criteria, including 5 randomized controlled trials and 6 single-arm prospective trials. The pooled mean difference estimate (95% confidence interval [CI]), based on a random-effects model, was −5.69 (95% CI −10.74 to −0.65), consistent with an overall decrease in AHI or RDI attributable to antihypertensive medications. The effect size was even more pronounced, −14.52 (95% CI −25.65 to −3.39), when only studies using diuretics were analyzed. There was no significant heterogeneity or publication bias among the studies. Meta-regression indicated neither age, baseline AHI, nor change in systolic/diastolic blood pressure influenced the results. Conclusions: Collectively, findings from these relatively small, short-term studies tend to support the contention that treatment with antihypertensive agents confers a statistically significant, albeit small, reduction in the severity of OSA, which may be more pronounced with the use of diuretics. Citation: Khurshid K, Yabes J, Weiss PM, Dharia S, Brown L, Unruh M, Jhamb M. Effect of antihypertensive medications on the severity of obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med 2016;12(8):1143–1151. PMID:27397663

Prevalence of tinnitus and hyperacusis in children and adolescents: a systematic review

PubMed Central

Rosing, Susanne Nemholt; Schmidt, Jesper Hvass; Wedderkopp, Niels; Baguley, David M

2016-01-01

Objectives To systematically review studies of the epidemiology of tinnitus and hyperacusis in children and young people, in order to determine the methodological differences implicated in the variability of prevalence estimates and the influence of population characteristics on childhood tinnitus and hyperacusis. Data sources Articles were retrieved from PubMed, EMBASE and Scopus databases and from the relevant reference lists using the methods described in the study protocol, which has previously been published. Reporting Items for Systematic Review (PRISMA) guidelines were followed. Eligibility criteria Studies addressing childhood prevalence, for example, children and young people aged 5–19 years. Data selection 2 reviewers independently assessed the studies for eligibility, extracted data and assessed study consistency. Owing to the heterogeneity in the methodologies among the reported studies, only narrative synthesis of the results was carried out. Results Having identified 1032 publications, 131 articles were selected and 25 articles met the inclusion criteria and had sufficient methodological consistency to be included. Prevalence estimates of tinnitus range from 4.7% to 46% in the general paediatric population and among children with normal hearing, and from 23.5% to 62.2% of population of children with hearing loss. Reported prevalence ranged from 6% to 41.9% when children with hearing loss and normal hearing were both included. The prevalence of hyperacusis varied from 3.2% to 17.1%. Conclusions Data on prevalence vary considerably according to the study design, study population and the research question posed. The age range of children studied was varied and a marked degree of variation between definitions (tinnitus, hyperacusis) and measures (severity, perception, annoyance) was observed. The lack of consistency among studies indicates the necessity of examining the epidemiology of tinnitus and hyperacusis in children and adolescents with a set of standardised criteria. Trial registration number CRD42014013456. PMID:27259524

Prevalence of hepatitis B and hepatitis C virus co-infection in India: A systematic review and meta-analysis.

PubMed

Desikan, Prabha; Khan, Zeba

2017-01-01

Hepatitis B virus (HBV) and hepatitis C virus (HCV) have several important similarities including worldwide distribution, hepato-tropism, similar modes of transmission and the ability to induce chronic infection that may lead to liver cirrhosis and hepatocellular carcinoma. Since both viruses are individually known to cause the pathologies mentioned above, co-infection with both HBV and HCV would be expected to be linked with higher morbidity as well as mortality and impact healthcare resource utilisation. Precise estimate of the prevalence of HBV/HCV co-infection would be needed to formulate policy decisions and plan communal health interventions. This systematic review and meta-analysis, therefore, aims to understand the prevalence of HBV and HCV co-infection in India based on the available literature. Following PRISMA guidelines, primary studies reporting the prevalence of HBV/HCV co-infection in India were retrieved through searches conducted in PubMed, Google SCHOLAR, Medline, Cochrane Library, WHO reports, Indian and International journals online. All online searches were conducted between December 2016 and February 2017. Meta-analysis was carried out using StatsDirect statistical software. Thirty studies published between 2000 and 2016 conducted across six regions of India were included in this review. The pooled HBV/HCV co-infection prevalence rate across the thirty studies was 1.89% (95% confidence intervals [CI] = 1.2%-2.4%). A high heterogeneity was observed between prevalence estimates. The HBV/HCV co-infection prevalence in different subgroups varied from 0.02% (95% CI = 0.0019%-0.090%) to 3.2% (95% CI = 1.3%-5.9%). The pooled prevalence of HBV/HCV co-infection in India was found to be 1.89%. This systematic review and meta-analysis revealed high prevalence of HBV/HCV co-infection in chronic liver patients, followed by HIV-positive patients, and then followed by persons who inject drugs and kidney disease patients.

Diabetes as a risk factor for stroke in women compared with men: a systematic review and meta-analysis of 64 cohorts, including 775,385 individuals and 12,539 strokes.

PubMed

Peters, Sanne A E; Huxley, Rachel R; Woodward, Mark

2014-06-07

Diabetes mellitus is a major cause of death and disability worldwide and is a strong risk factor for stroke. Whether and to what extent the excess risk of stroke conferred by diabetes differs between the sexes is unknown. We did a systematic review and meta-analysis to estimate the relative effect of diabetes on stroke risk in women compared with men. We systematically searched PubMed for reports of prospective, population-based cohort studies published between Jan 1, 1966, and Dec 16, 2013. Studies were selected if they reported sex-specific estimates of the relative risk (RR) for stroke associated with diabetes, and its associated variability. We pooled the sex-specific RRs and their ratio comparing women with men using random-effects meta-analysis with inverse-variance weighting. Data from 64 cohort studies, representing 775,385 individuals and 12,539 fatal and non-fatal strokes, were included in the analysis. The pooled maximum-adjusted RR of stroke associated with diabetes was 2·28 (95% CI 1·93-2·69) in women and 1·83 (1·60-2·08) in men. Compared with men with diabetes, women with diabetes therefore had a greater risk of stroke--the pooled ratio of RRs was 1·27 (1·10-1·46; I(2)=0%), with no evidence of publication bias. This sex differential was seen consistently across major predefined stroke, participant, and study subtypes. The excess risk of stroke associated with diabetes is significantly higher in women than men, independent of sex differences in other major cardiovascular risk factors. These data add to the existing evidence that men and women experience diabetes-related diseases differently and suggest the need for further work to clarify the biological, behavioural, or social mechanisms involved. None. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hybrid Gibbs Sampling and MCMC for CMB Analysis at Small Angular Scales

NASA Technical Reports Server (NTRS)

Jewell, Jeffrey B.; Eriksen, H. K.; Wandelt, B. D.; Gorski, K. M.; Huey, G.; O'Dwyer, I. J.; Dickinson, C.; Banday, A. J.; Lawrence, C. R.

2008-01-01

A) Gibbs Sampling has now been validated as an efficient, statistically exact, and practically useful method for "low-L" (as demonstrated on WMAP temperature polarization data). B) We are extending Gibbs sampling to directly propagate uncertainties in both foreground and instrument models to total uncertainty in cosmological parameters for the entire range of angular scales relevant for Planck. C) Made possible by inclusion of foreground model parameters in Gibbs sampling and hybrid MCMC and Gibbs sampling for the low signal to noise (high-L) regime. D) Future items to be included in the Bayesian framework include: 1) Integration with Hybrid Likelihood (or posterior) code for cosmological parameters; 2) Include other uncertainties in instrumental systematics? (I.e. beam uncertainties, noise estimation, calibration errors, other).

Standard errors and confidence intervals for variable importance in random forest regression, classification, and survival.

PubMed

Ishwaran, Hemant; Lu, Min

2018-06-04

Random forests are a popular nonparametric tree ensemble procedure with broad applications to data analysis. While its widespread popularity stems from its prediction performance, an equally important feature is that it provides a fully nonparametric measure of variable importance (VIMP). A current limitation of VIMP, however, is that no systematic method exists for estimating its variance. As a solution, we propose a subsampling approach that can be used to estimate the variance of VIMP and for constructing confidence intervals. The method is general enough that it can be applied to many useful settings, including regression, classification, and survival problems. Using extensive simulations, we demonstrate the effectiveness of the subsampling estimator and in particular find that the delete-d jackknife variance estimator, a close cousin, is especially effective under low subsampling rates due to its bias correction properties. These 2 estimators are highly competitive when compared with the .164 bootstrap estimator, a modified bootstrap procedure designed to deal with ties in out-of-sample data. Most importantly, subsampling is computationally fast, thus making it especially attractive for big data settings. Copyright © 2018 John Wiley & Sons, Ltd.

EFFECTS OF BIASES IN VIRIAL MASS ESTIMATION ON COSMIC SYNCHRONIZATION OF QUASAR ACCRETION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinhardt, Charles L.

2011-09-01

Recent work using virial mass estimates and the quasar mass-luminosity plane has yielded several new puzzles regarding quasar accretion, including a sub-Eddington boundary (SEB) on most quasar accretion, near-independence of the accretion rate from properties of the host galaxy, and a cosmic synchronization of accretion among black holes of a common mass. We consider how these puzzles might change if virial mass estimation turns out to have a systematic bias. As examples, we consider two recent claims of mass-dependent biases in Mg II masses. Under any such correction, the surprising cosmic synchronization of quasar accretion rates and independence from themore » host galaxy remain. The slope and location of the SEB are very sensitive to biases in virial mass estimation, and various mass calibrations appear to favor different possible physical explanations for feedback between the central black hole and its environment. The alternative mass estimators considered do not simply remove puzzling quasar behavior, but rather replace it with new puzzles that may be more difficult to solve than those using current virial mass estimators and the Shen et al. catalog.« less

Systematic Anomalies in Rainfall Intensity Estimates Over the Continental U.S.

NASA Technical Reports Server (NTRS)

Amitai, Eyal; Petersen, Walter Arthur; Llort, Xavier; Vasiloff, Steve

2010-01-01

Rainfall intensities during extreme events over the continental U.S. are compared for several advanced radar products. These products include: 1) TRMM spaceborne radar (PR) near surface estimates; 2) NOAA Next-Generation Quantitative Precipitation Estimation (QPE) very high-resolution (1 km) radar-only national mosaics (Q2); 3) very high-resolution instantaneous gauge adjusted radar national mosaics, which we have developed by applying gauge correction on the Q2 instantaneous radar-only products; and 4) several independent C-band dual-polarimetric radar-estimated rainfall samples collected with the ARMOR radar in northern Alabama. Though accumulated rainfall amounts are often similar, we find the satellite and the ground radar rain rate pdfs to be quite different. PR pdfs are shifted towards lower rain rates, implying a much larger stratiform/convective rain ratio than do ground radar products. The shift becomes more evident during strong continental convective storms and much less during tropical storms. Resolving the continental/maritime regime behavior and other large discrepancies between the products presents an important challenge. A challenge to improve our understanding of the source of the discrepancies, to determine the uncertainties of the estimates, and to improve remote-sensing estimates of precipitation in general.

VizieR Online Data Catalog: SDSS bulge, disk and total stellar mass estimates (Mendel+, 2014)

NASA Astrophysics Data System (ADS)

Mendel, J. T.; Simard, L.; Palmer, M.; Ellison, S. L.; Patton, D. R.

2014-01-01

We present a catalog of bulge, disk, and total stellar mass estimates for ~660000 galaxies in the Legacy area of the Sloan Digital Sky Survey Data (SDSS) Release 7. These masses are based on a homogeneous catalog of g- and r-band photometry described by Simard et al. (2011, Cat. J/ApJS/196/11), which we extend here with bulge+disk and Sersic profile photometric decompositions in the SDSS u, i, and z bands. We discuss the methodology used to derive stellar masses from these data via fitting to broadband spectral energy distributions (SEDs), and show that the typical statistical uncertainty on total, bulge, and disk stellar mass is ~0.15 dex. Despite relatively small formal uncertainties, we argue that SED modeling assumptions, including the choice of synthesis model, extinction law, initial mass function, and details of stellar evolution likely contribute an additional 60% systematic uncertainty in any mass estimate based on broadband SED fitting. We discuss several approaches for identifying genuine bulge+disk systems based on both their statistical likelihood and an analysis of their one-dimensional surface-brightness profiles, and include these metrics in the catalogs. Estimates of the total, bulge and disk stellar masses for both normal and dust-free models and their uncertainties are made publicly available here. (4 data files).

Risk of pneumonia associated with use of angiotensin converting enzyme inhibitors and angiotensin receptor blockers: systematic review and meta-analysis

PubMed Central

Caldeira, Daniel; Alarcão, Joana; Vaz-Carneiro, António

2012-01-01

Objective To systematically review longitudinal studies evaluating use of angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) and risk of pneumonia. Design Systematic review and meta-analysis. Data sources Medline through PubMed, Web of Science with conference proceedings (inception to June 2011), and US Food and Drug Administration website (June 2011). Systematic reviews and references of retrieved articles were also searched. Study selection Two reviewers independently selected randomised controlled trials and cohort and case-control studies evaluating the use of ACE inhibitors or ARBs and risk of pneumonia and retrieved characteristics of the studies and data estimates. Data synthesis The primary outcome was incidence of pneumonia and the secondary outcome was pneumonia related mortality. Subgroup analyses were carried according to baseline morbidities (stroke, heart failure, and chronic kidney disease) and patients’ characteristics (Asian and non-Asian). Pooled estimates of odds ratios and 95% confidence intervals were derived by random effects meta-analysis. Adjusted frequentist indirect comparisons between ACE inhibitors and ARBs were estimated and combined with direct evidence whenever available. Heterogeneity was assessed using the I2 test. Results 37 eligible studies were included. ACE inhibitors were associated with a significantly reduced risk of pneumonia compared with control treatment (19 studies: odds ratio 0.66, 95% confidence interval 0.55 to 0.80; I2=79%) and ARBs (combined direct and indirect odds ratio estimate 0.69, 0.56 to 0.85). In patients with stroke, the risk of pneumonia was also lower in those treated with ACE inhibitors compared with control treatment (odds ratio 0.46, 0.34 to 0.62) and ARBs (0.42, 0.22 to 0.80). ACE inhibitors were associated with a significantly reduced risk of pneumonia among Asian patients (0.43, 0.34 to 0.54) compared with non-Asian patients (0.82, 0.67 to 1.00; P<0.001). Compared with control treatments, both ACE inhibitors (seven studies: odds ratio 0.73, 0.58 to 0.92; I2=51%) and ARBs (one randomised controlled trial: 0.63, 0.40 to 1.00) were associated with a decrease in pneumonia related mortality, without differences between interventions. Conclusions The best evidence available points towards a putative protective role of ACE inhibitors but not ARBs in risk of pneumonia. Patient populations that may benefit most are those with previous stroke and Asian patients. ACE inhibitors were also associated with a decrease in pneumonia related mortality, but the data lacked strength. PMID:22786934

Rate and predictors of conversion from unipolar to bipolar disorder: A systematic review and meta-analysis.

PubMed

Kessing, Lars Vedel; Willer, Inge; Andersen, Per Kragh; Bukh, Jens Drachman

2017-08-01

For the first time to present a systematic review and meta-analysis of the conversion rate and predictors of conversion from unipolar disorder to bipolar disorder. A systematic literature search up to October 2016 was performed. For the meta-analysis, we only included studies that used survival analysis to estimate the conversion rate. A total of 31 studies were identified, among which 11 used survival analyses, including two register-based studies. The yearly rate of conversion to bipolar disorder decreased with time from 3.9% in the first year after study entry with a diagnosis of unipolar disorder to 3.1% in years 1-2, 1.0% in years 2-5 and 0.8% in years 5-10. A total of eight risk factors were evaluated comprising gender, age at onset of unipolar disorder, number of depressive episodes, treatment resistance to antidepressants, family history of bipolar disorder, the prevalence of psychotic depression, the prevalence of chronic depression, and severity of depression. It was not possible to identify risk factors that were consistently or mainly confirmed to predict conversion across studies. The conversion rate from unipolar to bipolar disorder decreases with time. It was not possible to identify predictors of conversion that were consistently or mainly confirmed across studies, which may be due to variations in methodology across studies. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Association between eczema and major cardiovascular outcomes in population-based studies: a systematic review protocol.

PubMed

Ascott, Anna; Yu, Ashley M; Schmidt, Morten; Abuabara, Katrina; Smeeth, Liam; Langan, Sinéad M

2017-09-29

Chronic inflammatory diseases such as eczema (also known as atopic dermatitis) have been inconsistently linked to cardiovascular disease and stroke in both mechanistic and epidemiological studies. There is a need to review the existing epidemiological data examining the association between eczema and major cardiovascular outcomes, including angina, myocardial infarction, coronary revascularisation, heart failure, cardiac arrhythmias, stroke and cardiovascular death, in order to improve our understanding of the comorbidities of eczema. We will systematically review population-based studies, including cohort, case-control and cross-sectional studies, reporting on the association between eczema and cardiovascular outcomes. We will search Medline, Embase and Global Health, from their date of inception to April 2017, using a comprehensive search strategy formulated with the help of a librarian. Two reviewers will independently screen titles and abstracts in duplicate, followed by independent data extraction and quality assessment. We will group studies by the cardiovascular outcome under study and synthesise them narratively. If sufficient numbers of homogeneous studies are returned, we will perform meta-analyses to obtain pooled effect estimates. Preferred Reporting Items for Systematic Review and Meta-Analysis will be used to inform the reporting of this study. CRD42017060359. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Digital tomosynthesis in breast cancer: A systematic review.

PubMed

García-León, F J; Llanos-Méndez, A; Isabel-Gómez, R

2015-01-01

To estimate and compare the diagnostic validity of tomosynthesis and digital mammography for screening and diagnosing breast cancer. We systematically searched MedLine, EMBASE, and Web of Science for the terms breast cancer, screening, tomosynthesis, mammography, sensitivity, and specificity in publications in the period comprising June 2010 through February 2013. We included studies on diagnostic tests and systematic reviews. Two reviewers selected and evaluated the articles. We used QUADAS 2 to evaluate the risk of bias and the NICE criteria to determine the level of evidence. We compiled a narrative synthesis. Of the 151 original studies identified, we selected 11 that included a total of 2475 women. The overall quality was low, with a risk of bias and follow-up and limitations regarding the applicability of the results. The level of evidence was not greater than level II. The sensitivity of tomosynthesis ranged from 69% to 100% and the specificity ranged from 54% to 100%. The negative likelihood ratio was good, and this makes tomosynthesis useful as a test to confirm a diagnosis. One-view tomosynthesis was no better than two-view digital mammography, and the evidence for the superiority of two-view tomosynthesis was inconclusive. The results for the diagnostic validity of tomosynthesis in the diagnosis of breast cancer were inconclusive and there were no results for its use in screening. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Effectiveness of pre-surgical infant orthopedic treatment for cleft lip and palate patients: a systematic review and meta-analysis.

PubMed

Papadopoulos, M A; Koumpridou, E N; Vakalis, M L; Papageorgiou, S N

2012-11-01

The objective of the study was to systematically summarize current evidence on the effectiveness of pre-surgical infant orthopedics (PSIO) in cleft lip and palate (CLP) patients. Electronic and manual searches were conducted, and using specific inclusion and exclusion criteria, data extraction and analysis was performed by two independent investigators. When possible, overall pooled estimates with 95% confidence intervals were obtained using the random-effects model. Twenty-four of 885 original studies met the inclusion criteria and were included in the qualitative synthesis, whereas 10 of them were included in the quantitative synthesis (meta-analysis). Except for the variable M-T-C(5) assessing maxillary arch form, which presented an increase at 48 months of follow-up, all other variables concerning craniofacial and dentoalveolar changes demonstrated no significant differences, indicating that PSIO treatment has no effect on CLP patients. The limited evidence derived from this study does not seem to support the short- or long-term effectiveness of PSIO in CLP patients. © 2012 John Wiley & Sons A/S.