Approaching Career Criminals With An Intelligence Cycle

DTIC Science & Technology

2015-12-01

including arrest statistics and “arrest statistics have been used as the main barometer of juvenile delinquent activity, (but) many juvenile... Statistical Briefing Book,” 187. 26 guided by theories about the causes of delinquent behavior, but there was no determination if those efforts achieved the...children.”110 However, the most evidence-based comparison of juvenile delinquency reduction programs is the statistical meta-analysis (a systematic

Review of Statistical Learning Methods in Integrated Omics Studies (An Integrated Information Science).

PubMed

Zeng, Irene Sui Lan; Lumley, Thomas

2018-01-01

Integrated omics is becoming a new channel for investigating the complex molecular system in modern biological science and sets a foundation for systematic learning for precision medicine. The statistical/machine learning methods that have emerged in the past decade for integrated omics are not only innovative but also multidisciplinary with integrated knowledge in biology, medicine, statistics, machine learning, and artificial intelligence. Here, we review the nontrivial classes of learning methods from the statistical aspects and streamline these learning methods within the statistical learning framework. The intriguing findings from the review are that the methods used are generalizable to other disciplines with complex systematic structure, and the integrated omics is part of an integrated information science which has collated and integrated different types of information for inferences and decision making. We review the statistical learning methods of exploratory and supervised learning from 42 publications. We also discuss the strengths and limitations of the extended principal component analysis, cluster analysis, network analysis, and regression methods. Statistical techniques such as penalization for sparsity induction when there are fewer observations than the number of features and using Bayesian approach when there are prior knowledge to be integrated are also included in the commentary. For the completeness of the review, a table of currently available software and packages from 23 publications for omics are summarized in the appendix.

Trial Sequential Analysis in systematic reviews with meta-analysis.

PubMed

Wetterslev, Jørn; Jakobsen, Janus Christian; Gluud, Christian

2017-03-06

Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded as an interim analysis on its way towards a required information size. The results of the meta-analyses should relate the total number of randomised participants to the estimated required meta-analytic information size accounting for statistical diversity. When the number of participants and the corresponding number of trials in a meta-analysis are insufficient, the use of the traditional 95% confidence interval or the 5% statistical significance threshold will lead to too many false positive conclusions (type I errors) and too many false negative conclusions (type II errors). We developed a methodology for interpreting meta-analysis results, using generally accepted, valid evidence on how to adjust thresholds for significance in randomised clinical trials when the required sample size has not been reached. The Lan-DeMets trial sequential monitoring boundaries in Trial Sequential Analysis offer adjusted confidence intervals and restricted thresholds for statistical significance when the diversity-adjusted required information size and the corresponding number of required trials for the meta-analysis have not been reached. Trial Sequential Analysis provides a frequentistic approach to control both type I and type II errors. We define the required information size and the corresponding number of required trials in a meta-analysis and the diversity (D 2 ) measure of heterogeneity. We explain the reasons for using Trial Sequential Analysis of meta-analysis when the actual information size fails to reach the required information size. We present examples drawn from traditional meta-analyses using unadjusted naïve 95% confidence intervals and 5% thresholds for statistical significance. Spurious conclusions in systematic reviews with traditional meta-analyses can be reduced using Trial Sequential Analysis. Several empirical studies have demonstrated that the Trial Sequential Analysis provides better control of type I errors and of type II errors than the traditional naïve meta-analysis. Trial Sequential Analysis represents analysis of meta-analytic data, with transparent assumptions, and better control of type I and type II errors than the traditional meta-analysis using naïve unadjusted confidence intervals.

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.

Meta-analysis inside and outside particle physics: two traditions that should converge?

PubMed

Baker, Rose D; Jackson, Dan

2013-06-01

The use of meta-analysis in medicine and epidemiology really took off in the 1970s. However, in high-energy physics, the Particle Data Group has been carrying out meta-analyses of measurements of particle masses and other properties since 1957. Curiously, there has been virtually no interaction between those working inside and outside particle physics. In this paper, we use statistical models to study two major differences in practice. The first is the usefulness of systematic errors, which physicists are now beginning to quote in addition to statistical errors. The second is whether it is better to treat heterogeneity by scaling up errors as do the Particle Data Group or by adding a random effect as does the rest of the community. Besides fitting models, we derive and use an exact test of the error-scaling hypothesis. We also discuss the other methodological differences between the two streams of meta-analysis. Our conclusion is that systematic errors are not currently very useful and that the conventional random effects model, as routinely used in meta-analysis, has a useful role to play in particle physics. The moral we draw for statisticians is that we should be more willing to explore 'grassroots' areas of statistical application, so that good statistical practice can flow both from and back to the statistical mainstream. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.

Quasi-experimental Studies in the Fields of Infection Control and Antibiotic Resistance, Ten Years Later: A Systematic Review.

PubMed

Alsaggaf, Rotana; O'Hara, Lyndsay M; Stafford, Kristen A; Leekha, Surbhi; Harris, Anthony D

2018-02-01

OBJECTIVE A systematic review of quasi-experimental studies in the field of infectious diseases was published in 2005. The aim of this study was to assess improvements in the design and reporting of quasi-experiments 10 years after the initial review. We also aimed to report the statistical methods used to analyze quasi-experimental data. DESIGN Systematic review of articles published from January 1, 2013, to December 31, 2014, in 4 major infectious disease journals. METHODS Quasi-experimental studies focused on infection control and antibiotic resistance were identified and classified based on 4 criteria: (1) type of quasi-experimental design used, (2) justification of the use of the design, (3) use of correct nomenclature to describe the design, and (4) statistical methods used. RESULTS Of 2,600 articles, 173 (7%) featured a quasi-experimental design, compared to 73 of 2,320 articles (3%) in the previous review (P<.01). Moreover, 21 articles (12%) utilized a study design with a control group; 6 (3.5%) justified the use of a quasi-experimental design; and 68 (39%) identified their design using the correct nomenclature. In addition, 2-group statistical tests were used in 75 studies (43%); 58 studies (34%) used standard regression analysis; 18 (10%) used segmented regression analysis; 7 (4%) used standard time-series analysis; 5 (3%) used segmented time-series analysis; and 10 (6%) did not utilize statistical methods for comparisons. CONCLUSIONS While some progress occurred over the decade, it is crucial to continue improving the design and reporting of quasi-experimental studies in the fields of infection control and antibiotic resistance to better evaluate the effectiveness of important interventions. Infect Control Hosp Epidemiol 2018;39:170-176.

A New Methodology for Systematic Exploitation of Technology Databases.

ERIC Educational Resources Information Center

Bedecarrax, Chantal; Huot, Charles

1994-01-01

Presents the theoretical aspects of a data analysis methodology that can help transform sequential raw data from a database into useful information, using the statistical analysis of patents as an example. Topics discussed include relational analysis and a technology watch approach. (Contains 17 references.) (LRW)

Meta-analysis and The Cochrane Collaboration: 20 years of the Cochrane Statistical Methods Group

PubMed Central

2013-01-01

The Statistical Methods Group has played a pivotal role in The Cochrane Collaboration over the past 20 years. The Statistical Methods Group has determined the direction of statistical methods used within Cochrane reviews, developed guidance for these methods, provided training, and continued to discuss and consider new and controversial issues in meta-analysis. The contribution of Statistical Methods Group members to the meta-analysis literature has been extensive and has helped to shape the wider meta-analysis landscape. In this paper, marking the 20th anniversary of The Cochrane Collaboration, we reflect on the history of the Statistical Methods Group, beginning in 1993 with the identification of aspects of statistical synthesis for which consensus was lacking about the best approach. We highlight some landmark methodological developments that Statistical Methods Group members have contributed to in the field of meta-analysis. We discuss how the Group implements and disseminates statistical methods within The Cochrane Collaboration. Finally, we consider the importance of robust statistical methodology for Cochrane systematic reviews, note research gaps, and reflect on the challenges that the Statistical Methods Group faces in its future direction. PMID:24280020

Reporting quality of statistical methods in surgical observational studies: protocol for systematic review.

PubMed

Wu, Robert; Glen, Peter; Ramsay, Tim; Martel, Guillaume

2014-06-28

Observational studies dominate the surgical literature. Statistical adjustment is an important strategy to account for confounders in observational studies. Research has shown that published articles are often poor in statistical quality, which may jeopardize their conclusions. The Statistical Analyses and Methods in the Published Literature (SAMPL) guidelines have been published to help establish standards for statistical reporting.This study will seek to determine whether the quality of statistical adjustment and the reporting of these methods are adequate in surgical observational studies. We hypothesize that incomplete reporting will be found in all surgical observational studies, and that the quality and reporting of these methods will be of lower quality in surgical journals when compared with medical journals. Finally, this work will seek to identify predictors of high-quality reporting. This work will examine the top five general surgical and medical journals, based on a 5-year impact factor (2007-2012). All observational studies investigating an intervention related to an essential component area of general surgery (defined by the American Board of Surgery), with an exposure, outcome, and comparator, will be included in this systematic review. Essential elements related to statistical reporting and quality were extracted from the SAMPL guidelines and include domains such as intent of analysis, primary analysis, multiple comparisons, numbers and descriptive statistics, association and correlation analyses, linear regression, logistic regression, Cox proportional hazard analysis, analysis of variance, survival analysis, propensity analysis, and independent and correlated analyses. Each article will be scored as a proportion based on fulfilling criteria in relevant analyses used in the study. A logistic regression model will be built to identify variables associated with high-quality reporting. A comparison will be made between the scores of surgical observational studies published in medical versus surgical journals. Secondary outcomes will pertain to individual domains of analysis. Sensitivity analyses will be conducted. This study will explore the reporting and quality of statistical analyses in surgical observational studies published in the most referenced surgical and medical journals in 2013 and examine whether variables (including the type of journal) can predict high-quality reporting.

Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review.

PubMed

Weir, Christopher J; Butcher, Isabella; Assi, Valentina; Lewis, Stephanie C; Murray, Gordon D; Langhorne, Peter; Brady, Marian C

2018-03-07

Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis. We undertook two systematic literature reviews to identify methodological approaches used to deal with missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited reference searching and emailed topic experts to identify recent methodological developments. Details recorded included the description of the method, the information required to implement the method, any underlying assumptions and whether the method could be readily applied in standard statistical software. We provided a summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios. For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when replacing a missing SD the approximation using the range minimised loss of precision and generally performed better than omitting trials. When estimating missing means, a formula using the median, lower quartile and upper quartile performed best in preserving the precision of the meta-analysis findings, although in some scenarios, omitting trials gave superior results. Methods based on summary statistics (minimum, maximum, lower quartile, upper quartile, median) reported in the literature facilitate more comprehensive inclusion of randomised controlled trials with missing mean or variability summary statistics within meta-analyses.

Got Power? A Systematic Review of Sample Size Adequacy in Health Professions Education Research

ERIC Educational Resources Information Center

Cook, David A.; Hatala, Rose

2015-01-01

Many education research studies employ small samples, which in turn lowers statistical power. We re-analyzed the results of a meta-analysis of simulation-based education to determine study power across a range of effect sizes, and the smallest effect that could be plausibly excluded. We systematically searched multiple databases through May 2011,…

Synoptic scale forecast skill and systematic errors in the MASS 2.0 model. [Mesoscale Atmospheric Simulation System

NASA Technical Reports Server (NTRS)

Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K. F.

1985-01-01

The synoptic scale performance characteristics of MASS 2.0 are determined by comparing filtered 12-24 hr model forecasts to same-case forecasts made by the National Meteorological Center's synoptic-scale Limited-area Fine Mesh model. Characteristics of the two systems are contrasted, and the analysis methodology used to determine statistical skill scores and systematic errors is described. The overall relative performance of the two models in the sample is documented, and important systematic errors uncovered are presented.

Statistical and systematic errors in the measurement of weak-lensing Minkowski functionals: Application to the Canada-France-Hawaii Lensing Survey

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

Shirasaki, Masato; Yoshida, Naoki, E-mail: masato.shirasaki@utap.phys.s.u-tokyo.ac.jp

2014-05-01

The measurement of cosmic shear using weak gravitational lensing is a challenging task that involves a number of complicated procedures. We study in detail the systematic errors in the measurement of weak-lensing Minkowski Functionals (MFs). Specifically, we focus on systematics associated with galaxy shape measurements, photometric redshift errors, and shear calibration correction. We first generate mock weak-lensing catalogs that directly incorporate the actual observational characteristics of the Canada-France-Hawaii Lensing Survey (CFHTLenS). We then perform a Fisher analysis using the large set of mock catalogs for various cosmological models. We find that the statistical error associated with the observational effects degradesmore » the cosmological parameter constraints by a factor of a few. The Subaru Hyper Suprime-Cam (HSC) survey with a sky coverage of ∼1400 deg{sup 2} will constrain the dark energy equation of the state parameter with an error of Δw {sub 0} ∼ 0.25 by the lensing MFs alone, but biases induced by the systematics can be comparable to the 1σ error. We conclude that the lensing MFs are powerful statistics beyond the two-point statistics only if well-calibrated measurement of both the redshifts and the shapes of source galaxies is performed. Finally, we analyze the CFHTLenS data to explore the ability of the MFs to break degeneracies between a few cosmological parameters. Using a combined analysis of the MFs and the shear correlation function, we derive the matter density Ω{sub m0}=0.256±{sub 0.046}{sup 0.054}.« less

Effect and safety of early weight-bearing on the outcome after open-wedge high tibial osteotomy: a systematic review and meta-analysis.

PubMed

Lee, O-Sung; Ahn, Soyeon; Lee, Yong Seuk

2017-07-01

The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of early weight-bearing by comparing clinical and radiological outcomes between early and traditional delayed weight-bearing after OWHTO. A rigorous and systematic approach was used. The methodological quality was also assessed. Results that are possible to be compared in two or more than two articles were presented as forest plots. A 95% confidence interval was calculated for each effect size, and we calculated the I 2 statistic, which presents the percentage of total variation attributable to the heterogeneity among studies. The random-effects model was used to calculate the effect size. Six articles were included in the final analysis. All case groups were composed of early full weight-bearing within 2 weeks. All control groups were composed of late full weight-bearing between 6 weeks and 2 months. Pooled analysis was possible for the improvement in Lysholm score, but there was no statistically significant difference shown between groups. Other clinical results were also similar between groups. Four studies reported mechanical femorotibial angle (mFTA) and this result showed no statistically significant difference between groups in the pooled analysis. Furthermore, early weight-bearing showed more favorable results in some radiologic results (osseointegration and patellar height) and complications (thrombophlebitis and recurrence). Our analysis supports that early full weight-bearing after OWHTO using a locking plate leads to improvement in outcomes and was comparable to the delayed weight-bearing in terms of clinical and radiological outcomes. On the contrary, early weight-bearing was more favorable with respect to some radiologic parameters and complications compared with delayed weight-bearing.

Methodological and Reporting Quality of Systematic Reviews and Meta-analyses in Endodontics.

PubMed

Nagendrababu, Venkateshbabu; Pulikkotil, Shaju Jacob; Sultan, Omer Sheriff; Jayaraman, Jayakumar; Peters, Ove A

2018-06-01

The aim of this systematic review (SR) was to evaluate the quality of SRs and meta-analyses (MAs) in endodontics. A comprehensive literature search was conducted to identify relevant articles in the electronic databases from January 2000 to June 2017. Two reviewers independently assessed the articles for eligibility and data extraction. SRs and MAs on interventional studies with a minimum of 2 therapeutic strategies in endodontics were included in this SR. Methodologic and reporting quality were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), respectively. The interobserver reliability was calculated using the Cohen kappa statistic. Statistical analysis with the level of significance at P < .05 was performed using Kruskal-Wallis tests and simple linear regression analysis. A total of 30 articles were selected for the current SR. Using AMSTAR, the item related to the scientific quality of studies used in conclusion was adhered by less than 40% of studies. Using PRISMA, 3 items were reported by less than 40% of studies, which were on objectives, protocol registration, and funding. No association was evident comparing the number of authors and country with quality. Statistical significance was observed when quality was compared among journals, with studies published as Cochrane reviews superior to those published in other journals. AMSTAR and PRISMA scores were significantly related. SRs in endodontics showed variability in both methodologic and reporting quality. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Toward a New Conceptual Framework for Teaching about Flood Risk in Introductory Geoscience Courses

ERIC Educational Resources Information Center

Lutz, Tim

2011-01-01

An analysis of physical geology textbooks used in introductory courses shows that there is a systematic lack of clarity regarding flood risk. Some problems originate from confusion relating to statistical terms such as "100-year flood" and "100-year floodplain." However, the main problem is conceptual: statistics such as return…

Living systematic reviews: 3. Statistical methods for updating meta-analyses.

PubMed

Simmonds, Mark; Salanti, Georgia; McKenzie, Joanne; Elliott, Julian

2017-11-01

A living systematic review (LSR) should keep the review current as new research evidence emerges. Any meta-analyses included in the review will also need updating as new material is identified. If the aim of the review is solely to present the best current evidence standard meta-analysis may be sufficient, provided reviewers are aware that results may change at later updates. If the review is used in a decision-making context, more caution may be needed. When using standard meta-analysis methods, the chance of incorrectly concluding that any updated meta-analysis is statistically significant when there is no effect (the type I error) increases rapidly as more updates are performed. Inaccurate estimation of any heterogeneity across studies may also lead to inappropriate conclusions. This paper considers four methods to avoid some of these statistical problems when updating meta-analyses: two methods, that is, law of the iterated logarithm and the Shuster method control primarily for inflation of type I error and two other methods, that is, trial sequential analysis and sequential meta-analysis control for type I and II errors (failing to detect a genuine effect) and take account of heterogeneity. This paper compares the methods and considers how they could be applied to LSRs. Copyright © 2017 Elsevier Inc. All rights reserved.

A decade of individual participant data meta-analyses: A review of current practice.

PubMed

Simmonds, Mark; Stewart, Gavin; Stewart, Lesley

2015-11-01

Individual participant data (IPD) systematic reviews and meta-analyses are often considered to be the gold standard for meta-analysis. In the ten years since the first review into the methodology and reporting practice of IPD reviews was published much has changed in the field. This paper investigates current reporting and statistical practice in IPD systematic reviews. A systematic review was performed to identify systematic reviews that collected and analysed IPD. Data were extracted from each included publication on a variety of issues related to the reporting of IPD review process, and the statistical methods used. There has been considerable growth in the use of "one-stage" methods to perform IPD meta-analyses. The majority of reviews consider at least one covariate other than the primary intervention, either using subgroup analysis or including covariates in one-stage regression models. Random-effects analyses, however, are not often used. Reporting of review methods was often limited, with few reviews presenting a risk-of-bias assessment. Details on issues specific to the use of IPD were little reported, including how IPD were obtained; how data was managed and checked for consistency and errors; and for how many studies and participants IPD were sought and obtained. While the last ten years have seen substantial changes in how IPD meta-analyses are performed there remains considerable scope for improving the quality of reporting for both the process of IPD systematic reviews, and the statistical methods employed in them. It is to be hoped that the publication of the PRISMA-IPD guidelines specific to IPD reviews will improve reporting in this area. Copyright © 2015 Elsevier Inc. All rights reserved.

An evaluation of the quality of statistical design and analysis of published medical research: results from a systematic survey of general orthopaedic journals.

PubMed

Parsons, Nick R; Price, Charlotte L; Hiskens, Richard; Achten, Juul; Costa, Matthew L

2012-04-25

The application of statistics in reported research in trauma and orthopaedic surgery has become ever more important and complex. Despite the extensive use of statistical analysis, it is still a subject which is often not conceptually well understood, resulting in clear methodological flaws and inadequate reporting in many papers. A detailed statistical survey sampled 100 representative orthopaedic papers using a validated questionnaire that assessed the quality of the trial design and statistical analysis methods. The survey found evidence of failings in study design, statistical methodology and presentation of the results. Overall, in 17% (95% confidence interval; 10-26%) of the studies investigated the conclusions were not clearly justified by the results, in 39% (30-49%) of studies a different analysis should have been undertaken and in 17% (10-26%) a different analysis could have made a difference to the overall conclusions. It is only by an improved dialogue between statistician, clinician, reviewer and journal editor that the failings in design methodology and analysis highlighted by this survey can be addressed.

Patterns of Puffery: An Analysis of Non-Fiction Blurbs

ERIC Educational Resources Information Center

Cronin, Blaise; La Barre, Kathryn

2005-01-01

The blurb is a paratextual element which has not previously been subjected to systematic analysis. We describe the nature and purpose of this publishing epiphenomenon, highlight some of the related marketing issues and ethical concerns and provide a statistical analysis of almost 2000 blurbs identified in a sample of 450 non-fiction books.…

Child-Centered Play Therapy in the Schools: Review and Meta-Analysis

ERIC Educational Resources Information Center

Ray, Dee C.; Armstrong, Stephen A.; Balkin, Richard S.; Jayne, Kimberly M.

2015-01-01

The authors conducted a meta-analysis and systematic review that examined 23 studies evaluating the effectiveness of child centered play therapy (CCPT) conducted in elementary schools. Meta-analysis results were explored using a random effects model for mean difference and mean gain effect size estimates. Results revealed statistically significant…

Load Model Verification, Validation and Calibration Framework by Statistical Analysis on Field Data

NASA Astrophysics Data System (ADS)

Jiao, Xiangqing; Liao, Yuan; Nguyen, Thai

2017-11-01

Accurate load models are critical for power system analysis and operation. A large amount of research work has been done on load modeling. Most of the existing research focuses on developing load models, while little has been done on developing formal load model verification and validation (V&V) methodologies or procedures. Most of the existing load model validation is based on qualitative rather than quantitative analysis. In addition, not all aspects of model V&V problem have been addressed by the existing approaches. To complement the existing methods, this paper proposes a novel load model verification and validation framework that can systematically and more comprehensively examine load model's effectiveness and accuracy. Statistical analysis, instead of visual check, quantifies the load model's accuracy, and provides a confidence level of the developed load model for model users. The analysis results can also be used to calibrate load models. The proposed framework can be used as a guidance to systematically examine load models for utility engineers and researchers. The proposed method is demonstrated through analysis of field measurements collected from a utility system.

Modeling longitudinal data, I: principles of multivariate analysis.

PubMed

Ravani, Pietro; Barrett, Brendan; Parfrey, Patrick

2009-01-01

Statistical models are used to study the relationship between exposure and disease while accounting for the potential role of other factors' impact on outcomes. This adjustment is useful to obtain unbiased estimates of true effects or to predict future outcomes. Statistical models include a systematic component and an error component. The systematic component explains the variability of the response variable as a function of the predictors and is summarized in the effect estimates (model coefficients). The error element of the model represents the variability in the data unexplained by the model and is used to build measures of precision around the point estimates (confidence intervals).

Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis

PubMed Central

Roll, Stephanie; Müller-Nordhorn, Jacqueline; Keil, Thomas; Scholz, Hans; Eidt, Daniela; Greiner, Wolfgang; Willich, Stefan N

2008-01-01

Background In peripheral vascular bypass surgery different synthetic materials are available for bypass grafting. It is unclear which of the two commonly used materials, polytetrafluoroethylene (PTFE) or polyester (Dacron®) grafts, is to be preferred. Thus, the aim of this meta-analysis and systematic review was to compare the effectiveness of these two prosthetic bypass materials (Dacron® and PTFE). Methods We performed a systematic literature search in MEDLINE, Cochrane-Library – CENTRAL, EMBASE and other databases for relevant publications in English and German published between 1999 and 2008. Only randomized controlled trials were considered for inclusion. We assessed the methodological quality by means of standardized checklists. Primary patency was used as the main endpoint. Random-effect meta-analysis as well as pooling data in life table format was performed to combine study results. Results Nine randomized controlled trials (RCT) were included. Two trials showed statistically significant differences in primary patency, one favouring Dacron® and one favouring PTFE grafts, while 7 trials did not show statistically significant differences between the two materials. Meta-analysis on the comparison of PTFE vs. Dacron® grafts yielded no differences with regard to primary patency rates (hazard ratio 1.04 (95% confidence interval [0.85;1.28]), no significant heterogeneity (p = 0.32, I2 = 14%)). Similarly, there were no significant differences with regard to secondary patency rates. Conclusion Systematic evaluation and meta-analysis of randomized controlled trials comparing Dacron® and PTFE as bypass materials for peripheral vascular surgery showed no evidence of an advantage of one synthetic material over the other. PMID:19099583

Using data sources beyond PubMed has a modest impact on the results of systematic reviews of therapeutic interventions.

PubMed

Halladay, Christopher W; Trikalinos, Thomas A; Schmid, Ian T; Schmid, Christopher H; Dahabreh, Issa J

2015-09-01

Searching multiple sources when conducting systematic reviews is considered good practice. We aimed to investigate the impact of using sources beyond PubMed in systematic reviews of therapeutic interventions. We randomly selected 50 Cochrane reviews that searched the PubMed (or MEDLINE) and EMBASE databases and included a meta-analysis of ≥10 studies. We checked whether each eligible record in each review (n = 2,700) was retrievable in PubMed and EMBASE. For the first-listed meta-analysis of ≥10 studies in each review, we examined whether excluding studies not found in PubMed affected results. A median of one record per review was indexed in EMBASE but not in PubMed; a median of four records per review was not indexed in PubMed or EMBASE. Meta-analyses included a median of 13.5 studies; a median of zero studies per meta-analysis was indexed in EMBASE but not in PubMed; a median of one study per meta-analysis was not indexed in PubMed or EMBASE. Meta-analysis using only PubMed-indexed vs. all available studies led to a different conclusion in a single case (on the basis of conventional criteria for statistical significance). In meta-regression analyses, effects in PubMed- vs. non-PubMed-indexed studies were statistically significantly different in a single data set. For systematic reviews of the effects of therapeutic interventions, gains from searching sources beyond PubMed, and from searching EMBASE in particular are modest. Copyright © 2015 Elsevier Inc. All rights reserved.

Antiviral treatment of Bell's palsy based on baseline severity: a systematic review and meta-analysis.

PubMed

Turgeon, Ricky D; Wilby, Kyle J; Ensom, Mary H H

2015-06-01

We conducted a systematic review with meta-analysis to evaluate the efficacy of antiviral agents on complete recovery of Bell's palsy. We searched CENTRAL, Embase, MEDLINE, International Pharmaceutical Abstracts, and sources of unpublished literature to November 1, 2014. Primary and secondary outcomes were complete and satisfactory recovery, respectively. To evaluate statistical heterogeneity, we performed subgroup analysis of baseline severity of Bell's palsy and between-study sensitivity analyses based on risk of allocation and detection bias. The 10 included randomized controlled trials (2419 patients; 807 with severe Bell's palsy at onset) had variable risk of bias, with 9 trials having a high risk of bias in at least 1 domain. Complete recovery was not statistically significantly greater with antiviral use versus no antiviral use in the random-effects meta-analysis of 6 trials (relative risk, 1.06; 95% confidence interval, 0.97-1.16; I(2) = 65%). Conversely, random-effects meta-analysis of 9 trials showed a statistically significant difference in satisfactory recovery (relative risk, 1.10; 95% confidence interval, 1.02-1.18; I(2) = 63%). Response to antiviral agents did not differ visually or statistically between patients with severe symptoms at baseline and those with milder disease (test for interaction, P = .11). Sensitivity analyses did not show a clear effect of bias on outcomes. Antiviral agents are not efficacious in increasing the proportion of patients with Bell's palsy who achieved complete recovery, regardless of baseline symptom severity. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Vedolizumab Compared with Certolizumab in the Therapy of Crohn Disease: A Systematic Review and Indirect Comparison.

PubMed

Kawalec, Paweł; Moćko, Pawel; Pilc, Andrzej; Radziwon-Zalewska, Maria; Malinowska-Lipień, Iwona

2016-08-01

The increasing prevalence of Crohn disease (CD) underscores the need to identify new effective drugs, which is particularly important for patients who do not respond or do not tolerate standard biologic therapies. The purpose of this analysis was to compare the efficacy and safety of vedolizumab and certolizumab pegol in patients with active moderate to severe CD. This analysis was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic literature search of Medline (PubMed), Embase, and the Cochrane Library was conducted through March 5, 2016. Studies included were randomized controlled trials (RCTs) that enrolled patients treated for CD with vedolizumab or certolizumab pegol. All studies were critically appraised; indirect comparison was performed with the Bucher method. Eight RCTs were identified, and four were homogeneous enough to be included in the indirect comparison of the induction phase of treatment. No statistically significant differences were found in clinical response (relative risk [RR] 1.23, 95% confidence interval [CI] 0.81-1.88) or remission (RR 1.35, 95% CI 0.89-2.07) between vedolizumab and certolizumab pegol in the overall population. Similar nonstatistically significant differences in response and remission were noted in a subgroup analysis of anti-tumor necrosis factor-naive patients (RR 1.10, 95% CI 0.72-1.66 and RR 1.98, 95% CI 0.95-4.11, respectively). In addition, there were no statistically significant differences in safety profiles. This indirect comparison analysis demonstrated no statistically significant differences in efficacy and safety between vedolizumab and certolizumab pegol. © 2016 Pharmacotherapy Publications, Inc.

A third of systematic reviews changed or did not specify the primary outcome: a PROSPERO register study.

PubMed

Tricco, Andrea C; Cogo, Elise; Page, Matthew J; Polisena, Julie; Booth, Alison; Dwan, Kerry; MacDonald, Heather; Clifford, Tammy J; Stewart, Lesley A; Straus, Sharon E; Moher, David

2016-11-01

To examine outcome reporting bias of systematic reviews registered in PROSPERO. Retrospective cohort study. The primary outcomes from systematic review publications were compared with those reported in the corresponding PROSPERO records; discrepancies in the primary outcomes were assessed as upgrades, additions, omissions, or downgrades. Relative risks (RRs) and 95% confidence intervals (CI) were calculated to determine the likelihood of having a change in primary outcome when the meta-analysis result was favorable and statistically significant. Ninety-six systematic reviews were published. A discrepancy in the primary outcome occurred in 32% of the included reviews and 39% of the reviews did not explicitly specify a primary outcome(s); 6% of the primary outcomes were omitted. There was no significant increased risk of adding/upgrading (RR, 2.14; 95% CI: 0.53, 8.63) or decreased risk of downgrading (RR, 0.76; 95% CI: 0.27, 2.17) an outcome when the meta-analysis result was favorable and statistically significant. As well, there was no significant increased risk of adding/upgrading (RR, 0.89; 95% CI: 0.31, 2.53) or decreased risk of downgrading (RR, 0.56; 95% CI: 0.29, 1.08) an outcome when the conclusion was positive. We recommend review authors carefully consider primary outcome selection, and journals are encouraged to focus acceptance on registered systematic reviews. Copyright © 2016 Elsevier Inc. All rights reserved.

A Critical Review and Appropriation of Pierre Bourdieu's Analysis of Social and Cultural Reproduction

ERIC Educational Resources Information Center

Shirley, Dennis

1986-01-01

Makes accessible Bourdieu's comprehensive and systematic sociology of French education; which integrates classical sociological theory and statistical analysis. Isolates and explicates key terminology, links these concepts together, and critiques the work from the perspective of the philosophy of praxis. (LHW)

The GMO Sumrule and the πNN Coupling Constant

NASA Astrophysics Data System (ADS)

Ericson, T. E. O.; Loiseau, B.; Thomas, A. W.

The isovector GMO sumrule for forward πN scattering is critically evaluated using the precise π-p and π-d scattering lengths obtained recently from pionic atom measurements. The charged πNN coupling constant is then deduced with careful analysis of systematic and statistical sources of uncertainties. This determination gives directly from data gc2(GMO)/4π = 14.17±0.09 (statistic) ±0.17 (systematic) or fc2/ 4π=0.078(11). This value is half-way between that of indirect methods (phase-shift analyses) and the direct evaluation from from backward np differential scattering cross sections (extrapolation to pion pole). From the π-p and π-d scattering lengths our analysis leads also to accurate values for (1/2)(aπ-p+aπ-n) and (1/2) (aπ-p-aπ-n).

Association between Hypertension and Epistaxis: Systematic Review and Meta-analysis.

PubMed

Min, Hyun Jin; Kang, Hyun; Choi, Geun Joo; Kim, Kyung Soo

2017-12-01

Objective Whether there is an association or a cause-and-effect relationship between epistaxis and hypertension is a subject of longstanding controversy. The objective of this systematic review and meta-analysis was to determine the association between epistaxis and hypertension and to verify whether hypertension is an independent risk factor of epistaxis. Data Sources A comprehensive search was performed using the MEDLINE, EMBASE, and Cochrane Library databases. Review Methods The review was performed according to the Meta-analysis of Observational Studies in Epidemiology guidelines and reported using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Results We screened 2768 unique studies and selected 10 for this meta-analysis. Overall, the risk of epistaxis was significantly increased for patients with hypertension (odds ratio, 1.532 [95% confidence interval (CI), 1.181-1.986]; number needed to treat, 14.9 [95% CI, 12.3-19.0]). Results of the Q test and I 2 statistics suggested considerable heterogeneity ([Formula: see text] = 0.038, I 2 = 49.3%). The sensitivity analysis was performed by excluding 1 study at a time, and it revealed no change in statistical significance. Conclusion Although this meta-analysis had some limitations, our study demonstrated that hypertension was significantly associated with the risk of epistaxis. However, since this association does not support a causal relationship between hypertension and epistaxis, further clinical trials with large patient populations will be required to determine the impact of hypertension on epistaxis.

The same analysis approach: Practical protection against the pitfalls of novel neuroimaging analysis methods.

PubMed

Görgen, Kai; Hebart, Martin N; Allefeld, Carsten; Haynes, John-Dylan

2017-12-27

Standard neuroimaging data analysis based on traditional principles of experimental design, modelling, and statistical inference is increasingly complemented by novel analysis methods, driven e.g. by machine learning methods. While these novel approaches provide new insights into neuroimaging data, they often have unexpected properties, generating a growing literature on possible pitfalls. We propose to meet this challenge by adopting a habit of systematic testing of experimental design, analysis procedures, and statistical inference. Specifically, we suggest to apply the analysis method used for experimental data also to aspects of the experimental design, simulated confounds, simulated null data, and control data. We stress the importance of keeping the analysis method the same in main and test analyses, because only this way possible confounds and unexpected properties can be reliably detected and avoided. We describe and discuss this Same Analysis Approach in detail, and demonstrate it in two worked examples using multivariate decoding. With these examples, we reveal two sources of error: A mismatch between counterbalancing (crossover designs) and cross-validation which leads to systematic below-chance accuracies, and linear decoding of a nonlinear effect, a difference in variance. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessing the Kansas water-level monitoring program: An example of the application of classical statistics to a geological problem

USGS Publications Warehouse

Davis, J.C.

2000-01-01

Geologists may feel that geological data are not amenable to statistical analysis, or at best require specialized approaches such as nonparametric statistics and geostatistics. However, there are many circumstances, particularly in systematic studies conducted for environmental or regulatory purposes, where traditional parametric statistical procedures can be beneficial. An example is the application of analysis of variance to data collected in an annual program of measuring groundwater levels in Kansas. Influences such as well conditions, operator effects, and use of the water can be assessed and wells that yield less reliable measurements can be identified. Such statistical studies have resulted in yearly improvements in the quality and reliability of the collected hydrologic data. Similar benefits may be achieved in other geological studies by the appropriate use of classical statistical tools.

Propensity-score matching in the cardiovascular surgery literature from 2004 to 2006: a systematic review and suggestions for improvement.

PubMed

Austin, Peter C

2007-11-01

I conducted a systematic review of the use of propensity score matching in the cardiovascular surgery literature. I examined the adequacy of reporting and whether appropriate statistical methods were used. I examined 60 articles published in the Annals of Thoracic Surgery, European Journal of Cardio-thoracic Surgery, Journal of Cardiovascular Surgery, and the Journal of Thoracic and Cardiovascular Surgery between January 1, 2004, and December 31, 2006. Thirty-one of the 60 studies did not provide adequate information on how the propensity score-matched pairs were formed. Eleven (18%) of studies did not report on whether matching on the propensity score balanced baseline characteristics between treated and untreated subjects in the matched sample. No studies used appropriate methods to compare baseline characteristics between treated and untreated subjects in the propensity score-matched sample. Eight (13%) of the 60 studies explicitly used statistical methods appropriate for the analysis of matched data when estimating the effect of treatment on the outcomes. Two studies used appropriate methods for some outcomes, but not for all outcomes. Thirty-nine (65%) studies explicitly used statistical methods that were inappropriate for matched-pairs data when estimating the effect of treatment on outcomes. Eleven studies did not report the statistical tests that were used to assess the statistical significance of the treatment effect. Analysis of propensity score-matched samples tended to be poor in the cardiovascular surgery literature. Most statistical analyses ignored the matched nature of the sample. I provide suggestions for improving the reporting and analysis of studies that use propensity score matching.

The statistics of identifying differentially expressed genes in Expresso and TM4: a comparison

PubMed Central

Sioson, Allan A; Mane, Shrinivasrao P; Li, Pinghua; Sha, Wei; Heath, Lenwood S; Bohnert, Hans J; Grene, Ruth

2006-01-01

Background Analysis of DNA microarray data takes as input spot intensity measurements from scanner software and returns differential expression of genes between two conditions, together with a statistical significance assessment. This process typically consists of two steps: data normalization and identification of differentially expressed genes through statistical analysis. The Expresso microarray experiment management system implements these steps with a two-stage, log-linear ANOVA mixed model technique, tailored to individual experimental designs. The complement of tools in TM4, on the other hand, is based on a number of preset design choices that limit its flexibility. In the TM4 microarray analysis suite, normalization, filter, and analysis methods form an analysis pipeline. TM4 computes integrated intensity values (IIV) from the average intensities and spot pixel counts returned by the scanner software as input to its normalization steps. By contrast, Expresso can use either IIV data or median intensity values (MIV). Here, we compare Expresso and TM4 analysis of two experiments and assess the results against qRT-PCR data. Results The Expresso analysis using MIV data consistently identifies more genes as differentially expressed, when compared to Expresso analysis with IIV data. The typical TM4 normalization and filtering pipeline corrects systematic intensity-specific bias on a per microarray basis. Subsequent statistical analysis with Expresso or a TM4 t-test can effectively identify differentially expressed genes. The best agreement with qRT-PCR data is obtained through the use of Expresso analysis and MIV data. Conclusion The results of this research are of practical value to biologists who analyze microarray data sets. The TM4 normalization and filtering pipeline corrects microarray-specific systematic bias and complements the normalization stage in Expresso analysis. The results of Expresso using MIV data have the best agreement with qRT-PCR results. In one experiment, MIV is a better choice than IIV as input to data normalization and statistical analysis methods, as it yields as greater number of statistically significant differentially expressed genes; TM4 does not support the choice of MIV input data. Overall, the more flexible and extensive statistical models of Expresso achieve more accurate analytical results, when judged by the yardstick of qRT-PCR data, in the context of an experimental design of modest complexity. PMID:16626497

Exploratory statistical and geographical freight traffic data analysis

DOT National Transportation Integrated Search

2000-08-01

Data from freight traffic roadside surveys in Mexican highways are analyzed in order to find consistent patterns or systematic relationships between variables characterizing this traffic. Patterns traced are validated by contrasting against new data ...

An evidence-based systematic review of elderberry and elderflower (Sambucus nigra) by the Natural Standard Research Collaboration.

PubMed

Ulbricht, Catherine; Basch, Ethan; Cheung, Lisa; Goldberg, Harley; Hammerness, Paul; Isaac, Richard; Khalsa, Karta Purkh Singh; Romm, Aviva; Rychlik, Idalia; Varghese, Minney; Weissner, Wendy; Windsor, Regina C; Wortley, Jayme

2014-03-01

An evidence-based systematic review of elderberry and elderflower (Sambucus nigra) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

A systematic review and meta-analysis of music therapy for the older adults with depression.

PubMed

Zhao, K; Bai, Z G; Bo, A; Chi, I

2016-11-01

To determine the efficacy of music therapy in the management of depression in the elderly. We conducted a systematic review and meta-analysis of randomized controlled trials. Change in depressive symptoms was measured with various scales. Standardized mean differences were calculated for each therapy-control contrast. A comprehensive search yielded 2,692 citations; 19 articles met inclusion criteria. Meta-analysis suggests that music therapy plus standard treatment has statistical significance in reducing depressive symptoms among older adults (standardized mean differences = 1.02; 95% CI = 0.87, 1.17). This systematic review and meta-analysis suggests that music therapy has an effect on reducing depressive symptoms to some extent. However, high-quality trials evaluating the effects of music therapy on depression are required. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Statistical Analysis on the Mechanical Properties of Magnesium Alloys

PubMed Central

Liu, Ruoyu; Jiang, Xianquan; Zhang, Hongju; Zhang, Dingfei; Wang, Jingfeng; Pan, Fusheng

2017-01-01

Knowledge of statistical characteristics of mechanical properties is very important for the practical application of structural materials. Unfortunately, the scatter characteristics of magnesium alloys for mechanical performance remain poorly understood until now. In this study, the mechanical reliability of magnesium alloys is systematically estimated using Weibull statistical analysis. Interestingly, the Weibull modulus, m, of strength for magnesium alloys is as high as that for aluminum and steels, confirming the very high reliability of magnesium alloys. The high predictability in the tensile strength of magnesium alloys represents the capability of preventing catastrophic premature failure during service, which is essential for safety and reliability assessment. PMID:29113116

Preoperative radiation and free flap outcomes for head and neck reconstruction: a systematic review and meta-analysis.

PubMed

Herle, Pradyumna; Shukla, Lipi; Morrison, Wayne A; Shayan, Ramin

2015-03-01

There is a general consensus among reconstructive surgeons that preoperative radiotherapy is associated with a higher risk of flap failure and complications in head and neck surgery. Opinion is also divided regarding the effects of radiation dose on free flap outcomes and timing of preoperative radiation to minimize adverse outcomes. Our meta-analysis will attempt to address these issues. A systematic review of the literature was conducted in concordance to PRISMA protocol. Data were combined using STATA 12 and Open Meta-Analyst software programmes. Twenty-four studies were included comparing 2842 flaps performed in irradiated fields and 3491 flaps performed in non-irradiated fields. Meta-analysis yielded statistically significant risk ratios for flap failure (RR 1.48, P = 0.004), complications (RR 1.84, P < 0.001), reoperation (RR 2.06, P < 0.001) and fistula (RR 2.05, P < 0.001). Mean radiation dose demonstrated a trend towards increased risk of flap failure, but this was not statistically significant. On subgroup analysis, flaps with >60 Gy radiation had a non-statistically significant higher risk of flap failure (RR 1.61, P = 0.145). Preoperative radiation is associated with a statistically significant increased risk of flap complications, failure and fistula. Preoperative radiation in excess of 60 Gy after radiotherapy represents a potential risk factor for increased flap loss and should be avoided where possible. © 2014 Royal Australasian College of Surgeons.

Early repositioning through compound set enrichment analysis: a knowledge-recycling strategy.

PubMed

Temesi, Gergely; Bolgár, Bence; Arany, Adám; Szalai, Csaba; Antal, Péter; Mátyus, Péter

2014-04-01

Despite famous serendipitous drug repositioning success stories, systematic projects have not yet delivered the expected results. However, repositioning technologies are gaining ground in different phases of routine drug development, together with new adaptive strategies. We demonstrate the power of the compound information pool, the ever-growing heterogeneous information repertoire of approved drugs and candidates as an invaluable catalyzer in this transition. Systematic, computational utilization of this information pool for candidates in early phases is an open research problem; we propose a novel application of the enrichment analysis statistical framework for fusion of this information pool, specifically for the prediction of indications. Pharmaceutical consequences are formulated for a systematic and continuous knowledge recycling strategy, utilizing this information pool throughout the drug-discovery pipeline.

Asymptotic modal analysis and statistical energy analysis

NASA Technical Reports Server (NTRS)

Dowell, Earl H.

1992-01-01

Asymptotic Modal Analysis (AMA) is a method which is used to model linear dynamical systems with many participating modes. The AMA method was originally developed to show the relationship between statistical energy analysis (SEA) and classical modal analysis (CMA). In the limit of a large number of modes of a vibrating system, the classical modal analysis result can be shown to be equivalent to the statistical energy analysis result. As the CMA result evolves into the SEA result, a number of systematic assumptions are made. Most of these assumptions are based upon the supposition that the number of modes approaches infinity. It is for this reason that the term 'asymptotic' is used. AMA is the asymptotic result of taking the limit of CMA as the number of modes approaches infinity. AMA refers to any of the intermediate results between CMA and SEA, as well as the SEA result which is derived from CMA. The main advantage of the AMA method is that individual modal characteristics are not required in the model or computations. By contrast, CMA requires that each modal parameter be evaluated at each frequency. In the latter, contributions from each mode are computed and the final answer is obtained by summing over all the modes in the particular band of interest. AMA evaluates modal parameters only at their center frequency and does not sum the individual contributions from each mode in order to obtain a final result. The method is similar to SEA in this respect. However, SEA is only capable of obtaining spatial averages or means, as it is a statistical method. Since AMA is systematically derived from CMA, it can obtain local spatial information as well.

A two-point diagnostic for the H II galaxy Hubble diagram

NASA Astrophysics Data System (ADS)

Leaf, Kyle; Melia, Fulvio

2018-03-01

A previous analysis of starburst-dominated H II galaxies and H II regions has demonstrated a statistically significant preference for the Friedmann-Robertson-Walker cosmology with zero active mass, known as the Rh = ct universe, over Λcold dark matter (ΛCDM) and its related dark-matter parametrizations. In this paper, we employ a two-point diagnostic with these data to present a complementary statistical comparison of Rh = ct with Planck ΛCDM. Our two-point diagnostic compares, in a pairwise fashion, the difference between the distance modulus measured at two redshifts with that predicted by each cosmology. Our results support the conclusion drawn by a previous comparative analysis demonstrating that Rh = ct is statistically preferred over Planck ΛCDM. But we also find that the reported errors in the H II measurements may not be purely Gaussian, perhaps due to a partial contamination by non-Gaussian systematic effects. The use of H II galaxies and H II regions as standard candles may be improved even further with a better handling of the systematics in these sources.

Optimizing construction quality management of pavements using mechanistic performance analysis.

DOT National Transportation Integrated Search

2004-08-01

This report presents a statistical-based algorithm that was developed to reconcile the results from several pavement performance models used in the state of practice with systematic process control techniques. These algorithms identify project-specif...

Thr105Ile (rs11558538) polymorphism in the histamine N-methyltransferase (HNMT) gene and risk for Parkinson disease

PubMed Central

Jiménez-Jiménez, Félix Javier; Alonso-Navarro, Hortensia; García-Martín, Elena; Agúndez, José A.G.

2016-01-01

Abstract Background/aims: Several neuropathological, biochemical, and pharmacological data suggested a possible role of histamine in the etiopathogenesis of Parkinson disease (PD). The single nucleotide polymorphism (SNP) rs11558538 in the histamine N-methyltransferase (HNMT) gene has been associated with the risk of developing PD by several studies but not by some others. We carried out a systematic review that included all the studies published on PD risk related to the rs11558538 SNP, and we conducted a meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Methods: We used several databases to perform the systematic review, the software Meta-DiSc 1.1.1 to perform the meta-analysis of the eligible studies, and the Q-statistic to test heterogeneity between studies. Results: The meta-analysis included 4 eligible case–control association studies for the HNMT rs11558538 SNP and the risk for PD (2108 patients, 2158 controls). The frequency of the minor allele positivity showed a statistically significant association with a decreased risk for PD, both in the total series and in Caucasians. Although homozygosity for the minor allele did not reach statistical significance, the test for trend indicates the occurrence of a gene–dose effect. Global diagnostic odds ratios (95% confidence intervals) for rs11558538T were 0.61 (0.46–0.81) for the total group, and 0.63 (0.45–0.88) for Caucasian patients. Conclusion: The present meta-analysis confirms published evidence suggesting that the HNMT rs11558538 minor allele is related to a reduced risk of developing PD. PMID:27399132

Structure and performance of different DRG classification systems for neonatal medicine.

PubMed

Muldoon, J H

1999-01-01

There are a number of Diagnosis-Related Group (DRG) classification systems that have evolved over the past 2 decades, each with their own strengths and weaknesses. DRG systems are used for case-mix trending, utilization management and quality improvement, comparative reporting, prospective payment, and price negotiations. For any of these applications it is essential to know the accuracy with which the DRG system classifies patients, specifically for predicting resource use and also mortality. The objective of this study was to assess the adequacy of the three most commonly used DRG systems for neonatal patients-Medicare DRGs, All Patient Diagnosis-Related Groups (AP-DRGs), and All Patient Refined Diagnosis-Related Groups (APR-DRGs). A 2-part methodology is used to assess adequacy. The first part is a descriptive analysis that examines the structural characteristics of each system. This provides a framework for understanding the inherent strengths and weaknesses of each system and for interpreting their statistical performance. The second part examines the statistical performance of each system on a large nationally representative hospital database. The analysis identifies major differences in the structure and statistical performance of the three DRG systems for neonates. The Medicare DRGs are structurally the least developed and yield the poorest overall statistical performance (cost R2 = 0.292; mortality R2 = 0.083). The APR-DRGs are structurally the most developed and yield the best statistical performance (cost R2 = 0.627; mortality R2 = 0.416). The AP-DRGs are intermediate to Medicare DRGs and APR-DRGs, although closer to APR-DRGs (cost R2 = 0.507; mortality R2 = 0.304). An analysis of payment impacts and systematic effects identifies there are major systematic biases with the Medicare DRGs. At the patient level, there is substantial underpayment for surgical neonates, transferred-in neonates, neonates discharged to home health services, and neonates who die. In contrast, there is substantial overpayment for normal newborns. At the facility level, there is substantial underpayment for freestanding acute children's hospitals and major teaching general hospitals. There is overpayment for other urban general hospitals but this pattern varies by hospital size. There is very substantial overpayment for other rural hospitals. The AP-DRGs remove the majority of the systematic effects but significant biases remain. The APR-DRGs remove most of the systematic effects but some biases remain.

Systematic review and meta-analysis of the effect of equine assisted activities and therapies on gross motor outcome in children with cerebral palsy.

PubMed

Tseng, Sung-Hui; Chen, Hung-Chou; Tam, Ka-Wai

2013-01-01

To evaluate the literature on the efficacy of equine assisted activities and therapies (EAAT) on gross motor outcomes representing the ICF component of body functions and activity in children with cerebral palsy (CP). We conducted a systematic review and meta-analysis of randomized controlled trials and observational studies of hippotherapy (HPOT) and therapeutic horseback riding (TR) for children with spastic CP. Gross motor outcomes, assessed via muscle activity and muscle tone, gait, posture and Gross Motor Function Measures (GMFM) were evaluated. Five TR studies and nine HPOT studies were included. Our meta-analysis indicated that short-term HPOT (total riding time 8-10 min) significantly reduced asymmetrical activity of the hip adductor muscles. HPOT could improve postural control in children with spastic CP, GMFCS level < 5. However, the evidence did not show a statistically significant effect on GMFM after long-term HPOT or TR (total riding time, 8-22 h) in children with spastic CP. This systematic review found insufficient evidence to support the claim that long-term TR or HPOT provide a significant benefit to children with spastic CP. We found no statistically significant evidence of either therapeutic effect or maintenance effects on the gross motor activity status in CP children.

Effects of Instructional Design with Mental Model Analysis on Learning.

ERIC Educational Resources Information Center

Hong, Eunsook

This paper presents a model for systematic instructional design that includes mental model analysis together with the procedures used in developing computer-based instructional materials in the area of statistical hypothesis testing. The instructional design model is based on the premise that the objective for learning is to achieve expert-like…

What Happens to Students Placed into Developmental Education? A Meta-Analysis of Regression Discontinuity Studies

ERIC Educational Resources Information Center

Valentine, Jeffrey C.; Konstantopoulos, Spyros; Goldrick-Rab, Sara

2017-01-01

This article reports a systematic review and meta-analysis of studies that use regression discontinuity to examine the effects of placement into developmental education. Results suggest that placement into developmental education is associated with effects that are negative, statistically significant, and substantively large for three outcomes:…

[Nurse supervision in health basic units].

PubMed

Correia, Valesca Silveira; Servo, Maria Lúcia Silva

2006-01-01

This qualitative study intends to evaluate the pattern of supervision of the nurse in health basic units, in Feira de Santana city (Bahía-Brasil), between August 2001 and June 2002. The objective was to describe the supervision and the existence of supervision systematics for the nurse. A questionnaire was used to take informations from a group of sixteen (16) nurses in actual professional work. Descriptive statistical procedures for data analysis were used. It can be concluded that systematic supervision is practiced in 64% of the nurses and in 36% of the cases systematic supervision do not occur.

[Applications of meta-analysis in multi-omics].

PubMed

Han, Mingfei; Zhu, Yunping

2014-07-01

As a statistical method integrating multi-features and multi-data, meta-analysis was introduced to the field of life science in the 1990s. With the rapid advances in high-throughput technologies, life omics, the core of which are genomics, transcriptomics and proteomics, is becoming the new hot spot of life science. Although the fast output of massive data has promoted the development of omics study, it results in excessive data that are difficult to integrate systematically. In this case, meta-analysis is frequently applied to analyze different types of data and is improved continuously. Here, we first summarize the representative meta-analysis methods systematically, and then study the current applications of meta-analysis in various omics fields, finally we discuss the still-existing problems and the future development of meta-analysis.

Dietary Inflammatory Potential Score and Risk of Breast Cancer: Systematic Review and Meta-analysis.

PubMed

Zahedi, Hoda; Djalalinia, Shirin; Sadeghi, Omid; Asayesh, Hamid; Noroozi, Mehdi; Gorabi, Armita Mahdavi; Mohammadi, Rasool; Qorbani, Mostafa

2018-02-07

Several studies have been conducted on the relationship between dietary inflammatory potential (DIP) and breast cancer. However, the findings are conflicting. This systematic review and meta-analysis summarizes the findings on the association between DIP and the risk of breast cancer. We used relevant keywords and searched online international electronic databases, including PubMed and NLM Gateway (for Medline), Institute for Scientific Information (ISI), and Scopus for articles published through February 2017. All cross-sectional, case-control, and cohort studies were included in this meta-analysis. Meta-analysis was performed using the random effects meta-analysis method to address heterogeneity among studies. Findings were analyzed statistically. Nine studies were included in the present systematic review and meta-analysis. The total sample size of these studies was 296,102, and the number of participants varied from 1453 to 122,788. The random effects meta-analysis showed a positive and significant association between DIP and the risk of breast cancer (pooled odds ratio, 1.14; 95% confidence interval, 1.01-1.27). The pooled effect size was not statistically significant because of the type of studies, including cohort (pooled relative risk, 1.04; 95% confidence interval, 0.98-1.10) and case-control (pooled odds ratio, 1.63; 95% confidence interval, 0.89-2.37) studies. We found a significant and positive association between higher DIP score and risk of breast cancer. Modifying inflammatory characteristics of diet can substantially reduce the risk of breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Hamstring autograft versus soft-tissue allograft in anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Cvetanovich, Gregory L; Mascarenhas, Randy; Saccomanno, Maristella F; Verma, Nikhil N; Cole, Brian J; Bush-Joseph, Charles A; Bach, Bernard R

2014-12-01

To compare outcomes of anterior cruciate ligament (ACL) reconstruction with hamstring autograft versus soft-tissue allograft by systematic review and meta-analysis. A systematic review of randomized controlled studies comparing hamstring autograft with soft-tissue allograft in ACL reconstruction was performed. Studies were identified by strict inclusion and exclusion criteria. Descriptive statistics were reported. Where possible, the data were pooled and a meta-analysis was performed using RevMan software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). Dichotomous data were reported as risk ratios, whereas continuous data were reported as standardized mean differences and 95% confidence intervals. Heterogeneity was assessed by use of I(2) for each meta-analysis. Study methodologic quality was analyzed with the Modified Coleman Methodology Score and Jadad scale. Five studies with 504 combined patients (251 autograft and 253 allograft; 374 male and 130 female patients) with a mean age of 29.9 ± 2.2 years were included. The allografts used were fresh-frozen hamstring, irradiated hamstring, mixture of fresh-frozen and cryopreserved hamstring, fresh-frozen tibialis anterior, and fresh-frozen Achilles tendon grafts without bone blocks. The mean follow-up period was 47.4 ± 26.9 months, with a mean follow-up rate of 83.3% ± 8.6%. Two studies found a longer operative time with autograft than with allograft (77.1 ± 2.0 minutes v 59.9 ± 0.9 minutes, P = .008). Meta-analysis showed no statistically significant differences between autografts and allografts for any outcome measures (P > .05 for all tests). One study found significantly greater laxity for irradiated allograft than for autograft. The methodologic quality of the 5 studies was poor, with a mean Modified Coleman Methodology Score of 54.4 ± 6.9 and mean Jadad score of 1.6 ± 1.5. On the basis of this systematic review and meta-analysis of 5 randomized controlled trials, there is no statistically significant difference in outcome between patients undergoing ACL reconstruction with hamstring autograft and those undergoing ACL reconstruction with soft-tissue allograft. These results may not extrapolate to younger patient populations. The methodology of the available randomized controlled trials comparing hamstring autograft and soft-tissue allograft is poor. Level II, systematic review of Level I and II studies. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A systematic review of statistical methods used to test for reliability of medical instruments measuring continuous variables.

PubMed

Zaki, Rafdzah; Bulgiba, Awang; Nordin, Noorhaire; Azina Ismail, Noor

2013-06-01

Reliability measures precision or the extent to which test results can be replicated. This is the first ever systematic review to identify statistical methods used to measure reliability of equipment measuring continuous variables. This studyalso aims to highlight the inappropriate statistical method used in the reliability analysis and its implication in the medical practice. In 2010, five electronic databases were searched between 2007 and 2009 to look for reliability studies. A total of 5,795 titles were initially identified. Only 282 titles were potentially related, and finally 42 fitted the inclusion criteria. The Intra-class Correlation Coefficient (ICC) is the most popular method with 25 (60%) studies having used this method followed by the comparing means (8 or 19%). Out of 25 studies using the ICC, only 7 (28%) reported the confidence intervals and types of ICC used. Most studies (71%) also tested the agreement of instruments. This study finds that the Intra-class Correlation Coefficient is the most popular method used to assess the reliability of medical instruments measuring continuous outcomes. There are also inappropriate applications and interpretations of statistical methods in some studies. It is important for medical researchers to be aware of this issue, and be able to correctly perform analysis in reliability studies.

Qualitative fusion technique based on information poor system and its application to factor analysis for vibration of rolling bearings

NASA Astrophysics Data System (ADS)

Xia, Xintao; Wang, Zhongyu

2008-10-01

For some methods of stability analysis of a system using statistics, it is difficult to resolve the problems of unknown probability distribution and small sample. Therefore, a novel method is proposed in this paper to resolve these problems. This method is independent of probability distribution, and is useful for small sample systems. After rearrangement of the original data series, the order difference and two polynomial membership functions are introduced to estimate the true value, the lower bound and the supper bound of the system using fuzzy-set theory. Then empirical distribution function is investigated to ensure confidence level above 95%, and the degree of similarity is presented to evaluate stability of the system. Cases of computer simulation investigate stable systems with various probability distribution, unstable systems with linear systematic errors and periodic systematic errors and some mixed systems. The method of analysis for systematic stability is approved.

Global Longitudinal Strain Using Speckle-Tracking Echocardiography as a Mortality Predictor in Sepsis: A Systematic Review.

PubMed

Vallabhajosyula, Saraschandra; Rayes, Hamza A; Sakhuja, Ankit; Murad, Mohammad Hassan; Geske, Jeffrey B; Jentzer, Jacob C

2018-01-01

The data on speckle-tracking echocardiography (STE) in patients with sepsis are limited. This systematic review from 1975 to 2016 included studies in adults and children evaluating cardiovascular dysfunction in sepsis, severe sepsis, and septic shock utilizing STE for systolic global longitudinal strain (GLS). The primary outcome was short- or long-term mortality. Given the significant methodological and statistical differences between published studies, combining the data using meta-analysis methods was not appropriate. A total of 120 studies were identified, with 5 studies (561 patients) included in the final analysis. All studies were prospective observational studies using the 2001 criteria for defining sepsis. Three studies demonstrated worse systolic GLS to be associated with higher mortality, whereas 2 did not show a statistically significant association. Various cutoffs between -10% and -17% were used to define abnormal GLS across studies. This systematic review revealed that STE may predict mortality in patients with sepsis; however, the strength of evidence is low due to heterogeneity in study populations, GLS technologies, cutoffs, and timing of STE. Further dedicated studies are needed to understand the optimal application of STE in patients with sepsis.

Multivariate analysis techniques

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

Bendavid, Josh; Fisher, Wade C.; Junk, Thomas R.

2016-01-01

The end products of experimental data analysis are designed to be simple and easy to understand: hypothesis tests and measurements of parameters. But, the experimental data themselves are voluminous and complex. Furthermore, in modern collider experiments, many petabytes of data must be processed in search of rare new processes which occur together with much more copious background processes that are of less interest to the task at hand. The systematic uncertainties on the background may be larger than the expected signal in many cases. The statistical power of an analysis and its sensitivity to systematic uncertainty can therefore usually bothmore » be improved by separating signal events from background events with higher efficiency and purity.« less

An Evidence-Based Systematic Review of Beta-Sitosterol, Sitosterol (22,23- dihydrostigmasterol, 24-ethylcholesterol) by the Natural Standard Research Collaboration.

PubMed

Ulbricht, Catherine E

2016-01-01

An evidence-based systematic review of beta-sitosterol, sitosterol (22,23-dihydrostigmasterol, 24-ethylcholesterol) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: theoretical systematics and Baryon Acoustic Oscillations in the galaxy correlation function

NASA Astrophysics Data System (ADS)

Vargas-Magaña, Mariana; Ho, Shirley; Cuesta, Antonio J.; O'Connell, Ross; Ross, Ashley J.; Eisenstein, Daniel J.; Percival, Will J.; Grieb, Jan Niklas; Sánchez, Ariel G.; Tinker, Jeremy L.; Tojeiro, Rita; Beutler, Florian; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Prada, Francisco; Rodríguez-Torres, Sergio A.; Rossi, Graziano; Seo, Hee-Jong; Brownstein, Joel R.; Olmstead, Matthew; Thomas, Daniel

2018-06-01

We investigate the potential sources of theoretical systematics in the anisotropic Baryon Acoustic Oscillation (BAO) distance scale measurements from the clustering of galaxies in configuration space using the final Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS). We perform a detailed study of the impact on BAO measurements from choices in the methodology such as fiducial cosmology, clustering estimators, random catalogues, fitting templates, and covariance matrices. The theoretical systematic uncertainties in BAO parameters are found to be 0.002 in the isotropic dilation α and 0.003 in the quadrupolar dilation ɛ. The leading source of systematic uncertainty is related to the reconstruction techniques. Theoretical uncertainties are sub-dominant compared with the statistical uncertainties for BOSS survey, accounting 0.2σstat for α and 0.25σstat for ɛ (σα, stat ˜ 0.010 and σɛ, stat ˜ 0.012, respectively). We also present BAO-only distance scale constraints from the anisotropic analysis of the correlation function. Our constraints on the angular diameter distance DA(z) and the Hubble parameter H(z), including both statistical and theoretical systematic uncertainties, are 1.5 per cent and 2.8 per cent at zeff = 0.38, 1.4 per cent and 2.4 per cent at zeff = 0.51, and 1.7 per cent and 2.6 per cent at zeff = 0.61. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are cross-checked with other BAO analysis in Alam et al. The systematic error budget concerning the methodology on post-reconstruction BAO analysis presented here is used in Alam et al. to produce the final cosmological constraints from BOSS.

The role of revision surgery and adjuvant therapy following subtotal resection of osteosarcoma of the spine: a systematic review with meta-analysis.

PubMed

Shankar, Ganesh M; Clarke, Michelle J; Ailon, Tamir; Rhines, Laurence D; Patel, Shreyaskumar R; Sahgal, Arjun; Laufer, Ilya; Chou, Dean; Bilsky, Mark H; Sciubba, Daniel M; Fehlings, Michael G; Fisher, Charles G; Gokaslan, Ziya L; Shin, John H

2017-07-01

OBJECTIVE Primary osteosarcoma of the spine is a rare osseous neoplasm. While previously reported retrospective studies have demonstrated that overall patient survival is impacted mostly by en bloc resection and chemotherapy, the continued management of residual disease remains to be elucidated. This systematic review was designed to address the role of revision surgery and multimodal adjuvant therapy in cases in which en bloc excision is not initially achieved. METHODS A systematic literature search spanning the years 1966 to 2015 was performed on PubMed, Medline, EMBASE, and Web of Science to identify reports describing outcomes of patients who underwent biopsy alone, neurological decompression, or intralesional resection for osteosarcoma of the spine. Studies were reviewed qualitatively, and the clinical course of individual patients was aggregated for quantitative meta-analysis. RESULTS A total of 16 studies were identified for inclusion in the systematic review, of which 8 case reports were summarized qualitatively. These studies strongly support the role of chemotherapy for overall survival and moderately support adjuvant radiation therapy for local control. The meta-analysis revealed a statistically significant benefit in overall survival for performing revision tumor debulking (p = 0.01) and also for chemotherapy at relapse (p < 0.01). Adjuvant radiation therapy was associated with longer survival, although this did not reach statistical significance (p = 0.06). CONCLUSIONS While the initial therapeutic goal in the management of osteosarcoma of the spine is neoadjuvant chemotherapy followed by en bloc marginal resection, this objective is not always achievable given anatomical constraints and other limitations at the time of initial clinical presentation. This systematic review supports the continued aggressive use of revision surgery and multimodal adjuvant therapy when possible to improve outcomes in patients who initially undergo subtotal debulking of osteosarcoma. A limitation of this systematic review is that lesions amenable to subsequent resection or tumors inherently more sensitive to adjuvants would exaggerate a therapeutic effect of these interventions when studied in a retrospective fashion.

Epidemiology of brucellosis in Iran: A comprehensive systematic review and meta-analysis study.

PubMed

Mirnejad, Reza; Jazi, Faramarz Masjedian; Mostafaei, Shayan; Sedighi, Mansour

2017-08-01

Brucellosis is still one of the most challenging issues for health and the economy in many developing countries such as Iran. Considering the high prevalence of brucellosis, the aim of the current study was to systematically review published data about the annual incidence rate of this infection from different parts of Iran and provide an overall relative frequency (RF) for Iran using meta-analysis. We searched several databases including PubMed, ISI Web of Science, Scopus, google scholar, IranMedex and Iranian Scientific Information Database (SID) by using the following keywords: "Brucella", "Brucellosis", "Malta fever", "Mediterranean fever", "undulant fever", "zoonosis" and "Iran" in Title/Abstract/Keywords fields. Articles/Abstracts, which used clinical specimens and reported the incidence of brucellosis, were included in this review. Quality of studies was assessed by STROB and PRISMA forms. All statistical analyses were performed using STATA 11.0 (STATA Corp, College Station, TX) and P-values under 0.05 were considered statistically significant. Out of the 8326 results, we found 34 articles suitable, according to inclusion and exlusion criteria, for inclusion in this systematic review and meta-analysis. The pooled incidence of brucellosis was estimated 0.001% (95% confidence interval (CI) = 0.0005-0.0015%) annually. Relative frequency of brucellosis in different studies varied from 7.0/100000 to 276.41/100000 in Qom and Kermanshah provinces, respectively. This systematic-review and meta-analysis study showed that the highest incidences of brucellosis are occurred in west and northwest regions of Iran. Totally, the incidence of the disease in Iran is in the high range. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Meta-Analysis of the Effects of Computer Technology on School Students' Mathematics Learning

ERIC Educational Resources Information Center

Li, Qing; Ma, Xin

2010-01-01

This study examines the impact of computer technology (CT) on mathematics education in K-12 classrooms through a systematic review of existing literature. A meta-analysis of 85 independent effect sizes extracted from 46 primary studies involving a total of 36,793 learners indicated statistically significant positive effects of CT on mathematics…

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.

Statistics and Discoveries at the LHC (1/4)

ScienceCinema

Cowan, Glen

2018-02-09

The lectures will give an introduction to statistics as applied in particle physics and will provide all the necessary basics for data analysis at the LHC. Special emphasis will be placed on the the problems and questions that arise when searching for new phenomena, including p-values, discovery significance, limit setting procedures, treatment of small signals in the presence of large backgrounds. Specific issues that will be addressed include the advantages and drawbacks of different statistical test procedures (cut-based, likelihood-ratio, etc.), the look-elsewhere effect and treatment of systematic uncertainties.

Statistics and Discoveries at the LHC (3/4)

ScienceCinema

Cowan, Glen

2018-02-19

The lectures will give an introduction to statistics as applied in particle physics and will provide all the necessary basics for data analysis at the LHC. Special emphasis will be placed on the the problems and questions that arise when searching for new phenomena, including p-values, discovery significance, limit setting procedures, treatment of small signals in the presence of large backgrounds. Specific issues that will be addressed include the advantages and drawbacks of different statistical test procedures (cut-based, likelihood-ratio, etc.), the look-elsewhere effect and treatment of systematic uncertainties.

Statistics and Discoveries at the LHC (4/4)

ScienceCinema

Cowan, Glen

2018-05-22

The lectures will give an introduction to statistics as applied in particle physics and will provide all the necessary basics for data analysis at the LHC. Special emphasis will be placed on the the problems and questions that arise when searching for new phenomena, including p-values, discovery significance, limit setting procedures, treatment of small signals in the presence of large backgrounds. Specific issues that will be addressed include the advantages and drawbacks of different statistical test procedures (cut-based, likelihood-ratio, etc.), the look-elsewhere effect and treatment of systematic uncertainties.

Statistics and Discoveries at the LHC (2/4)

ScienceCinema

Cowan, Glen

2018-04-26

The lectures will give an introduction to statistics as applied in particle physics and will provide all the necessary basics for data analysis at the LHC. Special emphasis will be placed on the the problems and questions that arise when searching for new phenomena, including p-values, discovery significance, limit setting procedures, treatment of small signals in the presence of large backgrounds. Specific issues that will be addressed include the advantages and drawbacks of different statistical test procedures (cut-based, likelihood-ratio, etc.), the look-elsewhere effect and treatment of systematic uncertainties.

Surveys Assessing Students' Attitudes toward Statistics: A Systematic Review of Validity and Reliability

ERIC Educational Resources Information Center

Nolan, Meaghan M.; Beran, Tanya; Hecker, Kent G.

2012-01-01

Students with positive attitudes toward statistics are likely to show strong academic performance in statistics courses. Multiple surveys measuring students' attitudes toward statistics exist; however, a comparison of the validity and reliability of interpretations based on their scores is needed. A systematic review of relevant electronic…

Effect of the absolute statistic on gene-sampling gene-set analysis methods.

PubMed

Nam, Dougu

2017-06-01

Gene-set enrichment analysis and its modified versions have commonly been used for identifying altered functions or pathways in disease from microarray data. In particular, the simple gene-sampling gene-set analysis methods have been heavily used for datasets with only a few sample replicates. The biggest problem with this approach is the highly inflated false-positive rate. In this paper, the effect of absolute gene statistic on gene-sampling gene-set analysis methods is systematically investigated. Thus far, the absolute gene statistic has merely been regarded as a supplementary method for capturing the bidirectional changes in each gene set. Here, it is shown that incorporating the absolute gene statistic in gene-sampling gene-set analysis substantially reduces the false-positive rate and improves the overall discriminatory ability. Its effect was investigated by power, false-positive rate, and receiver operating curve for a number of simulated and real datasets. The performances of gene-set analysis methods in one-tailed (genome-wide association study) and two-tailed (gene expression data) tests were also compared and discussed.

The benefit of silicone stents in primary endonasal dacryocystorhinostomy: a systematic review and meta-analysis.

PubMed

Sarode, D; Bari, D A; Cain, A C; Syed, M I; Williams, A T

2017-04-01

To critically evaluate the evidence comparing success rates of endonasal dacryocystorhinostomy (EN-DCR) with and without silicone tubing and to thus determine whether silicone intubation is beneficial in primary EN-DCR. Systematic review and meta-analysis. A literature search was performed on AMED, EMBASE, HMIC, MEDLINE, PsycINFO, BNI, CINAHL, HEALTH BUSINESS ELITE, CENTRAL and Cochrane Ear, Nose and Throat disorders groups trials register using a combination of various MeSH. The date of last search was January 2016. This review was limited to randomised controlled trials (RCTs) in English language. Risk of bias was assessed using the Cochrane Collaboration's risk of bias tool. Chi-square and I 2 statistics were calculated to determine the presence and extent of statistical heterogeneity. Study selection, data extraction and risk of bias scoring were performed independently by two authors in concordance with the PRISMA statement. Five RCTs (447 primary EN-DCR procedures in 426 patients) were included for analysis. Moderate interstudy statistical heterogeneity was demonstrated (Chi 2 = 6.18; d.f. = 4; I 2 = 35%). Bicanalicular silicone stents were used in 229 and not used in 218 procedures. The overall success rate of EN-DCR was 92.8% (415/447). The success rate of EN-DCR was 93.4% (214/229) with silicone tubing and 92.2% (201/218) without silicone tubing. Meta-analysis using a random-effects model showed no statistically significant difference in outcomes between the two groups (P = 0.63; RR = 0.79; 95% CI = 0.3-2.06). Our review and meta-analysis did not demonstrate an additional advantage of silicone stenting. A high-quality well-powered prospective multicentre RCT is needed to further clarify on the benefit of silicone stents. © 2016 John Wiley & Sons Ltd.

The Effect of Folate and Folate Plus Zinc Supplementation on Endocrine Parameters and Sperm Characteristics in Sub-Fertile Men: A Systematic Review and Meta-Analysis.

PubMed

Irani, Morvarid; Amirian, Malihe; Sadeghi, Ramin; Lez, Justine Le; Latifnejad Roudsari, Robab

2017-08-29

To evaluate the effect of folate and folate plus zinc supplementation on endocrine parameters and sperm characteristics in sub fertile men. We conducted a systematic review and meta-analysis. Electronic databases of Medline, Scopus , Google scholar and Persian databases (SID, Iran medex, Magiran, Medlib, Iran doc) were searched from 1966 to December 2016 using a set of relevant keywords including "folate or folic acid AND (infertility, infertile, sterility)".All available randomized controlled trials (RCTs), conducted on a sample of sub fertile men with semen analyses, who took oral folic acid or folate plus zinc, were included. Data collected included endocrine parameters and sperm characteristics. Statistical analyses were done by Comprehensive Meta-analysis Version 2. In total, seven studies were included. Six studies had sufficient data for meta-analysis. "Sperm concentration was statistically higher in men supplemented with folate than with placebo (P < .001)". However, folate supplementation alone did not seem to be more effective than the placebo on the morphology (P = .056) and motility of the sperms (P = .652). Folate plus zinc supplementation did not show any statistically different effect on serum testosterone (P = .86), inhibin B (P = .84), FSH (P = .054), and sperm motility (P = .169) as compared to the placebo. Yet, folate plus zinc showed statistically higher effect on the sperm concentration (P < .001), morphology (P < .001), and serum folate level (P < .001) as compared to placebo. Folate plus zinc supplementation has a positive effect on sperm characteristics in sub fertile men. However, these results should be interpreted with caution due to the important heterogeneity of the studies included in this meta-analysis. Further trials are still needed to confirm the current findings.

Constraining the mass–richness relationship of redMaPPer clusters with angular clustering

DOE PAGES

Baxter, Eric J.; Rozo, Eduardo; Jain, Bhuvnesh; ...

2016-08-04

The potential of using cluster clustering for calibrating the mass–richness relation of galaxy clusters has been recognized theoretically for over a decade. In this paper, we demonstrate the feasibility of this technique to achieve high-precision mass calibration using redMaPPer clusters in the Sloan Digital Sky Survey North Galactic Cap. By including cross-correlations between several richness bins in our analysis, we significantly improve the statistical precision of our mass constraints. The amplitude of the mass–richness relation is constrained to 7 per cent statistical precision by our analysis. However, the error budget is systematics dominated, reaching a 19 per cent total errormore » that is dominated by theoretical uncertainty in the bias–mass relation for dark matter haloes. We confirm the result from Miyatake et al. that the clustering amplitude of redMaPPer clusters depends on galaxy concentration as defined therein, and we provide additional evidence that this dependence cannot be sourced by mass dependences: some other effect must account for the observed variation in clustering amplitude with galaxy concentration. Assuming that the observed dependence of redMaPPer clustering on galaxy concentration is a form of assembly bias, we find that such effects introduce a systematic error on the amplitude of the mass–richness relation that is comparable to the error bar from statistical noise. Finally, the results presented here demonstrate the power of cluster clustering for mass calibration and cosmology provided the current theoretical systematics can be ameliorated.« 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.

Interferon alpha adjuvant therapy in patients with high-risk melanoma: a systematic review and meta-analysis.

PubMed

Mocellin, Simone; Pasquali, Sandro; Rossi, Carlo R; Nitti, Donato

2010-04-07

Based on previous meta-analyses of randomized controlled trials (RCTs), the use of interferon alpha (IFN-alpha) in the adjuvant setting improves disease-free survival (DFS) in patients with high-risk cutaneous melanoma. However, RCTs have yielded conflicting data on the effect of IFN-alpha on overall survival (OS). We conducted a systematic review and meta-analysis to examine the effect of IFN-alpha on DFS and OS in patients with high-risk cutaneous melanoma. The systematic review was performed by searching MEDLINE, EMBASE, Cancerlit, Cochrane, ISI Web of Science, and ASCO databases. The meta-analysis was performed using time-to-event data from which hazard ratios (HRs) and 95% confidence intervals (CIs) of DFS and OS were estimated. Subgroup and meta-regression analyses to investigate the effect of dose and treatment duration were also performed. Statistical tests were two-sided. The meta-analysis included 14 RCTs, published between 1990 and 2008, and involved 8122 patients, of which 4362 patients were allocated to the IFN-alpha arm. IFN-alpha alone was compared with observation in 12 of the 14 trials, and 17 comparisons (IFN-alpha vs comparator) were generated in total. IFN-alpha treatment was associated with a statistically significant improvement in DFS in 10 of the 17 comparisons (HR for disease recurrence = 0.82, 95% CI = 0.77 to 0.87; P < .001) and improved OS in four of the 14 comparisons (HR for death = 0.89, 95% CI = 0.83 to 0.96; P = .002). No between-study heterogeneity in either DFS or OS was observed. No optimal IFN-alpha dose and/or treatment duration or a subset of patients more responsive to adjuvant therapy was identified using subgroup analysis and meta-regression. In patients with high-risk cutaneous melanoma, IFN-alpha adjuvant treatment showed statistically significant improvement in both DFS and OS.

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.

A systematic review and meta-analysis of factors that relate to aggression perpetrated against nurses by patients/relatives or staff.

PubMed

Edward, Karen-leigh; Stephenson, John; Ousey, Karen; Lui, Steve; Warelow, Philip; Giandinoto, Jo-Ann

2016-02-01

The aim of this meta-analysis was to identify the factors that related to aggression (verbal abuse or physical abuse/assault) perpetrated against the nurse or other health professionals by patients/relatives or staff. In the light of the paucity of systematic reviews on this common issue in nursing, the objective was to present a comprehensive systematic review and meta-analysis of these papers. Aggression towards nurses is common around the world and can be the impetus for nurses leaving the profession or developing anxiety when working in particular settings. Systematic review with meta-analysis. Meta-analyses were conducted to assess the effect of the factors of gender and context (dichotomised as mental health/psychiatric or nonmental health/psychiatric). The databases of Medline (1966-2015), CINAHL (1982-2015) and PsychInfo (1920-2015). A total of 1571 papers were screened by two reviewers. At the final decision 14 were selected for analysis. A higher proportion of female nurses than male nurses were reported to be the victims of verbal abuse, with the difference in proportions being statistically significant. A statistically significant higher proportion of male nurses than female nurses were reported to be the victims of physical abuse. There was a significantly higher proportion of mental health nurses reported experiencing physical abuse as compared to nonmental health nurses. The analysis reveal female nurses have greater odds of verbal abuse than male nurses and male nurses have greater odds of physical abuse than female nurses. Overall mental health nurses had three times higher odds of physical assault than other nurses. In the light of the findings it is recommended organisational support improve in high aggression potential clinical areas and for nursing curriculums to incorporate education about the management of challenging behaviours in undergraduate programmes. © 2015 John Wiley & Sons Ltd.

The Effectiveness of Computer-Assisted Instruction to Teach Physical Examination to Students and Trainees in the Health Sciences Professions: A Systematic Review and Meta-Analysis.

PubMed

Tomesko, Jennifer; Touger-Decker, Riva; Dreker, Margaret; Zelig, Rena; Parrott, James Scott

2017-01-01

To explore knowledge and skill acquisition outcomes related to learning physical examination (PE) through computer-assisted instruction (CAI) compared with a face-to-face (F2F) approach. A systematic literature review and meta-analysis published between January 2001 and December 2016 was conducted. Databases searched included Medline, Cochrane, CINAHL, ERIC, Ebsco, Scopus, and Web of Science. Studies were synthesized by study design, intervention, and outcomes. Statistical analyses included DerSimonian-Laird random-effects model. In total, 7 studies were included in the review, and 5 in the meta-analysis. There were no statistically significant differences for knowledge (mean difference [MD] = 5.39, 95% confidence interval [CI]: -2.05 to 12.84) or skill acquisition (MD = 0.35, 95% CI: -5.30 to 6.01). The evidence does not suggest a strong consistent preference for either CAI or F2F instruction to teach students/trainees PE. Further research is needed to identify conditions which examine knowledge and skill acquisition outcomes that favor one mode of instruction over the other.

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers

PubMed Central

Chang, Ellen T.; Delzell, Elizabeth

2016-01-01

ABSTRACT This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0–1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0–1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7–1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6–1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC. PMID:27015139

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers.

PubMed

Chang, Ellen T; Delzell, Elizabeth

2016-01-01

This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0-1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0-1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7-1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6-1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.

Combination of pharmacotherapy and psychotherapy in the treatment of chronic depression: A systematic review and meta-analysis

PubMed Central

2012-01-01

Background Chronic depression represents a substantial portion of depressive disorders and is associated with severe consequences. This review examined whether the combination of pharmacological treatments and psychotherapy is associated with higher effectiveness than pharmacotherapy alone via meta-analysis; and identified possible treatment effect modifiers via meta-regression-analysis. Methods A systematic search was conducted in the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, ISI Web of Science, BIOSIS, PsycINFO, and CINAHL. Primary efficacy outcome was a response to treatment; primary acceptance outcome was dropping out of the study. Only randomized controlled trials were considered. Results We identified 8 studies with a total of 9 relevant comparisons. Our analysis revealed small, but statistically not significant effects of combined therapies on outcomes directly related to depression (BR = 1.20) with substantial heterogeneity between studies (I² = 67%). Three treatment effect modifiers were identified: target disorders, the type of psychotherapy and the type of pharmacotherapy. Small but statistically significant effects of combined therapies on quality of life (SMD = 0.18) were revealed. No differences in acceptance rates and the long-term effects between combined treatments and pure pharmacological interventions were observed. Conclusions This systematic review could not provide clear evidence for the combination of pharmacotherapy and psychotherapy. However, due to the small amount of primary studies further research is needed for a conclusive decision. PMID:22694751

Inactive Hepatitis B Carrier and Pregnancy Outcomes: A Systematic Review and Meta-analysis.

PubMed

Keramat, Afsaneh; Younesian, Masud; Gholami Fesharaki, Mohammad; Hasani, Maryam; Mirzaei, Samaneh; Ebrahimi, Elham; Alavian, Seyed Moaed; Mohammadi, Fatemeh

2017-04-01

We aimed to explore whether maternal asymptomatic hepatitis B (HB) infection effects on pre-term rupture of membranous (PROM), stillbirth, preeclampsia, eclampsia, gestational hypertension, or antepartum hemorrhage. We searched the PubMed, Scopus, and ISI web of science from 1990 to Feb 2015. In addition, electronic literature searches supplemented by searching the gray literature (e.g., conference abstracts thesis and the result of technical reports) and scanning the reference lists of included studies and relevant systematic reviews. We explored statistical heterogeneity using the, I2 and tau-squared (Tau2) statistical tests. Eighteen studies were included. Preterm rupture of membranous (PROM), stillbirth, preeclampsia, eclampsia, gestational hypertension and antepartum hemorrhage were considerable outcomes in this survey. The results showed no significant association between inactive HB and these complications in pregnancy. The small amounts of P -value and chi-square and large amount of I2 suggested the probable heterogeneity in this part, which we tried to modify with statistical methods such as subgroup analysis. Inactive HB infection did not increase the risk of adversely mentioned outcomes in this study. Further, well-designed studies should be performed to confirm the results.

Educational games in geriatric medicine education: a systematic review

PubMed Central

2010-01-01

Objective To systematically review the medical literature to assess the effect of geriatric educational games on the satisfaction, knowledge, beliefs, attitudes and behaviors of health care professionals. Methods We conducted a systematic review following the Cochrane Collaboration methodology including an electronic search of 10 electronic databases. We included randomized controlled trials (RCT) and controlled clinical trials (CCT) and excluded single arm studies. Population of interests included members (practitioners or students) of the health care professions. Outcomes of interests were participants' satisfaction, knowledge, beliefs, attitude, and behaviors. Results We included 8 studies evaluating 5 geriatric role playing games, all conducted in United States. All studies suffered from one or more methodological limitations but the overall quality of evidence was acceptable. None of the studies assessed the effects of the games on beliefs or behaviors. None of the 8 studies reported a statistically significant difference between the 2 groups in terms of change in attitude. One study assessed the impact on knowledge and found non-statistically significant difference between the 2 groups. Two studies found levels of satisfaction among participants to be high. We did not conduct a planned meta-analysis because the included studies either reported no statistical data or reported different summary statistics. Conclusion The available evidence does not support the use of role playing interventions in geriatric medical education with the aim of improving the attitudes towards the elderly. PMID:20416055

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.

Primary prevention of dental erosion by calcium and fluoride: a systematic review.

PubMed

Zini, A; Krivoroutski, Y; Vered, Y

2014-02-01

Overviews of the current literature only provide summaries of existing relevant preventive strategies for dental erosion. To perform a systematic review according to the quantitative meta-analysis method of the scientific literature on prevention of dental erosion. The focused question will address primary prevention of dental erosion by calcium and fluoride. Randomized clinical trials (RCTs) regarding dental erosion prevention. The search included five databases: Embase, Cochrane database of systematic reviews, PubMed (MEDLINE), FDA publication and Berman medical library of the Hebrew University. The search included data in the English language, with effect on preventing dental erosion always presented as mean enamel loss and measured by profilometer. Statistical meta-analysis was performed by StatsDirect program and PEPI statistical software. Fixed- and random-effect models were used to analyse the data. Heterogeneity tests were employed to validate the fixed-effect model assumption. A total of 475 articles on dental erosion prevention were located. A four-stage selection process was employed, and 10 RCT articles were found to be suitable for meta-analysis. The number of studies on prevention of dental erosion maintaining standards of evidence-based dentistry remains insufficient to reach any definite conclusions. The focused questions of this review cannot be addressed according to the existing literature. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Systematic Review of Clinical Functional Outcomes After Medial Stabilized Versus Non-Medial Stabilized Total Knee Joint Replacement

PubMed Central

Young, Tony; Dowsey, Michelle M.; Pandy, Marcus; Choong, Peter F.

2018-01-01

Background Medial stabilized total knee joint replacement (TKJR) construct is designed to closely replicate the kinematics of the knee. Little is known regarding comparison of clinical functional outcomes of patients utilising validated patient reported outcome measures (PROM) after medial stabilized TKJR and other construct designs. Purpose To perform a systematic review of the available literature related to the assessment of clinical functional outcomes following a TKJR employing a medial stabilized construct design. Methods The review was performed with a Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) algorithm. The literature search was performed using variouscombinations of keywords. The statistical analysis was completed using Review Manager (RevMan), Version 5.3. Results In the nineteen unique studies identified, there were 2,448 medial stabilized TKJRs implanted in 2,195 participants, there were 1,777 TKJRs with non-medial stabilized design constructs implanted in 1,734 subjects. The final mean Knee Society Score (KSS) value in the medial stabilized group was 89.92 compared to 90.76 in the non-medial stabilized group, with the final KSS mean value difference between the two groups was statistically significant and favored the non-medial stabilized group (SMD 0.21; 95% CI: 0.01 to 0.41; p = 004). The mean difference in the final WOMAC values between the two groups was also statistically significant and favored the medial stabilized group (SMD: −0.27; 95% CI: −0.47 to −0.07; p = 0.009). Moderate to high values (I2) of heterogeneity were observed during the statistical comparison of these functional outcomes. Conclusion Based on the small number of studies with appropriate statistical analysis, we are unable to reach a clear conclusion in the clinical performance of medial stabilized knee replacement construct. Level of Evidence Level II PMID:29696144

A Systematic Review of Clinical Functional Outcomes After Medial Stabilized Versus Non-Medial Stabilized Total Knee Joint Replacement.

PubMed

Young, Tony; Dowsey, Michelle M; Pandy, Marcus; Choong, Peter F

2018-01-01

Medial stabilized total knee joint replacement (TKJR) construct is designed to closely replicate the kinematics of the knee. Little is known regarding comparison of clinical functional outcomes of patients utilising validated patient reported outcome measures (PROM) after medial stabilized TKJR and other construct designs. To perform a systematic review of the available literature related to the assessment of clinical functional outcomes following a TKJR employing a medial stabilized construct design. The review was performed with a Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) algorithm. The literature search was performed using variouscombinations of keywords. The statistical analysis was completed using Review Manager (RevMan), Version 5.3. In the nineteen unique studies identified, there were 2,448 medial stabilized TKJRs implanted in 2,195 participants, there were 1,777 TKJRs with non-medial stabilized design constructs implanted in 1,734 subjects. The final mean Knee Society Score (KSS) value in the medial stabilized group was 89.92 compared to 90.76 in the non-medial stabilized group, with the final KSS mean value difference between the two groups was statistically significant and favored the non-medial stabilized group (SMD 0.21; 95% CI: 0.01 to 0.41; p = 004). The mean difference in the final WOMAC values between the two groups was also statistically significant and favored the medial stabilized group (SMD: -0.27; 95% CI: -0.47 to -0.07; p = 0.009). Moderate to high values ( I 2 ) of heterogeneity were observed during the statistical comparison of these functional outcomes. Based on the small number of studies with appropriate statistical analysis, we are unable to reach a clear conclusion in the clinical performance of medial stabilized knee replacement construct. Level II.

ACCOUNTING FOR CALIBRATION UNCERTAINTIES IN X-RAY ANALYSIS: EFFECTIVE AREAS IN SPECTRAL FITTING

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

Lee, Hyunsook; Kashyap, Vinay L.; Drake, Jeremy J.

2011-04-20

While considerable advance has been made to account for statistical uncertainties in astronomical analyses, systematic instrumental uncertainties have been generally ignored. This can be crucial to a proper interpretation of analysis results because instrumental calibration uncertainty is a form of systematic uncertainty. Ignoring it can underestimate error bars and introduce bias into the fitted values of model parameters. Accounting for such uncertainties currently requires extensive case-specific simulations if using existing analysis packages. Here, we present general statistical methods that incorporate calibration uncertainties into spectral analysis of high-energy data. We first present a method based on multiple imputation that can bemore » applied with any fitting method, but is necessarily approximate. We then describe a more exact Bayesian approach that works in conjunction with a Markov chain Monte Carlo based fitting. We explore methods for improving computational efficiency, and in particular detail a method of summarizing calibration uncertainties with a principal component analysis of samples of plausible calibration files. This method is implemented using recently codified Chandra effective area uncertainties for low-resolution spectral analysis and is verified using both simulated and actual Chandra data. Our procedure for incorporating effective area uncertainty is easily generalized to other types of calibration uncertainties.« less

The Effect of Unequal Samples, Heterogeneity of Covariance Matrices, and Number of Variables on Discriminant Analysis Classification Tables and Related Statistics.

ERIC Educational Resources Information Center

Spearing, Debra; Woehlke, Paula

To assess the effect on discriminant analysis in terms of correct classification into two groups, the following parameters were systematically altered using Monte Carlo techniques: sample sizes; proportions of one group to the other; number of independent variables; and covariance matrices. The pairing of the off diagonals (or covariances) with…

Statistical strategy for anisotropic adventitia modelling in IVUS.

PubMed

Gil, Debora; Hernández, Aura; Rodriguez, Oriol; Mauri, Josepa; Radeva, Petia

2006-06-01

Vessel plaque assessment by analysis of intravascular ultrasound sequences is a useful tool for cardiac disease diagnosis and intervention. Manual detection of luminal (inner) and media-adventitia (external) vessel borders is the main activity of physicians in the process of lumen narrowing (plaque) quantification. Difficult definition of vessel border descriptors, as well as, shades, artifacts, and blurred signal response due to ultrasound physical properties trouble automated adventitia segmentation. In order to efficiently approach such a complex problem, we propose blending advanced anisotropic filtering operators and statistical classification techniques into a vessel border modelling strategy. Our systematic statistical analysis shows that the reported adventitia detection achieves an accuracy in the range of interobserver variability regardless of plaque nature, vessel geometry, and incomplete vessel borders.

Statistical trends of episiotomy around the world: Comparative systematic review of changing practices.

PubMed

Clesse, Christophe; Lighezzolo-Alnot, Joëlle; De Lavergne, Sylvie; Hamlin, Sandrine; Scheffler, Michèle

2018-06-01

The authors' purpose for this article is to identify, review and interpret all publications about the episiotomy rates worldwide. Based on the criteria from the PRISMA guidelines, twenty databases were scrutinized. All studies which include national statistics related to episiotomy were selected, as well as studies presenting estimated data. Sixty-one papers were selected with publication dates between 1995 and 2016. A static and dynamic analysis of all the results was carried out. The assumption for the decline in the number of episiotomies is discussed and confirmed, recalling that nowadays high rates of episiotomy remain in less industrialized countries and East Asia. Finally, our analysis aims to investigate the potential determinants which influence apparent statistical disparities.

The Content of Statistical Requirements for Authors in Biomedical Research Journals

PubMed Central

Liu, Tian-Yi; Cai, Si-Yu; Nie, Xiao-Lu; Lyu, Ya-Qi; Peng, Xiao-Xia; Feng, Guo-Shuang

2016-01-01

Background: Robust statistical designing, sound statistical analysis, and standardized presentation are important to enhance the quality and transparency of biomedical research. This systematic review was conducted to summarize the statistical reporting requirements introduced by biomedical research journals with an impact factor of 10 or above so that researchers are able to give statistical issues’ serious considerations not only at the stage of data analysis but also at the stage of methodological design. Methods: Detailed statistical instructions for authors were downloaded from the homepage of each of the included journals or obtained from the editors directly via email. Then, we described the types and numbers of statistical guidelines introduced by different press groups. Items of statistical reporting guideline as well as particular requirements were summarized in frequency, which were grouped into design, method of analysis, and presentation, respectively. Finally, updated statistical guidelines and particular requirements for improvement were summed up. Results: Totally, 21 of 23 press groups introduced at least one statistical guideline. More than half of press groups can update their statistical instruction for authors gradually relative to issues of new statistical reporting guidelines. In addition, 16 press groups, covering 44 journals, address particular statistical requirements. The most of the particular requirements focused on the performance of statistical analysis and transparency in statistical reporting, including “address issues relevant to research design, including participant flow diagram, eligibility criteria, and sample size estimation,” and “statistical methods and the reasons.” Conclusions: Statistical requirements for authors are becoming increasingly perfected. Statistical requirements for authors remind researchers that they should make sufficient consideration not only in regards to statistical methods during the research design, but also standardized statistical reporting, which would be beneficial in providing stronger evidence and making a greater critical appraisal of evidence more accessible. PMID:27748343

The Content of Statistical Requirements for Authors in Biomedical Research Journals.

PubMed

Liu, Tian-Yi; Cai, Si-Yu; Nie, Xiao-Lu; Lyu, Ya-Qi; Peng, Xiao-Xia; Feng, Guo-Shuang

2016-10-20

Robust statistical designing, sound statistical analysis, and standardized presentation are important to enhance the quality and transparency of biomedical research. This systematic review was conducted to summarize the statistical reporting requirements introduced by biomedical research journals with an impact factor of 10 or above so that researchers are able to give statistical issues' serious considerations not only at the stage of data analysis but also at the stage of methodological design. Detailed statistical instructions for authors were downloaded from the homepage of each of the included journals or obtained from the editors directly via email. Then, we described the types and numbers of statistical guidelines introduced by different press groups. Items of statistical reporting guideline as well as particular requirements were summarized in frequency, which were grouped into design, method of analysis, and presentation, respectively. Finally, updated statistical guidelines and particular requirements for improvement were summed up. Totally, 21 of 23 press groups introduced at least one statistical guideline. More than half of press groups can update their statistical instruction for authors gradually relative to issues of new statistical reporting guidelines. In addition, 16 press groups, covering 44 journals, address particular statistical requirements. The most of the particular requirements focused on the performance of statistical analysis and transparency in statistical reporting, including "address issues relevant to research design, including participant flow diagram, eligibility criteria, and sample size estimation," and "statistical methods and the reasons." Statistical requirements for authors are becoming increasingly perfected. Statistical requirements for authors remind researchers that they should make sufficient consideration not only in regards to statistical methods during the research design, but also standardized statistical reporting, which would be beneficial in providing stronger evidence and making a greater critical appraisal of evidence more accessible.

Reporting guidance considerations from a statistical perspective: overview of tools to enhance the rigour of reporting of randomised trials and systematic reviews.

PubMed

Hutton, Brian; Wolfe, Dianna; Moher, David; Shamseer, Larissa

2017-05-01

Research waste has received considerable attention from the biomedical community. One noteworthy contributor is incomplete reporting in research publications. When detailing statistical methods and results, ensuring analytic methods and findings are completely documented improves transparency. For publications describing randomised trials and systematic reviews, guidelines have been developed to facilitate complete reporting. This overview summarises aspects of statistical reporting in trials and systematic reviews of health interventions. A narrative approach to summarise features regarding statistical methods and findings from reporting guidelines for trials and reviews was taken. We aim to enhance familiarity of statistical details that should be reported in biomedical research among statisticians and their collaborators. We summarise statistical reporting considerations for trials and systematic reviews from guidance documents including the Consolidated Standards of Reporting Trials (CONSORT) Statement for reporting of trials, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) Statement for trial protocols, the Statistical Analyses and Methods in the Published Literature (SAMPL) Guidelines for statistical reporting principles, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement for systematic reviews and PRISMA for Protocols (PRISMA-P). Considerations regarding sharing of study data and statistical code are also addressed. Reporting guidelines provide researchers with minimum criteria for reporting. If followed, they can enhance research transparency and contribute improve quality of biomedical publications. Authors should employ these tools for planning and reporting of their research. 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 the menstrual cycle on voice quality.

PubMed

Silverman, E M; Zimmer, C H

1978-01-01

The question addressed was whether most young women with no vocal training exhibit premenstrual hoarseness. Spectral (acoustical) analyses of the sustained productions of three vowels produced by 20 undergraduates at and at premenstruation were rated for degree of hoarseness. Statistical analysis of the data indicated that the typical subject was no more hoarse of premenstruation than at ovulation. To determine whether this finding represented a genuine characteristic of women's voices or a type II statistical error, a systematic replication was undertaken with another sample of 27 undergraduates. The finding replicated that of the original investigation, suggesting that premenstrual hoarseness is a rarely occurring condition among young women with no vocal training. The apparent differential effect of the menstrual cycle on trained as opposed to untrained voices deserves systematic investigation.

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.

Meta-analysis is not an exact science: Call for guidance on quantitative synthesis decisions.

PubMed

Haddaway, Neal R; Rytwinski, Trina

2018-05-01

Meta-analysis is becoming increasingly popular in the field of ecology and environmental management. It increases the effective power of analyses relative to single studies, and allows researchers to investigate effect modifiers and sources of heterogeneity that could not be easily examined within single studies. Many systematic reviewers will set out to conduct a meta-analysis as part of their synthesis, but meta-analysis requires a niche set of skills that are not widely held by the environmental research community. Each step in the process of carrying out a meta-analysis requires decisions that have both scientific and statistical implications. Reviewers are likely to be faced with a plethora of decisions over which effect size to choose, how to calculate variances, and how to build statistical models. Some of these decisions may be simple based on appropriateness of the options. At other times, reviewers must choose between equally valid approaches given the information available to them. This presents a significant problem when reviewers are attempting to conduct a reliable synthesis, such as a systematic review, where subjectivity is minimised and all decisions are documented and justified transparently. We propose three urgent, necessary developments within the evidence synthesis community. Firstly, we call on quantitative synthesis experts to improve guidance on how to prepare data for quantitative synthesis, providing explicit detail to support systematic reviewers. Secondly, we call on journal editors and evidence synthesis coordinating bodies (e.g. CEE) to ensure that quantitative synthesis methods are adequately reported in a transparent and repeatable manner in published systematic reviews. Finally, where faced with two or more broadly equally valid alternative methods or actions, reviewers should conduct multiple analyses, presenting all options, and discussing the implications of the different analytical approaches. We believe it is vital to tackle the possible subjectivity in quantitative synthesis described herein to ensure that the extensive efforts expended in producing systematic reviews and other evidence synthesis products is not wasted because of a lack of rigour or reliability in the final synthesis step. Copyright © 2018 Elsevier Ltd. All rights reserved.

Methodological quality and reporting of systematic reviews in hand and wrist pathology.

PubMed

Wasiak, J; Shen, A Y; Ware, R; O'Donohoe, T J; Faggion, C M

2017-10-01

The objective of this study was to assess methodological and reporting quality of systematic reviews in hand and wrist pathology. MEDLINE, EMBASE and Cochrane Library were searched from inception to November 2016 for relevant studies. Reporting quality was evaluated using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and methodological quality using a measurement tool to assess systematic reviews, the Assessment of Multiple Systematic Reviews (AMSTAR). Descriptive statistics and linear regression were used to identify features associated with improved methodological quality. A total of 91 studies were included in the analysis. Most reviews inadequately reported PRISMA items regarding study protocol, search strategy and bias and AMSTAR items regarding protocol, publication bias and funding. Systematic reviews published in a plastics journal, or which included more authors, were associated with higher AMSTAR scores. A large proportion of systematic reviews within hand and wrist pathology literature score poorly with validated methodological assessment tools, which may affect the reliability of their conclusions. I.

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

Lee, Chien-Hsiu, E-mail: leech@naoj.org

Eclipsing binaries offer a unique opportunity to determine basic stellar properties. With the advent of wide-field camera and all-sky time-domain surveys, thousands of eclipsing binaries have been charted via light curve classification, yet their fundamental properties remain unexplored mainly due to the extensive efforts needed for spectroscopic follow-ups. In this paper, we present the discovery of a short-period ( P  = 0.313 day), double-lined M-dwarf eclipsing binary, CSSJ114804.3+255132/SDSSJ114804.35+255132.6, by cross-matching binary light curves from the Catalina Sky Survey and spectroscopically classified M dwarfs from the Sloan Digital Sky Survey. We obtain follow-up spectra using the Gemini telescope, enabling us to determinemore » the mass, radius, and temperature of the primary and secondary component to be M {sub 1} = 0.47 ± 0.03(statistic) ± 0.03(systematic) M {sub ⊙}, M {sub 2} = 0.46 ± 0.03(statistic) ± 0.03(systematic) M {sub ⊙}, R {sub 1} = 0.52 ± 0.08(statistic) ± 0.07(systematic) R {sub ⊙}, R {sub 2} =0.60 ± 0.08(statistic) ± 0.08(systematic) R {sub ⊙}, T {sub 1} = 3560 ± 100 K, and T {sub 2} = 3040 ± 100 K, respectively. The systematic error was estimated using the difference between eccentric and non-eccentric fits. Our analysis also indicates that there is definitively third-light contamination (66%) in the CSS photometry. The secondary star seems inflated, probably due to tidal locking of the close secondary companion, which is common for very short-period binary systems. Future spectroscopic observations with high resolution will narrow down the uncertainties of stellar parameters for both components, rendering this system as a benchmark for studying fundamental properties of M dwarfs.« less

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 Importance of Medical Students' Attitudes Regarding Cognitive Competence for Teaching Applied Statistics: Multi-Site Study and Meta-Analysis

PubMed Central

Milic, Natasa M.; Masic, Srdjan; Milin-Lazovic, Jelena; Trajkovic, Goran; Bukumiric, Zoran; Savic, Marko; Milic, Nikola V.; Cirkovic, Andja; Gajic, Milan; Kostic, Mirjana; Ilic, Aleksandra; Stanisavljevic, Dejana

2016-01-01

Background The scientific community increasingly is recognizing the need to bolster standards of data analysis given the widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. The aim of this study was to investigate students’ attitudes towards statistics within a multi-site medical educational context, monitor their changes and impact on student achievement. In addition, we performed a systematic review to better support our future pedagogical decisions in teaching applied statistics to medical students. Methods A validated Serbian Survey of Attitudes Towards Statistics (SATS-36) questionnaire was administered to medical students attending obligatory introductory courses in biostatistics from three medical universities in the Western Balkans. A systematic review of peer-reviewed publications was performed through searches of Scopus, Web of Science, Science Direct, Medline, and APA databases through 1994. A meta-analysis was performed for the correlation coefficients between SATS component scores and statistics achievement. Pooled estimates were calculated using random effects models. Results SATS-36 was completed by 461 medical students. Most of the students held positive attitudes towards statistics. Ability in mathematics and grade point average were associated in a multivariate regression model with the Cognitive Competence score, after adjusting for age, gender and computer ability. The results of 90 paired data showed that Affect, Cognitive Competence, and Effort scores demonstrated significant positive changes. The Cognitive Competence score showed the largest increase (M = 0.48, SD = 0.95). The positive correlation found between the Cognitive Competence score and students’ achievement (r = 0.41; p<0.001), was also shown in the meta-analysis (r = 0.37; 95% CI 0.32–0.41). Conclusion Students' subjective attitudes regarding Cognitive Competence at the beginning of the biostatistics course, which were directly linked to mathematical knowledge, affected their attitudes at the end of the course that, in turn, influenced students' performance. This indicates the importance of positively changing not only students’ cognitive competency, but also their perceptions of gained competency during the biostatistics course. PMID:27764123

The Importance of Medical Students' Attitudes Regarding Cognitive Competence for Teaching Applied Statistics: Multi-Site Study and Meta-Analysis.

PubMed

Milic, Natasa M; Masic, Srdjan; Milin-Lazovic, Jelena; Trajkovic, Goran; Bukumiric, Zoran; Savic, Marko; Milic, Nikola V; Cirkovic, Andja; Gajic, Milan; Kostic, Mirjana; Ilic, Aleksandra; Stanisavljevic, Dejana

2016-01-01

The scientific community increasingly is recognizing the need to bolster standards of data analysis given the widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. The aim of this study was to investigate students' attitudes towards statistics within a multi-site medical educational context, monitor their changes and impact on student achievement. In addition, we performed a systematic review to better support our future pedagogical decisions in teaching applied statistics to medical students. A validated Serbian Survey of Attitudes Towards Statistics (SATS-36) questionnaire was administered to medical students attending obligatory introductory courses in biostatistics from three medical universities in the Western Balkans. A systematic review of peer-reviewed publications was performed through searches of Scopus, Web of Science, Science Direct, Medline, and APA databases through 1994. A meta-analysis was performed for the correlation coefficients between SATS component scores and statistics achievement. Pooled estimates were calculated using random effects models. SATS-36 was completed by 461 medical students. Most of the students held positive attitudes towards statistics. Ability in mathematics and grade point average were associated in a multivariate regression model with the Cognitive Competence score, after adjusting for age, gender and computer ability. The results of 90 paired data showed that Affect, Cognitive Competence, and Effort scores demonstrated significant positive changes. The Cognitive Competence score showed the largest increase (M = 0.48, SD = 0.95). The positive correlation found between the Cognitive Competence score and students' achievement (r = 0.41; p<0.001), was also shown in the meta-analysis (r = 0.37; 95% CI 0.32-0.41). Students' subjective attitudes regarding Cognitive Competence at the beginning of the biostatistics course, which were directly linked to mathematical knowledge, affected their attitudes at the end of the course that, in turn, influenced students' performance. This indicates the importance of positively changing not only students' cognitive competency, but also their perceptions of gained competency during the biostatistics course.

A Statistical Analysis of Reviewer Agreement and Bias in Evaluating Medical Abstracts 1

PubMed Central

Cicchetti, Domenic V.; Conn, Harold O.

1976-01-01

Observer variability affects virtually all aspects of clinical medicine and investigation. One important aspect, not previously examined, is the selection of abstracts for presentation at national medical meetings. In the present study, 109 abstracts, submitted to the American Association for the Study of Liver Disease, were evaluated by three “blind” reviewers for originality, design-execution, importance, and overall scientific merit. Of the 77 abstracts rated for all parameters by all observers, interobserver agreement ranged between 81 and 88%. However, corresponding intraclass correlations varied between 0.16 (approaching statistical significance) and 0.37 (p < 0.01). Specific tests of systematic differences in scoring revealed statistically significant levels of observer bias on most of the abstract components. Moreover, the mean differences in interobserver ratings were quite small compared to the standard deviations of these differences. These results emphasize the importance of evaluating the simple percentage of rater agreement within the broader context of observer variability and systematic bias. PMID:997596

Treatment of Selective Mutism: A Best-Evidence Synthesis.

ERIC Educational Resources Information Center

Stone, Beth Pionek; Kratochwill, Thomas R.; Sladezcek, Ingrid; Serlin, Ronald C.

2002-01-01

Presents systematic analysis of the major treatment approaches used for selective mutism. Based on nonparametric statistical tests of effect sizes, major findings include the following: treatment of selective mutism is more effective than no treatment; behaviorally oriented treatment approaches are more effective than no treatment; and no…

Stress ulcer prophylaxis versus placebo or no prophylaxis in critically ill patients. A systematic review of randomised clinical trials with meta-analysis and trial sequential analysis.

PubMed

Krag, Mette; Perner, Anders; Wetterslev, Jørn; Wise, Matt P; Hylander Møller, Morten

2014-01-01

To assess the effects of stress ulcer prophylaxis (SUP) versus placebo or no prophylaxis on all-cause mortality, gastrointestinal (GI) bleeding and hospital-acquired pneumonia in adult critically ill patients in the intensive care unit (ICU). We performed a systematic review using meta-analysis and trial sequential analysis (TSA). Eligible trials were randomised clinical trials comparing proton pump inhibitors or histamine 2 receptor antagonists with either placebo or no prophylaxis. Two reviewers independently assessed studies for inclusion and extracted data. The Cochrane Collaboration methodology was used. Risk ratios/relative risks (RR) with 95% confidence intervals (CI) were estimated. The predefined outcome measures were all-cause mortality, GI bleeding, and hospital-acquired pneumonia. Twenty trials (n = 1,971) were included; all were judged as having a high risk of bias. There was no statistically significant difference in mortality (fixed effect: RR 1.00, 95% CI 0.84-1.20; P = 0.87; I(2) = 0%) or hospital-acquired pneumonia (random effects: RR 1.23, 95% CI 0.86-1.78; P = 0.28; I(2) = 19%) between SUP patients and the no prophylaxis/placebo patients. These findings were confirmed in the TSA. With respect to GI bleeding, a statistically significant difference was found in the conventional meta-analysis (random effects: RR 0.44, 95% CI 0.28-0.68; P = 0.01; I(2) = 48%); however, TSA (TSA adjusted 95% CI 0.18-1.11) and subgroup analyses could not confirm this finding. This systematic review using meta-analysis and TSA demonstrated that both the quality and the quantity of evidence supporting the use of SUP in adult ICU patients is low. Consequently, large randomised clinical trials are warranted.

Efficacy of workplace interventions for shoulder pain: A systematic review and meta-analysis.

PubMed

Lowry, Veronique; Desjardins-Charbonneau, Ariel; Roy, Jean-Sébastien; Dionne, Clermont E; Frémont, Pierre; MacDermid, Joy C; Desmeules, François

2017-07-07

To perform a systematic review and meta-analysis of randomized controlled trials on the efficacy of workplace-based interventions to prevent or treat shoulder pain. A systematic review of 4 databases was performed up to January 2016. Randomized controlled trials were included if the intervention under study was a workplace-based intervention performed to prevent or reduce shoulder pain and disability in workers. The methodological quality of the studies was evaluated and meta-analyses were conducted. Pooled mean differences and risk ratios were calculated. Data from 4 studies on strengthening exercises performed in the workplace for workers with shoulder pain (n = 368) were pooled. A statistically significant reduction in pain intensity was observed compared with different control interventions (mean differences (scale out of 10) 1.31 (95% confidence interval (95% CI) 0.86-1.76)). Pooled data from 5 studies on the efficacy of workstation modifications (n = 2,148) showed a statistically significant reduction in the prevalence of shoulder pain with a risk ratio of 1.88 (95% CI 1.20-2.96) compared with different control interventions. Low-grade evidence exists that a workplace exercise programme may reduce the intensity of shoulder pain, and that workstation modifications may reduce the prevalence of shoulder pain.

Is reiki or prayer effective in relieving pain during hospitalization for cesarean? A systematic review and meta-analysis of randomized controlled trials.

PubMed

Ferraz, Guilherme Augusto Rago; Rodrigues, Meline Rosseto Kron; Lima, Silvana Andrea Molina; Lima, Marcelo Aparecido Ferraz; Maia, Gabriela Lopes; Pilan, Carlos Alberto; Omodei, Michelle Sako; Molina, Ana Cláudia; El Dib, Regina; Rudge, Marilza Vieira Cunha

2017-01-01

This systematic review compared reiki and prayer with drug use for relieving pain during hospitalization for cesarean, given that the popularity of integrative medicine and spiritual healing has been increasing. It had the aim of evaluating whether reiki or prayer is effective in relieving pain during cesarean section. Systematic review with meta-analysis conducted at Botucatu Medical School, UNESP, São Paulo, Brazil. The following databases were searched up to March 2016: MEDLINE, Embase, LILACS and CENTRAL. Randomized controlled trials published in English or Portuguese were included in the review. Two reviewers independently screened eligible articles, extracted data and assessed the risk of bias. A GRADE table was produced to evaluate the risk of bias. There was evidence with a high risk of bias showing a statistically significant decrease in pain score through use of reiki and prayer, in relation to the protocol group: mean difference = -1.68; 95% confidence interval: -1.92 to -1.43; P < 0.00001; I2 = 92%. Furthermore, there was no statistically significant difference in heart rate or systolic or diastolic blood pressure. Evidence with a high risk of bias suggested that reiki and prayer meditation might be associated with pain reduction.

Therapeutic clowns in pediatrics: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Sridharan, Kannan; Sivaramakrishnan, Gowri

2016-10-01

Children and/or their parents are in fear and anxiety when admitted to hospitals or undergo invasive surgeries or investigations. Clown therapy has been shown as an effective measure in reducing this hospital fear and anxiety. Hence, we carried out a systematic compilation of the existing evidence on the clinical utility of hospital clowns in pediatric population. Electronic databases were searched with an appropriate search strategy, and only randomized controlled trials comparing the effect of clown therapy with standard care in children were included. The key outcome measures were as follows: extent of anxiety and pain felt by children and extent of state and trait parental anxiety. Random effect model was applied when moderate to severe heterogeneity was observed. Forest plot, I(2) statistics and risk of bias were evaluated using RevMan 5.3 software. A total of 19 studies were found eligible to be included in the systematic review and 16 for meta-analysis. The pooled SMD [95 % CI] for child anxiety score was -0.83 [-1.16, -0.51] favoring clown therapy. Similarly, a statistically significant reduction {SMD [95 % CI] -0.46 [-0.7, -0.21]} in the state anxiety was observed amongst parents. We found that hospital clowns play a significant role in reducing stress and anxiety levels in children admitted to hospitals as well as their parents. • Trials with clown doctors in pediatric population have shown conflicting results in allaying anxiety amongst children undergoing either hospitalization or invasive procedures What is new: • This is the first systematic review and meta-analysis on hospital clowns • We found out that hospital clowns reduce anxiety amongst children before undergoing either hospitalization or invasive procedures.

Observational difference between gamma and X-ray properties of optically dark and bright GRBs

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

Balazs, L. G.; Horvath, I.; Bagoly, Zs.

2008-05-22

Using the discriminant analysis of the multivariate statistical analysis we compared the distribution of the physical quantities of the optically dark and bright GRBs, detected by the BAT and XRT on board of the Swift Satellite. We found that the GRBs having detected optical transients (OT) have systematically higher peak fluxes and lower HI column densities than those without OT.

Review of the patient positioning reproducibility in head-and-neck radiotherapy using Statistical Process Control.

PubMed

Moore, Sarah J; Herst, Patries M; Louwe, Robert J W

2018-05-01

A remarkable improvement in patient positioning was observed after the implementation of various process changes aiming to increase the consistency of patient positioning throughout the radiotherapy treatment chain. However, no tool was available to describe these changes over time in a standardised way. This study reports on the feasibility of Statistical Process Control (SPC) to highlight changes in patient positioning accuracy and facilitate correlation of these changes with the underlying process changes. Metrics were designed to quantify the systematic and random patient deformation as input for the SPC charts. These metrics were based on data obtained from multiple local ROI matches for 191 patients who were treated for head-and-neck cancer during the period 2011-2016. SPC highlighted a significant improvement in patient positioning that coincided with multiple intentional process changes. The observed improvements could be described as a combination of a reduction in outliers and a systematic improvement in the patient positioning accuracy of all patients. SPC is able to track changes in the reproducibility of patient positioning in head-and-neck radiation oncology, and distinguish between systematic and random process changes. Identification of process changes underlying these trends requires additional statistical analysis and seems only possible when the changes do not overlap in time. Copyright © 2018 Elsevier B.V. All rights reserved.

ESL Student Bias in Instructional Evaluation.

ERIC Educational Resources Information Center

Wennerstrom, Ann K.; Heiser, Patty

1992-01-01

Reports on a statistical analysis of English-as-a-Second-Language (ESL) student evaluations of teachers in two large programs. Results indicated a systematic bias occurs in ESL student evaluations, raising issues of fairness in the use of student evaluations of ESL teachers for purposes of personnel decisions. (21 references) (GLR)

Aerosol climatology using a tunable spectral variability cloud screening of AERONET data

NASA Technical Reports Server (NTRS)

Kaufman, Yoram J.; Gobbi, Gian Paolo; Koren, Ilan

2005-01-01

Can cloud screening of an aerosol data set, affect the aerosol optical thickness (AOT) climatology? Aerosols, humidity and clouds are correlated. Therefore, rigorous cloud screening can systematically bias towards less cloudy conditions, underestimating the average AOT. Here, using AERONET data we show that systematic rejection of variable atmospheric optical conditions can generate such bias in the average AOT. Therefore we recommend (1) to introduce more powerful spectral variability cloud screening and (2) to change the philosophy behind present aerosol climatologies: Instead of systematically rejecting all cloud contaminations, we suggest to intentionally allow the presence of cloud contamination, estimate the statistical impact of the contamination and correct for it. The analysis, applied to 10 AERONET stations with approx. 4 years of data, shows almost no change for Rome (Italy), but up to a change in AOT of 0.12 in Beijing (PRC). Similar technique may be explored for satellite analysis, e.g. MODIS.

A meta-analysis of aneurysm formation in laser assisted vascular anastomosis (LAVA)

NASA Astrophysics Data System (ADS)

Chen, Chen; Peng, Fei; Xu, Dahai; Cheng, Qinghua

2009-08-01

Laser assisted vascular anastomosis (LAVA) is looked as a particularly promising non-suture method in future. However, aneurysm formation is one of the main reasons delay the clinical application of LAVA. Some scientists investigated the incidence of aneurysms in animal model. To systematically analyze the literature on reported incidence of aneurysm formation in LAVA therapy, we performed a meta-analysis comparing LAVA with conventional suture anastomosis (CSA) in animal model. Data were systematically retrieved and selected from PUBMED. In total, 23 studies were retrieved. 18 studies were excluded, and 5 studies involving 647 animals were included. Analysis suggested no statistically significant difference between LAVA and CSA (OR 1.24, 95%CI 0.66-2.32, P=0.51). Result of meta analysis shows that the technology of LAVA is very close to clinical application.

Estimation of trends

NASA Technical Reports Server (NTRS)

1981-01-01

The application of statistical methods to recorded ozone measurements. The effects of a long term depletion of ozone at magnitudes predicted by the NAS is harmful to most forms of life. Empirical prewhitening filters the derivation of which is independent of the underlying physical mechanisms were analyzed. Statistical analysis performs a checks and balances effort. Time series filters variations into systematic and random parts, errors are uncorrelated, and significant phase lag dependencies are identified. The use of time series modeling to enhance the capability of detecting trends is discussed.

Outcomes Definitions and Statistical Tests in Oncology Studies: A Systematic Review of the Reporting Consistency.

PubMed

Rivoirard, Romain; Duplay, Vianney; Oriol, Mathieu; Tinquaut, Fabien; Chauvin, Franck; Magne, Nicolas; Bourmaud, Aurelie

2016-01-01

Quality of reporting for Randomized Clinical Trials (RCTs) in oncology was analyzed in several systematic reviews, but, in this setting, there is paucity of data for the outcomes definitions and consistency of reporting for statistical tests in RCTs and Observational Studies (OBS). The objective of this review was to describe those two reporting aspects, for OBS and RCTs in oncology. From a list of 19 medical journals, three were retained for analysis, after a random selection: British Medical Journal (BMJ), Annals of Oncology (AoO) and British Journal of Cancer (BJC). All original articles published between March 2009 and March 2014 were screened. Only studies whose main outcome was accompanied by a corresponding statistical test were included in the analysis. Studies based on censored data were excluded. Primary outcome was to assess quality of reporting for description of primary outcome measure in RCTs and of variables of interest in OBS. A logistic regression was performed to identify covariates of studies potentially associated with concordance of tests between Methods and Results parts. 826 studies were included in the review, and 698 were OBS. Variables were described in Methods section for all OBS studies and primary endpoint was clearly detailed in Methods section for 109 RCTs (85.2%). 295 OBS (42.2%) and 43 RCTs (33.6%) had perfect agreement for reported statistical test between Methods and Results parts. In multivariable analysis, variable "number of included patients in study" was associated with test consistency: aOR (adjusted Odds Ratio) for third group compared to first group was equal to: aOR Grp3 = 0.52 [0.31-0.89] (P value = 0.009). Variables in OBS and primary endpoint in RCTs are reported and described with a high frequency. However, statistical tests consistency between methods and Results sections of OBS is not always noted. Therefore, we encourage authors and peer reviewers to verify consistency of statistical tests in oncology studies.

Outcomes Definitions and Statistical Tests in Oncology Studies: A Systematic Review of the Reporting Consistency

PubMed Central

Rivoirard, Romain; Duplay, Vianney; Oriol, Mathieu; Tinquaut, Fabien; Chauvin, Franck; Magne, Nicolas; Bourmaud, Aurelie

2016-01-01

Background Quality of reporting for Randomized Clinical Trials (RCTs) in oncology was analyzed in several systematic reviews, but, in this setting, there is paucity of data for the outcomes definitions and consistency of reporting for statistical tests in RCTs and Observational Studies (OBS). The objective of this review was to describe those two reporting aspects, for OBS and RCTs in oncology. Methods From a list of 19 medical journals, three were retained for analysis, after a random selection: British Medical Journal (BMJ), Annals of Oncology (AoO) and British Journal of Cancer (BJC). All original articles published between March 2009 and March 2014 were screened. Only studies whose main outcome was accompanied by a corresponding statistical test were included in the analysis. Studies based on censored data were excluded. Primary outcome was to assess quality of reporting for description of primary outcome measure in RCTs and of variables of interest in OBS. A logistic regression was performed to identify covariates of studies potentially associated with concordance of tests between Methods and Results parts. Results 826 studies were included in the review, and 698 were OBS. Variables were described in Methods section for all OBS studies and primary endpoint was clearly detailed in Methods section for 109 RCTs (85.2%). 295 OBS (42.2%) and 43 RCTs (33.6%) had perfect agreement for reported statistical test between Methods and Results parts. In multivariable analysis, variable "number of included patients in study" was associated with test consistency: aOR (adjusted Odds Ratio) for third group compared to first group was equal to: aOR Grp3 = 0.52 [0.31–0.89] (P value = 0.009). Conclusion Variables in OBS and primary endpoint in RCTs are reported and described with a high frequency. However, statistical tests consistency between methods and Results sections of OBS is not always noted. Therefore, we encourage authors and peer reviewers to verify consistency of statistical tests in oncology studies. PMID:27716793

Faith-adapted psychological therapies for depression and anxiety: Systematic review and meta-analysis.

PubMed

Anderson, Naomi; Heywood-Everett, Suzanne; Siddiqi, Najma; Wright, Judy; Meredith, Jodi; McMillan, Dean

2015-05-01

Incorporating faith (religious or spiritual) perspectives into psychological treatments has attracted significant interest in recent years. However, previous suggestion that good psychiatric care should include spiritual components has provoked controversy. To try to address ongoing uncertainty in this field we present a systematic review and meta-analysis to assess the efficacy of faith-based adaptations of bona fide psychological therapies for depression or anxiety. A systematic review and meta-analysis of randomised controlled trials were performed. The literature search yielded 2274 citations of which 16 studies were eligible for inclusion. All studies used cognitive or cognitive behavioural models as the basis for their faith-adapted treatment (F-CBT). We identified statistically significant benefits of using F-CBT. However, quality assessment using the Cochrane risk of bias tool revealed methodological limitations that reduce the apparent strength of these findings. Whilst the effect sizes identified here were statistically significant, there were relatively a few relevant RCTs available, and those included were typically small and susceptible to significant biases. Biases associated with researcher or therapist allegiance were identified as a particular concern. Despite some suggestion that faith-adapted CBT may out-perform both standard CBT and control conditions (waiting list or "treatment as usual"), the effect sizes identified in this meta-analysis must be considered in the light of the substantial methodological limitations that affect the primary research data. Before firm recommendations about the value of faith-adapted treatments can be made, further large-scale, rigorously performed trials are required. Copyright © 2015 Elsevier B.V. All rights reserved.

QUALITY OF LIFE IN CHILDREN WITH HEARING IMPAIRMENT: SYSTEMATIC REVIEW AND META-ANALYSIS

PubMed Central

Roland, Lauren; Fischer, Caroline; Tran, Kayla; Rachakonda, Tara; Kallogjeri, Dorina; Lieu, Judith

2017-01-01

Objective To determine the impact of pediatric hearing loss on quality of life (QOL). Data Sources A qualified medical librarian conducted a literature search for relevant publications that evaluate QOL in school-aged children with hearing loss (HL). Review Methods Studies were assessed independently by two reviewers for inclusion in the systematic review and meta-analysis. Results From 979 abstracts, 69 were identified as relevant; ultimately 41 articles were included in the systematic review. This review revealed that children with HL generally report a lower QOL than their normal hearing peers, and QOL improves after interventions. The extent of these differences is variable among studies, and depends on the QOL measure. Four studies using the Pediatric Quality of Life Inventory (PedsQL) had sufficient data for inclusion in a meta-analysis. After pooling studies, statistically and clinically significant differences in PedsQL scores were found between children with normal hearing and those with HL, specifically in the Social and School domains. Statistically significant differences were also noted in in total scores for children with unilateral HL and in the physical domain for children with bilateral HL as compared to normal hearing, however these differences were not clinically meaningful. Conclusions Our analysis reveals that decreased QOL in children with HL is detected in distinct domains of the PedsQL questionnaire. These domains of school functioning and social interactions are especially important for development and learning. Future work should focus on these specific aspects of QOL when assessing HL in the pediatric population. PMID:27118820

Concurrent chemo-radiotherapy with S-1 as an alternative therapy for elderly Chinese patients with non-metastatic esophageal squamous cancer: evidence based on a systematic review and meta-analysis.

PubMed

Song, Guo-Min; Tian, Xu; Liu, Xiao-Ling; Chen, Hui; Zhou, Jian-Guo; Bian, Wei; Chen, Wei-Qing

2017-06-06

This systematic review and meta-analysis aims to systematically assess the effects of concurrent chemo-radiotherapy (CRT) compared with radiotherapy (RT) alone for elderly Chinese patients with non-metastatic esophageal squamous cancer. We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), China Biomedical Literature Database (CBM), and China National Knowledge Infrastructure (CNKI) databases. We retrieved randomized controlled trials on concurrent CRT with Gimeraciland Oteracil Porassium (S-1) compared with RT alone for aged Chinese patients with non-metastatic esophageal squamous cancer performed until August 2016. Eight eligible studies involving 536 patients were subjected to meta-analysis. As a response rate measure, a relative risk (RR) of 1.37 [95% confidence intervals (CIs): 1.24, 1.53; P = 0.00], which reached statistical significance, was estimated when concurrent CRT with S-1 was performed compared with RT alone. Sensitivity analysis on response rate confirmed the robustness of the pooled result. The RR values of 1.44 (95% CIs: 1.22, 1.70; P = 0.00) and 1.77 (95% CIs: 1.26, 2.48; P = 0.00) estimated for 1- and 2-year survival rate indices, respectively, were also statistically significant. The incidence of adverse events was similar in both groups. This review concluded that concurrent CRT with S-1 can improve the efficacy and prolong the survival period of elderly Chinese patients with non-metastatic esophageal squamous cancer and does not significantly increase the acute adverse effects of RT alone.

Effect of Graft Thickness on Visual Acuity After Descemet Stripping Endothelial Keratoplasty: A Systematic Review and Meta-Analysis.

PubMed

Wacker, Katrin; Bourne, William M; Patel, Sanjay V

2016-03-01

To assess the relationship between graft thickness and best-corrected visual acuity (BCVA) after Descemet stripping endothelial keratoplasty (DSEK). Systematic review and meta-analysis. PubMed, EMBASE, Web of Science, and conference abstracts were searched for studies published up to October 2015 with standard systematic review methodology. Eligibility criteria included studies evaluating graft thickness in primary DSEK and visual outcomes. There were no restrictions to study design, study population, or language. Correlation coefficients were pooled using random-effects models. Of 480 articles and conference abstracts, 31 met inclusion criteria (2214 eyes) after full-text review. Twenty-three studies assessed correlations between BCVA and graft thickness, and 8 studies used different statistical methods. All associations were reported dimensionless. Studies generally had small sample sizes and were heterogeneous, especially with respect to data and analysis quality (P = .02). Most studies did not measure BCVA in a standardized manner. The pooled correlation coefficient for graft thickness vs BCVA was 0.20 (95% CI, 0.14-0.26) for 17 studies without data concerns; this did not include 7 studies (815 eyes) that used different statistical methods and did not find significant associations. There is insufficient evidence that graft thickness is clinically important with respect to BCVA after DSEK, with meta-analysis suggesting a weak relationship. Although well-designed longitudinal studies with standardized measurements of visual acuity and graft thickness are necessary to better characterize this relationship, current evidence suggests that graft thickness is not important for surgical planning. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of historical information in extreme storm surges frequency analysis

NASA Astrophysics Data System (ADS)

Hamdi, Yasser; Duluc, Claire-Marie; Deville, Yves; Bardet, Lise; Rebour, Vincent

2013-04-01

The prevention of storm surge flood risks is critical for protection and design of coastal facilities to very low probabilities of failure. The effective protection requires the use of a statistical analysis approach having a solid theoretical motivation. Relating extreme storm surges to their frequency of occurrence using probability distributions has been a common issue since 1950s. The engineer needs to determine the storm surge of a given return period, i.e., the storm surge quantile or design storm surge. Traditional methods for determining such a quantile have been generally based on data from the systematic record alone. However, the statistical extrapolation, to estimate storm surges corresponding to high return periods, is seriously contaminated by sampling and model uncertainty if data are available for a relatively limited period. This has motivated the development of approaches to enlarge the sample extreme values beyond the systematic period. The nonsystematic data occurred before the systematic period is called historical information. During the last three decades, the value of using historical information as a nonsystematic data in frequency analysis has been recognized by several authors. The basic hypothesis in statistical modeling of historical information is that a perception threshold exists and that during a giving historical period preceding the period of tide gauging, all exceedances of this threshold have been recorded. Historical information prior to the systematic records may arise from high-sea water marks left by extreme surges on the coastal areas. It can also be retrieved from archives, old books, earliest newspapers, damage reports, unpublished written records and interviews with local residents. A plotting position formula, to compute empirical probabilities based on systematic and historical data, is used in this communication paper. The objective of the present work is to examine the potential gain in estimation accuracy with the use of historical information (to the Brest tide gauge located in the French Atlantic coast). In addition, the present work contributes to addressing the problem of the presence of outliers in data sets. Historical data are generally imprecise, and their inaccuracy should be properly accounted for in the analysis. However, as several authors believe, even with substantial uncertainty in the data, the use of historical information is a viable mean to improve estimates of rare events related to extreme environmental conditions. The preliminary results of this study suggest that the use of historical information increases the representativity of an outlier in the systematic data. It is also shown that the use of historical information, specifically the perception sea water level, can be considered as a reliable solution for the optimal planning and design of facilities to withstand extreme environmental conditions, which will occur during its lifetime, with an appropriate optimum of risk level. Findings are of practical relevance for applications in storm surge risk analysis and flood management.

A systematic review of the quality of statistical methods employed for analysing quality of life data in cancer randomised controlled trials.

PubMed

Hamel, Jean-Francois; Saulnier, Patrick; Pe, Madeline; Zikos, Efstathios; Musoro, Jammbe; Coens, Corneel; Bottomley, Andrew

2017-09-01

Over the last decades, Health-related Quality of Life (HRQoL) end-points have become an important outcome of the randomised controlled trials (RCTs). HRQoL methodology in RCTs has improved following international consensus recommendations. However, no international recommendations exist concerning the statistical analysis of such data. The aim of our study was to identify and characterise the quality of the statistical methods commonly used for analysing HRQoL data in cancer RCTs. Building on our recently published systematic review, we analysed a total of 33 published RCTs studying the HRQoL methods reported in RCTs since 1991. We focussed on the ability of the methods to deal with the three major problems commonly encountered when analysing HRQoL data: their multidimensional and longitudinal structure and the commonly high rate of missing data. All studies reported HRQoL being assessed repeatedly over time for a period ranging from 2 to 36 months. Missing data were common, with compliance rates ranging from 45% to 90%. From the 33 studies considered, 12 different statistical methods were identified. Twenty-nine studies analysed each of the questionnaire sub-dimensions without type I error adjustment. Thirteen studies repeated the HRQoL analysis at each assessment time again without type I error adjustment. Only 8 studies used methods suitable for repeated measurements. Our findings show a lack of consistency in statistical methods for analysing HRQoL data. Problems related to multiple comparisons were rarely considered leading to a high risk of false positive results. It is therefore critical that international recommendations for improving such statistical practices are developed. Copyright © 2017. Published by Elsevier Ltd.

Stability of tapered and parallel-walled dental implants: A systematic review and meta-analysis.

PubMed

Atieh, Momen A; Alsabeeha, Nabeel; Duncan, Warwick J

2018-05-15

Clinical trials have suggested that dental implants with a tapered configuration have improved stability at placement, allowing immediate placement and/or loading. The aim of this systematic review and meta-analysis was to evaluate the implant stability of tapered dental implants compared to standard parallel-walled dental implants. Applying the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, randomized controlled trials (RCTs) were searched for in electronic databases and complemented by hand searching. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool and data were analyzed using statistical software. A total of 1199 studies were identified, of which, five trials were included with 336 dental implants in 303 participants. Overall meta-analysis showed that tapered dental implants had higher implant stability values than parallel-walled dental implants at insertion and 8 weeks but the difference was not statistically significant. Tapered dental implants had significantly less marginal bone loss compared to parallel-walled dental implants. No significant differences in implant failure rate were found between tapered and parallel-walled dental implants. There is limited evidence to demonstrate the effectiveness of tapered dental implants in achieving greater implant stability compared to parallel-walled dental implants. Superior short-term results in maintaining peri-implant marginal bone with tapered dental implants are possible. Further properly designed RCTs are required to endorse the supposed advantages of tapered dental implants in immediate loading protocol and other complex clinical scenarios. © 2018 Wiley Periodicals, Inc.

Adverse effects of lingual and buccal orthodontic techniques: A systematic review and meta-analysis.

PubMed

Ata-Ali, Fadi; Ata-Ali, Javier; Ferrer-Molina, Marcela; Cobo, Teresa; De Carlos, Felix; Cobo, Juan

2016-06-01

The aim of this systematic review was to assess the prevalence of adverse effects associated with lingual and buccal fixed orthodontic techniques. Two authors searched the PubMed, EMBASE, Cochrane Library, and LILACS databases up to October 2014. Agreement between the authors was quantified by the Cohen kappa statistic. The following variables were analyzed: pain, caries, eating and speech difficulties, and oral hygiene. The Newcastle-Ottawa scale was used to assess risk of bias in nonrandomized studies, and the Cochrane Collaboration's tool for assessing risk of bias was used for randomized controlled trials. Eight articles were included in this systematic review. Meta-analysis showed a statistically greater risk of pain of the tongue (odds ratio [OR], 28.32; 95% confidence interval [95% CI], 8.60-93.28; P <0.001), cheeks (OR, 0.087; 95% CI, 0.036-0.213; P <0.0010), and lips (OR, 0.13; 95% CI, 0.04-0.39; P <0.001), as well as for the variables of speech difficulties (OR, 9.39; 95% CI, 3.78-23.33; P <0.001) and oral hygiene (OR, 3.49; 95% CI, 1.02-11.95; P = 0.047) with lingual orthodontics. However, no statistical difference was found with respect to eating difficulties (OR, 3.74; 95% CI, 0.86-16.28; P = 0.079) and caries (OR, 1.15; 95% CI, 0.17-7.69; P = 0.814 [Streptococcus mutans] and OR, 0.67; 95% CI, 0.20-2.23; P = 0.515 [Lactobacillus]). This systematic review suggests that patients wearing lingual appliances have more pain, speech difficulties, and problems in maintaining adequate oral hygiene, although no differences for eating and caries risk were identified. Further prospective studies involving larger sample sizes and longer follow-up periods are needed to confirm these results. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Co-administration of furosemide with albumin for overcoming diuretic resistance in patients with hypoalbuminemia: a meta-analysis.

PubMed

Kitsios, Georgios D; Mascari, Paolo; Ettunsi, Riad; Gray, Anthony W

2014-04-01

To systematically review clinical studies of co-administration of albumin and loop diuretics in hypoalbuminemic patients as a strategy to overcome diuretic resistance. Systematic search of electronic databases up to October 2012. We included randomized clinical trials of adults with hypoalbuminemia, comparing co-administration of loop diuretics and albumin versus loop diuretics alone. Quantitative data were synthesized with meta-analytic techniques for clinical, surrogate (urinary volume and urinary sodium excretion) and intermediate (pharmacokinetic and hemodynamic parameters) outcomes. Ten studies were included, of which 8 trials with crossover design were synthesized with meta-analysis. A statistically significant increase in the amount of urine volume (increment of 231 mL [95% confidence interval 135.5-326.5]) and sodium excreted (15.9 mEq [4.9-26.8]) at 8 hours were found in favor of co-administration of albumin and furosemide. These differences were no longer statistically significant at 24 hours. Meta-analyses for intermediate outcomes (ie, furosemide excretion, distribution volume etc.) did not reveal statistically significant differences. Synthesis of a heterogeneous body of evidence shows transient effects of modest clinical significance for co-administration of albumin with furosemide in hypoalbuminemic patients. Pragmatic, large-scale randomized studies are needed to delineate the role of this strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

Methodological quality of behavioural weight loss studies: a systematic review

PubMed Central

Lemon, S. C.; Wang, M. L.; Haughton, C. F.; Estabrook, D. P.; Frisard, C. F.; Pagoto, S. L.

2018-01-01

Summary This systematic review assessed the methodological quality of behavioural weight loss intervention studies conducted among adults and associations between quality and statistically significant weight loss outcome, strength of intervention effectiveness and sample size. Searches for trials published between January, 2009 and December, 2014 were conducted using PUBMED, MEDLINE and PSYCINFO and identified ninety studies. Methodological quality indicators included study design, anthropometric measurement approach, sample size calculations, intent-to-treat (ITT) analysis, loss to follow-up rate, missing data strategy, sampling strategy, report of treatment receipt and report of intervention fidelity (mean = 6.3). Indicators most commonly utilized included randomized design (100%), objectively measured anthropometrics (96.7%), ITT analysis (86.7%) and reporting treatment adherence (76.7%). Most studies (62.2%) had a follow-up rate >75% and reported a loss to follow-up analytic strategy or minimal missing data (69.9%). Describing intervention fidelity (34.4%) and sampling from a known population (41.1%) were least common. Methodological quality was not associated with reporting a statistically significant result, effect size or sample size. This review found the published literature of behavioural weight loss trials to be of high quality for specific indicators, including study design and measurement. Identified for improvement include utilization of more rigorous statistical approaches to loss to follow up and better fidelity reporting. PMID:27071775

[Long-term use of mobile phone and its association with glioma: a systematic review and meta-analysis].

PubMed

Gong, Xiu; Wu, Jinsong; Mao, Ying; Zhou, Liangfu

2014-10-28

The hypothesis that "cell phone induces brain tumor" has become a target of much controversy for several decades and is still a matter of debate even now. We aim to make a systematic review and meta-analysis based on published studies on glioma to identify current evidences for evaluating mobile phones and glioma risk, especially on long-term use of mobile phones. The study was conducted according to the Cochrane systematic review methods and reported according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement according to a prospective research protocol accessed via http://www.crd.york.ac.uk/prospero. The software RevMan 5 was used for statistic analysis. Latency and lateralization were used for the examining the dose-response relationship. Overall evidence suggested the increased risk of glioma among long-term ipsilateral users of mobile phone with an odds ratio (OR) of 1.46[1.12, 1.92] based on meta-analysis. Especially, for low-grade glioma, long-term use yielded an OR value of 2.27 [1.81, 2.85]. The evidence is currently insufficient on this issue, especially on long-term use of mobile phone. Neither a definite answer nor a clear explanation may be offered for the relationship. And larger prospective trials are warranted.

Effects of lifestyle change interventions for people with intellectual disabilities: Systematic review and meta-analysis of randomized controlled trials.

PubMed

Willems, Mariël; Waninge, Aly; Hilgenkamp, Thessa I M; van Empelen, Pepijn; Krijnen, Wim P; van der Schans, Cees P; Melville, Craig A

2018-05-08

Promotion of a healthy lifestyle for people with intellectual disabilities is important; however, the effectiveness of lifestyle change interventions is unclear. This research will examine the effectiveness of lifestyle change interventions for people with intellectual disabilities. Randomized controlled trials (RCTs) of lifestyle change interventions for people with intellectual disabilities were included in a systematic review and meta-analysis. Data on study and intervention characteristics were extracted, as well as data on outcome measures and results. Internal validity of the selected papers was assessed using the Cochrane Collaboration's risk bias tool. Eight RCTs were included. Multiple outcome measures were used, whereby outcome measures targeting environmental factors and participation were lacking and personal outcome measures were mostly used by a single study. Risks of bias were found for all studies. Meta-analysis showed some effectiveness for lifestyle change interventions, and a statistically significant decrease was found for waist circumference. Some effectiveness was found for lifestyle change interventions for people with intellectual disabilities. However, the effects were only statistically significant for waist circumference, so current lifestyle change interventions may not be optimally tailored to meet the needs of people with intellectual disabilities. © 2018 John Wiley & Sons Ltd.

The Effectiveness of Computer-Assisted Instruction to Teach Physical Examination to Students and Trainees in the Health Sciences Professions: A Systematic Review and Meta-Analysis

PubMed Central

Tomesko, Jennifer; Touger-Decker, Riva; Dreker, Margaret; Zelig, Rena; Parrott, James Scott

2017-01-01

Purpose: To explore knowledge and skill acquisition outcomes related to learning physical examination (PE) through computer-assisted instruction (CAI) compared with a face-to-face (F2F) approach. Method: A systematic literature review and meta-analysis published between January 2001 and December 2016 was conducted. Databases searched included Medline, Cochrane, CINAHL, ERIC, Ebsco, Scopus, and Web of Science. Studies were synthesized by study design, intervention, and outcomes. Statistical analyses included DerSimonian-Laird random-effects model. Results: In total, 7 studies were included in the review, and 5 in the meta-analysis. There were no statistically significant differences for knowledge (mean difference [MD] = 5.39, 95% confidence interval [CI]: −2.05 to 12.84) or skill acquisition (MD = 0.35, 95% CI: −5.30 to 6.01). Conclusions: The evidence does not suggest a strong consistent preference for either CAI or F2F instruction to teach students/trainees PE. Further research is needed to identify conditions which examine knowledge and skill acquisition outcomes that favor one mode of instruction over the other. PMID:29349338

Statistical analysis and handling of missing data in cluster randomized trials: a systematic review.

PubMed

Fiero, Mallorie H; Huang, Shuang; Oren, Eyal; Bell, Melanie L

2016-02-09

Cluster randomized trials (CRTs) randomize participants in groups, rather than as individuals and are key tools used to assess interventions in health research where treatment contamination is likely or if individual randomization is not feasible. Two potential major pitfalls exist regarding CRTs, namely handling missing data and not accounting for clustering in the primary analysis. The aim of this review was to evaluate approaches for handling missing data and statistical analysis with respect to the primary outcome in CRTs. We systematically searched for CRTs published between August 2013 and July 2014 using PubMed, Web of Science, and PsycINFO. For each trial, two independent reviewers assessed the extent of the missing data and method(s) used for handling missing data in the primary and sensitivity analyses. We evaluated the primary analysis and determined whether it was at the cluster or individual level. Of the 86 included CRTs, 80 (93%) trials reported some missing outcome data. Of those reporting missing data, the median percent of individuals with a missing outcome was 19% (range 0.5 to 90%). The most common way to handle missing data in the primary analysis was complete case analysis (44, 55%), whereas 18 (22%) used mixed models, six (8%) used single imputation, four (5%) used unweighted generalized estimating equations, and two (2%) used multiple imputation. Fourteen (16%) trials reported a sensitivity analysis for missing data, but most assumed the same missing data mechanism as in the primary analysis. Overall, 67 (78%) trials accounted for clustering in the primary analysis. High rates of missing outcome data are present in the majority of CRTs, yet handling missing data in practice remains suboptimal. Researchers and applied statisticians should carry out appropriate missing data methods, which are valid under plausible assumptions in order to increase statistical power in trials and reduce the possibility of bias. Sensitivity analysis should be performed, with weakened assumptions regarding the missing data mechanism to explore the robustness of results reported in the primary analysis.

Method for factor analysis of GC/MS data

DOEpatents

Van Benthem, Mark H; Kotula, Paul G; Keenan, Michael R

2012-09-11

The method of the present invention provides a fast, robust, and automated multivariate statistical analysis of gas chromatography/mass spectroscopy (GC/MS) data sets. The method can involve systematic elimination of undesired, saturated peak masses to yield data that follow a linear, additive model. The cleaned data can then be subjected to a combination of PCA and orthogonal factor rotation followed by refinement with MCR-ALS to yield highly interpretable results.

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/.

Prevalence of nephropathy in type 1 diabetes in the Arab world: A systematic review and meta-analysis.

PubMed

Abdel-Motal, Ussama M; G, Akila; Abdelalim, Essam M; Ponnuraja, Chinnaiyan; Iken, Khadija; Jahromi, Mohamed; Doss, George Priya; El Bekay, Rajaa; Zayed, Hatem

2018-05-17

The aim of this study was to conduct a systematic review and meta-analysis and determine the prevalence of diabetic nephropathy (DN) among Arab patients with T1D. A systematic literature search was conducted using 4 different literature databases (PubMed, ScienceDirect, Web of Science, and Embase) to capture all relevant data about Arab patients with T1D that had DN. Meta-analysis and systematic review were performed using the random effect model, and the heterogeneity of the studies was assessed using the Q-test, I2, and Tau-squared statistics. Publication bias was assessed using the funnel-plot test. Our search strategy captured 372 studies in only 10 out of the 22 Arab countries in a period of 48 years (1969-2017); of which, 41 met our inclusion criteria for full article analysis, of those, 15 were eligible for meta-analysis. We estimated the prevalence of DN among Arab people with T1D to be 18.2% (95% confidence interval 13.1%-24.8%). In conclusion, DN prevalence is underexplored among Arab patients with T1D and represents a significant risk for the well-being of Arab patients with T1D. Therefore, there is an urgent need for comprehensive epidemiological studies for DN among Arab patients with T1D. Copyright © 2018 John Wiley & Sons, Ltd.

Primer on statistical interpretation or methods report card on propensity-score matching in the cardiology literature from 2004 to 2006: a systematic review.

PubMed

Austin, Peter C

2008-09-01

Propensity-score matching is frequently used in the cardiology literature. Recent systematic reviews have found that this method is, in general, poorly implemented in the medical literature. The study objective was to examine the quality of the implementation of propensity-score matching in the general cardiology literature. A total of 44 articles published in the American Heart Journal, the American Journal of Cardiology, Circulation, the European Heart Journal, Heart, the International Journal of Cardiology, and the Journal of the American College of Cardiology between January 1, 2004, and December 31, 2006, were examined. Twenty of the 44 studies did not provide adequate information on how the propensity-score-matched pairs were formed. Fourteen studies did not report whether matching on the propensity score balanced baseline characteristics between treated and untreated subjects in the matched sample. Only 4 studies explicitly used statistical methods appropriate for matched studies to compare baseline characteristics between treated and untreated subjects. Only 11 (25%) of the 44 studies explicitly used statistical methods appropriate for the analysis of matched data when estimating the effect of treatment on the outcomes. Only 2 studies described the matching method used, assessed balance in baseline covariates by appropriate methods, and used appropriate statistical methods to estimate the treatment effect and its significance. Application of propensity-score matching was poor in the cardiology literature. Suggestions for improving the reporting and analysis of studies that use propensity-score matching are provided.

Impact of searching clinical trial registries in systematic reviews of pharmaceutical treatments: methodological systematic review and reanalysis of meta-analyses.

PubMed

Baudard, Marie; Yavchitz, Amélie; Ravaud, Philippe; Perrodeau, Elodie; Boutron, Isabelle

2017-02-17

Objective  To evaluate the impact of searching clinical trial registries in systematic reviews. Design  Methodological systematic review and reanalyses of meta-analyses. Data sources  Medline was searched to identify systematic reviews of randomised controlled trials (RCTs) assessing pharmaceutical treatments published between June 2014 and January 2015. For all systematic reviews that did not report a trial registry search but reported the information to perform it, the World Health Organization International Trials Registry Platform (WHO ICTRP search portal) was searched for completed or terminated RCTs not originally included in the systematic review. Data extraction  For each systematic review, two researchers independently extracted the outcomes analysed, the number of patients included, and the treatment effect estimated. For each RCT identified, two researchers independently determined whether the results were available (ie, posted, published, or available on the sponsor website) and extracted the data. When additional data were retrieved, we reanalysed meta-analyses and calculated the weight of the additional RCTs and the change in summary statistics by comparison with the original meta-analysis. Results  Among 223 selected systematic reviews, 116 (52%) did not report a search of trial registries; 21 of these did not report the information to perform the search (key words, search date). A search was performed for 95 systematic reviews; for 54 (57%), no additional RCTs were found and for 41 (43%) 122 additional RCTs were identified. The search allowed for increasing the number of patients by more than 10% in 19 systematic reviews, 20% in 10, 30% in seven, and 50% in four. Moreover, 63 RCTs had results available; the results for 45 could be included in a meta-analysis. 14 systematic reviews including 45 RCTs were reanalysed. The weight of the additional RCTs in the recalculated meta-analyses ranged from 0% to 58% and was greater than 10% in five of 14 systematic reviews, 20% in three, and 50% in one. The change in summary statistics ranged from 0% to 29% and was greater than 10% for five of 14 systematic reviews and greater than 20% for two. However, none of the changes to summary effect estimates led to a qualitative change in the interpretation of the results once the new trials were added. Conclusions  Trial registries are an important source for identifying additional RCTs. The additional number of RCTs and patients included if a search were performed varied across systematic reviews. 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.

How Effective are Mindfulness-Based Interventions for Reducing Stress Among Healthcare Professionals? A Systematic Review and Meta-Analysis.

PubMed

Burton, Amy; Burgess, Catherine; Dean, Sarah; Koutsopoulou, Gina Z; Hugh-Jones, Siobhan

2017-02-01

Workplace stress is high among healthcare professionals (HCPs) and is associated with reduced psychological health, quality of care and patient satisfaction. This systematic review and meta-analysis reviews evidence on the effectiveness of mindfulness-based interventions (MBIs) for reducing stress in HCPs. A systematic literature search was conducted. Papers were screened for suitability using inclusion criteria and nine papers were subjected to review and quality assessment. Seven papers, for which full statistical findings could be obtained, were also subjected to meta-analysis. Results of the meta-analysis suggest that MBIs have the potential to significantly improve stress among HCPs; however, there was evidence of a file drawer problem. The quality of the studies was high in relation to the clarity of aims, data collection and analysis, but weaker in terms of sample size and the use of theoretical frameworks. MBIs have the potential to reduce stress among HCPs; however, more high-quality research is needed before this finding can be confirmed. Future studies would benefit from long-term follow-up measures to determine any continuing effects of mindfulness training on stress outcomes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Which are the most useful scales for predicting repeat self-harm? A systematic review evaluating risk scales using measures of diagnostic accuracy

PubMed Central

Quinlivan, L; Cooper, J; Davies, L; Hawton, K; Gunnell, D; Kapur, N

2016-01-01

Objectives The aims of this review were to calculate the diagnostic accuracy statistics of risk scales following self-harm and consider which might be the most useful scales in clinical practice. Design Systematic review. Methods We based our search terms on those used in the systematic reviews carried out for the National Institute for Health and Care Excellence self-harm guidelines (2012) and evidence update (2013), and updated the searches through to February 2015 (CINAHL, EMBASE, MEDLINE, and PsychINFO). Methodological quality was assessed and three reviewers extracted data independently. We limited our analysis to cohort studies in adults using the outcome of repeat self-harm or attempted suicide. We calculated diagnostic accuracy statistics including measures of global accuracy. Statistical pooling was not possible due to heterogeneity. Results The eight papers included in the final analysis varied widely according to methodological quality and the content of scales employed. Overall, sensitivity of scales ranged from 6% (95% CI 5% to 6%) to 97% (CI 95% 94% to 98%). The positive predictive value (PPV) ranged from 5% (95% CI 3% to 9%) to 84% (95% CI 80% to 87%). The diagnostic OR ranged from 1.01 (95% CI 0.434 to 2.5) to 16.3 (95%CI 12.5 to 21.4). Scales with high sensitivity tended to have low PPVs. Conclusions It is difficult to be certain which, if any, are the most useful scales for self-harm risk assessment. No scales perform sufficiently well so as to be recommended for routine clinical use. Further robust prospective studies are warranted to evaluate risk scales following an episode of self-harm. Diagnostic accuracy statistics should be considered in relation to the specific service needs, and scales should only be used as an adjunct to assessment. PMID:26873046

Effectiveness of aquatic exercise and balneotherapy: a summary of systematic reviews based on randomized controlled trials of water immersion therapies.

PubMed

Kamioka, Hiroharu; Tsutani, Kiichiro; Okuizumi, Hiroyasu; Mutoh, Yoshiteru; Ohta, Miho; Handa, Shuichi; Okada, Shinpei; Kitayuguchi, Jun; Kamada, Masamitsu; Shiozawa, Nobuyoshi; Honda, Takuya

2010-01-01

The objective of this review was to summarize findings on aquatic exercise and balneotherapy and to assess the quality of systematic reviews based on randomized controlled trials. Studies were eligible if they were systematic reviews based on randomized clinical trials (with or without a meta-analysis) that included at least 1 treatment group that received aquatic exercise or balneotherapy. We searched the following databases: Cochrane Database Systematic Review, MEDLINE, CINAHL, Web of Science, JDream II, and Ichushi-Web for articles published from the year 1990 to August 17, 2008. We found evidence that aquatic exercise had small but statistically significant effects on pain relief and related outcome measures of locomotor diseases (eg, arthritis, rheumatoid diseases, and low back pain). However, long-term effectiveness was unclear. Because evidence was lacking due to the poor methodological quality of balneotherapy studies, we were unable to make any conclusions on the effects of intervention. There were frequent flaws regarding the description of excluded RCTs and the assessment of publication bias in several trials. Two of the present authors independently assessed the quality of articles using the AMSTAR checklist. Aquatic exercise had a small but statistically significant short-term effect on locomotor diseases. However, the effectiveness of balneotherapy in curing disease or improving health remains unclear.

Systematic review of learning curves for minimally invasive abdominal surgery: a review of the methodology of data collection, depiction of outcomes, and statistical analysis.

PubMed

Harrysson, Iliana J; Cook, Jonathan; Sirimanna, Pramudith; Feldman, Liane S; Darzi, Ara; Aggarwal, Rajesh

2014-07-01

To determine how minimally invasive surgical learning curves are assessed and define an ideal framework for this assessment. Learning curves have implications for training and adoption of new procedures and devices. In 2000, a review of the learning curve literature was done by Ramsay et al and it called for improved reporting and statistical evaluation of learning curves. Since then, a body of literature is emerging on learning curves but the presentation and analysis vary. A systematic search was performed of MEDLINE, EMBASE, ISI Web of Science, ERIC, and the Cochrane Library from 1985 to August 2012. The inclusion criteria are minimally invasive abdominal surgery formally analyzing the learning curve and English language. 592 (11.1%) of the identified studies met the selection criteria. Time is the most commonly used proxy for the learning curve (508, 86%). Intraoperative outcomes were used in 316 (53%) of the articles, postoperative outcomes in 306 (52%), technical skills in 102 (17%), and patient-oriented outcomes in 38 (6%) articles. Over time, there was evidence of an increase in the relative amount of laparoscopic and robotic studies (P < 0.001) without statistical evidence of a change in the complexity of analysis (P = 0.121). Assessment of learning curves is needed to inform surgical training and evaluate new clinical procedures. An ideal analysis would account for the degree of complexity of individual cases and the inherent differences between surgeons. There is no single proxy that best represents the success of surgery, and hence multiple outcomes should be collected.

Methodology to assess clinical liver safety data.

PubMed

Merz, Michael; Lee, Kwan R; Kullak-Ublick, Gerd A; Brueckner, Andreas; Watkins, Paul B

2014-11-01

Analysis of liver safety data has to be multivariate by nature and needs to take into account time dependency of observations. Current standard tools for liver safety assessment such as summary tables, individual data listings, and narratives address these requirements to a limited extent only. Using graphics in the context of a systematic workflow including predefined graph templates is a valuable addition to standard instruments, helping to ensure completeness of evaluation, and supporting both hypothesis generation and testing. Employing graphical workflows interactively allows analysis in a team-based setting and facilitates identification of the most suitable graphics for publishing and regulatory reporting. Another important tool is statistical outlier detection, accounting for the fact that for assessment of Drug-Induced Liver Injury, identification and thorough evaluation of extreme values has much more relevance than measures of central tendency in the data. Taken together, systematical graphical data exploration and statistical outlier detection may have the potential to significantly improve assessment and interpretation of clinical liver safety data. A workshop was convened to discuss best practices for the assessment of drug-induced liver injury (DILI) in clinical trials.

esATAC: An Easy-to-use Systematic pipeline for ATAC-seq data analysis.

PubMed

Wei, Zheng; Zhang, Wei; Fang, Huan; Li, Yanda; Wang, Xiaowo

2018-03-07

ATAC-seq is rapidly emerging as one of the major experimental approaches to probe chromatin accessibility genome-wide. Here, we present "esATAC", a highly integrated easy-to-use R/Bioconductor package, for systematic ATAC-seq data analysis. It covers essential steps for full analyzing procedure, including raw data processing, quality control and downstream statistical analysis such as peak calling, enrichment analysis and transcription factor footprinting. esATAC supports one command line execution for preset pipelines, and provides flexible interfaces for building customized pipelines. esATAC package is open source under the GPL-3.0 license. It is implemented in R and C ++. Source code and binaries for Linux, MAC OS X and Windows are available through Bioconductor https://www.bioconductor.org/packages/release/bioc/html/esATAC.html). xwwang@tsinghua.edu.cn. Supplementary data are available at Bioinformatics online.

Longitudinal analysis of reporting and quality of systematic reviews in high-impact surgical journals.

PubMed

Chapman, S J; Drake, T M; Bolton, W S; Barnard, J; Bhangu, A

2017-02-01

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement aims to optimize the reporting of systematic reviews. The performance of the PRISMA Statement in improving the reporting and quality of surgical systematic reviews remains unclear. Systematic reviews published in five high-impact surgical journals between 2007 and 2015 were identified from online archives. Manuscripts blinded to journal, publication year and authorship were assessed according to 27 reporting criteria described by the PRISMA Statement and scored using a validated quality appraisal tool (AMSTAR, Assessing the Methodological Quality of Systematic Reviews). Comparisons were made between studies published before (2007-2009) and after (2011-2015) its introduction. The relationship between reporting and study quality was measured using Spearman's rank test. Of 281 eligible manuscripts, 80 were published before the PRISMA Statement and 201 afterwards. Most manuscripts (208) included a meta-analysis, with the remainder comprising a systematic review only. There was no meaningful change in median compliance with the PRISMA Statement (19 (i.q.r. 16-21) of 27 items before versus 19 (17-22) of 27 after introduction of PRISMA) despite achieving statistical significance (P = 0·042). Better reporting compliance was associated with higher methodological quality (r s  = 0·70, P < 0·001). The PRISMA Statement has had minimal impact on the reporting of surgical systematic reviews. Better compliance was associated with higher-quality methodology. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

The Efficacy of Guanxinning Injection in Treating Angina Pectoris: Systematic Review and Meta-Analysis of Randomized Controlled Trials

PubMed Central

Jia, Yongliang; Leung, Siu-wai; Lee, Ming-Yuen; Cui, Guozhen; Huang, Xiaohui; Pan, Fongha

2013-01-01

Objective. The randomized controlled trials (RCTs) on Guanxinning injection (GXN) in treating angina pectoris were published only in Chinese and have not been systematically reviewed. This study aims to provide a PRISMA-compliant and internationally accessible systematic review to evaluate the efficacy of GXN in treating angina pectoris. Methods. The RCTs were included according to prespecified eligibility criteria. Meta-analysis was performed to evaluate the symptomatic (SYMPTOMS) and electrocardiographic (ECG) improvements after treatment. Odds ratios (ORs) were used to measure effect sizes. Subgroup analysis, sensitivity analysis, and metaregression were conducted to evaluate the robustness of the results. Results. Sixty-five RCTs published between 2002 and 2012 with 6064 participants were included. Overall ORs comparing GXN with other drugs were 3.32 (95% CI: [2.72, 4.04]) in SYMPTOMS and 2.59 (95% CI: [2.14, 3.15]) in ECG. Subgroup analysis, sensitivity analysis, and metaregression found no statistically significant dependence of overall ORs upon specific study characteristics. Conclusion. This meta-analysis of eligible RCTs provides evidence that GXN is effective in treating angina pectoris. This evidence warrants further RCTs of higher quality, longer follow-up periods, larger sample sizes, and multicentres/multicountries for more extensive subgroup, sensitivity, and metaregression analyses. PMID:23634167

The Effectiveness of Corticosteroid Injection for De Quervain's Stenosing Tenosynovitis (DQST): A Systematic Review and Meta-Analysis.

PubMed

Rowland, Patrick; Phelan, Nigel; Gardiner, Sean; Linton, Kenneth N; Galvin, Rose

2015-01-01

De Quervain's stenosing tenosynovitis (DQST) treatments include corticosteroid injection around the tendon sheath; however there is some ambiguity concerning the efficacy of this treatment. The aim of this systematic review and meta-analysis is to examine the totality of evidence relating to the use of corticosteroid injection in DQST when compared to placebo or other active treatments. A systematic literature search was conducted in July 2014. Only randomized control trials (RCTs) were included. Outcome measures included impairment, activity limitation and participation restriction. Five RCTs were identified with 165 patients, 88 in the treatment group and 77 in the control group.Patients who received corticosteroid injection (n=142) had a higher rate of resolution of symptoms [RR 2.59, 95% CI: 1.25 to 5.37, p=0.05, I2=62%]. This group reported greater pain relief as assessed by Visual Analogue Scale (VAS) at first assessment [mean difference -2.51, 95% CI: -3.11 to -1.90, p=0.0003, I2=65%] and demonstrated a statistically significant improvement in function (n=78) as measured by the DASH score and Dutch AIMS-HFF score [SMD -0.83, 95% CI: -1.54 to -0.12, p=0.02, I2=48]. This review confirms that corticosteroid injection results in a statistically significant increase in resolution of symptoms, pain relief and increased function in the treatment of DQST.

Global 3ν oscillation analysis: Status of unknown parameters and future systematic challenges for ORCA and PINGU

NASA Astrophysics Data System (ADS)

Capozzi, Francesco; Lisi, Eligio; Marrone, Antonio

2016-04-01

Within the standard 3ν oscillation framework, we illustrate the status of currently unknown oscillation parameters: the θ23 octant, the mass hierarchy (normal or inverted), and the possible CP-violating phase δ, as derived by a (preliminary) global analysis of oscillation data available in 2015. We then discuss some challenges that will be faced by future, high-statistics analyses of spectral data, starting with one-dimensional energy spectra in reactor experiments, and concluding with two-dimensional energy-angle spectra in large-volume atmospheric experiments. It is shown that systematic uncertainties in the spectral shapes can noticeably affect the prospective sensitivities to unknown oscillation parameters, in particular to the mass hierarchy.

Clinical periodontal variables in patients with and without dementia-a systematic review and meta-analysis.

PubMed

Maldonado, Alejandra; Laugisch, Oliver; Bürgin, Walter; Sculean, Anton; Eick, Sigrun

2018-06-22

Considering the increasing number of elderly people, dementia has gained an important role in today's society. Although the contributing factors for dementia have not been fully understood, chronic periodontitis (CP) seems to have a possible link to dementia. To conduct a systematic review including meta-analysis in order to assess potential differences in clinical periodontal variables between patients with dementia and non-demented individuals. The following focused question was evaluated: is periodontitis associated with dementia? Electronic searches in two databases, MEDLINE and EMBASE, were conducted. Meta-analysis was performed with the collected data in order to find a statistically significant difference in clinical periodontal variables between the group of dementia and the cognitive normal controls. Forty-two articles remained for full text reading. Finally, seven articles met the inclusion criteria and only five studies provided data suitable for meta-analysis. Periodontal probing depth (PPD), bleeding on probing (BOP), gingival bleeding index (GBI), clinical attachment level (CAL), and plaque index (PI) were included as periodontal variables in the meta-analysis. Each variable revealed a statistically significant difference between the groups. In an attempt to reveal an overall difference between the periodontal variables in dementia patients and non-demented individuals, the chosen variables were transformed into units that resulted in a statistically significant overall difference (p < 0.00001). The current findings indicate that compared to systemically healthy individuals, demented patients show significantly worse clinical periodontal variables. However, further epidemiological studies including a high numbers of participants, the use of exact definitions both for dementia and chronic periodontitis and adjusted for cofounders is warranted. These findings appear to support the putative link between CP and dementia. Consequently, the need for periodontal screening and treatment of elderly demented people should be emphasized.

Markov model plus k-word distributions: a synergy that produces novel statistical measures for sequence comparison.

PubMed

Dai, Qi; Yang, Yanchun; Wang, Tianming

2008-10-15

Many proposed statistical measures can efficiently compare biological sequences to further infer their structures, functions and evolutionary information. They are related in spirit because all the ideas for sequence comparison try to use the information on the k-word distributions, Markov model or both. Motivated by adding k-word distributions to Markov model directly, we investigated two novel statistical measures for sequence comparison, called wre.k.r and S2.k.r. The proposed measures were tested by similarity search, evaluation on functionally related regulatory sequences and phylogenetic analysis. This offers the systematic and quantitative experimental assessment of our measures. Moreover, we compared our achievements with these based on alignment or alignment-free. We grouped our experiments into two sets. The first one, performed via ROC (receiver operating curve) analysis, aims at assessing the intrinsic ability of our statistical measures to search for similar sequences from a database and discriminate functionally related regulatory sequences from unrelated sequences. The second one aims at assessing how well our statistical measure is used for phylogenetic analysis. The experimental assessment demonstrates that our similarity measures intending to incorporate k-word distributions into Markov model are more efficient.

A blinded determination of H0 from low-redshift Type Ia supernovae, calibrated by Cepheid variables

NASA Astrophysics Data System (ADS)

Zhang, Bonnie R.; Childress, Michael J.; Davis, Tamara M.; Karpenka, Natallia V.; Lidman, Chris; Schmidt, Brian P.; Smith, Mathew

2017-10-01

Presently, a >3σ tension exists between values of the Hubble constant H0 derived from analysis of fluctuations in the cosmic microwave background by Planck, and local measurements of the expansion using calibrators of Type Ia supernovae (SNe Ia). We perform a blinded re-analysis of Riess et al. (2011) to measure H0 from low-redshift SNe Ia, calibrated by Cepheid variables and geometric distances including to NGC 4258. This paper is a demonstration of techniques to be applied to the Riess et al. (2016) data. Our end-to-end analysis starts from available Harvard -Smithsonian Center for Astrophysics (CfA3) and Lick Observatory Supernova Search (LOSS) photometries, providing an independent validation of Riess et al. (2011). We obscure the value of H0 throughout our analysis and the first stage of the referee process, because calibration of SNe Ia requires a series of often subtle choices, and the potential for results to be affected by human bias is significant. Our analysis departs from that of Riess et al. (2011) by incorporating the covariance matrix method adopted in Supernova Legacy Survey and Joint Lightcurve Analysis to quantify SN Ia systematics, and by including a simultaneous fit of all SN Ia and Cepheid data. We find H_0 = 72.5 ± 3.1 ({stat}) ± 0.77 ({sys}) km s-1 Mpc-1with a three-galaxy (NGC 4258+LMC+MW) anchor. The relative uncertainties are 4.3 per cent statistical, 1.1 per cent systematic, and 4.4 per cent total, larger than in Riess et al. (2011) (3.3 per cent total) and the Efstathiou (2014) re-analysis (3.4 per cent total). Our error budget for H0 is dominated by statistical errors due to the small size of the SN sample, whilst the systematic contribution is dominated by variation in the Cepheid fits, and for the SNe Ia, uncertainties in the host galaxy mass dependence and Malmquist bias.

Metabolic changes after licorice consumption: A systematic review with meta-analysis and trial sequential analysis of clinical trials.

PubMed

Luís, Ângelo; Domingues, Fernanda; Pereira, Luísa

2018-01-15

Licorice, also known as liquorice, refers to the root of Glycyrrhiza glabra L., a product widely available in the market in the form of licorice flavonoid oil (LFO), which is a concentrate of licorice flavonoids, being a dietary ingredient for functional foods with potential benefits for overweight subjects. To summarize the results of the numerous clinical trials, and to clarify the metabolic changes after licorice consumption, through a systematic review with meta-analysis and Trial Sequential Analysis (TSA) of clinical trials. This review was designed according to the PRISMA (Preferred Reported Items for Systematic Reviews and Meta-Analysis) recommendations. Several electronic databases were searched to identify the clinical trials. A meta-analysis approach was then developed to statistically analyze the results, followed by TSA and meta-regression analyses. A total 26 clinical trials were considered for the quantitative synthesis of the data, totalizing 985 patients enrolled. Overall, it was possible to verify that the licorice consumption significantly reduces the body weight (WMD: -0.433 kg; 95% CI: -0.683 to -0.183; p-value = 0.001) and consequently the body mass index (BMI) of patients (WMD: -0.150 kg/m 2 ; 95% CI: -0.241 to -0.058; p-value = 0.001). Another result with statistical significance was the increase in the diastolic blood pressure (DBP) (1.737 mmHg; 95% CI: 0.835 to 2.621; p-value < 0.0001) observed for the group subjected to licorice consumption, which is related to the hypernatremia also caused by licorice. The present meta-analysis demonstrated the positive effects of licorice consumption on the reduction of body weight and BMI of patients. However, the results also show the increase in blood pressure of patients associated with the hypernatremia caused by licorice. Consequently, licorice consumption should be avoided by hypertensive patients. Copyright © 2017 Elsevier GmbH. All rights reserved.

Statistical flaws in design and analysis of fertility treatment studies on cryopreservation raise doubts on the conclusions

PubMed Central

van Gelder, P.H.A.J.M.; Nijs, M.

2011-01-01

Decisions about pharmacotherapy are being taken by medical doctors and authorities based on comparative studies on the use of medications. In studies on fertility treatments in particular, the methodological quality is of utmost importance in the application of evidence-based medicine and systematic reviews. Nevertheless, flaws and omissions appear quite regularly in these types of studies. Current study aims to present an overview of some of the typical statistical flaws, illustrated by a number of example studies which have been published in peer reviewed journals. Based on an investigation of eleven studies at random selected on fertility treatments with cryopreservation, it appeared that the methodological quality of these studies often did not fulfil the required statistical criteria. The following statistical flaws were identified: flaws in study design, patient selection, and units of analysis or in the definition of the primary endpoints. Other errors could be found in p-value and power calculations or in critical p-value definitions. Proper interpretation of the results and/or use of these study results in a meta analysis should therefore be conducted with care. PMID:24753877

Statistical flaws in design and analysis of fertility treatment -studies on cryopreservation raise doubts on the conclusions.

PubMed

van Gelder, P H A J M; Nijs, M

2011-01-01

Decisions about pharmacotherapy are being taken by medical doctors and authorities based on comparative studies on the use of medications. In studies on fertility treatments in particular, the methodological quality is of utmost -importance in the application of evidence-based medicine and systematic reviews. Nevertheless, flaws and omissions appear quite regularly in these types of studies. Current study aims to present an overview of some of the typical statistical flaws, illustrated by a number of example studies which have been published in peer reviewed journals. Based on an investigation of eleven studies at random selected on fertility treatments with cryopreservation, it appeared that the methodological quality of these studies often did not fulfil the -required statistical criteria. The following statistical flaws were identified: flaws in study design, patient selection, and units of analysis or in the definition of the primary endpoints. Other errors could be found in p-value and power calculations or in critical p-value definitions. Proper -interpretation of the results and/or use of these study results in a meta analysis should therefore be conducted with care.

Statistical assessment of the learning curves of health technologies.

PubMed

Ramsay, C R; Grant, A M; Wallace, S A; Garthwaite, P H; Monk, A F; Russell, I T

2001-01-01

(1) To describe systematically studies that directly assessed the learning curve effect of health technologies. (2) Systematically to identify 'novel' statistical techniques applied to learning curve data in other fields, such as psychology and manufacturing. (3) To test these statistical techniques in data sets from studies of varying designs to assess health technologies in which learning curve effects are known to exist. METHODS - STUDY SELECTION (HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW): For a study to be included, it had to include a formal analysis of the learning curve of a health technology using a graphical, tabular or statistical technique. METHODS - STUDY SELECTION (NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH): For a study to be included, it had to include a formal assessment of a learning curve using a statistical technique that had not been identified in the previous search. METHODS - DATA SOURCES: Six clinical and 16 non-clinical biomedical databases were searched. A limited amount of handsearching and scanning of reference lists was also undertaken. METHODS - DATA EXTRACTION (HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW): A number of study characteristics were abstracted from the papers such as study design, study size, number of operators and the statistical method used. METHODS - DATA EXTRACTION (NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH): The new statistical techniques identified were categorised into four subgroups of increasing complexity: exploratory data analysis; simple series data analysis; complex data structure analysis, generic techniques. METHODS - TESTING OF STATISTICAL METHODS: Some of the statistical methods identified in the systematic searches for single (simple) operator series data and for multiple (complex) operator series data were illustrated and explored using three data sets. The first was a case series of 190 consecutive laparoscopic fundoplication procedures performed by a single surgeon; the second was a case series of consecutive laparoscopic cholecystectomy procedures performed by ten surgeons; the third was randomised trial data derived from the laparoscopic procedure arm of a multicentre trial of groin hernia repair, supplemented by data from non-randomised operations performed during the trial. RESULTS - HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW: Of 4571 abstracts identified, 272 (6%) were later included in the study after review of the full paper. Some 51% of studies assessed a surgical minimal access technique and 95% were case series. The statistical method used most often (60%) was splitting the data into consecutive parts (such as halves or thirds), with only 14% attempting a more formal statistical analysis. The reporting of the studies was poor, with 31% giving no details of data collection methods. RESULTS - NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH: Of 9431 abstracts assessed, 115 (1%) were deemed appropriate for further investigation and, of these, 18 were included in the study. All of the methods for complex data sets were identified in the non-clinical literature. These were discriminant analysis, two-stage estimation of learning rates, generalised estimating equations, multilevel models, latent curve models, time series models and stochastic parameter models. In addition, eight new shapes of learning curves were identified. RESULTS - TESTING OF STATISTICAL METHODS: No one particular shape of learning curve performed significantly better than another. The performance of 'operation time' as a proxy for learning differed between the three procedures. Multilevel modelling using the laparoscopic cholecystectomy data demonstrated and measured surgeon-specific and confounding effects. The inclusion of non-randomised cases, despite the possible limitations of the method, enhanced the interpretation of learning effects. CONCLUSIONS - HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW: The statistical methods used for assessing learning effects in health technology assessment have been crude and the reporting of studies poor. CONCLUSIONS - NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH: A number of statistical methods for assessing learning effects were identified that had not hitherto been used in health technology assessment. There was a hierarchy of methods for the identification and measurement of learning, and the more sophisticated methods for both have had little if any use in health technology assessment. This demonstrated the value of considering fields outside clinical research when addressing methodological issues in health technology assessment. CONCLUSIONS - TESTING OF STATISTICAL METHODS: It has been demonstrated that the portfolio of techniques identified can enhance investigations of learning curve effects. (ABSTRACT TRUNCATED)

The effect of exercise training on cutaneous microvascular reactivity: A systematic review and meta-analysis.

PubMed

Lanting, Sean M; Johnson, Nathan A; Baker, Michael K; Caterson, Ian D; Chuter, Vivienne H

2017-02-01

This study aimed to review the efficacy of exercise training for improving cutaneous microvascular reactivity in response to local stimulus in human adults. Systematic review with meta-analysis. A systematic search of Medline, Cinahl, AMED, Web of Science, Scopus, and Embase was conducted up to June 2015. Included studies were controlled trials assessing the effect of an exercise training intervention on cutaneous microvascular reactivity as instigated by local stimulus such as local heating, iontophoresis and post-occlusive reactive hyperaemia. Studies where the control was only measured at baseline or which included participants with vasospastic disorders were excluded. Two authors independently reviewed and selected relevant controlled trials and extracted data. Quality was assessed using the Downs and Black checklist. Seven trials were included, with six showing a benefit of exercise training but only two reaching statistical significance with effect size ranging from -0.14 to 1.03. The meta-analysis revealed that aerobic exercise had a moderate statistically significant effect on improving cutaneous microvascular reactivity (effect size (ES)=0.43, 95% CI: 0.08-0.78, p=0.015). Individual studies employing an exercise training intervention have tended to have small sample sizes and hence lacked sufficient power to detect clinically meaningful benefits to cutaneous microvascular reactivity. Pooled analysis revealed a clear benefit of exercise training on improving cutaneous microvascular reactivity in older and previously inactive adult cohorts. Exercise training may provide a cost-effective option for improving cutaneous microvascular reactivity in adults and may be of benefit to those with cardiovascular disease and metabolic disorders such as diabetes. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Major bleeding after percutaneous coronary intervention and risk of subsequent mortality: a systematic review and meta-analysis

PubMed Central

Kwok, Chun Shing; Rao, Sunil V; Myint, Phyo K; Keavney, Bernard; Nolan, James; Ludman, Peter F; de Belder, Mark A; Loke, Yoon K; Mamas, Mamas A

2014-01-01

Objectives To examine the relationship between periprocedural bleeding complications and major adverse cardiovascular events (MACEs) and mortality outcomes following percutaneous coronary intervention (PCI) and study differences in the prognostic impact of different bleeding definitions. Methods We conducted a systematic review and meta-analysis of PCI studies that evaluated periprocedural bleeding complications and their impact on MACEs and mortality outcomes. A systematic search of MEDLINE and EMBASE was conducted to identify relevant studies. Data from relevant studies were extracted and random effects meta-analysis was used to estimate the risk of adverse outcomes with periprocedural bleeding. Statistical heterogeneity was assessed by considering the I2 statistic. Results 42 relevant studies were identified including 533 333 patients. Meta-analysis demonstrated that periprocedural major bleeding complications was independently associated with increased risk of mortality (OR 3.31 (2.86 to 3.82), I2=80%) and MACEs (OR 3.89 (3.26 to 4.64), I2=42%). A differential impact of major bleeding as defined by different bleeding definitions on mortality outcomes was observed, in which the REPLACE-2 (OR 6.69, 95% CI 2.26 to 19.81), STEEPLE (OR 6.59, 95% CI 3.89 to 11.16) and BARC (OR 5.40, 95% CI 1.74 to 16.74) had the worst prognostic impacts while HORIZONS-AMI (OR 1.51, 95% CI 1.11 to 2.05) had the least impact on mortality outcomes. Conclusions Major bleeding after PCI is independently associated with a threefold increase in mortality and MACEs outcomes. Different contemporary bleeding definitions have differential impacts on mortality outcomes, with 1.5–6.7-fold increases in mortality observed depending on the definition of major bleeding used. PMID:25332786

Computerised interventions designed to reduce potentially inappropriate prescribing in hospitalised older adults: a systematic review and meta-analysis.

PubMed

Dalton, Kieran; O'Brien, Gary; O'Mahony, Denis; Byrne, Stephen

2018-06-08

computerised interventions have been suggested as an effective strategy to reduce potentially inappropriate prescribing (PIP) for hospitalised older adults. This systematic review and meta-analysis examined the evidence for efficacy of computerised interventions designed to reduce PIP in this patient group. an electronic literature search was conducted using eight databases up to October 2017. Included studies were controlled trials of computerised interventions aiming to reduce PIP in hospitalised older adults (≥65 years). Risk of bias was assessed using Cochrane's Effective Practice and Organisation of Care criteria. of 653 records identified, eight studies were included-two randomised controlled trials, two interrupted time series analysis studies and four controlled before-after studies. Included studies were mostly at a low risk of bias. Overall, seven studies showed either a statistically significant reduction in the proportion of patients prescribed a potentially inappropriate medicine (PIM) (absolute risk reduction {ARR} 1.3-30.1%), or in PIMs ordered (ARR 2-5.9%). However, there is insufficient evidence thus far to suggest that these interventions can routinely improve patient-related outcomes. It was only possible to include three studies in the meta-analysis-which demonstrated that intervention patients were less likely to be prescribed a PIM (odds ratio 0.6; 95% CI 0.38, 0.93). No computerised intervention targeting potential prescribing omissions (PPOs) was identified. this systematic review concludes that computerised interventions are capable of statistically significantly reducing PIMs in hospitalised older adults. Future interventions should strive to target both PIMs and PPOs, ideally demonstrating both cost-effectiveness data and clinically significant improvements in patient-related outcomes.

Temporal scaling and spatial statistical analyses of groundwater level fluctuations

NASA Astrophysics Data System (ADS)

Sun, H.; Yuan, L., Sr.; Zhang, Y.

2017-12-01

Natural dynamics such as groundwater level fluctuations can exhibit multifractionality and/or multifractality due likely to multi-scale aquifer heterogeneity and controlling factors, whose statistics requires efficient quantification methods. This study explores multifractionality and non-Gaussian properties in groundwater dynamics expressed by time series of daily level fluctuation at three wells located in the lower Mississippi valley, after removing the seasonal cycle in the temporal scaling and spatial statistical analysis. First, using the time-scale multifractional analysis, a systematic statistical method is developed to analyze groundwater level fluctuations quantified by the time-scale local Hurst exponent (TS-LHE). Results show that the TS-LHE does not remain constant, implying the fractal-scaling behavior changing with time and location. Hence, we can distinguish the potentially location-dependent scaling feature, which may characterize the hydrology dynamic system. Second, spatial statistical analysis shows that the increment of groundwater level fluctuations exhibits a heavy tailed, non-Gaussian distribution, which can be better quantified by a Lévy stable distribution. Monte Carlo simulations of the fluctuation process also show that the linear fractional stable motion model can well depict the transient dynamics (i.e., fractal non-Gaussian property) of groundwater level, while fractional Brownian motion is inadequate to describe natural processes with anomalous dynamics. Analysis of temporal scaling and spatial statistics therefore may provide useful information and quantification to understand further the nature of complex dynamics in hydrology.

Bayesian Sensitivity Analysis of Statistical Models with Missing Data

PubMed Central

ZHU, HONGTU; IBRAHIM, JOSEPH G.; TANG, NIANSHENG

2013-01-01

Methods for handling missing data depend strongly on the mechanism that generated the missing values, such as missing completely at random (MCAR) or missing at random (MAR), as well as other distributional and modeling assumptions at various stages. It is well known that the resulting estimates and tests may be sensitive to these assumptions as well as to outlying observations. In this paper, we introduce various perturbations to modeling assumptions and individual observations, and then develop a formal sensitivity analysis to assess these perturbations in the Bayesian analysis of statistical models with missing data. We develop a geometric framework, called the Bayesian perturbation manifold, to characterize the intrinsic structure of these perturbations. We propose several intrinsic influence measures to perform sensitivity analysis and quantify the effect of various perturbations to statistical models. We use the proposed sensitivity analysis procedure to systematically investigate the tenability of the non-ignorable missing at random (NMAR) assumption. Simulation studies are conducted to evaluate our methods, and a dataset is analyzed to illustrate the use of our diagnostic measures. PMID:24753718

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.

Effectiveness of practices to reduce blood culture contamination: a Laboratory Medicine Best Practices systematic review and meta-analysis.

PubMed

Snyder, Susan R; Favoretto, Alessandra M; Baetz, Rich Ann; Derzon, James H; Madison, Bereneice M; Mass, Diana; Shaw, Colleen S; Layfield, Christopher D; Christenson, Robert H; Liebow, Edward B

2012-09-01

This article is a systematic review of the effectiveness of three practices for reducing blood culture contamination rates: venipuncture, phlebotomy teams, and prepackaged preparation/collection (prep) kits. The CDC-funded Laboratory Medicine Best Practices Initiative systematic review methods for quality improvement practices were used. Studies included as evidence were: 9 venipuncture (vs. versus intravenous catheter), 5 phlebotomy team; and 7 prep kit. All studies for venipuncture and phlebotomy teams favored these practices, with meta-analysis mean odds ratios for venipuncture of 2.69 and phlebotomy teams of 2.58. For prep kits 6 studies' effect sizes were not statistically significantly different from no effect (meta-analysis mean odds ratio 1.12). Venipuncture and the use of phlebotomy teams are effective practices for reducing blood culture contamination rates in diverse hospital settings and are recommended as evidence-based "best practices" with high overall strength of evidence and substantial effect size ratings. No recommendation is made for or against prep kits based on uncertain improvement. Copyright © 2012 The Canadian Society of Clinical Chemists. All rights reserved.

Statistical Methodologies to Integrate Experimental and Computational Research

NASA Technical Reports Server (NTRS)

Parker, P. A.; Johnson, R. T.; Montgomery, D. C.

2008-01-01

Development of advanced algorithms for simulating engine flow paths requires the integration of fundamental experiments with the validation of enhanced mathematical models. In this paper, we provide an overview of statistical methods to strategically and efficiently conduct experiments and computational model refinement. Moreover, the integration of experimental and computational research efforts is emphasized. With a statistical engineering perspective, scientific and engineering expertise is combined with statistical sciences to gain deeper insights into experimental phenomenon and code development performance; supporting the overall research objectives. The particular statistical methods discussed are design of experiments, response surface methodology, and uncertainty analysis and planning. Their application is illustrated with a coaxial free jet experiment and a turbulence model refinement investigation. Our goal is to provide an overview, focusing on concepts rather than practice, to demonstrate the benefits of using statistical methods in research and development, thereby encouraging their broader and more systematic application.

A systematic assessment of normalization approaches for the Infinium 450K methylation platform.

PubMed

Wu, Michael C; Joubert, Bonnie R; Kuan, Pei-fen; Håberg, Siri E; Nystad, Wenche; Peddada, Shyamal D; London, Stephanie J

2014-02-01

The Illumina Infinium HumanMethylation450 BeadChip has emerged as one of the most popular platforms for genome wide profiling of DNA methylation. While the technology is wide-spread, systematic technical biases are believed to be present in the data. For example, this array incorporates two different chemical assays, i.e., Type I and Type II probes, which exhibit different technical characteristics and potentially complicate the computational and statistical analysis. Several normalization methods have been introduced recently to adjust for possible biases. However, there is considerable debate within the field on which normalization procedure should be used and indeed whether normalization is even necessary. Yet despite the importance of the question, there has been little comprehensive comparison of normalization methods. We sought to systematically compare several popular normalization approaches using the Norwegian Mother and Child Cohort Study (MoBa) methylation data set and the technical replicates analyzed with it as a case study. We assessed both the reproducibility between technical replicates following normalization and the effect of normalization on association analysis. Results indicate that the raw data are already highly reproducible, some normalization approaches can slightly improve reproducibility, but other normalization approaches may introduce more variability into the data. Results also suggest that differences in association analysis after applying different normalizations are not large when the signal is strong, but when the signal is more modest, different normalizations can yield very different numbers of findings that meet a weaker statistical significance threshold. Overall, our work provides useful, objective assessment of the effectiveness of key normalization methods.

Comparing Percutaneous Transluminal Angioplasty and Stent Placement for Treatment of Subclavian Arterial Occlusive Disease: A Systematic Review and Meta-Analysis

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

Ahmed, Ahmed T., E-mail: Ahmed.Ahmed1@mayo.edu; Mohammed, Khaled, E-mail: Mohammed.Khaled@mayo.edu; Chehab, Monzer, E-mail: moe.chehab@beumont.edu

Background and PurposeSubclavian artery occlusive disease (SAOD) is often associated with cerebrovascular symptoms such as subclavian steal syndrome and stroke. We conducted a systematic review and meta-analysis to compare percutaneous transluminal angioplasty (PTA) and stent placement for the treatment of SAOD.Materials and MethodsWe searched Medline, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus through October 16, 2014. From each study, we abstracted baseline patient characteristics, study design variables, and outcome data including rates of technical success, primary patency (≤2 and >2 years follow-up), symptom resolution, and complications. Meta-analysis was performed using a random-effects model.ResultsA total ofmore » 35 non-comparative studies with 1726 patients were included. Technical success rate was significantly higher in the stent group than the PTA group (92.8 vs 86.8 %, p = 0.007). Long-term primary patency rates (76.9 vs 79.6 %, p = 0.729) and symptom resolution rates (82.2 vs 73.0 %, p = 0.327) were not statistically different. There was no statistically significant difference in the rates of stroke or death.ConclusionStent placement for treatment of SAOD may be associated with higher rates of technical success but similar rates of symptom resolution and long-term outcomes. The confidence in the available estimates is low. Further comparative studies are needed to guide patients and clinicians in shared decision making.« less

Effects of falls prevention interventions on falls outcomes for hospitalised adults: protocol for a systematic review with meta-analysis.

PubMed

Slade, Susan C; Carey, David L; Hill, Anne-Marie; Morris, Meg E

2017-11-12

Falls are a major global public health problem and leading cause of accidental or unintentional injury and hospitalisation. Falls in hospital are associated with longer length of stay, readmissions and poor outcomes. Falls prevention is informed by knowledge of reversible falls risk factors and accurate risk identification. The extent to which hospital falls are prevented by evidence-based practice, patient self-management initiatives, environmental modifications and optimisation of falls prevention systems awaits confirmation. Published reviews have mainly evaluated community settings and residential care facilities. A better understanding of hospital falls and the most effective strategies to prevent them is vital to keeping people safe. To evaluate the effectiveness of falls prevention interventions on reducing falls in hospitalised adults (acute and subacute wards, rehabilitation, mental health, operating theatre and emergency departments). We also summarise components of effective falls prevention interventions. This protocol has been registered. The systematic review will be informed by Cochrane guidelines and reported according to the Preferred Reporting Items for Systematic review and Meta-Analysis statement. randomised controlled trials, quasi-randomised trials or controlled clinical trials that evaluate falls prevention interventions for use by hospitalised adults or employees. Electronic databases will be searched using key terms including falls, accidental falls, prevention, hospital, rehabilitation, emergency, mental health, acute and subacute. Pairs of independent reviewers will conduct all review steps. Included studies will be evaluated for risk of bias. Data for variables such as age, participant characteristics, settings and interventions will be extracted and analysed with descriptive statistics and meta-analysis where possible. The results will be presented textually, with flow charts, summary tables, statistical analysis (and meta-analysis where possible) and narrative summaries. Ethical approval is not required. The systematic review will be published in a peer-reviewed journal and disseminated electronically, in print and at conferences. Updates will guide healthcare translation into practice. PROSPERO 2017: CRD 42017058887. Available from https://www.crd.york.ac.uk/prospero. © 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.

Landslide Susceptibility Statistical Methods: A Critical and Systematic Literature Review

NASA Astrophysics Data System (ADS)

Mihir, Monika; Malamud, Bruce; Rossi, Mauro; Reichenbach, Paola; Ardizzone, Francesca

2014-05-01

Landslide susceptibility assessment, the subject of this systematic review, is aimed at understanding the spatial probability of slope failures under a set of geomorphological and environmental conditions. It is estimated that about 375 landslides that occur globally each year are fatal, with around 4600 people killed per year. Past studies have brought out the increasing cost of landslide damages which primarily can be attributed to human occupation and increased human activities in the vulnerable environments. Many scientists, to evaluate and reduce landslide risk, have made an effort to efficiently map landslide susceptibility using different statistical methods. In this paper, we do a critical and systematic landslide susceptibility literature review, in terms of the different statistical methods used. For each of a broad set of studies reviewed we note: (i) study geography region and areal extent, (ii) landslide types, (iii) inventory type and temporal period covered, (iv) mapping technique (v) thematic variables used (vi) statistical models, (vii) assessment of model skill, (viii) uncertainty assessment methods, (ix) validation methods. We then pulled out broad trends within our review of landslide susceptibility, particularly regarding the statistical methods. We found that the most common statistical methods used in the study of landslide susceptibility include logistic regression, artificial neural network, discriminant analysis and weight of evidence. Although most of the studies we reviewed assessed the model skill, very few assessed model uncertainty. In terms of geographic extent, the largest number of landslide susceptibility zonations were in Turkey, Korea, Spain, Italy and Malaysia. However, there are also many landslides and fatalities in other localities, particularly India, China, Philippines, Nepal and Indonesia, Guatemala, and Pakistan, where there are much fewer landslide susceptibility studies available in the peer-review literature. This raises some concern that existing studies do not always cover all the regions globally that currently experience landslides and landslide fatalities.

49 CFR Appendix B to Part 222 - Alternative Safety Measures

Code of Federal Regulations, 2014 CFR

2014-10-01

... statistically valid baseline violation rate must be established through automated or systematic manual... enforcement, a program of public education and awareness directed at motor vehicle drivers, pedestrians and..., a statistically valid baseline violation rate must be established through automated or systematic...

49 CFR Appendix B to Part 222 - Alternative Safety Measures

Code of Federal Regulations, 2013 CFR

2013-10-01

... statistically valid baseline violation rate must be established through automated or systematic manual... enforcement, a program of public education and awareness directed at motor vehicle drivers, pedestrians and..., a statistically valid baseline violation rate must be established through automated or systematic...

Empirical and Genealogical Analysis of Non-Vocational Adult Education in Europe

ERIC Educational Resources Information Center

Manninen, Jyri

2017-01-01

Non-formal, non-vocational adult education (NFNVAE) is a low-cost, low-threshold learning activity that generates many benefits for individuals and society, and it should play a more central role in educational policy. NFNVAE's challenge is that it lacks clear concepts and definitions and is, therefore, less systematically covered in statistics,…

Analysis of Arterial Blood Gas Report in Chronic Kidney Diseases - Comparison between Bedside and Multistep Systematic Method.

PubMed

Ghatak, Ishita; Dhat, Vaishali; Tilak, Mona A; Roy, Indranath

2016-08-01

Acid Base Disorders (ABDs) are commonly encountered in critically ill Chronic Kidney Disease (CKD) patients. Timely and correct analysis of Arterial Blood Gases (ABG) is critical for the diagnosis, treatment and prediction of outcome of the patients. The aim was to explore type and prevalence of ABDs in 31 critically ill CKD patients from a tertiary care hospital in Maharashtra, to compare two methods of analysis- bedside and systematic approaches and to clinically correlate the nature of ABDs in these patients. The initial ABG reports of 31 consecutive CKD patients were analysed by two methods. Medica Easy stat analyser was the equipment for analysis with Principle of potentiometry and ion selective electrode for pH and pCO2 and amperometry for pO2. Serum albumin was also measured by Bromocresol green dye binding method using liquixx albumin kit in Erba XL 300 autoanalyser. Chi-square test was used for statistical analysis using Epi Info version 3.5.4 and SPSS 14.0 softwares. The systematic method showed a significantly higher prevalence of mixed disorders (50%) compared to bedside method (12.9%). Most prevalent disorder by bedside method was metabolic acidosis in 15 cases (48.39%). By the systematic method, 3 reports were invalid. As a single category, most prevalent type was both simple respiratory alkalosis and mixed metabolic acidosis with respiratory alkalosis- 6 of 31 cases in each type (19.36% each). As a whole, metabolic acidosis (including both High Anion Gap Metabolic Acidosis or HAGMA and Non Anion Gap Metabolic Acidosis or NAGMA with 4 in each type) was most prevalent- 8 of 31(25.8%). Systematic approach was more effective in diagnosing mixed acid base disorders. By systematic method the findings of analysis in most cases could be correlated with the clinical condition and provisional diagnosis. Thus interpretation of ABDs by using stepwise approach could be useful to the clinicians in early diagnosis and management of the patients.

Statistical Model Analysis of (n,p) Cross Sections and Average Energy For Fission Neutron Spectrum

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

Odsuren, M.; Khuukhenkhuu, G.

2011-06-28

Investigation of charged particle emission reaction cross sections for fast neutrons is important to both nuclear reactor technology and the understanding of nuclear reaction mechanisms. In particular, the study of (n,p) cross sections is necessary to estimate radiation damage due to hydrogen production, nuclear heating and transmutations in the structural materials of fission and fusion reactors. On the other hand, it is often necessary in practice to evaluate the neutron cross sections of the nuclides for which no experimental data are available.Because of this, we carried out the systematical analysis of known experimental (n,p) and (n,a) cross sections for fastmore » neutrons and observed a systematical regularity in the wide energy interval of 6-20 MeV and for broad mass range of target nuclei. To explain this effect using the compound, pre-equilibrium and direct reaction mechanisms some formulae were deduced. In this paper, in the framework of the statistical model known experimental (n,p) cross sections averaged over the thermal fission neutron spectrum of U-235 are analyzed. It was shown that the experimental data are satisfactorily described by the statistical model. Also, in the case of (n,p) cross sections the effective average neutron energy for fission spectrum of U-235 was found to be around 3 MeV.« less

AutoBayes Program Synthesis System Users Manual

NASA Technical Reports Server (NTRS)

Schumann, Johann; Jafari, Hamed; Pressburger, Tom; Denney, Ewen; Buntine, Wray; Fischer, Bernd

2008-01-01

Program synthesis is the systematic, automatic construction of efficient executable code from high-level declarative specifications. AutoBayes is a fully automatic program synthesis system for the statistical data analysis domain; in particular, it solves parameter estimation problems. It has seen many successful applications at NASA and is currently being used, for example, to analyze simulation results for Orion. The input to AutoBayes is a concise description of a data analysis problem composed of a parameterized statistical model and a goal that is a probability term involving parameters and input data. The output is optimized and fully documented C/C++ code computing the values for those parameters that maximize the probability term. AutoBayes can solve many subproblems symbolically rather than having to rely on numeric approximation algorithms, thus yielding effective, efficient, and compact code. Statistical analysis is faster and more reliable, because effort can be focused on model development and validation rather than manual development of solution algorithms and code.

Cognitive Behavioral Therapy Compared with Non-specialized Therapy for Alleviating the Effect of Auditory Hallucinations in People with Reoccurring Schizophrenia: A Systematic Review and Meta-analysis.

PubMed

Kennedy, Laura; Xyrichis, Andreas

2017-02-01

Cognitive behavioral therapy (CBT) is recommended as a psychological intervention for those diagnosed with schizophrenia. The prevalence of auditory hallucinations is high among this group, many of whom are cared for by community mental health teams that may not have easy access to qualified CBT practitioners. This systematic review examined the evidence for the superiority of CBT compared to non-specialized therapy in alleviating auditory hallucinations in community patients with schizophrenia. Two RCTs met the inclusion criteria totaling 105 participants. The Positive and Negative Syndrome Scale (PANSS)-Positive Scale was the outcome measure examined. A meta-analysis revealed a pooled mean difference of -0.86 [95 % CI -2.38, 0.65] in favor of CBT, although this did not reach statistical significance. This systematic review concluded there is no clinically significant difference in the reduction of positive symptoms of schizophrenia when treated by CBT compared to a non-specialized therapy for adults experiencing auditory hallucinations.

Quality assessment of systematic reviews on alveolar socket preservation.

PubMed

Moraschini, V; Barboza, E Dos S P

2016-09-01

The aim of this overview was to evaluate and compare the quality of systematic reviews, with or without meta-analysis, that have evaluated studies on techniques or biomaterials used for the preservation of alveolar sockets post tooth extraction in humans. An electronic search was conducted without date restrictions using the Medline/PubMed, Cochrane Library, and Web of Science databases up to April 2015. Eligibility criteria included systematic reviews, with or without meta-analysis, focused on the preservation of post-extraction alveolar sockets in humans. Two independent authors assessed the quality of the included reviews using AMSTAR and the checklist proposed by Glenny et al. in 2003. After the selection process, 12 systematic reviews were included. None of these reviews obtained the maximum score using the quality assessment tools implemented, and the results of the analyses were highly variable. A significant statistical correlation was observed between the scores of the two checklists. A wide structural and methodological variability was observed between the systematic reviews published on the preservation of alveolar sockets post tooth extraction. None of the reviews evaluated obtained the maximum score using the two quality assessment tools implemented. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Patellar denervation with electrocautery in total knee arthroplasty without patellar resurfacing: a meta-analysis.

PubMed

Cheng, Tao; Zhu, Chen; Guo, Yongyuan; Shi, Sifeng; Chen, Desheng; Zhang, Xianlong

2014-11-01

The impact of patellar denervation with electrocautery in total knee arthroplasty (TKA) on post-operative outcomes has been under debate. This study aims to conduct a meta-analysis and systematic review to compare the benefits and risks of circumpatellar electrocautery with those of non-electrocautery in primary TKAs. Comparative and randomized clinical studies were identified by conducting an electronic search of articles dated up to September 2012 in PubMed, EMBASE, Scopus, and the Cochrane databases. Six studies that focus on a total of 849 knees were analysed. A random-effects model was conducted using the inverse-variance method for continuous variables and the Mantel-Haenszel method for dichotomous variables. There was no significant difference in the incidence of anterior knee pain between the electrocautery and non-electrocautery groups. In term of patellar score and Knee Society Score, circumpatellar electrocautery improved clinical outcomes compared with non-electrocautery in TKAs. The statistical differences were in favour of the electrocautery group but have minimal clinical significance. In addition, the overall complications indicate no statistical significance between the two groups. This study shows no strong evidence either for or against electrocautery compared with non-electrocautery in TKAs. Therapeutic study (systematic review and meta-analysis), Level III.

Systematic review and meta-analysis of dropout rates in individual psychotherapy for generalized anxiety disorder.

PubMed

Gersh, Elon; Hallford, David J; Rice, Simon M; Kazantzis, Nikolaos; Gersh, Hannah; Gersh, Benji; McCarty, Carolyn A

2017-12-01

Despite being a relatively prevalent and debilitating disorder, Generalized Anxiety Disorder (GAD) is the second least studied anxiety disorder and among the most difficult to treat. Dropout from psychotherapy is concerning as it is associated with poorer outcomes, leads to service inefficiencies and can disproportionately affect disadvantaged populations. No study to date has calculated a weighted mean dropout rate for GAD and explored associated correlates. A systematic review was conducted using PsycINFO, Medline and Embase databases, identifying studies investigating individual psychotherapies for adults with GAD. Forty-five studies, involving 2224 participants, were identified for meta-analysis. The weighted mean dropout rate was 16.99% (95% confidence interval 14.42%-19.91%). The Q-statistic indicated significant heterogeneity among studies. Moderator analysis and meta-regressions indicated no statistically significant effect of client age, sex, symptom severity, comorbidity, treatment type, study type (randomized trial or not), study quality, number of sessions or therapist experience. In research investigating psychotherapy for GAD, approximately one in six clients can be expected to drop out of treatment. Dropout rate was not significantly moderated by the client, therapist or treatment variables investigated. Future research should specify the definition of dropout, reasons for dropout and associated correlates to assist the field's progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Laser diagnostics of native cervix dabs with human papilloma virus in high carcinogenic risk

NASA Astrophysics Data System (ADS)

Peresunko, O. P.; Karpenko, Ju. G.; Burkovets, D. N.; Ivashko, P. V.; Nikorych, A. V.; Yermolenko, S. B.; Gruia, Ion; Gruia, M. J.

2015-11-01

The results of experimental studies of coordinate distributions of Mueller matrix elements of the following types of cervical scraping tissue are presented: rate- low-grade - highly differentiated dysplasia (CIN1-CIN3) - adenocarcinoma of high, medium and low levels of differentiation (G1-G3). The rationale for the choice of statistical points 1-4 orders polarized coherent radiation field, transformed as a result of interaction with the oncologic modified biological layers "epithelium-stroma" as a quantitative criterion of polarimetric optical differentiation state of human biological tissues are shown here. The analysis of the obtained Mueller matrix elements and statistical correlation methods, the systematized by types studied tissues is accomplished. The results of research images of Mueller matrix elements m34 for this type of pathology as low-grade dysplasia (CIN2), the results of its statistical and correlation analysis are presented.

Performance of Between-Study Heterogeneity Measures in the Cochrane Library.

PubMed

Ma, Xiaoyue; Lin, Lifeng; Qu, Zhiyong; Zhu, Motao; Chu, Haitao

2018-05-29

The growth in comparative effectiveness research and evidence-based medicine has increased attention to systematic reviews and meta-analyses. Meta-analysis synthesizes and contrasts evidence from multiple independent studies to improve statistical efficiency and reduce bias. Assessing heterogeneity is critical for performing a meta-analysis and interpreting results. As a widely used heterogeneity measure, the I statistic quantifies the proportion of total variation across studies that is due to real differences in effect size. The presence of outlying studies can seriously exaggerate the I statistic. Two alternative heterogeneity measures, the Ir and Im, have been recently proposed to reduce the impact of outlying studies. To evaluate these measures' performance empirically, we applied them to 20,599 meta-analyses in the Cochrane Library. We found that the Ir and Im have strong agreement with the I, while they are more robust than the I when outlying studies appear.

Baseline estimation in flame's spectra by using neural networks and robust statistics

NASA Astrophysics Data System (ADS)

Garces, Hugo; Arias, Luis; Rojas, Alejandro

2014-09-01

This work presents a baseline estimation method in flame spectra based on artificial intelligence structure as a neural network, combining robust statistics with multivariate analysis to automatically discriminate measured wavelengths belonging to continuous feature for model adaptation, surpassing restriction of measuring target baseline for training. The main contributions of this paper are: to analyze a flame spectra database computing Jolliffe statistics from Principal Components Analysis detecting wavelengths not correlated with most of the measured data corresponding to baseline; to systematically determine the optimal number of neurons in hidden layers based on Akaike's Final Prediction Error; to estimate baseline in full wavelength range sampling measured spectra; and to train an artificial intelligence structure as a Neural Network which allows to generalize the relation between measured and baseline spectra. The main application of our research is to compute total radiation with baseline information, allowing to diagnose combustion process state for optimization in early stages.

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.

Radiosurgery of Glomus Jugulare Tumors: A Meta-Analysis

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

Guss, Zachary D.; Batra, Sachin; Limb, Charles J.

2011-11-15

Purpose: During the past two decades, radiosurgery has arisen as a promising approach to the management of glomus jugulare. In the present study, we report on a systematic review and meta-analysis of the available published data on the radiosurgical management of glomus jugulare tumors. Methods and Materials: To identify eligible studies, systematic searches of all glomus jugulare tumors treated with radiosurgery were conducted in major scientific publication databases. The data search yielded 19 studies, which were included in the meta-analysis. The data from 335 glomus jugulare patients were extracted. The fixed effects pooled proportions were calculated from the data whenmore » Cochrane's statistic was statistically insignificant and the inconsistency among studies was <25%. Bias was assessed using the Egger funnel plot test. Results: Across all studies, 97% of patients achieved tumor control, and 95% of patients achieved clinical control. Eight studies reported a mean or median follow-up time of >36 months. In these studies, 95% of patients achieved clinical control and 96% achieved tumor control. The gamma knife, linear accelerator, and CyberKnife technologies all exhibited high rates of tumor and clinical control. Conclusions: The present study reports the results of a meta-analysis for the radiosurgical management of glomus jugulare. Because of its high effectiveness, we suggest considering radiosurgery for the primary management of glomus jugulare tumors.« less

Biosimilarity and Interchangeability: Principles and Evidence: A Systematic Review.

PubMed

McKinnon, Ross A; Cook, Matthew; Liauw, Winston; Marabani, Mona; Marschner, Ian C; Packer, Nicolle H; Prins, Johannes B

2018-02-01

The efficacy, safety and immunogenicity risk of switching between an originator biologic and a biosimilar or from one biosimilar to another are of potential concern. The aim was to conduct a systematic literature review of the outcomes of switching between biologics and their biosimilars and identify any evidence gaps. A systematic literature search was conducted in PubMed, EMBASE and Cochrane Library from inception to June 2017. Relevant societal meetings were also checked. Peer-reviewed studies reporting efficacy and/or safety data on switching between originator and biosimilar products or from one biosimilar to another were selected. Studies with fewer than 20 switched patients were excluded. Data were extracted on interventions, study population, reason for treatment switching, efficacy outcomes, safety and anti-drug antibodies. The systematic literature search identified 63 primary publications covering 57 switching studies. The reason for switching was reported as non-medical in 50 studies (23 clinical, 27 observational). Seven studies (all observational) did not report whether the reasons for switching were medical or non-medical. In 38 of the 57 studies, fewer than 100 patients were switched. Follow-up after switching went beyond 1 year in eight of the 57 studies. Of the 57 studies, 33 included statistical analysis of disease activity or patient outcomes; the majority of these studies found no statistically significant differences between groups for main efficacy parameters (based on P < 0.05 or predefined acceptance ranges), although some studies observed changes for some parameters. Most studies reported similar safety profiles between groups. There are important evidence gaps around the safety of switching between biologics and their biosimilars. Sufficiently powered and appropriately statistically analysed clinical trials and pharmacovigilance studies, with long-term follow-ups and multiple switches, are needed to support decision-making around biosimilar switching.

Comparative clinical effectiveness of management strategies for sciatica: systematic review and network meta-analyses.

PubMed

Lewis, Ruth A; Williams, Nefyn H; Sutton, Alex J; Burton, Kim; Din, Nafees Ud; Matar, Hosam E; Hendry, Maggie; Phillips, Ceri J; Nafees, Sadia; Fitzsimmons, Deborah; Rickard, Ian; Wilkinson, Clare

2015-06-01

There are numerous treatment approaches for sciatica. Previous systematic reviews have not compared all these strategies together. To compare the clinical effectiveness of different treatment strategies for sciatica simultaneously. Systematic review and network meta-analysis. We searched 28 electronic databases and online trial registries, along with bibliographies of previous reviews for comparative studies evaluating any intervention to treat sciatica in adults, with outcome data on global effect or pain intensity. Network meta-analysis methods were used to simultaneously compare all treatment strategies and allow indirect comparisons of treatments between studies. The study was funded by the UK National Institute for Health Research Health Technology Assessment program; there are no potential conflict of interests. We identified 122 relevant studies; 90 were randomized controlled trials (RCTs) or quasi-RCTs. Interventions were grouped into 21 treatment strategies. Internal and external validity of included studies was very low. For overall recovery as the outcome, compared with inactive control or conventional care, there was a statistically significant improvement following disc surgery, epidural injections, nonopioid analgesia, manipulation, and acupuncture. Traction, percutaneous discectomy, and exercise therapy were significantly inferior to epidural injections or surgery. For pain as the outcome, epidural injections and biological agents were significantly better than inactive control, but similar findings for disc surgery were not statistically significant. Biological agents were significantly better for pain reduction than bed rest, nonopioids, and opioids. Opioids, education/advice alone, bed rest, and percutaneous discectomy were inferior to most other treatment strategies; although these findings represented large effects, they were statistically equivocal. For the first time, many different treatment strategies for sciatica have been compared in the same systematic review and meta-analysis. This approach has provided new data to assist shared decision-making. The findings support the effectiveness of nonopioid medication, epidural injections, and disc surgery. They also suggest that spinal manipulation, acupuncture, and experimental treatments, such as anti-inflammatory biological agents, may be considered. The findings do not provide support for the effectiveness of opioid analgesia, bed rest, exercise therapy, education/advice (when used alone), percutaneous discectomy, or traction. The issue of how best to estimate the effectiveness of treatment approaches according to their order within a sequential treatment pathway remains an important challenge. Copyright © 2015 Elsevier Inc. All rights reserved.

Uncertainty Analysis of the NASA Glenn 8x6 Supersonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Stephens, Julia; Hubbard, Erin; Walter, Joel; McElroy, Tyler

2016-01-01

This paper presents methods and results of a detailed measurement uncertainty analysis that was performed for the 8- by 6-foot Supersonic Wind Tunnel located at the NASA Glenn Research Center. The statistical methods and engineering judgments used to estimate elemental uncertainties are described. The Monte Carlo method of propagating uncertainty was selected to determine the uncertainty of calculated variables of interest. A detailed description of the Monte Carlo method as applied for this analysis is provided. Detailed uncertainty results for the uncertainty in average free stream Mach number as well as other variables of interest are provided. All results are presented as random (variation in observed values about a true value), systematic (potential offset between observed and true value), and total (random and systematic combined) uncertainty. The largest sources contributing to uncertainty are determined and potential improvement opportunities for the facility are investigated.

Social Network Analysis for Assessing College-Aged Adults' Health: A Systematic Review.

PubMed

Patterson, Megan S; Go Odson, Patricia

2018-04-13

Social network analysis (SNA) is a useful, emerging method for studying health. College students are especially prone to social influence when it comes to health. This review aimed to identify network variables related to college student health and determine how SNA was used in the literature. A systematic review of relevant literature was conducted in October 2015. Studies employing egocentric or whole network analysis to study college student health were included. We used Garrard's Matrix Method to extract data from reviewed articles (n = 15). Drinking, smoking, aggression, homesickness, and stress were predicted by network variables in the reviewed literature. Methodological inconsistencies concerning boundary specification, data collection, nomination limits, and statistical analyses were revealed across studies. Results show the consistent relationship between network variables and college health outcomes, justifying further use of SNA to research college health. Suggestions and considerations for future use of SNA are provided.

Association between prospective registration and overall reporting and methodological quality of systematic reviews: a meta-epidemiological study.

PubMed

Ge, Long; Tian, Jin-Hui; Li, Ya-Nan; Pan, Jia-Xue; Li, Ge; Wei, Dang; Xing, Xin; Pan, Bei; Chen, Yao-Long; Song, Fu-Jian; Yang, Ke-Hu

2018-01-01

The aim of this study was to investigate the differences in main characteristics, reporting and methodological quality between prospectively registered and nonregistered systematic reviews. PubMed was searched to identify systematic reviews of randomized controlled trials published in 2015 in English. After title and abstract screening, potentially relevant reviews were divided into three groups: registered non-Cochrane reviews, Cochrane reviews, and nonregistered reviews. For each group, random number tables were generated in Microsoft Excel, and the first 50 eligible studies from each group were randomly selected. Data of interest from systematic reviews were extracted. Regression analyses were conducted to explore the association between total Revised Assessment of Multiple Systematic Review (R-AMSTAR) or Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) scores and the selected characteristics of systematic reviews. The conducting and reporting of literature search in registered reviews were superior to nonregistered reviews. Differences in 9 of the 11 R-AMSTAR items were statistically significant between registered and nonregistered reviews. The total R-AMSTAR score of registered reviews was higher than nonregistered reviews [mean difference (MD) = 4.82, 95% confidence interval (CI): 3.70, 5.94]. Sensitivity analysis by excluding the registration-related item presented similar result (MD = 4.34, 95% CI: 3.28, 5.40). Total PRISMA scores of registered reviews were significantly higher than nonregistered reviews (all reviews: MD = 1.47, 95% CI: 0.64-2.30; non-Cochrane reviews: MD = 1.49, 95% CI: 0.56-2.42). However, the difference in the total PRISMA score was no longer statistically significant after excluding the item related to registration (item 5). Regression analyses showed similar results. Prospective registration may at least indirectly improve the overall methodological quality of systematic reviews, although its impact on the overall reporting quality was not significant. Copyright © 2017 Elsevier Inc. All rights reserved.

Meta-analysis of neutropenia or leukopenia as a prognostic factor in patients with malignant disease undergoing chemotherapy.

PubMed

Shitara, Kohei; Matsuo, Keitaro; Oze, Isao; Mizota, Ayako; Kondo, Chihiro; Nomura, Motoo; Yokota, Tomoya; Takahari, Daisuke; Ura, Takashi; Muro, Kei

2011-08-01

We performed a systematic review and meta-analysis to determine the impact of neutropenia or leukopenia experienced during chemotherapy on survival. Eligible studies included prospective or retrospective analyses that evaluated neutropenia or leukopenia as a prognostic factor for overall survival or disease-free survival. Statistical analyses were conducted to calculate a summary hazard ratio and 95% confidence interval (CI) using random-effects or fixed-effects models based on the heterogeneity of the included studies. Thirteen trials were selected for the meta-analysis, with a total of 9,528 patients. The hazard ratio of death was 0.69 (95% CI, 0.64-0.75) for patients with higher-grade neutropenia or leukopenia compared to patients with lower-grade or lack of cytopenia. Our analysis was also stratified by statistical method (any statistical method to decrease lead-time bias; time-varying analysis or landmark analysis), but no differences were observed. Our results indicate that neutropenia or leukopenia experienced during chemotherapy is associated with improved survival in patients with advanced cancer or hematological malignancies undergoing chemotherapy. Future prospective analyses designed to investigate the potential impact of chemotherapy dose adjustment coupled with monitoring of neutropenia or leukopenia on survival are warranted.

Effectiveness of Aquatic Exercise and Balneotherapy: A Summary of Systematic Reviews Based on Randomized Controlled Trials of Water Immersion Therapies

PubMed Central

Kamioka, Hiroharu; Tsutani, Kiichiro; Okuizumi, Hiroyasu; Mutoh, Yoshiteru; Ohta, Miho; Handa, Shuichi; Okada, Shinpei; Kitayuguchi, Jun; Kamada, Masamitsu; Shiozawa, Nobuyoshi; Honda, Takuya

2010-01-01

Background The objective of this review was to summarize findings on aquatic exercise and balneotherapy and to assess the quality of systematic reviews based on randomized controlled trials. Methods Studies were eligible if they were systematic reviews based on randomized clinical trials (with or without a meta-analysis) that included at least 1 treatment group that received aquatic exercise or balneotherapy. We searched the following databases: Cochrane Database Systematic Review, MEDLINE, CINAHL, Web of Science, JDream II, and Ichushi-Web for articles published from the year 1990 to August 17, 2008. Results We found evidence that aquatic exercise had small but statistically significant effects on pain relief and related outcome measures of locomotor diseases (eg, arthritis, rheumatoid diseases, and low back pain). However, long-term effectiveness was unclear. Because evidence was lacking due to the poor methodological quality of balneotherapy studies, we were unable to make any conclusions on the effects of intervention. There were frequent flaws regarding the description of excluded RCTs and the assessment of publication bias in several trials. Two of the present authors independently assessed the quality of articles using the AMSTAR checklist. Conclusions Aquatic exercise had a small but statistically significant short-term effect on locomotor diseases. However, the effectiveness of balneotherapy in curing disease or improving health remains unclear. PMID:19881230

The effectiveness of the teach-back method on adherence and self-management in health education for people with chronic disease: a systematic review.

PubMed

Ha Dinh, Thi Thuy; Bonner, Ann; Clark, Robyn; Ramsbotham, Joanne; Hines, Sonia

2016-01-01

Chronic diseases are increasing worldwide and have become a significant burden to those affected by those diseases. Disease-specific education programs have demonstrated improved outcomes, although people do forget information quickly or memorize it incorrectly. The teach-back method was introduced in an attempt to reinforce education to patients. To date, the evidence regarding the effectiveness of health education employing the teach-back method in improved care has not yet been reviewed systematically. This systematic review examined the evidence on using the teach-back method in health education programs for improving adherence and self-management of people with chronic disease. Adults aged 18 years and over with one or more than one chronic disease.All types of interventions which included the teach-back method in an education program for people with chronic diseases. The comparator was chronic disease education programs that did not involve the teach-back method.Randomized and non-randomized controlled trials, cohort studies, before-after studies and case-control studies.The outcomes of interest were adherence, self-management, disease-specific knowledge, readmission, knowledge retention, self-efficacy and quality of life. Searches were conducted in CINAHL, MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science, ProQuest Nursing and Allied Health Source, and Google Scholar databases. Search terms were combined by AND or OR in search strings. Reference lists of included articles were also searched for further potential references. Two reviewers conducted quality appraisal of papers using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. Data were extracted using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument data extraction instruments. There was significant heterogeneity in selected studies, hence a meta-analysis was not possible and the results were presented in narrative form. Of the 21 articles retrieved in full, 12 on the use of the teach-back method met the inclusion criteria and were selected for analysis. Four studies confirmed improved disease-specific knowledge in intervention participants. One study showed a statistically significant improvement in adherence to medication and diet among type 2 diabetics patients in the intervention group compared to the control group (p < 0.001). Two studies found statistically significant improvements in self-efficacy (p = 0.0026 and p < 0.001) in the intervention groups. One study examined quality of life in heart failure patients but the results did not improve from the intervention (p = 0.59). Five studies found a reduction in readmission rates and hospitalization but these were not always statistically significant. Two studies showed improvement in daily weighing among heart failure participants, and in adherence to diet, exercise and foot care among those with type 2 diabetes. Overall, the teach-back method showed positive effects in a wide range of health care outcomes although these were not always statistically significant. Studies in this systematic review revealed improved outcomes in disease-specific knowledge, adherence, self-efficacy and the inhaler technique. There was a positive but inconsistent trend also seen in improved self-care and reduction of hospital readmission rates. There was limited evidence on improvement in quality of life or disease related knowledge retention.Evidence from the systematic review supports the use of the teach-back method in educating people with chronic disease to maximize their disease understanding and promote knowledge, adherence, self-efficacy and self-care skills.Future studies are required to strengthen the evidence on effects of the teach-back method. Larger randomized controlled trials will be needed to determine the effectiveness of the teach-back method in quality of life, reduction of readmission, and hospitalizations.

Accuracy comparison of guided surgery for dental implants according to the tissue of support: a systematic review and meta-analysis.

PubMed

Raico Gallardo, Yolanda Natali; da Silva-Olivio, Isabela Rodrigues Teixeira; Mukai, Eduardo; Morimoto, Susana; Sesma, Newton; Cordaro, Luca

2017-05-01

To systematically assess the current dental literature comparing the accuracy of computer-aided implant surgery when using different supporting tissues (tooth, mucosa, or bone). Two reviewers searched PubMed (1972 to January 2015) and the Cochrane Central Register of Controlled Trials (Central) (2002 to January 2015). For the assessment of accuracy, studies were included with the following outcome measures: (i) angle deviation, (ii) deviation at the entry point, and (iii) deviation at the apex. Eight clinical studies from the 1602 articles initially identified met the inclusion criteria for the qualitative analysis. Four studies (n = 599 implants) were evaluated using meta-analysis. The bone-supported guides showed a statistically significant greater deviation in angle (P < 0.001), entry point (P = 0.01), and the apex (P = 0.001) when compared to the tooth-supported guides. Conversely, when only retrospective studies were analyzed, not significant differences are revealed in the deviation of the entry point and apex. The mucosa-supported guides indicated a statistically significant greater reduction in angle deviation (P = 0.02), deviation at the entry point (P = 0.002), and deviation at the apex (P = 0.04) when compared to the bone-supported guides. Between the mucosa- and tooth-supported guides, there were no statistically significant differences for any of the outcome measures. It can be concluded that the tissue of the guide support influences the accuracy of computer-aided implant surgery. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Traditional Chinese Medicine and Relevant Treatment for the Efficacy and Safety of Atopic Dermatitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PubMed Central

Shi, Zhao-feng; Song, Tie-bing; Xie, Juan; Yan, Yi-quan

2017-01-01

Background Atopic dermatitis (AD) has become a common skin disease that requires systematic and comprehensive treatment to achieve adequate clinical control. Traditional Chinese medicines and related treatments have shown clinical effects for AD in many studies. But the systematic reviews and meta-analyses for them are lacking. Objective The systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were conducted to evaluate the efficacy and safety of traditional Chinese medicines and related treatments for AD treatment. Methods Randomized controlled trials (RCTs) were searched based on standardized searching rules in eight medical databases from the inception up to December 2016 and a total of 24 articles with 1,618 patients were enrolled in this meta-analysis. Results The results revealed that traditional Chinese medicines and related treatments did not show statistical differences in clinical effectiveness, SCORAD amelioration, and SSRI amelioration for AD treatment compared with control group. However, EASI amelioration of traditional Chinese medicines and related treatments for AD was superior to control group. Conclusion We need to make conclusion cautiously for the efficacy and safety of traditional Chinese medicine and related treatment on AD therapy. More standard, multicenter, double-blind randomized controlled trials (RCTs) of traditional Chinese medicine and related treatment for AD were required to be conducted for more clinical evidences providing in the future. PMID:28713436

Statistical design of quantitative mass spectrometry-based proteomic experiments.

PubMed

Oberg, Ann L; Vitek, Olga

2009-05-01

We review the fundamental principles of statistical experimental design, and their application to quantitative mass spectrometry-based proteomics. We focus on class comparison using Analysis of Variance (ANOVA), and discuss how randomization, replication and blocking help avoid systematic biases due to the experimental procedure, and help optimize our ability to detect true quantitative changes between groups. We also discuss the issues of pooling multiple biological specimens for a single mass analysis, and calculation of the number of replicates in a future study. When applicable, we emphasize the parallels between designing quantitative proteomic experiments and experiments with gene expression microarrays, and give examples from that area of research. We illustrate the discussion using theoretical considerations, and using real-data examples of profiling of disease.

Angular filter refractometry analysis using simulated annealing.

PubMed

Angland, P; Haberberger, D; Ivancic, S T; Froula, D H

2017-10-01

Angular filter refractometry (AFR) is a novel technique used to characterize the density profiles of laser-produced, long-scale-length plasmas [Haberberger et al., Phys. Plasmas 21, 056304 (2014)]. A new method of analysis for AFR images was developed using an annealing algorithm to iteratively converge upon a solution. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on the minimization of the χ 2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in an average uncertainty in the density profile of 5%-20% in the region of interest.

Searching for hidden unexpected features in the SnIa data

NASA Astrophysics Data System (ADS)

Shafieloo, A.; Perivolaropoulos, L.

2010-06-01

It is known that κ2 statistic and likelihood analysis may not be sensitive to the all features of the data. Despite of the fact that by using κ2 statistic we can measure the overall goodness of fit for a model confronted to a data set, some specific features of the data can stay undetectable. For instance, it has been pointed out that there is an unexpected brightness of the SnIa data at z > 1 in the Union compilation. We quantify this statement by constructing a new statistic, called Binned Normalized Difference (BND) statistic, which is applicable directly on the Type Ia Supernova (SnIa) distance moduli. This statistic is designed to pick up systematic brightness trends of SnIa data points with respect to a best fit cosmological model at high redshifts. According to this statistic there are 2.2%, 5.3% and 12.6% consistency between the Gold06, Union08 and Constitution09 data and spatially flat ΛCDM model when the real data is compared with many realizations of the simulated monte carlo datasets. The corresponding realization probability in the context of a (w0,w1) = (-1.4,2) model is more than 30% for all mentioned datasets indicating a much better consistency for this model with respect to the BND statistic. The unexpected high z brightness of SnIa can be interpreted either as a trend towards more deceleration at high z than expected in the context of ΛCDM or as a statistical fluctuation or finally as a systematic effect perhaps due to a mild SnIa evolution at high z.

Is low-level laser therapy in relieving neck pain effective? Systematic review and meta-analysis.

PubMed

Kadhim-Saleh, Amjed; Maganti, Harinad; Ghert, Michelle; Singh, Sheila; Farrokhyar, Forough

2013-10-01

The aim of this study is to determine the efficacy of low-level laser therapy (LLLT) in reducing acute and chronic neck pain as measured by the visual analog scale (VAS). A systematic search of nine electronic databases was conducted to identify original articles. For study selection, two reviewers independently assessed titles, abstracts, and full text for eligibility. Methodological quality was assessed using the Detsky scale. Data were analyzed using random-effects model in the presence of heterogeneity and fixed-effect model in its absence. Heterogeneity was assessed using Cochran's Q statistic and quantifying I (2). Risk ratios (RR) with 95 % confidence intervals (CI) were reported. Eight randomized controlled trials involving 443 patients met the strict inclusion criteria. Inter-rater reliability for study selection was 92.8 % (95 % CIs 80.9-100 %) and for methodological quality assessment was 83.9 % (95 % CIs 19.4-96.8 %). Five trials included patients with cervical myofascial pain syndrome (CMPS), and three trials included different patient populations. A meta-analysis of five CMPS trials revealed a mean improvement of VAS score of 10.54 with LLLT (95 % CI 0.37-20.71; Heterogeneity I (2 )= 65 %, P = 0.02). This systematic review provides inconclusive evidence because of significant between-study heterogeneity and potential risk of bias. The benefit seen in the use of LLLT, although statistically significant, does not constitute the threshold of minimally important clinical difference.

The Effectiveness of Corticosteroid Injection for De Quervain’s Stenosing Tenosynovitis (DQST): A Systematic Review and Meta-Analysis

PubMed Central

Rowland, Patrick; Phelan, Nigel; Gardiner, Sean; Linton, Kenneth N; Galvin, Rose

2015-01-01

De Quervain’s stenosing tenosynovitis (DQST) treatments include corticosteroid injection around the tendon sheath; however there is some ambiguity concerning the efficacy of this treatment. The aim of this systematic review and meta-analysis is to examine the totality of evidence relating to the use of corticosteroid injection in DQST when compared to placebo or other active treatments. A systematic literature search was conducted in July 2014. Only randomized control trials (RCTs) were included. Outcome measures included impairment, activity limitation and participation restriction. Five RCTs were identified with 165 patients, 88 in the treatment group and 77 in the control group. Patients who received corticosteroid injection (n=142) had a higher rate of resolution of symptoms [RR 2.59, 95% CI: 1.25 to 5.37, p=0.05, I2=62%]. This group reported greater pain relief as assessed by Visual Analogue Scale (VAS) at first assessment [mean difference -2.51, 95% CI: -3.11 to -1.90, p=0.0003, I2=65%] and demonstrated a statistically significant improvement in function (n=78) as measured by the DASH score and Dutch AIMS-HFF score [SMD -0.83, 95% CI: -1.54 to -0.12, p=0.02, I2=48]. This review confirms that corticosteroid injection results in a statistically significant increase in resolution of symptoms, pain relief and increased function in the treatment of DQST. PMID:26587059

Influence of Japanese consumer gender and age on sensory attributes and preference (a case study on deep-fried peanuts).

PubMed

Miyagi, Atsushi

2017-09-01

Detailed exploration of sensory perception as well as preference across gender and age for a certain food is very useful for developing a vendible food commodity related to physiological and psychological motivation for food preference. Sensory tests including color, sweetness, bitterness, fried peanut aroma, textural preference and overall liking of deep-fried peanuts with varying frying time (2, 4, 6, 9, 12 and 15 min) at 150 °C were carried out using 417 healthy Japanese consumers. To determine the influence of gender and age on sensory evaluation, systematic statistical analysis including one-way analysis of variance, polynomial regression analysis and multiple regression analysis was conducted using the collected data. The results indicated that females were more sensitive to bitterness than males. This may affect sensory preference; female subjects favored peanuts prepared with a shorter frying time more than male subjects did. With advancing age, textural preference played a more important role in overall preference. Older subjects liked deeper-fried peanuts, which are more brittle, more than younger subjects did. In the present study, systematic statistical analysis based on collected sensory evaluation data using deep-fried peanuts was conducted and the tendency of sensory perception and preference across gender and age was clarified. These results may be useful for engineering optimal strategies to target specific segments to gain greater acceptance in the market. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Strong nonadditivity as a key structure-activity relationship feature: distinguishing structural changes from assay artifacts.

PubMed

Kramer, Christian; Fuchs, Julian E; Liedl, Klaus R

2015-03-23

Nonadditivity in protein-ligand affinity data represents highly instructive structure-activity relationship (SAR) features that indicate structural changes and have the potential to guide rational drug design. At the same time, nonadditivity is a challenge for both basic SAR analysis as well as many ligand-based data analysis techniques such as Free-Wilson Analysis and Matched Molecular Pair analysis, since linear substituent contribution models inherently assume additivity and thus do not work in such cases. While structural causes for nonadditivity have been analyzed anecdotally, no systematic approaches to interpret and use nonadditivity prospectively have been developed yet. In this contribution, we lay the statistical framework for systematic analysis of nonadditivity in a SAR series. First, we develop a general metric to quantify nonadditivity. Then, we demonstrate the non-negligible impact of experimental uncertainty that creates apparent nonadditivity, and we introduce techniques to handle experimental uncertainty. Finally, we analyze public SAR data sets for strong nonadditivity and use recourse to the original publications and available X-ray structures to find structural explanations for the nonadditivity observed. We find that all cases of strong nonadditivity (ΔΔpKi and ΔΔpIC50 > 2.0 log units) with sufficient structural information to generate reasonable hypothesis involve changes in binding mode. With the appropriate statistical basis, nonadditivity analysis offers a variety of new attempts for various areas in computer-aided drug design, including the validation of scoring functions and free energy perturbation approaches, binding pocket classification, and novel features in SAR analysis tools.

Social relationships and risk of dementia: A systematic review and meta-analysis of longitudinal cohort studies.

PubMed

Kuiper, Jisca S; Zuidersma, Marij; Oude Voshaar, Richard C; Zuidema, Sytse U; van den Heuvel, Edwin R; Stolk, Ronald P; Smidt, Nynke

2015-07-01

It is unclear to what extent poor social relationships are related to the development of dementia. A comprehensive systematic literature search identified 19 longitudinal cohort studies investigating the association between various social relationship factors and incident dementia in the general population. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled using random-effects meta-analysis. Low social participation (RR: 1.41 (95% CI: 1.13-1.75)), less frequent social contact (RR: 1.57 (95% CI: 1.32-1.85)), and more loneliness (RR: 1.58 (95% CI: 1.19-2.09)) were statistically significant associated with incident dementia. The results of the association between social network size and dementia were inconsistent. No statistically significant association was found for low satisfaction with social network and the onset of dementia (RR: 1.25 (95% CI: 0.96-1.62). We conclude that social relationship factors that represent a lack of social interaction are associated with incident dementia. The strength of the associations between poor social interaction and incident dementia is comparable with other well-established risk factors for dementia, including low education attainment, physical inactivity, and late-life depression. Copyright © 2015 Elsevier B.V. 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.

Combined data preprocessing and multivariate statistical analysis characterizes fed-batch culture of mouse hybridoma cells for rational medium design.

PubMed

Selvarasu, Suresh; Kim, Do Yun; Karimi, Iftekhar A; Lee, Dong-Yup

2010-10-01

We present an integrated framework for characterizing fed-batch cultures of mouse hybridoma cells producing monoclonal antibody (mAb). This framework systematically combines data preprocessing, elemental balancing and statistical analysis technique. Initially, specific rates of cell growth, glucose/amino acid consumptions and mAb/metabolite productions were calculated via curve fitting using logistic equations, with subsequent elemental balancing of the preprocessed data indicating the presence of experimental measurement errors. Multivariate statistical analysis was then employed to understand physiological characteristics of the cellular system. The results from principal component analysis (PCA) revealed three major clusters of amino acids with similar trends in their consumption profiles: (i) arginine, threonine and serine, (ii) glycine, tyrosine, phenylalanine, methionine, histidine and asparagine, and (iii) lysine, valine and isoleucine. Further analysis using partial least square (PLS) regression identified key amino acids which were positively or negatively correlated with the cell growth, mAb production and the generation of lactate and ammonia. Based on these results, the optimal concentrations of key amino acids in the feed medium can be inferred, potentially leading to an increase in cell viability and productivity, as well as a decrease in toxic waste production. The study demonstrated how the current methodological framework using multivariate statistical analysis techniques can serve as a potential tool for deriving rational medium design strategies. Copyright © 2010 Elsevier B.V. All rights reserved.

SystEmatic review and meta-aNAlysis of infanT and young child feeding Practices (ENAT-P) in Ethiopia: protocol

PubMed Central

Islam, Md. Atiqul; Sharew, Nigussie Tadesse; Birhanu, Mulugeta Molla; Tegegne, Balewgizie Sileshi

2017-01-01

Introduction Infant and young child feeding (IYCF) is the cornerstone of infant and child survival, healthy growth and development, healthy future generations and national development. In spite of the importance of optimal nutrition in low- and middle-income countries, there has been no review conducted in Ethiopia. Thus, the aim of this systematic review and meta-analysis is to estimate the national coverage and identify the associated factors of IYCF practices in Ethiopia. Methods PubMed, Scopus, EMBASE, CINHAL, EBSCO, Web of Science and WHO Global Health Library databases will be searched for all available publications from 1 January 2000 to 30 September 2017. All published studies on the timely initiation of breast feeding, exclusive breast feeding and timely initiation of complementary feeding practice in Ethiopia will be screened, selected and reviewed. Bibliographies of identified articles and grey literature will be hand-searched as well. Heterogeneity of studies will be quantified using Higgins’s method where I2 statistic >80% indicates substantial heterogeneity. Funnel plots and Egger’s regression test will be used to assess potential publication bias. The Newcastle–Ottawa Scale (NOS) will be used to assess the quality of evidence and risk of bias. Meta-analysis and meta-regression will be carried out to estimate the pooled national prevalence rate and an OR of each associated factor of IYCF practices. Narrative synthesis will be performed if meta-analysis is not feasible due to the substantial heterogeneity of studies. Ethics and dissemination Ethical clearance is not required for this study because primary data will not be collected. The results of this systematic review and meta-analysis will be published in a peer-reviewed journal and presented at an (inter)national research symposium. Systematic review registration This systematic review and meta-analysis has been registered with the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42017056768. PMID:28775196

Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: a cross-sectional, descriptive analysis

PubMed Central

2011-01-01

Background Cochrane systematic reviews collate and summarise studies of the effects of healthcare interventions. The characteristics of these reviews and the meta-analyses and individual studies they contain provide insights into the nature of healthcare research and important context for the development of relevant statistical and other methods. Methods We classified every meta-analysis with at least two studies in every review in the January 2008 issue of the Cochrane Database of Systematic Reviews (CDSR) according to the medical specialty, the types of interventions being compared and the type of outcome. We provide descriptive statistics for numbers of meta-analyses, numbers of component studies and sample sizes of component studies, broken down by these categories. Results We included 2321 reviews containing 22,453 meta-analyses, which themselves consist of data from 112,600 individual studies (which may appear in more than one meta-analysis). Meta-analyses in the areas of gynaecology, pregnancy and childbirth (21%), mental health (13%) and respiratory diseases (13%) are well represented in the CDSR. Most meta-analyses address drugs, either with a control or placebo group (37%) or in a comparison with another drug (25%). The median number of meta-analyses per review is six (inter-quartile range 3 to 12). The median number of studies included in the meta-analyses with at least two studies is three (inter-quartile range 2 to 6). Sample sizes of individual studies range from 2 to 1,242,071, with a median of 91 participants. Discussion It is clear that the numbers of studies eligible for meta-analyses are typically very small for all medical areas, outcomes and interventions covered by Cochrane reviews. This highlights the particular importance of suitable methods for the meta-analysis of small data sets. There was little variation in number of studies per meta-analysis across medical areas, across outcome data types or across types of interventions being compared. PMID:22114982

Utilization of Clinical Trials Registries in Obstetrics and Gynecology Systematic Reviews.

PubMed

Bibens, Michael E; Chong, A Benjamin; Vassar, Matt

2016-02-01

To evaluate the use of clinical trials registries in published obstetrics and gynecologic systematic reviews and meta-analyses. We performed a metaepidemiologic study of systematic reviews between January 1, 2007, and December 31, 2015, from six obstetric and gynecologic journals (Obstetrics & Gynecology, Obstetrical & Gynecological Survey, Human Reproduction Update, Gynecologic Oncology, British Journal of Obstetrics and Gynaecology, and American Journal of Obstetrics & Gynecology). All systematic reviews included after exclusions were independently reviewed to determine whether clinical trials registries had been included as part of the search process. Studies that reported using a trials registry were further examined to determine whether trial data were included in the analysis of these systematic reviews. Our initial search resulted in 292 articles, which was narrowed to 256 after exclusions. Of the 256 systematic reviews meeting our selection criteria, 47 (18.4%) used a clinical trials registry. Eleven of the 47 (23.4%) systematic reviews found unpublished data and two included unpublished data in their results. A majority of systematic reviews in clinical obstetrics and gynecology journals do not conduct searches of clinical trials registries or do not make use of data obtained from these searches. Failure to make use of such data may lead to an inaccurate summary of available evidence and may contribute to an overrepresentation of published, statistically significant outcomes.

A Systematic Review of the Effectiveness of Antianxiety and Antidepressive Agents for Functional Dyspepsia.

PubMed

Hojo, Mariko; Nagahara, Akihito; Asaoka, Daisuke; Shimada, Yuji; Sasaki, Hitoshi; Matsumoto, Kohei; Takeda, Tsutomu; Ueyama, Hiroya; Matsumoto, Kenshi; Watanabe, Sumio

2017-12-01

Objective Functional dyspepsia (FD) is defined as persistent or recurrent pain or discomfort centered in the upper abdomen without organic disease. Psychosocial factors have been proposed as an important element in the pathophysiology of FD. Therefore, psychotropic agents having antianxiety or antidepressive action are expected to alleviate FD. We previously reported on the treatment of FD using such agents in a systematic review, wherein the effectiveness of the agents on FD was suggested, although there were several limitations. We searched for articles on this subject after our systematic review and re-reviewed them systematically. Methods Articles were searched for in MEDLINE from 2003 to 2014 using terms related to antianxiety or antidepressive agents. Clinical studies in which the effectiveness of such agents was clearly stated were selected from the retrieved articles. The newly selected and previously selected studies were combined, and statistical analyses were carried out. Results Nine studies were selected. Five of the studies indicated a significant symptomatic improvement using psychotropic drugs. A statistical analysis suggested a significant treatment effect of psychotropic agents having antianxiety or antidepressive action [pooled relative risk (PRR), 0.72; 95% confidence interval (95% CI), 0.52-0.99; p=0.0406] but did not show a significant benefit of treatment with agents having an antidepressive action alone (PRR, 0.63; 95% CI, 0.38-1.03; p=0.0665). Conclusion Our systematic review suggested that psychotropic drugs having antianxiety and antidepressive actions as a whole might be effective in alleviating FD symptoms, whereas those having only antidepressive action were not effective.

A Systematic Review of the Effectiveness of Antianxiety and Antidepressive Agents for Functional Dyspepsia

PubMed Central

Hojo, Mariko; Nagahara, Akihito; Asaoka, Daisuke; Shimada, Yuji; Sasaki, Hitoshi; Matsumoto, Kohei; Takeda, Tsutomu; Ueyama, Hiroya; Matsumoto, Kenshi; Watanabe, Sumio

2017-01-01

Objective Functional dyspepsia (FD) is defined as persistent or recurrent pain or discomfort centered in the upper abdomen without organic disease. Psychosocial factors have been proposed as an important element in the pathophysiology of FD. Therefore, psychotropic agents having antianxiety or antidepressive action are expected to alleviate FD. We previously reported on the treatment of FD using such agents in a systematic review, wherein the effectiveness of the agents on FD was suggested, although there were several limitations. We searched for articles on this subject after our systematic review and re-reviewed them systematically. Methods Articles were searched for in MEDLINE from 2003 to 2014 using terms related to antianxiety or antidepressive agents. Clinical studies in which the effectiveness of such agents was clearly stated were selected from the retrieved articles. The newly selected and previously selected studies were combined, and statistical analyses were carried out. Results Nine studies were selected. Five of the studies indicated a significant symptomatic improvement using psychotropic drugs. A statistical analysis suggested a significant treatment effect of psychotropic agents having antianxiety or antidepressive action [pooled relative risk (PRR), 0.72; 95% confidence interval (95% CI), 0.52-0.99; p=0.0406] but did not show a significant benefit of treatment with agents having an antidepressive action alone (PRR, 0.63; 95% CI, 0.38-1.03; p=0.0665). Conclusion Our systematic review suggested that psychotropic drugs having antianxiety and antidepressive actions as a whole might be effective in alleviating FD symptoms, whereas those having only antidepressive action were not effective. PMID:29021437

Charm dimuon production in neutrino-nucleon interactions in the NOMAD experiment

NASA Astrophysics Data System (ADS)

Petti, Roberto; Samoylov, Oleg

2012-09-01

We present our new measurement of charm dimuon production in neutrino-iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15,340 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample (about 9 million events after all analysis cuts) to constrain the total systematic uncertainty to about 2%. The extraction of strange sea and charm production parameters is also discussed.

Charm dimuon production in neutrino-nucleon interactions in the NOMAD experiment

NASA Astrophysics Data System (ADS)

Petti, R.; Samoylov, O. B.

2011-12-01

We present our new measurement of charm dimuon production in neutrino-iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15,340 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample (about 9 million events after all analysis cuts) to constrain the total systematic uncertainty to ˜2%. The extraction of strange sea and charm production parameters is also discussed.

The Effects of Perioperative Music Interventions in Pediatric Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PubMed

van der Heijden, Marianne J E; Oliai Araghi, Sadaf; van Dijk, Monique; Jeekel, Johannes; Hunink, M G Myriam

2015-01-01

Music interventions are widely used, but have not yet gained a place in guidelines for pediatric surgery or pediatric anesthesia. In this systematic review and meta-analysis we examined the effects of music interventions on pain, anxiety and distress in children undergoing invasive surgery. We searched 25 electronic databases from their first available date until October 2014. Included were all randomized controlled trials with a parallel group, crossover or cluster design that included pediatric patients from 1 month to 18 years old undergoing minimally invasive or invasive surgical procedures, and receiving either live music therapy or recorded music. 4846 records were retrieved from the searches, 26 full text reports were evaluated and data was extracted by two independent investigators. Pain was measured with the Visual Analogue Scale, the Coloured Analogue Scale and the Facial Pain Scale. Anxiety and distress were measured with an emotional index scale (not validated), the Spielberger short State Trait Anxiety Inventory and a Facial Affective Scale. Three RCTs were eligible for inclusion encompassing 196 orthopedic, cardiac and day surgery patients (age of 1 day to 18 years) receiving either live music therapy or recorded music. Overall a statistically significant positive effect was demonstrated on postoperative pain (SMD -1.07; 95%CI-2.08; -0.07) and on anxiety and distress (SMD -0.34 95% CI -0.66; -0.01 and SMD -0.50; 95% CI -0.84; - 0.16. This systematic review and meta-analysis indicates that music interventions may have a statistically significant effect in reducing post-operative pain, anxiety and distress in children undergoing a surgical procedure. Evidence from this review and other reviews suggests music therapy may be considered for clinical use.

Associations of health literacy with diabetic foot outcomes: a systematic review and meta-analysis.

PubMed

Chen, P Y; Elmer, S; Callisaya, M; Wills, K; Greenaway, T M; Winzenberg, T M

2018-05-26

People with diabetes have low health literacy, but the role of the latter in diabetic foot disease is unclear. To determine, through a systematic review and meta-analysis, if health literacy is associated with diabetic foot disease, its risk factors, or foot care. We searched PubMed, EMBASE, CINAHL, Web of Science, Scopus and Science Direct. All studies were screened and data extracted by two independent reviewers. Studies in English with valid and reliable measures of health literacy and published tests of association were included. Data were extracted on the associations between the outcomes and health literacy. Meta-analyses were performed using random effects models. Sixteen articles were included in the systematic review, with 11 in the meta-analysis. In people with inadequate health literacy, the odds of having diabetic foot disease were twice those in people with adequate health literacy, but this was not statistically significant [odds ratio 1.99 (95% CI 0.83, 4.78); two studies in 1278 participants]. There was no statistically significant difference in health literacy levels between people with and without peripheral neuropathy [standardized mean difference -0.14 (95% CI -0.47, 0.18); two studies in 399 participants]. There was no association between health literacy and foot care [correlation coefficient 0.01 (95% CI -0.07, 0.10); seven studies in 1033 participants]. There were insufficient data to exclude associations between health literacy and diabetic foot disease and its risk factors, but health literacy appears unlikely to have a role in foot care. The contribution of low health literacy to diabetic foot disease requires definitive assessment through robust longitudinal studies. © 2018 Diabetes UK.

Quality of care in for-profit and not-for-profit nursing homes: systematic review and meta-analysis

PubMed Central

Comondore, Vikram R; Zhou, Qi; Stone, Samuel B; Busse, Jason W; Ravindran, Nikila C; Burns, Karen E; Haines, Ted; Stringer, Bernadette; Cook, Deborah J; Walter, Stephen D; Sullivan, Terrence; Berwanger, Otavio; Bhandari, Mohit; Banglawala, Sarfaraz; Lavis, John N; Petrisor, Brad; Schünemann, Holger; Walsh, Katie; Bhatnagar, Neera; Guyatt, Gordon H

2009-01-01

Objective To compare quality of care in for-profit and not-for-profit nursing homes. Design Systematic review and meta-analysis of observational studies and randomised controlled trials investigating quality of care in for-profit versus not-for-profit nursing homes. Results A comprehensive search yielded 8827 citations, of which 956 were judged appropriate for full text review. Study characteristics and results of 82 articles that met inclusion criteria were summarised, and results for the four most frequently reported quality measures were pooled. Included studies reported results dating from 1965 to 2003. In 40 studies, all statistically significant comparisons (P<0.05) favoured not-for-profit facilities; in three studies, all statistically significant comparisons favoured for-profit facilities, and the remaining studies had less consistent findings. Meta-analyses suggested that not-for-profit facilities delivered higher quality care than did for-profit facilities for two of the four most frequently reported quality measures: more or higher quality staffing (ratio of effect 1.11, 95% confidence interval 1.07 to 1.14, P<0.001) and lower pressure ulcer prevalence (odds ratio 0.91, 95% confidence interval 0.83 to 0.98, P=0.02). Non-significant results favouring not-for-profit homes were found for the two other most frequently used measures: physical restraint use (odds ratio 0.93, 0.82 to 1.05, P=0.25) and fewer deficiencies in governmental regulatory assessments (ratio of effect 0.90, 0.78 to 1.04, P=0.17). Conclusions This systematic review and meta-analysis of the evidence suggests that, on average, not-for-profit nursing homes deliver higher quality care than do for-profit nursing homes. Many factors may, however, influence this relation in the case of individual institutions. PMID:19654184

Does the piezoelectric surgical technique produce fewer postoperative sequelae after lower third molar surgery than conventional rotary instruments? A systematic review and meta analysis.

PubMed

Al-Moraissi, E A; Elmansi, Y A; Al-Sharaee, Y A; Alrmali, A E; Alkhutari, A S

2016-03-01

A systematic review and meta-analysis was conducted to answer the clinical question "Does the piezoelectric surgical technique produce fewer postoperative sequelae after lower third molar surgery than conventional rotary instruments?" A systematic and electronic search of several databases with specific key words, a reference search, and a manual search were performed from respective dates of inception through November 2014. The inclusion criteria were clinical human studies, including randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies, with the aim of comparing the piezoelectric surgical osteotomy technique to the standard rotary instrument technique in lower third molar surgery. Postoperative sequelae (oedema, trismus, and pain), the total number of analgesics taken, and the duration of surgery were analyzed. A total of nine articles were included, six RCTs, two CCTs, and one retrospective study. Six studies had a low risk of bias and three had a moderate risk of bias. A statistically significant difference was found between piezoelectric surgery and conventional rotary instrument surgery for lower third molar extraction with regard to postoperative sequelae (oedema, trismus, and pain) and the total number of analgesics taken (P=0.0001, P=0.0001, P<0.00001, and P<0.0001, respectively). However, a statistically significant increased surgery time was required in the piezoelectric osteotomy group (P<0.00001). The results of the meta-analysis showed that piezoelectric surgery significantly reduced the occurrence of postoperative sequelae (oedema, trismus, and pain) and the total number of analgesics taken compared to the conventional rotary instrument technique in lower third molar surgery, but required a longer surgery time. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

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.

Analysis of determinations of the distance between the sun and the galactic center

NASA Astrophysics Data System (ADS)

Malkin, Z. M.

2013-02-01

The paper investigates the question of whether or not determinations of the distance between the Sun and the Galactic center R 0 are affected by the so-called "bandwagon effect", leading to selection effects in published data that tend to be close to expected values, as was suggested by some authors. It is difficult to estimate numerically a systematic uncertainty in R 0 due to the bandwagon effect; however, it is highly probable that, even if widely accepted values differ appreciably from the true value, the published results should eventually approach the true value despite the bandwagon effect. This should be manifest as a trend in the published R 0 data: if this trend is statistically significant, the presence of the bandwagon effect can be suspected in the data. Fifty two determinations of R 0 published over the last 20 years were analyzed. These data reveal no statistically significant trend, suggesting they are unlikely to involve any systematic uncertainty due to the bandwagon effect. At the same time, the published data show a gradual and statistically significant decrease in the uncertainties in the R 0 determinations with time.

A guide to understanding meta-analysis.

PubMed

Israel, Heidi; Richter, Randy R

2011-07-01

With the focus on evidence-based practice in healthcare, a well-conducted systematic review that includes a meta-analysis where indicated represents a high level of evidence for treatment effectiveness. The purpose of this commentary is to assist clinicians in understanding meta-analysis as a statistical tool using both published articles and explanations of components of the technique. We describe what meta-analysis is, what heterogeneity is, and how it affects meta-analysis, effect size, the modeling techniques of meta-analysis, and strengths and weaknesses of meta-analysis. Common components like forest plot interpretation, software that may be used, special cases for meta-analysis, such as subgroup analysis, individual patient data, and meta-regression, and a discussion of criticisms, are included.

What does my neighbourhood have to do with my weight? A protocol for systematic review and meta-analysis of the association between neighbourhood socioeconomic status and body weight.

PubMed

Mohammed, Shimels Hussien; Birhanu, Mulugeta Molla; Sissay, Tesfamichael Awoke; Habtewold, Tesfa Dejenie; Tegegn, Balewgizie Sileshi; Esmaillzadeh, Ahmad

2017-09-27

Individuals living in poor neighbourhoods are at a higher risk of overweight/obesity. There is no systematic review and meta-analysis study on the association of neighbourhood socioeconomic status (NSES) with overweight/obesity. We aimed to systematically review and meta-analyse the existing evidence on the association of NSES with overweight/obesity. Cross-sectional, case-control and cohort studies published in English from inception to 15 May 2017 will be systematically searched using the following databases: PubMed, EMBASE, Web of Sciences and Google Scholar. Selection, screening, reviewing and data extraction will be done by two reviewers, independently and in duplicate. The Newcastle-Ottawa Scale (NOS) will be used to assess the quality of evidence. Publication bias will be checked by visual inspection of funnel plots and Egger's regression test. Heterogeneity will be checked by Higgins's method (I 2 statistics). Meta-analysis will be done to estimate the pooled OR. Narrative synthesis will be performed if meta-analysis is not feasible due to high heterogeneity of studies. Ethical clearance is not required as we will be using data from published articles. Findings will be communicated through a publication in a peer-reviewed journal and presentations at professional conferences. CRD42017063889. © 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.

Arthroscopic Debridement for Primary Degenerative Osteoarthritis of the Elbow Leads to Significant Improvement in Range of Motion and Clinical Outcomes: A Systematic Review.

PubMed

Sochacki, Kyle R; Jack, Robert A; Hirase, Takashi; McCulloch, Patrick C; Lintner, David M; Liberman, Shari R; Harris, Joshua D

2017-12-01

The purpose of this investigation was to determine whether arthroscopic debridement of primary elbow osteoarthritis results in statistically significant and clinically relevant improvement in (1) elbow range of motion and (2) clinical outcomes with (3) low complication and reoperation rates. A systematic review was registered with PROSPERO and performed using PRISMA guidelines. Databases were searched for studies that investigated the outcomes of arthroscopic debridement for the treatment of primary osteoarthritis of the elbow in adult human patients. Study methodological quality was analyzed. Studies that included post-traumatic arthritis were excluded. Elbow motion and all elbow-specific patient-reported outcome scores were eligible for analysis. Comparisons between preoperative and postoperative values from each study were made using 2-sample Z-tests (http://in-silico.net/tools/statistics/ztest) using a P value < .05. Nine articles (209 subjects, 213 elbows, 187 males, 22 females, mean age 45.7 ± 7.1 years, mean follow-up 41.7 ± 16.3. months; 75% right, 25% left; 79% dominant elbow, 21% nondominant) were analyzed. Elbow extension (23.4°-10.7°, Δ 12.7°), flexion (115.9°-128.7°, Δ 12.8°), and global arc of motion (94.5°-117.6°, Δ 23.1°) had statistically significant and clinically relevant improvement following arthroscopic debridement (P < .0001 for all). There was also a statistically significant (P < .0001) and clinically relevant improvement in the Mayo Elbow Performance Score (60.7-84.6, Δ 23.9) postoperatively. Six patients (2.8%) had postoperative complications. Nine (4.2%) underwent reoperation. Elbow arthroscopic debridement for primary degenerative osteoarthritis results in statistically significant and clinically relevant improvement in elbow range of motion and clinical outcomes with low complication and reoperation rates. Systematic review of level IV studies. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The emergence of modern statistics in agricultural science: analysis of variance, experimental design and the reshaping of research at Rothamsted Experimental Station, 1919-1933.

PubMed

Parolini, Giuditta

2015-01-01

During the twentieth century statistical methods have transformed research in the experimental and social sciences. Qualitative evidence has largely been replaced by quantitative results and the tools of statistical inference have helped foster a new ideal of objectivity in scientific knowledge. The paper will investigate this transformation by considering the genesis of analysis of variance and experimental design, statistical methods nowadays taught in every elementary course of statistics for the experimental and social sciences. These methods were developed by the mathematician and geneticist R. A. Fisher during the 1920s, while he was working at Rothamsted Experimental Station, where agricultural research was in turn reshaped by Fisher's methods. Analysis of variance and experimental design required new practices and instruments in field and laboratory research, and imposed a redistribution of expertise among statisticians, experimental scientists and the farm staff. On the other hand the use of statistical methods in agricultural science called for a systematization of information management and made computing an activity integral to the experimental research done at Rothamsted, permanently integrating the statisticians' tools and expertise into the station research programme. Fisher's statistical methods did not remain confined within agricultural research and by the end of the 1950s they had come to stay in psychology, sociology, education, chemistry, medicine, engineering, economics, quality control, just to mention a few of the disciplines which adopted them.

Relationship between sarcopenia and physical activity in older people: a systematic review and meta-analysis

PubMed Central

Steffl, Michal; Bohannon, Richard W; Sontakova, Lenka; Tufano, James J; Shiells, Kate; Holmerova, Iva

2017-01-01

Physical activity (PA) has been identified as beneficial for many diseases and health disorders, including sarcopenia. The positive influence of PA interventions on sarcopenia has been described previously on many occasions. Current reviews on the topic include studies with varied PA interventions for sarcopenia; nevertheless, no systematic review exploring the effects of PA in general on sarcopenia has been published. The main aim of this study was to explore the relationship between PA and sarcopenia in older people on the basis of cross-sectional and cohort studies. We searched PubMed, Scopus, EBSCOhost, and ScienceDirect for articles addressing the relationship between PA and sarcopenia. Twenty-five articles were ultimately included in the qualitative and quantitative syntheses. A statistically significant association between PA and sarcopenia was documented in most of the studies, as well as the protective role of PA against sarcopenia development. Furthermore, the meta-analysis indicated that PA reduces the odds of acquiring sarcopenia in later life (odds ratio [OR] =0.45; 95% confidence interval [CI] 0.37–0.55). The results of this systematic review and meta-analysis confirm the beneficial influence of PA in general for the prevention of sarcopenia. PMID:28553092

Relationship between sarcopenia and physical activity in older people: a systematic review and meta-analysis.

PubMed

Steffl, Michal; Bohannon, Richard W; Sontakova, Lenka; Tufano, James J; Shiells, Kate; Holmerova, Iva

2017-01-01

Physical activity (PA) has been identified as beneficial for many diseases and health disorders, including sarcopenia. The positive influence of PA interventions on sarcopenia has been described previously on many occasions. Current reviews on the topic include studies with varied PA interventions for sarcopenia; nevertheless, no systematic review exploring the effects of PA in general on sarcopenia has been published. The main aim of this study was to explore the relationship between PA and sarcopenia in older people on the basis of cross-sectional and cohort studies. We searched PubMed, Scopus, EBSCO host , and ScienceDirect for articles addressing the relationship between PA and sarcopenia. Twenty-five articles were ultimately included in the qualitative and quantitative syntheses. A statistically significant association between PA and sarcopenia was documented in most of the studies, as well as the protective role of PA against sarcopenia development. Furthermore, the meta-analysis indicated that PA reduces the odds of acquiring sarcopenia in later life (odds ratio [OR] =0.45; 95% confidence interval [CI] 0.37-0.55). The results of this systematic review and meta-analysis confirm the beneficial influence of PA in general for the prevention of sarcopenia.

A Preliminary Investigation of Systematic Noise in Data Acquired with the Airborne Imaging Spectrometer

NASA Technical Reports Server (NTRS)

Masuoka, E.

1985-01-01

Systematic noise is present in Airborne Imaging Spectrometer (AIS) data collected on October 26, 1983 and May 5, 1984 in grating position 0 (1.2 to 1.5 microns). In the October data set the noise occurs as 135 scan lines of low DN's every 270 scan lines. The noise is particularly bad in bands nine through thirty, restricting effective analysis to at best ten of the 32 bands. In the May data the regions of severe noise have been eliminated, but systematic noise is present with three frequencies (3, 106 and 200 scan lines) in all thirty two bands. The periodic nature of the noise in both data sets suggests that it could be removed as part of routine processing. This is necessary before classification routines or statistical analyses are used with these data.

Effectiveness of orthodontic miniscrew implants in anchorage reinforcement during en-masse retraction: A systematic review and meta-analysis.

PubMed

Antoszewska-Smith, Joanna; Sarul, Michał; Łyczek, Jan; Konopka, Tomasz; Kawala, Beata

2017-03-01

The aim of this systematic review was to compare the effectiveness of orthodontic miniscrew implants-temporary intraoral skeletal anchorage devices (TISADs)-in anchorage reinforcement during en-masse retraction in relation to conventional methods of anchorage. A search of PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science was performed. The keywords were orthodontic, mini-implants, miniscrews, miniplates, and temporary anchorage device. Relevant articles were assessed for quality according to Cochrane guidelines and the data extracted for statistical analysis. A meta-analysis of raw mean differences concerning anchorage loss, tipping of molars, retraction of incisors, tipping of incisors, and treatment duration was carried out. Initially, we retrieved 10,038 articles. The selection process finally resulted in 14 articles including 616 patients (451 female, 165 male) for detailed analysis. Quality of the included studies was assessed as moderate. Meta-analysis showed that use of TISADs facilitates better anchorage reinforcement compared with conventional methods. On average, TISADs enabled 1.86 mm more anchorage preservation than did conventional methods (P <0.001). The results of the meta-analysis showed that TISADs are more effective than conventional methods of anchorage reinforcement. The average difference of 2 mm seems not only statistically but also clinically significant. However, the results should be interpreted with caution because of the moderate quality of the included studies. More high-quality studies on this issue are necessary to enable drawing more reliable conclusions. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

SU-E-CAMPUS-J-05: Quantitative Investigation of Random and Systematic Uncertainties From Hardware and Software Components in the Frameless 6DBrainLAB ExacTrac System

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

Keeling, V; Jin, H; Hossain, S

2014-06-15

Purpose: To evaluate setup accuracy and quantify individual systematic and random errors for the various hardware and software components of the frameless 6D-BrainLAB ExacTrac system. Methods: 35 patients with cranial lesions, some with multiple isocenters (50 total lesions treated in 1, 3, 5 fractions), were investigated. All patients were simulated with a rigid head-and-neck mask and the BrainLAB localizer. CT images were transferred to the IPLAN treatment planning system where optimized plans were generated using stereotactic reference frame based on the localizer. The patients were setup initially with infrared (IR) positioning ExacTrac system. Stereoscopic X-ray images (XC: X-ray Correction) weremore » registered to their corresponding digitally-reconstructed-radiographs, based on bony anatomy matching, to calculate 6D-translational and rotational (Lateral, Longitudinal, Vertical, Pitch, Roll, Yaw) shifts. XC combines systematic errors of the mask, localizer, image registration, frame, and IR. If shifts were below tolerance (0.7 mm translational and 1 degree rotational), treatment was initiated; otherwise corrections were applied and additional X-rays were acquired to verify patient position (XV: X-ray Verification). Statistical analysis was used to extract systematic and random errors of the different components of the 6D-ExacTrac system and evaluate the cumulative setup accuracy. Results: Mask systematic errors (translational; rotational) were the largest and varied from one patient to another in the range (−15 to 4mm; −2.5 to 2.5degree) obtained from mean of XC for each patient. Setup uncertainty in IR positioning (0.97,2.47,1.62mm;0.65,0.84,0.96degree) was extracted from standard-deviation of XC. Combined systematic errors of the frame and localizer (0.32,−0.42,−1.21mm; −0.27,0.34,0.26degree) was extracted from mean of means of XC distributions. Final patient setup uncertainty was obtained from the standard deviations of XV (0.57,0.77,0.67mm,0.39,0.35,0.30degree). Conclusion: Statistical analysis was used to calculate cumulative and individual systematic errors from the different hardware and software components of the 6D-ExacTrac-system. Patients were treated with cumulative errors (<1mm,<1degree) with XV image guidance.« less

Is there a social gradient of sarcopenia? A meta-analysis and systematic review protocol.

PubMed

Green, Darci; Duque, Gustavo; Fredman, Nick; Rizvi, Aoun; Brennan-Olsen, Sharon Lee

2018-01-13

Sarcopenia (or loss of muscle mass and function) is a relatively new area within the field of musculoskeletal research and medicine. Investigating whether there is a social gradient, including occupation type and income level, of sarcopenia, as observed for other diseases, will contribute significantly to the limited evidence base for this disease. This new information may inform the prevention and management of sarcopenia and widen the evidence base to support existing and future health campaigns. We will conduct a systematic search of the databases PubMed, Ovid, CINAHL, Scopus and EMBASE to identify articles that investigate associations between social determinants of health and sarcopenia in adults aged 50 years and older. Eligibility of the selected studies will be determined by two independent reviewers. The methodological quality of eligible studies will be assessed according to predetermined criteria. Established statistical methods to identify and control for heterogeneity will be used, and where appropriate, we will conduct a meta-analysis. In the event that heterogeneity prevents numerical synthesis, a best evidence analysis will be employed. This systematic review protocol adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols reporting guidelines and will be registered with the International Prospective Register of Systematic Reviews (PROSPERO). This systematic review will use published data, thus ethical permissions will not be required. In addition to peer-reviewed publication, our results will be presented at (inter)national conferences relevant to the field of sarcopenia, ageing and/or musculoskeletal health and disseminated both electronically and in print. CRD42017072253. © 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.

Extracting semantic representations from word co-occurrence statistics: stop-lists, stemming, and SVD.

PubMed

Bullinaria, John A; Levy, Joseph P

2012-09-01

In a previous article, we presented a systematic computational study of the extraction of semantic representations from the word-word co-occurrence statistics of large text corpora. The conclusion was that semantic vectors of pointwise mutual information values from very small co-occurrence windows, together with a cosine distance measure, consistently resulted in the best representations across a range of psychologically relevant semantic tasks. This article extends that study by investigating the use of three further factors--namely, the application of stop-lists, word stemming, and dimensionality reduction using singular value decomposition (SVD)--that have been used to provide improved performance elsewhere. It also introduces an additional semantic task and explores the advantages of using a much larger corpus. This leads to the discovery and analysis of improved SVD-based methods for generating semantic representations (that provide new state-of-the-art performance on a standard TOEFL task) and the identification and discussion of problems and misleading results that can arise without a full systematic study.

Dietary patterns and risk of colorectal adenoma: a systematic review and meta-analysis of observational studies.

PubMed

Godos, J; Bella, F; Torrisi, A; Sciacca, S; Galvano, F; Grosso, G

2016-12-01

Current evidence suggests that dietary patterns may play an important role in colorectal cancer risk. The present study aimed to perform a systematic review and meta-analysis of observational studies exploring the association between dietary patterns and colorectal adenomas (a precancerous condition). Pubmed and EMBASE electronic databases were systematically searched to retrieve eligible studies. Only studies exploring the risk or association with colorectal adenomas for the highest versus lowest category of exposure to a posteriori dietary patterns were included in the quantitative analysis. Random-effects models were applied to calculate relative risks (RRs) of colorectal adenomas for high adherence to healthy or unhealthy dietary patterns. Statistical heterogeneity and publication bias were explored. Twelve studies were reviewed. Three studies explored a priori dietary patterns using scores identifying adherence to the Mediterranean, Paleolithic and Dietary Approaches to Stop Hypertension (DASH) diet and reported an association with decreased colorectal adenoma risk. Two studies tested the association with colorectal adenomas between a posteriori dietary patterns showing lower odds of disease related to plant-based compared to meat-based dietary patterns. Seven studies identified 23 a posteriori dietary patterns and the analysis revealed that higher adherence to healthy and unhealthy dietary patterns was significantly associated risk of colorectal adenomas (RR = 0.81, 95% confidence interval = 0.71, 0.94 and RR = 1.24, 95% confidence interval = 1.13, 1.35, respectively) with no evidence of heterogeneity or publication bias. The results of this systematic review and meta-analysis indicate that dietary patterns may be associated with the risk of colorectal adenomas. © 2016 The British Dietetic Association Ltd.

T-scan III system diagnostic tool for digital occlusal analysis in orthodontics - a modern approach.

PubMed

Trpevska, Vesna; Kovacevska, Gordana; Benedeti, Alberto; Jordanov, Bozidar

2014-01-01

This systematic literature review was performed to establish the mechanism, methodology, characteristics, clinical application and opportunities of the T-Scan III System as a diagnostic tool for digital occlusal analysis in different fields of dentistry, precisely in orthodontics. Searching of electronic databases, using MEDLINE and PubMed, hand searching of relevant key journals, and screening of reference lists of included studies with no language restriction was performed. Publications providing statistically examined data were included for systematic review. Twenty potentially relevant Randomized Controlled Trials (RCTs) were identified. Only ten met the inclusion criteria. The literature demonstrates that using digital occlusal analysis with T-Scan III System in orthodontics has significant advantage with regard to the capability of measuring occlusal parameters in static positions and during dynamic of the mandible. Within the scope of this systematic review, there is evidence to support that T-Scan system is rapid and accurate in identifying the distribution of the tooth contacts and it shows great promise as a clinical diagnostic screening device for occlusion and for improving the occlusion after various dental treatments. Additional clinical studies are required to advance the indication filed of this system. Importance of using digital occlusal T-Scan analysis in orthodontics deserves further investigation.

Herbal Medicine for Hot Flushes Induced by Endocrine Therapy in Women with Breast Cancer: A Systematic Review and Meta-Analysis.

PubMed

Li, Yuanqing; Zhu, Xiaoshu; Bensussan, Alan; Li, Pingping; Moylan, Eugene; Delaney, Geoff; McPherson, Luke

2016-01-01

Objective. This systematic review was conducted to evaluate the clinical effectiveness and safety of herbal medicine (HM) as an alternative management for hot flushes induced by endocrine therapy in breast cancer patients. Methods. Key English and Chinese language databases were searched from inception to July 2015. Randomized Controlled Trials (RCTs) evaluating the effects of HM on hot flushes induced by endocrine therapy in women with breast cancer were retrieved. We conducted data collection and analysis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. Statistical analysis was performed with the software (Review Manager 5.3). Results. 19 articles were selected from the articles retrieved, and 5 articles met the inclusion criteria for analysis. Some included individual studies showed that HM can relieve hot flushes as well as other menopausal symptoms induced by endocrine therapy among women with breast cancer and improve the quality of life. There are minor side effects related to HM which are well tolerated. Conclusion. Given the small number of included studies and relatively poor methodological quality, there is insufficient evidence to draw positive conclusions regarding the objective benefit of HM. Additional high quality studies are needed with more rigorous methodological approach to answer this question.

Multimodal interventions including nutrition in the prevention and management of disease-related malnutrition in adults: a systematic review of randomised control trials.

PubMed

Thorne, Frances; Baldwin, Christine

2014-06-01

There has been a move to improve nutritional status in malnourished patients through the use of multimodal interventions (MI). There are currently no systematic reviews that have examined their effectiveness. This analysis aimed to examine the effects on nutritional, clinical, functional and patient-centred outcomes. A systematic review and meta-analysis using Cochrane methodology. 15 studies were included in the analysis, 13 comparing MI with usual care and 2 comparing MI with a nutrition intervention alone. Quality of studies varied and studies reported few relevant outcomes. Only 3 outcomes were compatible with meta-analysis; weight, mortality and length of stay (LOS). No statistically significant differences between groups were found. Narrative review was inconclusive. There was no evidence of benefit in the intervention groups in relation to body composition, functional status or quality of life (QoL). Intervention groups appeared to show a trend towards increased energy and protein intake however data was provided by only 2 studies (301 participants). No conclusive evidence of benefit for MI on any of the reviewed outcomes was found. Well designed, high quality trials addressing the impact of MI on relevant nutritional, functional and clinical outcomes are required. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

The Accuracy of GBM GRB Localizations

NASA Astrophysics Data System (ADS)

Briggs, Michael Stephen; Connaughton, V.; Meegan, C.; Hurley, K.

2010-03-01

We report an study of the accuracy of GBM GRB localizations, analyzing three types of localizations: those produced automatically by the GBM Flight Software on board GBM, those produced automatically with ground software in near real time, and localizations produced with human guidance. The two types of automatic locations are distributed in near real-time via GCN Notices; the human-guided locations are distributed on timescale of many minutes or hours using GCN Circulars. This work uses a Bayesian analysis that models the distribution of the GBM total location error by comparing GBM locations to more accurate locations obtained with other instruments. Reference locations are obtained from Swift, Super-AGILE, the LAT, and with the IPN. We model the GBM total location errors as having systematic errors in addition to the statistical errors and use the Bayesian analysis to constrain the systematic errors.

Flux control coefficients determined by inhibitor titration: the design and analysis of experiments to minimize errors.

PubMed Central

Small, J R

1993-01-01

This paper is a study into the effects of experimental error on the estimated values of flux control coefficients obtained using specific inhibitors. Two possible techniques for analysing the experimental data are compared: a simple extrapolation method (the so-called graph method) and a non-linear function fitting method. For these techniques, the sources of systematic errors are identified and the effects of systematic and random errors are quantified, using both statistical analysis and numerical computation. It is shown that the graph method is very sensitive to random errors and, under all conditions studied, that the fitting method, even under conditions where the assumptions underlying the fitted function do not hold, outperformed the graph method. Possible ways of designing experiments to minimize the effects of experimental errors are analysed and discussed. PMID:8257434

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.

Methods to systematically review and meta-analyse observational studies: a systematic scoping review of recommendations.

PubMed

Mueller, Monika; D'Addario, Maddalena; Egger, Matthias; Cevallos, Myriam; Dekkers, Olaf; Mugglin, Catrina; Scott, Pippa

2018-05-21

Systematic reviews and meta-analyses of observational studies are frequently performed, but no widely accepted guidance is available at present. We performed a systematic scoping review of published methodological recommendations on how to systematically review and meta-analyse observational studies. We searched online databases and websites and contacted experts in the field to locate potentially eligible articles. We included articles that provided any type of recommendation on how to conduct systematic reviews and meta-analyses of observational studies. We extracted and summarised recommendations on pre-defined key items: protocol development, research question, search strategy, study eligibility, data extraction, dealing with different study designs, risk of bias assessment, publication bias, heterogeneity, statistical analysis. We summarised recommendations by key item, identifying areas of agreement and disagreement as well as areas where recommendations were missing or scarce. The searches identified 2461 articles of which 93 were eligible. Many recommendations for reviews and meta-analyses of observational studies were transferred from guidance developed for reviews and meta-analyses of RCTs. Although there was substantial agreement in some methodological areas there was also considerable disagreement on how evidence synthesis of observational studies should be conducted. Conflicting recommendations were seen on topics such as the inclusion of different study designs in systematic reviews and meta-analyses, the use of quality scales to assess the risk of bias, and the choice of model (e.g. fixed vs. random effects) for meta-analysis. There is a need for sound methodological guidance on how to conduct systematic reviews and meta-analyses of observational studies, which critically considers areas in which there are conflicting recommendations.

Inference from the small scales of cosmic shear with current and future Dark Energy Survey data

DOE PAGES

MacCrann, N.; Aleksić, J.; Amara, A.; ...

2016-11-05

Cosmic shear is sensitive to fluctuations in the cosmological matter density field, including on small physical scales, where matter clustering is affected by baryonic physics in galaxies and galaxy clusters, such as star formation, supernovae feedback and AGN feedback. While muddying any cosmological information that is contained in small scale cosmic shear measurements, this does mean that cosmic shear has the potential to constrain baryonic physics and galaxy formation. We perform an analysis of the Dark Energy Survey (DES) Science Verification (SV) cosmic shear measurements, now extended to smaller scales, and using the Mead et al. 2015 halo model tomore » account for baryonic feedback. While the SV data has limited statistical power, we demonstrate using a simulated likelihood analysis that the final DES data will have the statistical power to differentiate among baryonic feedback scenarios. We also explore some of the difficulties in interpreting the small scales in cosmic shear measurements, presenting estimates of the size of several other systematic effects that make inference from small scales difficult, including uncertainty in the modelling of intrinsic alignment on nonlinear scales, `lensing bias', and shape measurement selection effects. For the latter two, we make use of novel image simulations. While future cosmic shear datasets have the statistical power to constrain baryonic feedback scenarios, there are several systematic effects that require improved treatments, in order to make robust conclusions about baryonic feedback.« less

Statistics of baryon correlation functions in lattice QCD

NASA Astrophysics Data System (ADS)

Wagman, Michael L.; Savage, Martin J.; Nplqcd Collaboration

2017-12-01

A systematic analysis of the structure of single-baryon correlation functions calculated with lattice QCD is performed, with a particular focus on characterizing the structure of the noise associated with quantum fluctuations. The signal-to-noise problem in these correlation functions is shown, as long suspected, to result from a sign problem. The log-magnitude and complex phase are found to be approximately described by normal and wrapped normal distributions respectively. Properties of circular statistics are used to understand the emergence of a large time noise region where standard energy measurements are unreliable. Power-law tails in the distribution of baryon correlation functions, associated with stable distributions and "Lévy flights," are found to play a central role in their time evolution. A new method of analyzing correlation functions is considered for which the signal-to-noise ratio of energy measurements is constant, rather than exponentially degrading, with increasing source-sink separation time. This new method includes an additional systematic uncertainty that can be removed by performing an extrapolation, and the signal-to-noise problem reemerges in the statistics of this extrapolation. It is demonstrated that this new method allows accurate results for the nucleon mass to be extracted from the large-time noise region inaccessible to standard methods. The observations presented here are expected to apply to quantum Monte Carlo calculations more generally. Similar methods to those introduced here may lead to practical improvements in analysis of noisier systems.

Prostate-Specific Antigen (PSA)–Based Population Screening for Prostate Cancer: An Evidence-Based Analysis

PubMed Central

Pron, G

2015-01-01

Background Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and their second or third leading cause of cancer death. Prostate-specific antigen (PSA) testing for PC has been in common practice for more than 20 years. Objectives A systematic review of the scientific literature was conducted to determine the effectiveness of PSA-based population screening programs for PC to inform policy decisions in a publicly funded health care system. Data Sources A systematic review of bibliographic databases was performed for systematic reviews or randomized controlled trials (RCT) of PSA-based population screening programs for PC. Review Methods A broad search strategy was employed to identify studies reporting on key outcomes of PC mortality and all-cause mortality. Results The search identified 5 systematic reviews and 6 RCTs. None of the systematic reviews found a statistically significant reduction in relative risk (RR) of PC mortality or overall mortality with PSA-based screening. PC mortality reductions were found to vary by country, by screening program, and by age of men at study entry. The European Randomized Study of Screening for Prostate Cancer found a statistically significant reduction in RR in PC mortality at 11-year follow-up (0.79; 95% CI, 0.67–0.92), although the absolute risk reduction was small (1.0/10,000 person-years). However, the primary treatment for PCs differed significantly between countries and between trial arms. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) found a statistically non-significant increase in RR for PC mortality with 13-year follow-up (1.09; 95% CI, 0.87–1.36). The degree of opportunistic screening in the control arm of the PLCO trial, however, was high. None of the RCTs found a reduction in all-cause mortality and all found a statistically significant increase in the detection of mainly low-risk, organ-confined PCs in the screening arm. Conclusions There was no evidence of a PC mortality reduction in the American PLCO trial, which investigated a screening program in a setting where opportunistic screening was already common practice. Given that opportunistic PSA screening practices in Canada are similar, it is unlikely that the introduction of a formal PSA screening program would reduce PC mortality. PMID:26366236

Prostate-Specific Antigen (PSA)-Based Population Screening for Prostate Cancer: An Evidence-Based Analysis.

PubMed

Pron, G

2015-01-01

Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and their second or third leading cause of cancer death. Prostate-specific antigen (PSA) testing for PC has been in common practice for more than 20 years. A systematic review of the scientific literature was conducted to determine the effectiveness of PSA-based population screening programs for PC to inform policy decisions in a publicly funded health care system. A systematic review of bibliographic databases was performed for systematic reviews or randomized controlled trials (RCT) of PSA-based population screening programs for PC. A broad search strategy was employed to identify studies reporting on key outcomes of PC mortality and all-cause mortality. The search identified 5 systematic reviews and 6 RCTs. None of the systematic reviews found a statistically significant reduction in relative risk (RR) of PC mortality or overall mortality with PSA-based screening. PC mortality reductions were found to vary by country, by screening program, and by age of men at study entry. The European Randomized Study of Screening for Prostate Cancer found a statistically significant reduction in RR in PC mortality at 11-year follow-up (0.79; 95% CI, 0.67-0.92), although the absolute risk reduction was small (1.0/10,000 person-years). However, the primary treatment for PCs differed significantly between countries and between trial arms. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) found a statistically non-significant increase in RR for PC mortality with 13-year follow-up (1.09; 95% CI, 0.87-1.36). The degree of opportunistic screening in the control arm of the PLCO trial, however, was high. None of the RCTs found a reduction in all-cause mortality and all found a statistically significant increase in the detection of mainly low-risk, organ-confined PCs in the screening arm. There was no evidence of a PC mortality reduction in the American PLCO trial, which investigated a screening program in a setting where opportunistic screening was already common practice. Given that opportunistic PSA screening practices in Canada are similar, it is unlikely that the introduction of a formal PSA screening program would reduce PC mortality.

Physiological ICSI (PICSI) vs. Conventional ICSI in Couples with Male Factor: A Systematic Review.

PubMed

Avalos-Durán, Georgina; Ángel, Ana María Emilia Cañedo-Del; Rivero-Murillo, Juana; Zambrano-Guerrero, Jaime Enoc; Carballo-Mondragón, Esperanza; Checa-Vizcaíno, Miguel Ángel

2018-04-19

To determine the efficacy of the physiological ICSI technique (PICSI) vs. conventional ICSI in the prognosis of couples, with respect to the following outcome measures: live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage rates. A systematic review of the literature, extracting raw data and performing data analysis. Patient(s): Couples with the male factor, who were subjected to in-vitro fertilization. Main Outcome Measures: rates of live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage. In the systematic search, we found 2,918 studies and an additional study from other sources; only two studies fulfilled the inclusion criteria for this systematic review. The rates of live births, clinical pregnancy, implantation, embryo quality, fertilization and miscarriage were similar for both groups. There is no statistically significant difference between PICSI vs. ICSI, for any of the outcomes analyzed in this study. Enough information is still not available to prove the efficacy of the PICSI technique over ICSI in couples with male factor.

KiDS-450: cosmological constraints from weak lensing peak statistics - I. Inference from analytical prediction of high signal-to-noise ratio convergence peaks

NASA Astrophysics Data System (ADS)

Shan, HuanYuan; Liu, Xiangkun; Hildebrandt, Hendrik; Pan, Chuzhong; Martinet, Nicolas; Fan, Zuhui; Schneider, Peter; Asgari, Marika; Harnois-Déraps, Joachim; Hoekstra, Henk; Wright, Angus; Dietrich, Jörg P.; Erben, Thomas; Getman, Fedor; Grado, Aniello; Heymans, Catherine; Klaes, Dominik; Kuijken, Konrad; Merten, Julian; Puddu, Emanuella; Radovich, Mario; Wang, Qiao

2018-02-01

This paper is the first of a series of papers constraining cosmological parameters with weak lensing peak statistics using ˜ 450 deg2 of imaging data from the Kilo Degree Survey (KiDS-450). We measure high signal-to-noise ratio (SNR: ν) weak lensing convergence peaks in the range of 3 < ν < 5, and employ theoretical models to derive expected values. These models are validated using a suite of simulations. We take into account two major systematic effects, the boost factor and the effect of baryons on the mass-concentration relation of dark matter haloes. In addition, we investigate the impacts of other potential astrophysical systematics including the projection effects of large-scale structures, intrinsic galaxy alignments, as well as residual measurement uncertainties in the shear and redshift calibration. Assuming a flat Λ cold dark matter model, we find constraints for S_8=σ _8(Ω _m/0.3)^{0.5}=0.746^{+0.046}_{-0.107} according to the degeneracy direction of the cosmic shear analysis and Σ _8=σ _8(Ω _m/0.3)^{0.38}=0.696^{+0.048}_{-0.050} based on the derived degeneracy direction of our high-SNR peak statistics. The difference between the power index of S8 and in Σ8 indicates that combining cosmic shear with peak statistics has the potential to break the degeneracy in σ8 and Ωm. Our results are consistent with the cosmic shear tomographic correlation analysis of the same data set and ˜2σ lower than the Planck 2016 results.

Impact of e-learning on nurses' and student nurses knowledge, skills, and satisfaction: a systematic review and meta-analysis.

PubMed

Lahti, Mari; Hätönen, Heli; Välimäki, Maritta

2014-01-01

To review the impact of e-learning on nurses' and nursing student's knowledge, skills and satisfaction related to e-learning. We conducted a systematic review and meta-analysis of randomized controlled trials (RCT) to assess the impact of e-learning on nurses' and nursing student's knowledge, skills and satisfaction. Electronic databases including MEDLINE (1948-2010), CINAHL (1981-2010), Psychinfo (1967-2010) and Eric (1966-2010) were searched in May 2010 and again in December 2010. All RCT studies evaluating the effectiveness of e-learning and differentiating between traditional learning methods among nurses were included. Data was extracted related to the purpose of the trial, sample, measurements used, index test results and reference standard. An extraction tool developed for Cochrane reviews was used. Methodological quality of eligible trials was assessed. 11 trials were eligible for inclusion in the analysis. We identified 11 randomized controlled trials including a total of 2491 nurses and student nurses'. First, the random effect size for four studies showed some improvement associated with e-learning compared to traditional techniques on knowledge. However, the difference was not statistically significant (p=0.39, MD 0.44, 95% CI -0.57 to 1.46). Second, one study reported a slight impact on e-learning on skills, but the difference was not statistically significant, either (p=0.13, MD 0.03, 95% CI -0.09 to 0.69). And third, no results on nurses or student nurses' satisfaction could be reported as the statistical data from three possible studies were not available. Overall, there was no statistical difference between groups in e-learning and traditional learning relating to nurses' or student nurses' knowledge, skills and satisfaction. E-learning can, however, offer an alternative method of education. In future, more studies following the CONSORT and QUOROM statements are needed to evaluate the effects of these interventions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Statistical properties of DNA sequences

NASA Technical Reports Server (NTRS)

Peng, C. K.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Mantegna, R. N.; Simons, M.; Stanley, H. E.

1995-01-01

We review evidence supporting the idea that the DNA sequence in genes containing non-coding regions is correlated, and that the correlation is remarkably long range--indeed, nucleotides thousands of base pairs distant are correlated. We do not find such a long-range correlation in the coding regions of the gene. We resolve the problem of the "non-stationarity" feature of the sequence of base pairs by applying a new algorithm called detrended fluctuation analysis (DFA). We address the claim of Voss that there is no difference in the statistical properties of coding and non-coding regions of DNA by systematically applying the DFA algorithm, as well as standard FFT analysis, to every DNA sequence (33301 coding and 29453 non-coding) in the entire GenBank database. Finally, we describe briefly some recent work showing that the non-coding sequences have certain statistical features in common with natural and artificial languages. Specifically, we adapt to DNA the Zipf approach to analyzing linguistic texts. These statistical properties of non-coding sequences support the possibility that non-coding regions of DNA may carry biological information.

Quantitative Assessment of In-solution Digestion Efficiency Identifies Optimal Protocols for Unbiased Protein Analysis*

PubMed Central

León, Ileana R.; Schwämmle, Veit; Jensen, Ole N.; Sprenger, Richard R.

2013-01-01

The majority of mass spectrometry-based protein quantification studies uses peptide-centric analytical methods and thus strongly relies on efficient and unbiased protein digestion protocols for sample preparation. We present a novel objective approach to assess protein digestion efficiency using a combination of qualitative and quantitative liquid chromatography-tandem MS methods and statistical data analysis. In contrast to previous studies we employed both standard qualitative as well as data-independent quantitative workflows to systematically assess trypsin digestion efficiency and bias using mitochondrial protein fractions. We evaluated nine trypsin-based digestion protocols, based on standard in-solution or on spin filter-aided digestion, including new optimized protocols. We investigated various reagents for protein solubilization and denaturation (dodecyl sulfate, deoxycholate, urea), several trypsin digestion conditions (buffer, RapiGest, deoxycholate, urea), and two methods for removal of detergents before analysis of peptides (acid precipitation or phase separation with ethyl acetate). Our data-independent quantitative liquid chromatography-tandem MS workflow quantified over 3700 distinct peptides with 96% completeness between all protocols and replicates, with an average 40% protein sequence coverage and an average of 11 peptides identified per protein. Systematic quantitative and statistical analysis of physicochemical parameters demonstrated that deoxycholate-assisted in-solution digestion combined with phase transfer allows for efficient, unbiased generation and recovery of peptides from all protein classes, including membrane proteins. This deoxycholate-assisted protocol was also optimal for spin filter-aided digestions as compared with existing methods. PMID:23792921

The Relationship between Zinc Levels and Autism: A Systematic Review and Meta-analysis.

PubMed

Babaknejad, Nasim; Sayehmiri, Fatemeh; Sayehmiri, Kourosh; Mohamadkhani, Ashraf; Bahrami, Somaye

2016-01-01

Autism is a complex behaviorally defined disorder.There is a relationship between zinc (Zn) levels in autistic patients and development of pathogenesis, but the conclusion is not permanent. The present study conducted to estimate this probability using meta-analysis method. In this study, Fixed Effect Model, twelve articles published from 1978 to 2012 were selected by searching Google scholar, PubMed, ISI Web of Science, and Scopus and information were analyzed. I² statistics were calculated to examine heterogeneity. The information was analyzed using R and STATA Ver. 12.2. There was no significant statistical difference between hair, nail, and teeth Zn levels between controls and autistic patients: -0.471 [95% confidence interval (95% CI): -1.172 to 0.231]. There was significant statistical difference between plasma Zn concentration and autistic patients besides healthy controls: -0.253 (95% CI: 0.498 to -0.007). Using a Random Effect Model, the overall Integration of data from the two groups was -0.414 (95% CI: -0.878 to -0.051). Based on sensitivity analysis, zinc supplements can be used for the nutritional therapy for autistic patients.

Genome-wide association analysis of secondary imaging phenotypes from the Alzheimer's disease neuroimaging initiative study.

PubMed

Zhu, Wensheng; Yuan, Ying; Zhang, Jingwen; Zhou, Fan; Knickmeyer, Rebecca C; Zhu, Hongtu

2017-02-01

The aim of this paper is to systematically evaluate a biased sampling issue associated with genome-wide association analysis (GWAS) of imaging phenotypes for most imaging genetic studies, including the Alzheimer's Disease Neuroimaging Initiative (ADNI). Specifically, the original sampling scheme of these imaging genetic studies is primarily the retrospective case-control design, whereas most existing statistical analyses of these studies ignore such sampling scheme by directly correlating imaging phenotypes (called the secondary traits) with genotype. Although it has been well documented in genetic epidemiology that ignoring the case-control sampling scheme can produce highly biased estimates, and subsequently lead to misleading results and suspicious associations, such findings are not well documented in imaging genetics. We use extensive simulations and a large-scale imaging genetic data analysis of the Alzheimer's Disease Neuroimaging Initiative (ADNI) data to evaluate the effects of the case-control sampling scheme on GWAS results based on some standard statistical methods, such as linear regression methods, while comparing it with several advanced statistical methods that appropriately adjust for the case-control sampling scheme. Copyright © 2016 Elsevier Inc. All rights reserved.

Statistical analysis of the calibration procedure for personnel radiation measurement instruments

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

Bush, W.J.; Bengston, S.J.; Kalbeitzer, F.L.

1980-11-01

Thermoluminescent analyzer (TLA) calibration procedures were used to estimate personnel radiation exposure levels at the Idaho National Engineering Laboratory (INEL). A statistical analysis is presented herein based on data collected over a six month period in 1979 on four TLA's located in the Department of Energy (DOE) Radiological and Environmental Sciences Laboratory at the INEL. The data were collected according to the day-to-day procedure in effect at that time. Both gamma and beta radiation models are developed. Observed TLA readings of thermoluminescent dosimeters are correlated with known radiation levels. This correlation is then used to predict unknown radiation doses frommore » future analyzer readings of personnel thermoluminescent dosimeters. The statistical techniques applied in this analysis include weighted linear regression, estimation of systematic and random error variances, prediction interval estimation using Scheffe's theory of calibration, the estimation of the ratio of the means of two normal bivariate distributed random variables and their corresponding confidence limits according to Kendall and Stuart, tests of normality, experimental design, a comparison between instruments, and quality control.« less

[Development of an Excel spreadsheet for meta-analysis of indirect and mixed treatment comparisons].

PubMed

Tobías, Aurelio; Catalá-López, Ferrán; Roqué, Marta

2014-01-01

Meta-analyses in clinical research usually aimed to evaluate treatment efficacy and safety in direct comparison with a unique comparator. Indirect comparisons, using the Bucher's method, can summarize primary data when information from direct comparisons is limited or nonexistent. Mixed comparisons allow combining estimates from direct and indirect comparisons, increasing statistical power. There is a need for simple applications for meta-analysis of indirect and mixed comparisons. These can easily be conducted using a Microsoft Office Excel spreadsheet. We developed a spreadsheet for indirect and mixed effects comparisons of friendly use for clinical researchers interested in systematic reviews, but non-familiarized with the use of more advanced statistical packages. The use of the proposed Excel spreadsheet for indirect and mixed comparisons can be of great use in clinical epidemiology to extend the knowledge provided by traditional meta-analysis when evidence from direct comparisons is limited or nonexistent.

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.

Effectiveness of practices to reduce blood culture contamination: A Laboratory Medicine Best Practices systematic review and meta-analysis☆

PubMed Central

Snyder, Susan R.; Favoretto, Alessandra M.; Baetz, Rich Ann; Derzon, James H.; Madison, Bereneice M.; Mass, Diana; Shaw, Colleen S.; Layfield, Christopher D.; Christenson, Robert H.; Liebow, Edward B.

2015-01-01

Objectives This article is a systematic review of the effectiveness of three practices for reducing blood culture contamination rates: venipuncture, phlebotomy teams, and prepackaged preparation/collection (prep) kits. Design and methods The CDC-funded Laboratory Medicine Best Practices Initiative systematic review methods for quality improvement practices were used. Results Studies included as evidence were: 9 venipuncture (vs. versus intravenous catheter), 5 phlebotomy team; and 7 prep kit. All studies for venipuncture and phlebotomy teams favored these practices, with meta-analysis mean odds ratios for venipuncture of 2.69 and phlebotomy teams of 2.58. For prep kits 6 studies’ effect sizes were not statistically significantly different from no effect (meta-analysis mean odds ratio 1.12). Conclusions Venipuncture and the use of phlebotomy teams are effective practices for reducing blood culture contamination rates in diverse hospital settings and are recommended as evidence-based “best practices” with high overall strength of evidence and substantial effect size ratings. No recommendation is made for or against prep kits based on uncertain improvement. PMID:22709932

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.

Lost in Translation: Piloting a Novel Framework to Assess the Challenges in Translating Scientific Uncertainty From Empirical Findings to WHO Policy Statements

PubMed Central

Benmarhnia, Tarik; Huang, Jonathan Y.; Jones, Catherine M.

2017-01-01

Background: Calls for evidence-informed public health policy, with implicit promises of greater program effectiveness, have intensified recently. The methods to produce such policies are not self-evident, requiring a conciliation of values and norms between policy-makers and evidence producers. In particular, the translation of uncertainty from empirical research findings, particularly issues of statistical variability and generalizability, is a persistent challenge because of the incremental nature of research and the iterative cycle of advancing knowledge and implementation. This paper aims to assess how the concept of uncertainty is considered and acknowledged in World Health Organization (WHO) policy recommendations and guidelines. Methods: We selected four WHO policy statements published between 2008-2013 regarding maternal and child nutrient supplementation, infant feeding, heat action plans, and malaria control to represent topics with a spectrum of available evidence bases. Each of these four statements was analyzed using a novel framework to assess the treatment of statistical variability and generalizability. Results: WHO currently provides substantial guidance on addressing statistical variability through GRADE (Grading of Recommendations Assessment, Development, and Evaluation) ratings for precision and consistency in their guideline documents. Accordingly, our analysis showed that policy-informing questions were addressed by systematic reviews and representations of statistical variability (eg, with numeric confidence intervals). In contrast, the presentation of contextual or "background" evidence regarding etiology or disease burden showed little consideration for this variability. Moreover, generalizability or "indirectness" was uniformly neglected, with little explicit consideration of study settings or subgroups. Conclusion: In this paper, we found that non-uniform treatment of statistical variability and generalizability factors that may contribute to uncertainty regarding recommendations were neglected, including the state of evidence informing background questions (prevalence, mechanisms, or burden or distributions of health problems) and little assessment of generalizability, alternate interventions, and additional outcomes not captured by systematic review. These other factors often form a basis for providing policy recommendations, particularly in the absence of a strong evidence base for intervention effects. Consequently, they should also be subject to stringent and systematic evaluation criteria. We suggest that more effort is needed to systematically acknowledge (1) when evidence is missing, conflicting, or equivocal, (2) what normative considerations were also employed, and (3) how additional evidence may be accrued. PMID:29179291

A systematic review on the use of time series data in the study of antimicrobial consumption and Pseudomonas aeruginosa resistance.

PubMed

Athanasiou, Christos I; Kopsini, Angeliki

2018-06-12

In the field of antimicrobial resistance, the number of studies that use time series data has increased recently. The purpose of this study is the systematic review of all studies on antibacterial consumption and on Pseudomonas aeruginosa resistance in healthcare settings, that have used time series data. A systematic review of the literature till June 2017 was conducted. All the studies that have used time series data and have examined the inhospital antibiotic consumption and Ps. aeruginosa resistance rates or incidence were eligible. No other exclusion criteria were applied. Data on the structure, terminology used, methods used and results of each article were recorded and analyzed as possible. A total of thirty six studies were retrieved, twenty three of which were in accordance with our criteria. Thirteen of them were quasi experimental studies and ten were ecological observational studies. Eighteen studies collected time series data of both parameters and the statistical methodology of "time series analysis" was applied in nine studies. Most of the studies were published in the last eight years. The Interrupted Time Series design was the most widespread. As expected, there was high heterogeneity in regard to the study design, terminology and statistical methods applied. Copyright © 2018. Published by Elsevier Ltd.

Field-theoretic approach to fluctuation effects in neural networks

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

Buice, Michael A.; Cowan, Jack D.; Mathematics Department, University of Chicago, Chicago, Illinois 60637

A well-defined stochastic theory for neural activity, which permits the calculation of arbitrary statistical moments and equations governing them, is a potentially valuable tool for theoretical neuroscience. We produce such a theory by analyzing the dynamics of neural activity using field theoretic methods for nonequilibrium statistical processes. Assuming that neural network activity is Markovian, we construct the effective spike model, which describes both neural fluctuations and response. This analysis leads to a systematic expansion of corrections to mean field theory, which for the effective spike model is a simple version of the Wilson-Cowan equation. We argue that neural activity governedmore » by this model exhibits a dynamical phase transition which is in the universality class of directed percolation. More general models (which may incorporate refractoriness) can exhibit other universality classes, such as dynamic isotropic percolation. Because of the extremely high connectivity in typical networks, it is expected that higher-order terms in the systematic expansion are small for experimentally accessible measurements, and thus, consistent with measurements in neocortical slice preparations, we expect mean field exponents for the transition. We provide a quantitative criterion for the relative magnitude of each term in the systematic expansion, analogous to the Ginsburg criterion. Experimental identification of dynamic universality classes in vivo is an outstanding and important question for neuroscience.« less

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

[Efficacy of sildenafil citrate in men with erectile dysfunction following bilateral nerve-sparing radical prostatectomy: systematic review and meta-analysis].

PubMed

Lu, Xinxing; Han, Hu; Xing, Nianzeng; Tian, Long

2015-09-22

To systematically assess the efficacy and safety of oral sildenafil citrate for post bilateral nerve-sparig radical prostatectomy (post-BNSRP) erectile dysfunction (ED). The following keywords: sildenafil, radical prostatectomy were used to search in Medline, Pubmed, Web of Science, Cochrane Library, CNKI, WanFang Database. The title, abstract and keywords of each article were independently screened by two reviewers. Randomized controlled trials (RCT) published between 1990 and 2014 were retrieved according to our inclusion and exclusion criteria. The efficacy and safety of oral sildenafil citrate for post-BNSRP ED were systematically assessed by meta-analysis. Four RCTs with 320 cases were included after literature retrieval and filtering. The potency rates were 32.1% (35/109) and 11.3% (7/62) between sildenafil and placebo groups after meta-analysis and showed statistically significant differences (OR = 4.66, 95% CI: 1.79-12.11). IIEF-5 score in sildenafil group was significant higher than that in the placebo group (WMD: 4.73, 95% CI: 3.26-6.19). In subgroup meta-analysis, the potency rates in high-dose, low-dose sildenafil groups and placebo groups were 30.4% (14/46), 25.0% (10/40) and 4.5% (2/44), respectively. There were statistically significant differences between the high-dose subgroup and placebo group (OR = 9.32, 95% CI: 1.96-44.23), and the low-dose subgroup and placebo group (OR = 6.99, 95% CI: 1.43-34.22). But there was no significant difference between high-dose and low-dose subgroups (OR = 1.31, 95% CI: 0.51-3.40). Compared with placebo, sildenafil has considerable efficacy for erectile function rehabilitationas as a primary treatment for post-BNSRP ED. There is no significant difference between high-dose and low-dose schedule for its efficacy. However, further studies are required to optimize treatment.

Is combined topical with intravenous tranexamic acid superior than topical, intravenous tranexamic acid alone and control groups for blood loss controlling after total knee arthroplasty: A meta-analysis.

PubMed

Lin, Chunmei; Qi, Yingmei; Jie, Li; Li, Hong-Biao; Zhao, Xi-Cheng; Qin, Lei; Jiang, Xin-Qiang; Zhang, Zhen-Hua; Ma, Liping

2016-12-01

The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to evaluate the efficacy and safety of combined topical with intravenous tranexamic acid (TXA) versus topical, intravenous TXA alone or control for reducing blood loss after a total knee arthroplasty (TKA). In May 2016, a systematic computer-based search was conducted in the PubMed, Embase, Cochrane Library, Web of Science, and Chinese Wanfang database. This systematic review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement criteria. Only patients prepared for primary TKA that administration combined topical with intravenous TXA with topical TXA, intravenous (IV) TXA, or control group for reducing blood loss were included. Eligible criteria were published RCTs about combined topical with intravenous TXA with topical alone or intravenous alone. The primary endpoint was the total blood loss and need for transfusion. The complications of deep venous thrombosis (DVT) were also compiled to assess the safety of combined topical TXA with intravenous TXA. Relative risks (RRs) with 95% CIs were estimated for dichotomous outcomes, and mean differences (MDs) with 95% CIs for continuous outcomes. The Cochrane risk of bias tool was used to appraise a risk of bias. Stata 12.0 software was used for meta-analysis. Fifteen studies involving 1495 patients met the inclusion criteria. The pooled meta-analysis indicated that combined topical TXA with intravenous TXA can reduce the total blood loss compared with placebo with a mean of 458.66 mL and the difference is statistically significant (MD = -458.66, 95% CI: -655.40 to 261.91, P < 0.001). Compared with intravenous TXA, combined administrated TXA can decrease the total blood loss, and the difference is statistically significant (MD = -554.03, 95% CI: -1066.21 to -41.85, P = 0.034). Compared with the topical administration TXA, the pooled meta-analysis indicated that combined TXA can decrease the amount of total blood loss with mean 107.65 mL with statistically significant(MD = -107.65, 95% CI: -525.55 to -239.9141.85, P = 0.001). The pooled results indicated that combined topical with intravenous TXA can decrease the need for transfusion (RR = 0.34, 95% CI: 0.23-0.50, P < 0.001). There is no significant difference between combined topical with intravenous TXA with topical or intravenous TXA (P > 0.05) in terms of need for transfusion and the occurrence of DVT. Compared with topical, intravenous TXA alone or control group, combined topical with TXA, can decrease the total blood loss and subsequent need for transfusion without increasing the occurrence of DVT. The dose and timing to administration TXA is different, and more randomized controlled trials are warranted to clarify the optimal dosing and time to administration TXA.

Statistical Approaches Used to Assess the Equity of Access to Food Outlets: A Systematic Review

PubMed Central

Lamb, Karen E.; Thornton, Lukar E.; Cerin, Ester; Ball, Kylie

2015-01-01

Background Inequalities in eating behaviours are often linked to the types of food retailers accessible in neighbourhood environments. Numerous studies have aimed to identify if access to healthy and unhealthy food retailers is socioeconomically patterned across neighbourhoods, and thus a potential risk factor for dietary inequalities. Existing reviews have examined differences between methodologies, particularly focussing on neighbourhood and food outlet access measure definitions. However, no review has informatively discussed the suitability of the statistical methodologies employed; a key issue determining the validity of study findings. Our aim was to examine the suitability of statistical approaches adopted in these analyses. Methods Searches were conducted for articles published from 2000–2014. Eligible studies included objective measures of the neighbourhood food environment and neighbourhood-level socio-economic status, with a statistical analysis of the association between food outlet access and socio-economic status. Results Fifty-four papers were included. Outlet accessibility was typically defined as the distance to the nearest outlet from the neighbourhood centroid, or as the number of food outlets within a neighbourhood (or buffer). To assess if these measures were linked to neighbourhood disadvantage, common statistical methods included ANOVA, correlation, and Poisson or negative binomial regression. Although all studies involved spatial data, few considered spatial analysis techniques or spatial autocorrelation. Conclusions With advances in GIS software, sophisticated measures of neighbourhood outlet accessibility can be considered. However, approaches to statistical analysis often appear less sophisticated. Care should be taken to consider assumptions underlying the analysis and the possibility of spatially correlated residuals which could affect the results. PMID:29546115

The methodological and reporting quality of systematic reviews from China and the USA are similar.

PubMed

Tian, Jinhui; Zhang, Jun; Ge, Long; Yang, Kehu; Song, Fujian

2017-05-01

To compare the methodological and reporting quality of systematic reviews by authors from China and those from the United States (USA). From systematic reviews of randomized trials published in 2014 in English, we randomly selected 100 from China and 100 from the USA. The methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool, and reporting quality assessed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) tool. Compared with systematic reviews from the USA, those from China were more likely to be a meta-analysis, published in low-impact journals, and a non-Cochrane review. The mean summary Assessing the Methodological Quality of Systematic Reviews score was 6.7 (95% confidence interval: 6.5, 7.0) for reviews from China and 6.6 (6.1, 7.1) for reviews from the USA, and the mean summary Preferred Reporting Items for Systematic Reviews and Meta-analyses score was 21.2 (20.7, 21.6) for reviews from China and 20.6 (19.9, 21.3) for reviews from the USA. The differences in summary quality scores between China and the USA were statistically nonsignificant after adjusting for multiple review factors. The overall methodological and reporting quality of systematic reviews by authors from China are similar to those from the USA, although the quality of systematic reviews from both countries could be further improved. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Potential Pitfalls of Reporting and Bias in Observational Studies With Propensity Score Analysis Assessing a Surgical Procedure: A Methodological Systematic Review.

PubMed

Lonjon, Guillaume; Porcher, Raphael; Ergina, Patrick; Fouet, Mathilde; Boutron, Isabelle

2017-05-01

To describe the evolution of the use and reporting of propensity score (PS) analysis in observational studies assessing a surgical procedure. Assessing surgery in randomized controlled trials raises several challenges. Observational studies with PS analysis are a robust alternative for comparative effectiveness research. In this methodological systematic review, we identified all PubMed reports of observational studies with PS analysis that evaluated a surgical procedure and described the evolution of their use over time. Then, we selected a sample of articles published from August 2013 to July 2014 and systematically appraised the quality of reporting and potential bias of the PS analysis used. We selected 652 reports of observational studies with PS analysis. The publications increased over time, from 1 report in 1987 to 198 in 2013. Among the 129 reports assessed, 20% (n = 24) did not detail the covariates included in the PS and 77% (n = 100) did not report a justification for including these covariates in the PS. The rate of missing data for potential covariates was reported in 9% of articles. When a crossover by conversion was possible, only 14% of reports (n = 12) mentioned this issue. For matched analysis, 10% of articles reported all 4 key elements that allow for reproducibility of a PS-matched analysis (matching ratio, method to choose the nearest neighbors, replacement and method for statistical analysis). Observational studies with PS analysis in surgery are increasing in frequency, but specific methodological issues and weaknesses in reporting exist.

Lifestyle interventions for weight loss among overweight and obese adults with serious mental illness: A systematic review and meta-analysis.

PubMed

Naslund, John A; Whiteman, Karen L; McHugo, Gregory J; Aschbrenner, Kelly A; Marsch, Lisa A; Bartels, Stephen J

2017-07-01

To conduct a systematic review and meta-analysis to estimate effects of lifestyle intervention participation on weight reduction among overweight and obese adults with serious mental illness. We systematically searched electronic databases for randomized controlled trials comparing lifestyle interventions with other interventions or usual care controls in overweight and obese adults with serious mental illness, including schizophrenia spectrum or mood disorders. Included studies reported change in weight [kg] or body mass index (BMI) [kg/m 2 ] from baseline to follow-up. Standardized mean differences (SMD) were calculated for change in weight from baseline between intervention and control groups. Seventeen studies met inclusion criteria (1968 participants; 50% male; 66% schizophrenia spectrum disorders). Studies were grouped by intervention duration (≤6-months or ≥12-months). Lifestyle interventions of ≤6-months duration showed greater weight reduction compared with controls as indicated by effect size for weight change from baseline (SMD=-0.20; 95% CI=-0.34, -0.05; 10 studies), but high statistical heterogeneity (I 2 =90%). Lifestyle interventions of ≥12-months duration also showed greater weight reduction compared with controls (SMD=-0.24; 95% CI=-0.36, -0.12; 6 studies) with low statistical heterogeneity (I 2 =0%). Lifestyle interventions appear effective for treating overweight and obesity among people with serious mental illness. Interventions of ≥12-months duration compared to ≤6-months duration appear to achieve more consistent outcomes, though effect sizes are similar for both shorter and longer duration interventions. Copyright © 2017. Published by Elsevier Inc.

A systematic review of optimal treatment strategies for localized Ewing's sarcoma of bone after neo-adjuvant chemotherapy.

PubMed

Werier, Joel; Yao, Xiaomei; Caudrelier, Jean-Michel; Di Primio, Gina; Ghert, Michelle; Gupta, Abha A; Kandel, Rita; Verma, Shailendra

2016-03-01

To perform a systematic review to investigate the optimal treatment strategy among the options of surgery alone, radiotherapy (RT) alone, and the combination of RT plus surgery in the management of localized Ewing's sarcoma of bone following neo-adjuvant chemotherapy. MEDLINE and EMBASE (1999 to February 2015), the Cochrane Library, and relevant conferences were searched. Two systematic reviews and eight full texts met the pre-planned study selection criteria. When RT was compared with surgery, a meta-analysis combining two papers showed that surgery resulted in a higher event-free survival (EFS) than RT in any location (HR = 1.50, 95% CI 1.12-2.00; p = 0.007). However another paper did not find a statistically significant difference in patients with pelvic disease, and no papers identified a significant difference in overall survival. When surgery plus RT was compared with surgery alone, a meta-analysis did not demonstrate a statistically significant difference for EFS between the two groups (HR = 1.21, 95% CI 0.90-1.63). Both surgical morbidities and radiation toxicities were reported. The existing evidence is based on very low aggregate quality as assessed by the GRADE approach. In patients with localized Ewing's sarcoma, either surgery alone (if complete surgical excision with clear margin can be achieved) or RT alone may be a reasonable treatment option. The optimal local treatment for an individual patient should be decided through consideration of patient characteristics, the potential benefit and harm of the treatment options, and patient preference. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

A systematic review and meta-analysis of educational interventions for children and adolescents with acquired brain injury.

PubMed

Linden, Mark A; Glang, Ann E; McKinlay, Audrey

2018-01-01

Children with brain injuries face significant challenges in their recovery. One of the greatest is transitioning from hospital/home to school where they face issues such as reintegration, lack of understanding and catching up with missed work. Many children struggle with their altered circumstances and require additional supports to meet the academic demands of systems which are ill equipped to teach them. To summarise the best available evidence for the use of educational interventions to improve academic attainment in childhood survivors of acquired brain injury (ABI). Six electronic databases (Cinahl, Embase, Medline, PsycINFO, Pubmed, & Web of Science) were systematically searched for randomised controlled trials published between 1980 and 2017. Two authors independently reviewed these studies and extracted data on type of intervention, characteristics of participants, outcome measures, findings and recommendations. The Cochrane Collaboration's Risk of Bias tool was used to assess systematic error in the included studies. Four studies met the inclusion criteria (n = 296 children and adolescents). Three studies (n = 287) were included in meta-analysis for the primary outcome which showed no statistically significant difference between the intervention and control conditions on academic attainment (SMD 1.31, 95% CI -0.06 to 2.68, p = 0.06). No statistically significant differences were found which favoured the intervention for the secondary outcomes of attention, internalising or externalising behavior. All effect sizes were considered as small. This review suggests that no currently effective educational interventions exist for children with ABI. Greater efforts are required to produce effective and rigorously tested interventions to improve outcomes for these children.

Prognostic value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in acute pulmonary embolism: a systematic review and meta-analysis.

PubMed

Wang, Qian; Ma, Junfen; Jiang, Zhiyun; Ming, Liang

2018-02-01

Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been reported to predict prognosis of acute pulmonary embolism (PE). However, the prognostic value of NLR and PLR remained inconsistent between studies. The aim of this meta-analysis was to assess the prognostic role of NLR and PLR in acute PE. We systematically searched Pubmed, Embase, Web of Science and CNKI for relative literature up to March 2017. The pooled statistics for all outcomes were expressed as odds ratio (OR) and 95% confidence intervals (95% CI). The statistical analyses were performed using Review Manager 5.3.5 analysis software and Stata software. Totally 7 eligible studies consisting of 2323 patients were enrolled in our meta-analysis. Elevated NLR was significantly associated with overall (short-term and long-term) mortality (OR 10.13, 95% CI 6.57-15.64, P<0.001) and short-term (in-hospital and 30 days) mortality (OR 8.43, 95% CI 5.23-13.61, P<0.001). And elevated PLR was significantly associated with overall mortality (OR 6.32, 95% CI 4.52-8.84, P<0.001), short-term mortality (OR 6.69, 95% CI 2.86-15.66, P<0.001) and long-term mortality (OR 6.11, 95% CI 3.90-9.55, P<0.001). Our meta-analysis revealed that NLR and PLR are promising biomarkers in predicting prognosis in acute PE patients. We suggest NLR and PLR be used routinely in the PE prognostic assessment.

Biopersistent Granular Dust and Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

PubMed Central

Brüske, Irene; Thiering, Elisabeth; Heinrich, Joachim; Huster, Katharina; Nowak, Dennis

2013-01-01

Objective Applying a systematic review to identify studies eligible for meta-analysis of the association between occupational exposure to inorganic dust and the development of chronic obstructive pulmonary disease (COPD), and conducting a meta-analysis. Data Sources Searches of PubMed and Embase for the time period 1970–2010 yielded 257 cross-sectional and longitudinal studies on people exposed to inorganic dust at the workplace with data on lung function. These studies were independently abstracted and evaluated by two authors; any disagreement was resolved by a third reviewer. Of 55 publications accepted for meta-analysis, 27 investigated the effects of occupational exposure to biopersistent granular dust (bg-dust). Methods A random effects meta-analysis allowed us to provide an estimate of the average exposure effect on spirometric parameters presented in forest plots. Between-study heterogeneity was assessed by using I2 statistics, with I2>25% indicating significant heterogeneity. Publication bias was investigated by visual inspection of funnel plots. The influence of individual studies was assessed by dropping the respective study before pooling study-specific estimates. Results The mean FEV1 of workers exposed to bg-dust was 160 ml lower or 5.7% less than predicted compared to workers with no/low exposure. The risk of an obstructive airway disease—defined as FEV1/FVC < 70%—increased by 7% per 1 mg· m-3 respirable bg-dust. Conclusion Occupational inhalative exposure to bg-dust was associated with a statistically significant decreased FEV1 and FEV1/FVC revealing airway obstruction consistent with COPD. PMID:24278358

Structural texture similarity metrics for image analysis and retrieval.

PubMed

Zujovic, Jana; Pappas, Thrasyvoulos N; Neuhoff, David L

2013-07-01

We develop new metrics for texture similarity that accounts for human visual perception and the stochastic nature of textures. The metrics rely entirely on local image statistics and allow substantial point-by-point deviations between textures that according to human judgment are essentially identical. The proposed metrics extend the ideas of structural similarity and are guided by research in texture analysis-synthesis. They are implemented using a steerable filter decomposition and incorporate a concise set of subband statistics, computed globally or in sliding windows. We conduct systematic tests to investigate metric performance in the context of "known-item search," the retrieval of textures that are "identical" to the query texture. This eliminates the need for cumbersome subjective tests, thus enabling comparisons with human performance on a large database. Our experimental results indicate that the proposed metrics outperform peak signal-to-noise ratio (PSNR), structural similarity metric (SSIM) and its variations, as well as state-of-the-art texture classification metrics, using standard statistical measures.

Statistical hadronization with exclusive channels in e +e - annihilation

DOE PAGES

Ferroni, L.; Becattini, F.

2012-01-01

We present a systematic analysis of exclusive hadronic channels in e +e - collisions at centre-of-mass energies between 2.1 and 2.6 GeV within the statistical hadronization model. Because of the low multiplicities involved, calculations have been carried out in the full microcanonical ensemble, including conservation of energy-momentum, angular momentum, parity, isospin, and all relevant charges. We show that the data is in an overall good agreement with the model for an energy density of about 0.5 GeV/fm 3 and an extra strangeness suppression parameter γ S 0:7, essentially the same values found with fits to inclusive multiplicities at higher energy.

A Numerical Simulation and Statistical Modeling of High Intensity Radiated Fields Experiment Data

NASA Technical Reports Server (NTRS)

Smith, Laura J.

2004-01-01

Tests are conducted on a quad-redundant fault tolerant flight control computer to establish upset characteristics of an avionics system in an electromagnetic field. A numerical simulation and statistical model are described in this work to analyze the open loop experiment data collected in the reverberation chamber at NASA LaRC as a part of an effort to examine the effects of electromagnetic interference on fly-by-wire aircraft control systems. By comparing thousands of simulation and model outputs, the models that best describe the data are first identified and then a systematic statistical analysis is performed on the data. All of these efforts are combined which culminate in an extrapolation of values that are in turn used to support previous efforts used in evaluating the data.

Initial Systematic Investigations of the Weakly Coupled Free Fermionic Heterotic String Landscape Statistics

NASA Astrophysics Data System (ADS)

Renner, Timothy

2011-12-01

A C++ framework was constructed with the explicit purpose of systematically generating string models using the Weakly Coupled Free Fermionic Heterotic String (WCFFHS) method. The software, optimized for speed, generality, and ease of use, has been used to conduct preliminary systematic investigations of WCFFHS vacua. Documentation for this framework is provided in the Appendix. After an introduction to theoretical and computational aspects of WCFFHS model building, a study of ten-dimensional WCFFHS models is presented. Degeneracies among equivalent expressions of each of the known models are investigated and classified. A study of more phenomenologically realistic four-dimensional models based on the well known "NAHE" set is then presented, with statistics being reported on gauge content, matter representations, and space-time supersymmetries. The final study is a parallel to the NAHE study in which a variation of the NAHE set is systematically extended and examined statistically. Special attention is paid to models with "mirroring"---identical observable and hidden sector gauge groups and matter representations.

Research Pearls: The Significance of Statistics and Perils of Pooling. Part 3: Pearls and Pitfalls of Meta-analyses and Systematic Reviews.

PubMed

Harris, Joshua D; Brand, Jefferson C; Cote, Mark P; Dhawan, Aman

2017-08-01

Within the health care environment, there has been a recent and appropriate trend towards emphasizing the value of care provision. Reduced cost and higher quality improve the value of care. Quality is a challenging, heterogeneous, variably defined concept. At the core of quality is the patient's outcome, quantified by a vast assortment of subjective and objective outcome measures. There has been a recent evolution towards evidence-based medicine in health care, clearly elucidating the role of high-quality evidence across groups of patients and studies. Synthetic studies, such as systematic reviews and meta-analyses, are at the top of the evidence-based medicine hierarchy. Thus, these investigations may be the best potential source of guiding diagnostic, therapeutic, prognostic, and economic medical decision making. Systematic reviews critically appraise and synthesize the best available evidence to provide a conclusion statement (a "take-home point") in response to a specific answerable clinical question. A meta-analysis uses statistical methods to quantitatively combine data from single studies. Meta-analyses should be performed with high methodological quality homogenous studies (Level I or II) or evidence randomized studies, to minimize confounding variable bias. When it is known that the literature is inadequate or a recent systematic review has already been performed with a demonstration of insufficient data, then a new systematic review does not add anything meaningful to the literature. PROSPERO registration and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines assist authors in the design and conduct of systematic reviews and should always be used. Complete transparency of the conduct of the review permits reproducibility and improves fidelity of the conclusions. Pooling of data from overly dissimilar investigations should be avoided. This particularly applies to Level IV evidence, that is, noncomparative investigations. With proper technique, systematic reviews and meta-analyses have the potential to be powerful investigations that efficiently assist clinicians in decision making. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Evaluating test-retest reliability in patient-reported outcome measures for older people: A systematic review.

PubMed

Park, Myung Sook; Kang, Kyung Ja; Jang, Sun Joo; Lee, Joo Yun; Chang, Sun Ju

2018-03-01

This study aimed to evaluate the components of test-retest reliability including time interval, sample size, and statistical methods used in patient-reported outcome measures in older people and to provide suggestions on the methodology for calculating test-retest reliability for patient-reported outcomes in older people. This was a systematic literature review. MEDLINE, Embase, CINAHL, and PsycINFO were searched from January 1, 2000 to August 10, 2017 by an information specialist. This systematic review was guided by both the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and the guideline for systematic review published by the National Evidence-based Healthcare Collaborating Agency in Korea. The methodological quality was assessed by the Consensus-based Standards for the selection of health Measurement Instruments checklist box B. Ninety-five out of 12,641 studies were selected for the analysis. The median time interval for test-retest reliability was 14days, and the ratio of sample size for test-retest reliability to the number of items in each measure ranged from 1:1 to 1:4. The most frequently used statistical methods for continuous scores was intraclass correlation coefficients (ICCs). Among the 63 studies that used ICCs, 21 studies presented models for ICC calculations and 30 studies reported 95% confidence intervals of the ICCs. Additional analyses using 17 studies that reported a strong ICC (>0.09) showed that the mean time interval was 12.88days and the mean ratio of the number of items to sample size was 1:5.37. When researchers plan to assess the test-retest reliability of patient-reported outcome measures for older people, they need to consider an adequate time interval of approximately 13days and the sample size of about 5 times the number of items. Particularly, statistical methods should not only be selected based on the types of scores of the patient-reported outcome measures, but should also be described clearly in the studies that report the results of test-retest reliability. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Description of the Building Materials Data Base for Portland, Maine.

DTIC Science & Technology

1986-06-01

WORDS (Continue on reveree side if neceseary and Identify by block number)". Acid precipitation, , Data bases, Damage assessment, Environmental...protection) Damage from acid deposition, Portland, Maine Damage to buildings, - Statistical analysis, . 20. ASsrRACT (Conlaue a reverse e(A It n -cwery md...types and amounts of building surface materials ex- posed to acid deposition. The stratified, systematic, unaligned random sampling approach was used

Malignant changes developing from odontogenic cysts: A systematic review.

PubMed

Borrás-Ferreres, Jordi; Sánchez-Torres, Alba; Gay-Escoda, Cosme

2016-12-01

The aim of this study was to systematically review scientific literature in orderto describe the characteristics and prognosis of malignant entities developing from odontogenic cysts. A search in Pubmed (MEDLINE) and Cochrane databases was conducted. The inclusion criteria were articles published in English related to the malignisation of odontogenic cysts in humans. The exclusion criteria were articles that do not specify the type of odontogenic cyst, malignisation of parakeratinised keratocysts, the presence of an ameloblastic carcinoma and metastasis from distant primary tumours. The selected articles were classified according to Strength of Recommendation Taxonomy criteria. Statistical analysis of the data was carried out using statistical package software SPSS version 22.0. From the 1,237 articles initially obtained, the authors included 3 case series and 45 case reports in the end. Descriptive analysis showed that men have a disposition for malignisation from odontogenic cysts and they frequently appear at the posterior mandible, with pain and swelling being the most frequent signs and symptoms. Follicular cysts were the entities that underwent the most malignant changes with well differentiated squamous cell carcinomas being the most prevalent type of malignancy. The real prognosis of this malignancy is not known because of the heterogeneity of available studies. Key words: Odontogenic cysts, squamous cell carcinoma, neoplastic cell transformation, oral cancer.

Statistical detection of geographic clusters of resistant Escherichia coli in a regional network with WHONET and SaTScan.

PubMed

Park, Rachel; O'Brien, Thomas F; Huang, Susan S; Baker, Meghan A; Yokoe, Deborah S; Kulldorff, Martin; Barrett, Craig; Swift, Jamie; Stelling, John

2016-11-01

While antimicrobial resistance threatens the prevention, treatment, and control of infectious diseases, systematic analysis of routine microbiology laboratory test results worldwide can alert new threats and promote timely response. This study explores statistical algorithms for recognizing geographic clustering of multi-resistant microbes within a healthcare network and monitoring the dissemination of new strains over time. Escherichia coli antimicrobial susceptibility data from a three-year period stored in WHONET were analyzed across ten facilities in a healthcare network utilizing SaTScan's spatial multinomial model with two models for defining geographic proximity. We explored geographic clustering of multi-resistance phenotypes within the network and changes in clustering over time. Geographic clustering identified from both latitude/longitude and non-parametric facility groupings geographic models were similar, while the latter was offers greater flexibility and generalizability. Iterative application of the clustering algorithms suggested the possible recognition of the initial appearance of invasive E. coli ST131 in the clinical database of a single hospital and subsequent dissemination to others. Systematic analysis of routine antimicrobial resistance susceptibility test results supports the recognition of geographic clustering of microbial phenotypic subpopulations with WHONET and SaTScan, and iterative application of these algorithms can detect the initial appearance in and dissemination across a region prompting early investigation, response, and containment measures.

The effect of partially exposed connective tissue graft on root-coverage outcomes: a systematic review and meta-analysis.

PubMed

Dodge, Austin; Garcia, Jeffrey; Luepke, Paul; Lai, Yu-Lin; Kassab, Moawia; Lin, Guo-Hao

2018-04-01

The aim of this systematic review was to compare the root-coverage outcomes of using a partially exposed connective tissue graft (CTG) technique with a fully covered CTG technique for root coverage. An electronic search up to February 28 th , 2017, was performed to identify human clinical studies with data comparing outcomes of root coverage using CTG, with and without a partially exposed graft. Five clinical studies were selected for inclusion in this review. For each study, the gain of keratinized gingiva, reduction of recession depth, number of surgical sites achieving complete root coverage, percentage of root coverage, gain of tissue thickness, and changes of probing depth and clinical attachment level were recorded. Meta-analysis for the comparison of complete root coverage between the two techniques presented no statistically significant differences. A statistically significant gain of keratinized tissue in favor of the sites with an exposed CTG and a tendency of greater reduction in recession depth were seen at the sites with a fully covered CTG. Based on the results, the use of a partially exposed CTG in root-coverage procedures could achieve greater gain in keratinized gingiva, while a fully covered CTG might be indicated for procedures aiming to reduce recession depth. © 2018 Eur J Oral Sci.

MUSiC - Model-independent search for deviations from Standard Model predictions in CMS

NASA Astrophysics Data System (ADS)

Pieta, Holger

2010-02-01

We present an approach for a model independent search in CMS. Systematically scanning the data for deviations from the standard model Monte Carlo expectations, such an analysis can help to understand the detector and tune event generators. By minimizing the theoretical bias the analysis is furthermore sensitive to a wide range of models for new physics, including the uncounted number of models not-yet-thought-of. After sorting the events into classes defined by their particle content (leptons, photons, jets and missing transverse energy), a minimally prejudiced scan is performed on a number of distributions. Advanced statistical methods are used to determine the significance of the deviating regions, rigorously taking systematic uncertainties into account. A number of benchmark scenarios, including common models of new physics and possible detector effects, have been used to gauge the power of such a method. )

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.

Breast-feeding and postpartum weight retention: a systematic review and meta-analysis.

PubMed

He, Xiujie; Zhu, Meng; Hu, Chuanlai; Tao, Xingyong; Li, Yingchun; Wang, Qiuwei; Liu, Yue

2015-12-01

Weight gained during pregnancy and postpartum weight retention might contribute to obesity in women of childbearing age. Whether breast-feeding (BF) may decrease postpartum weight retention (PPWR) is still controversial. The purpose of our systematic review and meta-analysis was to investigate the relationship between BF and PPWR. Three databases were systematically reviewed and the reference lists of relevant articles were checked. Meta-analysis was performed to quantify the pooled standardized mean differences (SMD) of BF on PPWR by using a random-effect model. Heterogeneity was tested using the χ 2 test and I 2 statistics. Publication bias was estimated from Egger's test (linear regression method) or Begg's test (rank correlation method). Among 349 search hits, eleven studies met the inclusion criteria for the meta-analysis. Seven studies were conducted in the USA, one in Brazil, one in France, one in Georgia and one in Croatia. Compared with formula-feeding, BF for 3 to ≤6 months seemed to have a negative influence on PPWR and if BF continued for >6 months had little or no influence on PPWR. In a subgroup meta-analysis, the results did not change substantially after the analysis had been classified by available confounding factors. There was no indication of a publication bias from the result of either Egger's test or Begg's test. Although the available evidence held belief that BF decreases PPWR, more robust studies are needed to reliably assess the impact of patterns and duration of BF on PPWR.

Statistical metrology—measurement and modeling of variation for advanced process development and design rule generation

NASA Astrophysics Data System (ADS)

Boning, Duane S.; Chung, James E.

1998-11-01

Advanced process technology will require more detailed understanding and tighter control of variation in devices and interconnects. The purpose of statistical metrology is to provide methods to measure and characterize variation, to model systematic and random components of that variation, and to understand the impact of variation on both yield and performance of advanced circuits. Of particular concern are spatial or pattern-dependencies within individual chips; such systematic variation within the chip can have a much larger impact on performance than wafer-level random variation. Statistical metrology methods will play an important role in the creation of design rules for advanced technologies. For example, a key issue in multilayer interconnect is the uniformity of interlevel dielectric (ILD) thickness within the chip. For the case of ILD thickness, we describe phases of statistical metrology development and application to understanding and modeling thickness variation arising from chemical-mechanical polishing (CMP). These phases include screening experiments including design of test structures and test masks to gather electrical or optical data, techniques for statistical decomposition and analysis of the data, and approaches to calibrating empirical and physical variation models. These models can be integrated with circuit CAD tools to evaluate different process integration or design rule strategies. One focus for the generation of interconnect design rules are guidelines for the use of "dummy fill" or "metal fill" to improve the uniformity of underlying metal density and thus improve the uniformity of oxide thickness within the die. Trade-offs that can be evaluated via statistical metrology include the improvements to uniformity possible versus the effect of increased capacitance due to additional metal.

Analysis of histological findings obtained combining US/mp-MRI fusion-guided biopsies with systematic US biopsies: mp-MRI role in prostate cancer detection and false negative.

PubMed

Faiella, Eliodoro; Santucci, Domiziana; Greco, Federico; Frauenfelder, Giulia; Giacobbe, Viola; Muto, Giovanni; Zobel, Bruno Beomonte; Grasso, Rosario Francesco

2018-02-01

To evaluate the diagnostic accuracy of mp-MRI correlating US/mp-MRI fusion-guided biopsy with systematic random US-guided biopsy in prostate cancer diagnosis. 137 suspected prostatic abnormalities were identified on mp-MRI (1.5T) in 96 patients and classified according to PI-RADS score v2. All target lesions underwent US/mp-MRI fusion biopsy and prostatic sampling was completed by US-guided systematic random 12-core biopsies. Histological analysis and Gleason score were established for all the samples, both target lesions defined by mp-MRI, and random biopsies. PI-RADS score was correlated with the histological results, divided in three groups (benign tissue, atypia and carcinoma) and with Gleason groups, divided in four categories considering the new Grading system of the ISUP 2014, using t test. Multivariate analysis was used to correlate PI-RADS and Gleason categories to PSA level and abnormalities axial diameter. When the random core biopsies showed carcinoma (mp-MRI false-negatives), PSA value and lesions Gleason median value were compared with those of carcinomas identified by mp-MRI (true-positives), using t test. There was statistically significant difference between PI-RADS score in carcinoma, atypia and benign lesions groups (4.41, 3.61 and 3.24, respectively) and between PI-RADS score in Gleason < 7 group and Gleason > 7 group (4.14 and 4.79, respectively). mp-MRI performance was more accurate for lesions > 15 mm and in patients with PSA > 6 ng/ml. In systematic sampling, 130 (11.25%) mp-MRI false-negative were identified. There was no statistic difference in Gleason median value (7.0 vs 7.06) between this group and the mp-MRI true-positives, but a significant lower PSA median value was demonstrated (7.08 vs 7.53 ng/ml). mp-MRI remains the imaging modality of choice to identify PCa lesions. Integrating US-guided random sampling with US/mp-MRI fusion target lesions sampling, 3.49% of false-negative were identified.

Statistical modeling of interfractional tissue deformation and its application in radiation therapy planning

NASA Astrophysics Data System (ADS)

Vile, Douglas J.

In radiation therapy, interfraction organ motion introduces a level of geometric uncertainty into the planning process. Plans, which are typically based upon a single instance of anatomy, must be robust against daily anatomical variations. For this problem, a model of the magnitude, direction, and likelihood of deformation is useful. In this thesis, principal component analysis (PCA) is used to statistically model the 3D organ motion for 19 prostate cancer patients, each with 8-13 fractional computed tomography (CT) images. Deformable image registration and the resultant displacement vector fields (DVFs) are used to quantify the interfraction systematic and random motion. By applying the PCA technique to the random DVFs, principal modes of random tissue deformation were determined for each patient, and a method for sampling synthetic random DVFs was developed. The PCA model was then extended to describe the principal modes of systematic and random organ motion for the population of patients. A leave-one-out study tested both the systematic and random motion model's ability to represent PCA training set DVFs. The random and systematic DVF PCA models allowed the reconstruction of these data with absolute mean errors between 0.5-0.9 mm and 1-2 mm, respectively. To the best of the author's knowledge, this study is the first successful effort to build a fully 3D statistical PCA model of systematic tissue deformation in a population of patients. By sampling synthetic systematic and random errors, organ occupancy maps were created for bony and prostate-centroid patient setup processes. By thresholding these maps, PCA-based planning target volume (PTV) was created and tested against conventional margin recipes (van Herk for bony alignment and 5 mm fixed [3 mm posterior] margin for centroid alignment) in a virtual clinical trial for low-risk prostate cancer. Deformably accumulated delivered dose served as a surrogate for clinical outcome. For the bony landmark setup subtrial, the PCA PTV significantly (p<0.05) reduced D30, D20, and D5 to bladder and D50 to rectum, while increasing rectal D20 and D5. For the centroid-aligned setup, the PCA PTV significantly reduced all bladder DVH metrics and trended to lower rectal toxicity metrics. All PTVs covered the prostate with the prescription dose.

Association between periodontitis and ischemic stroke: a systematic review and meta-analysis.

PubMed

Leira, Yago; Seoane, Juan; Blanco, Miguel; Rodríguez-Yáñez, Manuel; Takkouche, Bahi; Blanco, Juan; Castillo, José

2017-01-01

Several observational studies have suggested an association between periodontitis and cerebral ischemia. This meta-analysis aimed to investigate whether this link exists, and if so, the degree to which it is significant. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline for systematic review was used. The search strategy included using electronic databases and hand searching works published up to March 2015. MEDLINE via PubMed, EMBASE, Proceedings Web of Science and Current Contents Connect were searched by two independent reviewers. Case-control, cross-sectional or cohort studies including patients with measures of periodontitis and ischemic stroke were eligible to be included in the analysis. Quality assessments of selected studies were performed. From a total of 414 titles and abstracts, 57 potentially relevant full text papers were identified. After inclusion criteria were applied, 8 studies were included in the present systematic review (5 case-control and 3 cohort studies). Although it was not the intention, cross-sectional studies were excluded due to eligibility criteria were not accomplished. Therefore, meta-analyses were conducted with data retrieved from the 8 studies included. These meta-analyses showed statistically significant association between periodontitis and ischemic stroke in both cohort pooled relative risks at 2.52 (1.77-3.58), and case-control studies pooled relative risks at 3.04 (1.10-8.43). In conclusion, the present meta-analysis demonstrated an association between periodontitis and ischemic stroke. However, well-designed prospective studies should be carried out to provide robust evidence of the link between both diseases. In regards to ischemic stroke subtypes, further case-control studies should be carried out to investigate whether there is any association between the different subtypes of cerebral infarcts and periodontitis.

Can electronic search engines optimize screening of search results in systematic reviews: an empirical study.

PubMed

Sampson, Margaret; Barrowman, Nicholas J; Moher, David; Clifford, Tammy J; Platt, Robert W; Morrison, Andra; Klassen, Terry P; Zhang, Li

2006-02-24

Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG and Ovid. Our objective is to test the ability of an Ultraseek search engine to rank MEDLINE records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers. Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS), provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000-6000 records when the MEDLINE search strategy was replicated. Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review. The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

Translational phases of evidence in a prognostic biomarker: a systematic review and meta-analysis of natriuretic peptides and the prognosis of stable coronary disease.

PubMed

Sutaria, Shailen; Philipson, Peter; Fitzpatrick, Natalie K; Abrams, Keith; Moreno, Santiago G; Timmis, Adam; Hingorani, Aroon D; Hemingway, Harry

2012-04-01

Translational phases of study are important in evaluating whether a prognostic biomarker is likely to have impact on clinical practice but systematic evaluations of such evidence are lacking. To systematically evaluate the clinical usefulness of the published literature on the association of natriuretic peptides (NP) and prognosis in stable coronary disease. MEDLINE and EMBASE until the end of July 2009, without restrictions. Prospective studies measuring NP in people with stable coronary disease who were followed-up for all cause mortality, coronary or cardiovascular events. Two independent reviewers categorised studies according to the American Heart Association phase of study, and extracted data according to the study reporting guidelines from the American Heart Association and REMARK. Systematic review of 19 studies found 17 which were phase 2, reporting an association between NP and events, two phase 3 studies, statistically examining the incremental prognostic value of NP, but no studies assessing whether NP predicted risk sufficiently to change management (phase 4), improve clinical outcomes (phase 5) or cost effectiveness (phase 6). No study referred to a statistical analytic protocol. Meta-analysis of 14 studies, reporting 18,841 patients and 1655 outcome events, found an RR for events of 3.28 (95% CI 2.45 to 4.38) comparing top versus bottom third of NP. This effect was 26% lower among the five studies which adjusted for a priori confounders (age, sex, renal function and left ventricular function) and 38% lower when adjusting for publication bias (Egger's p=0.001). The unbiased strength of association of NP with prognosis in stable coronary disease is unclear, and there is a lack of reports of clinically useful measures of prediction and discrimination or studies relating NP levels to clinical decision making. The available literature is confined to early phases and is of limited clinical usefulness.

Low-dose ionizing radiation increases the mortality risk of solid cancers in nuclear industry workers: A meta-analysis.

PubMed

Qu, Shu-Gen; Gao, Jin; Tang, Bo; Yu, Bo; Shen, Yue-Ping; Tu, Yu

2018-05-01

Low-dose ionizing radiation (LDIR) may increase the mortality of solid cancers in nuclear industry workers, but only few individual cohort studies exist, and the available reports have low statistical power. The aim of the present study was to focus on solid cancer mortality risk from LDIR in the nuclear industry using standard mortality ratios (SMRs) and 95% confidence intervals. A systematic literature search through the PubMed and Embase databases identified 27 studies relevant to this meta-analysis. There was statistical significance for total, solid and lung cancers, with meta-SMR values of 0.88, 0.80, and 0.89, respectively. There was evidence of stochastic effects by IR, but more definitive conclusions require additional analyses using standardized protocols to determine whether LDIR increases the risk of solid cancer-related mortality.

Hepatitis C virus infections in oral lichen planus: a systematic review and meta-analysis.

PubMed

Alaizari, N A; Al-Maweri, S A; Al-Shamiri, H M; Tarakji, B; Shugaa-Addin, B

2016-09-01

A role for hepatitis C virus in oral lichen planus has been postulated. This systematic review and meta-analysis of the existing epidemiological studies was conducted to determine if there is a correlation between oral lichen planus and hepatitis C virus infection. We examined the association between hepatitis C virus and oral lichen planus by conducting a systematic review and meta-analysis of case-control studies that examined the prevalence of anti-HCV antibodies in the serum of cases and controls. We searched PubMed, Embase and The Cochrane Library databases from 2005 to January 2015. Associations were measured using random-effect odds ratios (ORs) combined with 95% confidence intervals. Nineteen eligible studies, encompassing 1807 cases of OLP and 2519 controls, were retrieved and included in this review. The summary estimate OR for all studies was 6.07 (95% CI: 2.73-13.48), showing a statistically significant difference in the proportion of HCV seropositivity among oral lichen planus patients, compared with controls and substantial heterogeneity between studies (I(2) = 65%) as a result of a variety of geographical distributions. The association of hepatitis C virus infection with oral lichen planus emphasizes the importance of hepatitis C virus screening in oral lichen planus patients. © 2015 Australian Dental Association.

A comparison of short term radiological alignment outcomes of the patient specific and standard instrumentation for primary total knee arthroplasty: A systematic review and meta-analysis.

PubMed

Alcelik, Ilhan; Blomfield, Mark; Öztürk, Cenk; Soni, Ashish; Charity, Richard; Acornley, Alex

2017-05-01

The aim of this study was to review the radiological alignment outcomes of patient Specific (PS) cutting blocks and Standard Instrumentation in Primary Total Knee Arthroplasty. We hypothesized that the use of PS techniques would significantly improve sagittal, coronal and rotational alignment of the prosthesis on short term. We performed a systematic review and a meta-analysis including all the randomised controlled trials (RCT) using PS and standard (ST) total knee arthroplasty to date. A total of 538 PS TKA and 549 ST TKA were included in the study. Statistical analysis of the outliers for femoral component sagittal, coronal and rotational positioning, tibial component sagittal and coronal positioning and the overall mechanical axis were assessed. We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components. Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group. Our results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty. Level 1, Systematic review of therapeutic studies. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Influence of tooth bleaching on dental enamel microhardness: a systematic review and meta-analysis.

PubMed

Zanolla, J; Marques, Abc; da Costa, D C; de Souza, A S; Coutinho, M

2017-09-01

Several studies have investigated the effect of bleaching on dental tissues. The evaluation of the effect of home bleaching with 10% carbamide peroxide is important for assessing alterations in enamel microhardness that may affect dental health in terms of resistance to masticatory forces. This meta-analysis was performed in order to determine scientific evidence regarding the effects of home vital bleaching with 10% carbamide peroxide gel on the microhardness of human dental enamel. A systematic electronic literature search was conducted in the PubMed and Web of Science databases using search terms. Two independent researchers evaluated the information and methodological quality of the studies. Inclusion and exclusion criteria were established for article selection; further, only studies published in English were selected. Thirteen studies that met all of the inclusion and exclusion criteria were selected and underwent statistical analysis. The results of this meta-analysis showed no significant changes in enamel microhardness when using the 10% carbamide peroxide bleaching gel over periods of 7, 14 and 21 days. © 2016 Australian Dental Association.

Effect of psychosocial interventions on the quality of life of patients with colorectal cancer: a systematic review and meta-analysis.

PubMed

Son, Heesook; Son, Youn-Jung; Kim, Hyerang; Lee, Yoonju

2018-06-08

We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of psychosocial interventions on the quality of life of patients with colorectal cancer. We searched the main health-related databases for relevant papers. Then, we examined the titles and abstracts of the retrieved papers, applying exclusion criteria to filter out irrelevant papers; a more in-depth filtering process was then conducted by reading the full texts. Eight studies remained at the end of this process. Next, we performed data extraction and assessed the methodological quality of the selected studies. This was followed by computation of effect sizes and the heterogeneity of the results, and then an assessment of the potential bias. The systematic review found that most of the interventions in these eight studies did not have a significant effect on quality of life. Meanwhile, the meta-analysis, the overall effect of psychosocial interventions at the post-intervention period was found to be statistically significant but small. This meta-analysis provides evidence for the beneficial effect of face-to-face psychosocial interventions on the quality of life of colorectal cancer patients. It is, however, suggested that further studies be conducted on this topic to assess the roles of physical functioning and severity of symptoms before utilizing such face-to-face interventions.

Child–Pugh Versus MELD Score for the Assessment of Prognosis in Liver Cirrhosis

PubMed Central

Peng, Ying; Qi, Xingshun; Guo, Xiaozhong

2016-01-01

Abstract Child–Pugh and MELD scores have been widely used for the assessment of prognosis in liver cirrhosis. A systematic review and meta-analysis aimed to compare the discriminative ability of Child–Pugh versus MELD score to assess the prognosis of cirrhotic patients. PubMed and EMBASE databases were searched. The statistical results were summarized from every individual study. The summary areas under receiver operating characteristic curves, sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios were also calculated. Of the 1095 papers initially identified, 119 were eligible for the systematic review. Study population was heterogeneous among studies. They included 269 comparisons, of which 44 favored MELD score, 16 favored Child–Pugh score, 99 did not find any significant difference between them, and 110 did not report the statistical significance. Forty-two papers were further included in the meta-analysis. In patients with acute-on-chronic liver failure, Child–Pugh score had a higher sensitivity and a lower specificity than MELD score. In patients admitted to ICU, MELD score had a smaller negative likelihood ratio and a higher sensitivity than Child–Pugh score. In patients undergoing surgery, Child–Pugh score had a higher specificity than MELD score. In other subgroup analyses, Child–Pugh and MELD scores had statistically similar discriminative abilities or could not be compared due to the presence of significant diagnostic threshold effects. Although Child–Pugh and MELD scores had similar prognostic values in most of cases, their benefits might be heterogeneous in some specific conditions. The indications for Child–Pugh and MELD scores should be further identified. PMID:26937922

The efficacy and short-term effects of electronic cigarettes as a method for smoking cessation: a systematic review and a meta-analysis.

PubMed

Khoudigian, S; Devji, T; Lytvyn, L; Campbell, K; Hopkins, R; O'Reilly, D

2016-03-01

E-cigarettes are increasingly popular as smoking cessation aids. This review assessed the efficacy of e-cigarettes for smoking cessation as well as desire to smoke, withdrawal symptoms, and adverse events in adult smokers. A systematic review was conducted. Studies comparing e-cigarettes to other nicotine replacement therapies or placebo were included. Data were pooled using meta-analysis. Of 569 articles, 5 were eligible. Study participants were more likely to stop smoking when using nicotine e-cigarettes (43/489, 9 %) versus placebo e-cigarettes (8/173, 5 %); however, this difference was not statistically significant (RR 2.02; 95 % CI 0.97, 4.22). The pooled effect estimates for the desire to smoke (RR -0.22; 95 % CI -0.80, 0.36), irritability (RR -0.03; 95% CI -0.38, 0.31), restlessness (RR -0.03; 95 % CI -0.42, 0.35), poor concentration (RR -0.01; 95 % CI -0.35, 0.32), depression (RR -0.01; 95 % CI -0.22, 0.20), hunger (RR -0.01; 95 % CI -0.32, 0.30), and average number of non-serious adverse events (RR -0.09; 95 % CI -0.28, 0.46) were not statistically significantly different. Only one study reported serious adverse events with no apparent association with e-cigarette use. Limited low-quality evidence of a non-statistically significant trend toward smoking cessation in adults using nicotine e-cigarettes exists compared with other therapies or placebo. Larger, high-quality studies are needed to inform policy decisions.

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.

Late Postoperative Complications in Laparoscopic Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-en-y Gastric Bypass (LRYGB): Meta-analysis and Systematic Review.

PubMed

Osland, Emma; Yunus, Rossita M; Khan, Shahjahan; Memon, Breda; Memon, Muhammed A

2016-06-01

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy (LVSG), have been proposed as cost-effective strategies to manage obesity-related chronic disease. The objectives of this meta-analysis and systematic review were to analyze the "late postoperative complication rate (>30 days)" for these 2 procedures. Randomized controlled trials (RCTs) published between 2000 and 2015 comparing the late complication rates, that is, >30 days following LVSG and LRYGB in adult population (ie, 16 y and above) were selected from PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane database. The outcome variables analyzed included mortality rate, major and minor complications, and interventions required for their management and readmission rates. Random effects model was used to calculate the effect size of both binary and continuous data. Heterogeneity among the outcome variables of these trials was determined by the Cochran Q statistic and I index. The meta-analysis was prepared in accordance with the Preferred Reporting of Systematic Reviews and Meta-Analyses guidelines. Six RCTs involving a total of 685 patients (LVSG, n=345; LRYGB, n=340) reported late major complications. A nonstatistical reduction in relative odds favoring the LVSG procedure was observed [odds ratio (OR), 0.64; 95% confidence interval (CI), 0.21-1.97; P=0.4]. Four RCTs representing 408 patients (LVSG, n=208; LRYGB, n=200) reported late minor complications. A nonstatistically significant reduction of 36% in relative odds favoring the LVSG procedure was observed (OR, 0.64; 95% CI, 0.28-1.47; P=0.3). A 37% relative reduction in odds was observed in favor of the LVSG for the need for additional interventions to manage late postoperative complications that did not reach statistical significance (OR, 0.63; 95% CI, 0.19-2.05; P=0.4). No study specifically reported readmissions required for the management of late complication. This meta-analysis and systematic review of RCTs shows that the development of late (major and minor) complications is similar between LVSG and LRYGB procedures, 6 months to 3 years postoperatively, and they do not lead to higher readmission rate or reoperation rate for either procedure. However longer-term surveillance is required to accurately describe the patterns of late complications in these patients.

Systematic Review and Meta-Analysis of Recombinant Human Bone Morphogenetic Protein-2 in Localized Alveolar Ridge and Maxillary Sinus Augmentation.

PubMed

Kelly, Mick P; Vaughn, Olushola L Akinshemoyin; Anderson, Paul A

2016-05-01

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is approved by the Food and Drug Administration as a viable alternative to bone graft in spinal fusion and maxillary sinus lift. The research questions for meta-analysis were: Is rhBMP-2 an effective bone graft substitute in localized alveolar ridge augmentation and maxillary sinus floor augmentation? What are the potential adverse events? A search of MEDLINE from January 1980 to January 2014 using PubMed, the Cochrane Database of Systematic Reviews and Controlled Trials, CINAHL, and EMBASE was performed. Searches were performed from Medical Subject Headings. The quality of each study included was graded by Review Manager software. The primary outcome variable was bone formation measured as change in bone height on computed tomogram. A systematic review of adverse events also was performed. A random-effects model was chosen. Continuous variables were calculated using the standardized mean difference and 95% confidence intervals (CIs) comparing improvement from baseline of the experimental group with that of the control group. Change in bone height was calculated using logarithmic odds ratio. Test of significance used the Z statistic with a P value of .05. Ten studies met the criteria for systematic review; 8 studies were included in the meta-analysis. Five studies assessed localized alveolar ridge augmentation and resulted in an overall standardized mean difference of 0.56 (CI, 0.20-0.92) in favor of BMP; this result was statistically important. Three studies assessed maxillary sinus floor augmentation and resulted in an overall standardized mean difference of -0.50 (CI, -0.93 to -0.09), which was meaningfully different in favor of the control group. Adverse events were inconsistently reported, ranging from no complications to widespread adverse events. For localized alveolar ridge augmentation, this meta-analysis showed that rhBMP-2 substantially increases bone height. However, rhBMP-2 does not perform as well as the autograft or allograft in maxillary sinus floor augmentation. Long-term clinical success and adverse events need to be reported with more consistency before definitive conclusions can be made. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Probiotics and Subclinical Psychological Symptoms in Healthy Participants: A Systematic Review and Meta-Analysis.

PubMed

McKean, Jennifer; Naug, Helen; Nikbakht, Elham; Amiet, Bianca; Colson, Natalie

2017-04-01

Interest in the gut-brain axis and emerging evidence that the intestinal microbiota can influence central nervous system function has led to the hypothesis that probiotic supplementation can have a positive effect on mood and psychological symptoms such as depression and anxiety. Although several human clinical trials have investigated this, results have been inconsistent. Therefore, a systematic review and meta-analytic approach was chosen to examine if probiotic consumption has an effect on psychological symptoms. The online databases PubMed, Scopus, and the Cochrane Library were searched for relevant studies up to July 2016. Those that were randomized and placebo controlled and measured preclinical psychological symptoms of depression, anxiety, and perceived stress in healthy volunteers pre and post supplementation with a probiotic were included. To control for differences in scales of measurement, data were converted to percentage change, and the standardized mean difference between the probiotic and control groups was investigated using Revman software. A random effects model was used for analysis. Heterogeneity was assessed using the I 2 statistic. Quality assessment was undertaken using the Rosendal scale. Seven studies met the inclusion criteria and provided data for nine comparisons. All studies passed the quality analysis. The meta-analysis showed that supplementation with probiotics resulted in a statistically significant improvement in psychological symptoms (standardized mean difference 0.34; 95% confidence interval 0.07-0.61, Z = 2.49) compared with placebo. These results show that probiotic consumption may have a positive effect on psychological symptoms of depression, anxiety, and perceived stress in healthy human volunteers.

Objective Dysphonia Quantification in Vocal Fold Paralysis: Comparing Nonlinear with Classical Measures

PubMed Central

Little, Max A.; Costello, Declan A. E.; Harries, Meredydd L.

2010-01-01

Summary Clinical acoustic voice-recording analysis is usually performed using classical perturbation measures, including jitter, shimmer, and noise-to-harmonic ratios (NHRs). However, restrictive mathematical limitations of these measures prevent analysis for severely dysphonic voices. Previous studies of alternative nonlinear random measures addressed wide varieties of vocal pathologies. Here, we analyze a single vocal pathology cohort, testing the performance of these alternative measures alongside classical measures. We present voice analysis pre- and postoperatively in 17 patients with unilateral vocal fold paralysis (UVFP). The patients underwent standard medialization thyroplasty surgery, and the voices were analyzed using jitter, shimmer, NHR, nonlinear recurrence period density entropy (RPDE), detrended fluctuation analysis (DFA), and correlation dimension. In addition, we similarly analyzed 11 healthy controls. Systematizing the preanalysis editing of the recordings, we found that the novel measures were more stable and, hence, reliable than the classical measures on healthy controls. RPDE and jitter are sensitive to improvements pre- to postoperation. Shimmer, NHR, and DFA showed no significant change (P > 0.05). All measures detect statistically significant and clinically important differences between controls and patients, both treated and untreated (P < 0.001, area under curve [AUC] > 0.7). Pre- to postoperation grade, roughness, breathiness, asthenia, and strain (GRBAS) ratings show statistically significant and clinically important improvement in overall dysphonia grade (G) (AUC = 0.946, P < 0.001). Recalculating AUCs from other study data, we compare these results in terms of clinical importance. We conclude that, when preanalysis editing is systematized, nonlinear random measures may be useful for monitoring UVFP-treatment effectiveness, and there may be applications to other forms of dysphonia. PMID:19900790

Topology of Large-Scale Structures of Galaxies in two Dimensions—Systematic Effects

NASA Astrophysics Data System (ADS)

Appleby, Stephen; Park, Changbom; Hong, Sungwook E.; Kim, Juhan

2017-02-01

We study the two-dimensional topology of galactic distribution when projected onto two-dimensional spherical shells. Using the latest Horizon Run 4 simulation data, we construct the genus of the two-dimensional field and consider how this statistic is affected by late-time nonlinear effects—principally gravitational collapse and redshift space distortion (RSD). We also consider systematic and numerical artifacts, such as shot noise, galaxy bias, and finite pixel effects. We model the systematics using a Hermite polynomial expansion and perform a comprehensive analysis of known effects on the two-dimensional genus, with a view toward using the statistic for cosmological parameter estimation. We find that the finite pixel effect is dominated by an amplitude drop and can be made less than 1% by adopting pixels smaller than 1/3 of the angular smoothing length. Nonlinear gravitational evolution introduces time-dependent coefficients of the zeroth, first, and second Hermite polynomials, but the genus amplitude changes by less than 1% between z = 1 and z = 0 for smoothing scales {R}{{G}}> 9 {Mpc}/{{h}}. Non-zero terms are measured up to third order in the Hermite polynomial expansion when studying RSD. Differences in the shapes of the genus curves in real and redshift space are small when we adopt thick redshift shells, but the amplitude change remains a significant ˜ { O }(10 % ) effect. The combined effects of galaxy biasing and shot noise produce systematic effects up to the second Hermite polynomial. It is shown that, when sampling, the use of galaxy mass cuts significantly reduces the effect of shot noise relative to random sampling.

Systematic Correlation Matrix Evaluation (SCoMaE) - a bottom-up, science-led approach to identifying indicators

NASA Astrophysics Data System (ADS)

Mengis, Nadine; Keller, David P.; Oschlies, Andreas

2018-01-01

This study introduces the Systematic Correlation Matrix Evaluation (SCoMaE) method, a bottom-up approach which combines expert judgment and statistical information to systematically select transparent, nonredundant indicators for a comprehensive assessment of the state of the Earth system. The methods consists of two basic steps: (1) the calculation of a correlation matrix among variables relevant for a given research question and (2) the systematic evaluation of the matrix, to identify clusters of variables with similar behavior and respective mutually independent indicators. Optional further analysis steps include (3) the interpretation of the identified clusters, enabling a learning effect from the selection of indicators, (4) testing the robustness of identified clusters with respect to changes in forcing or boundary conditions, (5) enabling a comparative assessment of varying scenarios by constructing and evaluating a common correlation matrix, and (6) the inclusion of expert judgment, for example, to prescribe indicators, to allow for considerations other than statistical consistency. The example application of the SCoMaE method to Earth system model output forced by different CO2 emission scenarios reveals the necessity of reevaluating indicators identified in a historical scenario simulation for an accurate assessment of an intermediate-high, as well as a business-as-usual, climate change scenario simulation. This necessity arises from changes in prevailing correlations in the Earth system under varying climate forcing. For a comparative assessment of the three climate change scenarios, we construct and evaluate a common correlation matrix, in which we identify robust correlations between variables across the three considered scenarios.

Stacked Weak Lensing Mass Calibration: Estimators, Systematics, and Impact on Cosmological Parameter Constraints

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

Rozo, Eduardo; /U. Chicago /Chicago U., KICP; Wu, Hao-Yi

2011-11-04

When extracting the weak lensing shear signal, one may employ either locally normalized or globally normalized shear estimators. The former is the standard approach when estimating cluster masses, while the latter is the more common method among peak finding efforts. While both approaches have identical signal-to-noise in the weak lensing limit, it is possible that higher order corrections or systematic considerations make one estimator preferable over the other. In this paper, we consider the efficacy of both estimators within the context of stacked weak lensing mass estimation in the Dark Energy Survey (DES). We find that the two estimators havemore » nearly identical statistical precision, even after including higher order corrections, but that these corrections must be incorporated into the analysis to avoid observationally relevant biases in the recovered masses. We also demonstrate that finite bin-width effects may be significant if not properly accounted for, and that the two estimators exhibit different systematics, particularly with respect to contamination of the source catalog by foreground galaxies. Thus, the two estimators may be employed as a systematic cross-check of each other. Stacked weak lensing in the DES should allow for the mean mass of galaxy clusters to be calibrated to {approx}2% precision (statistical only), which can improve the figure of merit of the DES cluster abundance experiment by a factor of {approx}3 relative to the self-calibration expectation. A companion paper investigates how the two types of estimators considered here impact weak lensing peak finding efforts.« less

A systematic literature review of PTSD's latent structure in the Diagnostic and Statistical Manual of Mental Disorders: DSM-IV to DSM-5.

PubMed

Armour, Cherie; Műllerová, Jana; Elhai, Jon D

2016-03-01

The factor structure of posttraumatic stress disorder (PTSD) has been widely researched, but consensus regarding the exact number and nature of factors is yet to be reached. The aim of the current study was to systematically review the extant literature on PTSD's latent structure in the Diagnostic and Statistical Manual of Mental Disorders (DSM) in order to identify the best-fitting model. One hundred and twelve research papers published after 1994 using confirmatory factor analysis and DSM-based measures of PTSD were included in the review. In the DSM-IV literature, four-factor models received substantial support, but the five-factor Dysphoric arousal model demonstrated the best fit, regardless of gender, measurement instrument or trauma type. The recently proposed DSM-5 PTSD model was found to be a good representation of PTSD's latent structure, but studies analysing the six- and seven-factor models suggest that the DSM-5 PTSD factor structure may need further alterations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Incidence, prevalence and genetic determinants of neonatal diabetes mellitus: a systematic review and meta-analysis protocol.

PubMed

Nansseu, Jobert Richie N; Ngo-Um, Suzanne S; Balti, Eric V

2016-11-10

In the absence of existing data, the present review intends to determine the incidence, prevalence and/or genetic determinants of neonatal diabetes mellitus (NDM), with expected contribution to disease characterization. We will include cross-sectional, cohort or case-control studies which have reported the incidence, prevalence and/or genetic determinants of NDM between January 01, 2000 and May 31, 2016, published in English or French languages and without any geographical limitation. PubMed and EMBASE will be extensively screened to identify potentially eligible studies, completed by manual search. Two authors will independently screen, select studies, extract data, and assess the risk of bias; disagreements will be resolved by consensus. Clinical heterogeneity will be investigated by examining the design and setting (including geographic region), procedure used for genetic testing, calculation of incidence or prevalence, and outcomes in each study. Studies found to be clinically homogeneous will be pooled together through a random effects meta-analysis. Statistical heterogeneity will be assessed using the chi-square test of homogeneity and quantified using the I 2 statistic. In case of substantial heterogeneity, subgroup analyses will be undertaken. Publication bias will be assessed with funnel plots, complemented with the use of Egger's test of bias. This systematic review and meta-analysis is expected to draw a clear picture of phenotypic and genotypic presentations of NDM in order to better understand the condition and adequately address challenges in respect with its management. PROSPERO CRD42016039765.

The dose-response of salvage radiotherapy following radical prostatectomy: A systematic review and meta-analysis.

PubMed

King, Christopher R

2016-11-01

To date neither the optimal radiotherapy dose nor the existence of a dose-response has been established for salvage RT (SRT). A systematic review from 1996 to 2015 and meta-analysis was performed to identify the pathologic, clinical and treatment factors associated with relapse-free survival (RFS) after SRT (uniformly defined as a PSA>0.2ng/mL or rising above post-SRT nadir). A sigmoidal dose-response curve was objectively fitted and a non-parametric statistical test used to determine significance. 71 studies (10,034 patients) satisfied the meta-analysis criteria. SRT dose (p=0.0001), PSA prior to SRT (p=0.0009), ECE+ (p=0.039) and SV+ (p=0.046) had significant associations with RFS. Statistical analyses confirmed the independence of SRT dose-response. Omission of series with ADT did not alter results. Dose-response is well fit by a sigmoidal curve (p=0.0001) with a TCD 50 of 65.8Gy, with a dose of 70Gy achieving 58.4% RFS vs. 38.5% for 60Gy. A 2.0% [95% CI 1.1-3.2] improvement in RFS is achieved for each Gy. The SRT dose-response remarkably parallels that for definitive RT of localized disease. This study provides level 2a evidence for dose-escalated SRT>70Gy. The presence of an SRT dose-response for microscopic disease supports the hypothesis that prostate cancer is inherently radio-resistant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Quality Matters: Systematic Analysis of Endpoints Related to “Cellular Life” in Vitro Data of Radiofrequency Electromagnetic Field Exposure

PubMed Central

Simkó, Myrtill; Remondini, Daniel; Zeni, Olga; Scarfi, Maria Rosaria

2016-01-01

Possible hazardous effects of radiofrequency electromagnetic fields (RF-EMF) at low exposure levels are controversially discussed due to inconsistent study findings. Therefore, the main focus of the present study is to detect if any statistical association exists between RF-EMF and cellular responses, considering cell proliferation and apoptosis endpoints separately and with both combined as a group of “cellular life” to increase the statistical power of the analysis. We searched for publications regarding RF-EMF in vitro studies in the PubMed database for the period 1995–2014 and extracted the data to the relevant parameters, such as cell culture type, frequency, exposure duration, SAR, and five exposure-related quality criteria. These parameters were used for an association study with the experimental outcome in terms of the defined endpoints. We identified 104 published articles, from which 483 different experiments were extracted and analyzed. Cellular responses after exposure to RF-EMF were significantly associated to cell lines rather than to primary cells. No other experimental parameter was significantly associated with cellular responses. A highly significant negative association with exposure condition-quality and cellular responses was detected, showing that the more the quality criteria requirements were satisfied, the smaller the number of detected cellular responses. According to our knowledge, this is the first systematic analysis of specific RF-EMF bio-effects in association to exposure quality, highlighting the need for more stringent quality procedures for the exposure conditions. PMID:27420084

Endometriosis and obstetrics complications: a systematic review and meta-analysis.

PubMed

Zullo, Fabrizio; Spagnolo, Emanuela; Saccone, Gabriele; Acunzo, Miriam; Xodo, Serena; Ceccaroni, Marcello; Berghella, Vincenzo

2017-10-01

To evaluate the effect of endometriosis on pregnancy outcomes. Systematic review and meta-analysis. Not applicable. Women with or without endometriosis. Electronic databases searched from their inception until February 2017 with no limit for language and with all cohort studies reporting the incidence of obstetric complications in women with a diagnosis of endometriosis compared with a control group (women without a diagnosis of endometriosis) included. Primary outcome of incidence of preterm birth at <37 weeks with meta-analysis performed using the random effects model of DerSimonian and Laird to produce an odds ratio (OR) with 95% confidence interval (CI). Twenty-four studies were analyzed comprising 1,924,114 women. In most of them, the diagnosis of endometriosis was made histologically after surgery. Women with endometriosis had a statistically significantly higher risk of preterm birth (OR 1.63; 95% CI, 1.32-2.01), miscarriage (OR 1.75; 95% CI, 1.29-2.37), placenta previa (OR 3.03; 95% CI, 1.50-6.13), small for gestational age (OR 1.27; 95% CI, 1.03-1.57), and cesarean delivery (OR 1.57; 95% CI, 1.39-1.78) compared with the healthy controls. No differences were found in the incidence of gestational hypertension and preeclampsia. Women with endometriosis have a statistically significantly higher risk of preterm birth, miscarriage, placenta previa, small for gestational age infants, and cesarean delivery. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Certification of highly complex safety-related systems.

PubMed

Reinert, D; Schaefer, M

1999-01-01

The BIA has now 15 years of experience with the certification of complex electronic systems for safety-related applications in the machinery sector. Using the example of machining centres this presentation will show the systematic procedure for verifying and validating control systems using Application Specific Integrated Circuits (ASICs) and microcomputers for safety functions. One section will describe the control structure of machining centres with control systems using "integrated safety." A diverse redundant architecture combined with crossmonitoring and forced dynamization is explained. In the main section the steps of the systematic certification procedure are explained showing some results of the certification of drilling machines. Specification reviews, design reviews with test case specification, statistical analysis, and walk-throughs are the analytical measures in the testing process. Systematic tests based on the test case specification, Electro Magnetic Interference (EMI), and environmental testing, and site acceptance tests on the machines are the testing measures for validation. A complex software driven system is always undergoing modification. Most of the changes are not safety-relevant but this has to be proven. A systematic procedure for certifying software modifications is presented in the last section of the paper.

Quality improvement of diagnosis of the electromyography data based on statistical characteristics of the measured signals

NASA Astrophysics Data System (ADS)

Selivanova, Karina G.; Avrunin, Oleg G.; Zlepko, Sergii M.; Romanyuk, Sergii O.; Zabolotna, Natalia I.; Kotyra, Andrzej; Komada, Paweł; Smailova, Saule

2016-09-01

Research and systematization of motor disorders, taking into account the clinical and neurophysiologic phenomena, are important and actual problem of neurology. The article describes a technique for decomposing surface electromyography (EMG), using Principal Component Analysis. The decomposition is achieved by a set of algorithms that uses a specially developed for analyze EMG. The accuracy was verified by calculation of Mahalanobis distance and Probability error.

Impact of Early Enteral Nutrition on Nutritional and Immunological Outcomes of Gastric Cancer Patients Undergoing Gastrostomy: A Systematic Review and Meta-Analysis.

PubMed

Nikniaz, Zeinab; Somi, Mohammad Hossein; Nagashi, Shahnaz; Nikniaz, Leila

2017-07-01

The present systematic review and meta-analysis study evaluated the impact of early enteral nutrition (EN) on postoperative nutritional and immunological outcomes of gastric cancer (GC) patients. The databases of PubMed, Embase, Springer, and Cochrane library were searched till September 2016 to identify studies which evaluated the effects of EN compared with parenteral nutrition (PN) on postoperative immunological and nutritional status and hospitalization time in GC patients. Mean difference (MD) or standard mean difference (SMD) was calculated and I-square statistic test was used for heterogeneity analysis. The present systematic review and meta-analysis have consisted of seven trials, containing 835 GC patients. According to the result of meta-analysis, compared with PN, EN significantly resulted in more increase in the level of albumin [MD = 2.07 (0.49, 3.64)], prealbumin [MD = 9.41 (049, 33.55)], weight [MD = 1.52 (0.32, 2.72)], CD3+ [SMD = 1.96 (1.50, 2.43)], CD4+ [SMD = 2.45 (1.97, 2.93)], natural killers [MD = 5.80 (3.75, 7.85)], and also a decrease in the hospitalization time [MD=-2.39 (-2.74, -2.03)]. The results demonstrated that early administration of EN is more effective in improving postsurgical nutrition status and immune index in GC patients. So, based on these results, postoperative early administration of EN is recommended for GC patients where possible.

Not a Copernican observer: biased peculiar velocity statistics in the local Universe

NASA Astrophysics Data System (ADS)

Hellwing, Wojciech A.; Nusser, Adi; Feix, Martin; Bilicki, Maciej

2017-05-01

We assess the effect of the local large-scale structure on the estimation of two-point statistics of the observed radial peculiar velocities of galaxies. A large N-body simulation is used to examine these statistics from the perspective of random observers as well as 'Local Group-like' observers conditioned to reside in an environment resembling the observed Universe within 20 Mpc. The local environment systematically distorts the shape and amplitude of velocity statistics with respect to ensemble-averaged measurements made by a Copernican (random) observer. The Virgo cluster has the most significant impact, introducing large systematic deviations in all the statistics. For a simple 'top-hat' selection function, an idealized survey extending to ˜160 h-1 Mpc or deeper is needed to completely mitigate the effects of the local environment. Using shallower catalogues leads to systematic deviations of the order of 50-200 per cent depending on the scale considered. For a flat redshift distribution similar to the one of the CosmicFlows-3 survey, the deviations are even more prominent in both the shape and amplitude at all separations considered (≲100 h-1 Mpc). Conclusions based on statistics calculated without taking into account the impact of the local environment should be revisited.

Redshift data and statistical inference

NASA Technical Reports Server (NTRS)

Newman, William I.; Haynes, Martha P.; Terzian, Yervant

1994-01-01

Frequency histograms and the 'power spectrum analysis' (PSA) method, the latter developed by Yu & Peebles (1969), have been widely employed as techniques for establishing the existence of periodicities. We provide a formal analysis of these two classes of methods, including controlled numerical experiments, to better understand their proper use and application. In particular, we note that typical published applications of frequency histograms commonly employ far greater numbers of class intervals or bins than is advisable by statistical theory sometimes giving rise to the appearance of spurious patterns. The PSA method generates a sequence of random numbers from observational data which, it is claimed, is exponentially distributed with unit mean and variance, essentially independent of the distribution of the original data. We show that the derived random processes is nonstationary and produces a small but systematic bias in the usual estimate of the mean and variance. Although the derived variable may be reasonably described by an exponential distribution, the tail of the distribution is far removed from that of an exponential, thereby rendering statistical inference and confidence testing based on the tail of the distribution completely unreliable. Finally, we examine a number of astronomical examples wherein these methods have been used giving rise to widespread acceptance of statistically unconfirmed conclusions.

Topical tranexamic acid in total knee replacement: a systematic review and meta-analysis.

PubMed

Panteli, Michalis; Papakostidis, Costas; Dahabreh, Ziad; Giannoudis, Peter V

2013-10-01

To examine the safety and efficacy of topical use of tranexamic acid (TA) in total knee arthroplasty (TKA). An electronic literature search of PubMed Medline; Ovid Medline; Embase; and the Cochrane Library was performed, identifying studies published in any language from 1966 to February 2013. The studies enrolled adults undergoing a primary TKA, where topical TA was used. Inverse variance statistical method and either a fixed or random effect model, depending on the absence or presence of statistical heterogeneity were used; subgroup analysis was performed when possible. We identified a total of seven eligible reports for analysis. Our meta-analysis indicated that when compared with the control group, topical application of TA limited significantly postoperative drain output (mean difference: -268.36ml), total blood loss (mean difference=-220.08ml), Hb drop (mean difference=-0.94g/dL) and lowered the risk of transfusion requirements (risk ratio=0.47, 95CI=0.26-0.84), without increased risk of thromboembolic events. Sub-group analysis indicated that a higher dose of topical TA (>2g) significantly reduced transfusion requirements. Although the present meta-analysis proved a statistically significant reduction of postoperative blood loss and transfusion requirements with topical use of TA in TKA, the clinical importance of the respective estimates of effect size should be interpreted with caution. I, II. Copyright © 2013 Elsevier B.V. All rights reserved.

Association between the SERPINE1 (PAI-1) 4G/5G insertion/deletion promoter polymorphism (rs1799889) and pre-eclampsia: a systematic review and meta-analysis.

PubMed

Zhao, Linlu; Bracken, Michael B; Dewan, Andrew T; Chen, Suzan

2013-03-01

The SERPINE1 -675 4G/5G promoter region insertion/deletion polymorphism (rs1799889) has been implicated in the pathogenesis of pre-eclampsia (PE), but the genetic association has been inconsistently replicated. To derive a more precise estimate of the association, a systematic review and meta-analysis was conducted. This study conformed to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed (MEDLINE), Scopus and HuGE Literature Finder literature databases were systematically searched for relevant studies. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for the allelic comparison (4G versus 5G) and genotypic comparisons following the co-dominant (4G/4G versus 5G/5G and 4G/5G versus 5G/5G), dominant (4G/4G+4G/5G versus 5G/5G) and recessive (4G/4G versus 4G/5G+5G/5G) genetic models. Between-study heterogeneity was quantified by I(2) statistics and publication bias was appraised with funnel plots. Sensitivity analysis was conducted to evaluate the robustness of meta-analysis findings. Meta-analysis of 11 studies involving 1297 PE cases and 1791 controls found a significant association between the SERPINE1 -675 4G/5G polymorphism and PE for the recessive genetic model (OR = 1.36, 95% CI: 1.13-1.64, P = 0.001), a robust finding according to sensitivity analysis. A low level of between-study heterogeneity was detected (I(2) = 20%) in this comparison, which may be explained by ethnic differences. Funnel plot inspection did not reveal evidence of publication bias. In conclusion, this study provides a comprehensive examination of the available literature on the association between SERPINE1 -675 4G/5G and PE. Meta-analysis results support this polymorphism as a likely susceptibility variant for PE.

What Performance Analysts Need to Know About Research Trends in Association Football (2012-2016): A Systematic Review.

PubMed

Sarmento, Hugo; Clemente, Filipe Manuel; Araújo, Duarte; Davids, Keith; McRobert, Allistair; Figueiredo, António

2018-04-01

Evolving patterns of match analysis research need to be systematically reviewed regularly since this area of work is burgeoning rapidly and studies can offer new insights to performance analysts if theoretically and coherently organized. The purpose of this paper was to conduct a systematic review of published articles on match analysis in adult male football, identify and organize common research topics, and synthesize the emerging patterns of work between 2012 and 2016, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The Web of Science database was searched for relevant published studies using the following keywords: 'football' and 'soccer', each one associated with the terms 'match analysis', 'performance analysis', 'notational analysis', 'game analysis', 'tactical analysis' and 'patterns of play'. Of 483 studies initially identified, 77 were fully reviewed and their outcome measures extracted and analyzed. Results showed that research mainly focused on (1) performance at set pieces, i.e. corner kicks, free kicks, penalty kicks; (2) collective system behaviours, captured by established variables such as team centroid (geometrical centre of a set of players) and team dispersion (quantification of how far players are apart), as well as tendencies for team communication (establishing networks based on passing sequences), sequential patterns (predicting future passing sequences), and group outcomes (relationships between match-related statistics and final match scores); and (3) activity profile of players, i.e. playing roles, effects of fatigue, substitutions during matches, and the effects of environmental constraints on performance, such as heat and altitude. From the previous review, novel variables were identified that require new measurement techniques. It is evident that the complexity engendered during performance in competitive soccer requires an integrated approach that considers multiple aspects. A challenge for researchers is to align these new measures with the needs of the coaches through a more integrated relationship between coaches and researchers, to produce practical and usable information that improves player performance and coach activity.

Effects of Hypotensive Anesthesia on Reducing Intraoperative Blood Loss, Duration of Operation, and Quality of Surgical Field During Orthognathic Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PubMed

Lin, Susie; McKenna, Samuel J; Yao, Chuan-Fong; Chen, Yu-Ray; Chen, Chit

2017-01-01

The objective of this study was to evaluate the efficacy of hypotensive anesthesia in reducing intraoperative blood loss, decreasing operation time, and improving the quality of the surgical field during orthognathic surgery. A systematic review and meta-analysis of randomized controlled trials addressing these issues were carried out. An electronic database search was performed. The risk of bias was evaluated with the Jadad Scale and Delphi List. The inverse variance statistical method and a random-effects model were used. Ten randomized controlled trials were included for analysis. Our meta-analysis indicated that hypotensive anesthesia reduced intraoperative blood loss by a mean of about 169 mL. Hypotensive anesthesia was not shown to reduce the operation time for orthognathic surgery, but it did improve the quality of the surgical field. Subgroup analysis indicated that for blood loss in double-jaw surgery, the weighted mean difference favored the hypotensive group, with a reduction in blood loss of 175 mL, but no statistically significant reduction in blood loss was found for anterior maxillary osteotomy. If local anesthesia with epinephrine was used in conjunction with hypotensive anesthesia, the reduction in intraoperative blood loss was increased to 254.93 mL. Hypotensive anesthesia was effective in reducing blood loss and improving the quality of the surgical field, but it did not reduce the operation time for orthognathic surgery. The use of local anesthesia in conjunction with hypotensive general anesthesia further reduced the amount of intraoperative blood loss for orthognathic surgery. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of birth ball on labor pain relief: A systematic review and meta-analysis.

PubMed

Makvandi, Somayeh; Latifnejad Roudsari, Robab; Sadeghi, Ramin; Karimi, Leila

2015-11-01

To critically evaluate the available evidence related to the impact of using a birth ball on labor pain relief. The Cochrane library, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE/PubMed and Scopus were searched from their inception to January 2015 using keywords: (Birth* OR Swiss OR Swedish OR balance OR fitness OR gym* OR Pezzi OR sport* OR stability) AND (ball*) AND (labor OR labour OR Obstetric). All available randomized controlled trials involving women using a birth ball for pain relief during labor were considered. The search resulted in 341 titles and abstracts, which were narrowed down to eight potentially relevant articles. Of these, four studies met the inclusion criteria. Pain intensity on a 10 cm visual analogue scale was used as the main outcome measure. Risk of bias was assessed using the Cochrane Risk of Bias tool. Comprehensive Meta-Analysis Version 2 was used for statistical analysis. Four RCTs involving 220 women were included in the systematic review. One study was excluded from the meta-analysis because of heterogeneous interventions and a lack of mean and standard deviation results of labor pain score. The meta-analysis showed that birth ball exercises provided statistically significant improvements to labor pain (pooled mean difference -0.921; 95% confidence interval -1.28, -0.56; P = 0.0000005; I(2)  = 33.7%). The clinical implementation of a birth ball exercise could be an effective tool for parturient women to reduce labor pain. However, rigorous RCTs are needed to evaluate the effect of the birth ball on labor pain relief. © 2015 Japan Society of Obstetrics and Gynecology.

Experimental Design and Data Analysis Issues Contribute to Inconsistent Results of C-Bouton Changes in Amyotrophic Lateral Sclerosis.

PubMed

Dukkipati, S Shekar; Chihi, Aouatef; Wang, Yiwen; Elbasiouny, Sherif M

2017-01-01

The possible presence of pathological changes in cholinergic synaptic inputs [cholinergic boutons (C-boutons)] is a contentious topic within the ALS field. Conflicting data reported on this issue makes it difficult to assess the roles of these synaptic inputs in ALS. Our objective was to determine whether the reported changes are truly statistically and biologically significant and why replication is problematic. This is an urgent question, as C-boutons are an important regulator of spinal motoneuron excitability, and pathological changes in motoneuron excitability are present throughout disease progression. Using male mice of the SOD1-G93A high-expresser transgenic ( G93A ) mouse model of ALS, we examined C-boutons on spinal motoneurons. We performed histological analysis at high statistical power, which showed no difference in C-bouton size in G93A versus wild-type motoneurons throughout disease progression. In an attempt to examine the underlying reasons for our failure to replicate reported changes, we performed further histological analyses using several variations on experimental design and data analysis that were reported in the ALS literature. This analysis showed that factors related to experimental design, such as grouping unit, sampling strategy, and blinding status, potentially contribute to the discrepancy in published data on C-bouton size changes. Next, we systematically analyzed the impact of study design variability and potential bias on reported results from experimental and preclinical studies of ALS. Strikingly, we found that practices such as blinding and power analysis are not systematically reported in the ALS field. Protocols to standardize experimental design and minimize bias are thus critical to advancing the ALS field.

Cryptic or pseudocryptic: can morphological methods inform copepod taxonomy? An analysis of publications and a case study of the Eurytemora affinis species complex

PubMed Central

Lajus, Dmitry; Sukhikh, Natalia; Alekseev, Victor

2015-01-01

Interest in cryptic species has increased significantly with current progress in genetic methods. The large number of cryptic species suggests that the resolution of traditional morphological techniques may be insufficient for taxonomical research. However, some species now considered to be cryptic may, in fact, be designated pseudocryptic after close morphological examination. Thus the “cryptic or pseudocryptic” dilemma speaks to the resolution of morphological analysis and its utility for identifying species. We address this dilemma first by systematically reviewing data published from 1980 to 2013 on cryptic species of Copepoda and then by performing an in-depth morphological study of the former Eurytemora affinis complex of cryptic species. Analyzing the published data showed that, in 5 of 24 revisions eligible for systematic review, cryptic species assignment was based solely on the genetic variation of forms without detailed morphological analysis to confirm the assignment. Therefore, some newly described cryptic species might be designated pseudocryptic under more detailed morphological analysis as happened with Eurytemora affinis complex. Recent genetic analyses of the complex found high levels of heterogeneity without morphological differences; it is argued to be cryptic. However, next detailed morphological analyses allowed to describe a number of valid species. Our study, using deep statistical analyses usually not applied for new species describing, of this species complex confirmed considerable differences between former cryptic species. In particular, fluctuating asymmetry (FA), the random variation of left and right structures, was significantly different between forms and provided independent information about their status. Our work showed that multivariate statistical approaches, such as principal component analysis, can be powerful techniques for the morphological discrimination of cryptic taxons. Despite increasing cryptic species designations, morphological techniques have great potential in determining copepod taxonomy. PMID:26120427

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water.

PubMed

Lamm, Steven H; Ferdosi, Hamid; Dissen, Elisabeth K; Li, Ji; Ahn, Jaeil

2015-12-07

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1-1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100-150 µg/L arsenic.

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water

PubMed Central

Lamm, Steven H.; Ferdosi, Hamid; Dissen, Elisabeth K.; Li, Ji; Ahn, Jaeil

2015-01-01

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1–1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100–150 µg/L arsenic. PMID:26690190

Astrostatistics in X-ray Astronomy: Systematics and Calibration

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Kashyap, Vinay; CHASC

2014-01-01

Astrostatistics has been emerging as a new field in X-ray and gamma-ray astronomy, driven by the analysis challenges arising from data collected by high performance missions since the beginning of this century. The development and implementation of new analysis methods and techniques requires a close collaboration between astronomers and statisticians, and requires support from a reliable and continuous funding source. The NASA AISR program was one such, and played a crucial part in our work. Our group (CHASC; http://heawww.harvard.edu/AstroStat/), composed of a mixture of high energy astrophysicists and statisticians, was formed ~15 years ago to address specific issues related to Chandra X-ray Observatory data (Siemiginowska et al. 1997) and was initially fully supported by Chandra. We have developed several statistical methods that have laid the foundation for extensive application of Bayesian methodologies to Poisson data in high-energy astrophysics. I will describe one such project, on dealing with systematic uncertainties (Lee et al. 2011, ApJ ), and present the implementation of the method in Sherpa, the CIAO modeling and fitting application. This algorithm propagates systematic uncertainties in instrumental responses (e.g., ARFs) through the Sherpa spectral modeling chain to obtain realistic error bars on model parameters when the data quality is high. Recent developments include the ability to narrow the space of allowed calibration and obtain better parameter estimates as well as tighter error bars. Acknowledgements: This research is funded in part by NASA contract NAS8-03060. References: Lee, H., Kashyap, V.L., van Dyk, D.A., et al. 2011, ApJ, 731, 126 Siemiginowska, A., Elvis, M., Connors, A., et al. 1997, Statistical Challenges in Modern Astronomy II, 241

The Longterm Centimeter-band Total Flux and Linear Polarization Properties of the Pearson-Readhead Survey Sources

NASA Astrophysics Data System (ADS)

Aller, M. F.; Aller, H. D.; Hughes, P. A.

2001-12-01

Using centimeter-band total flux and linear polarization observations of the Pearson-Readhead sample sources systematically obtained with the UMRAO 26-m radio telescope during the past 16 years, we identify the range of variability properties and their temporal changes as functions of both optical and radio morphological classification. We find that our earlier statistical analysis, based on a time window of 6.4 years, did not delineate the full amplitude range of the total flux variability; further, several galaxies exhibit longterm, systematic changes or rather infrequent outbursts requiring long term observations for detection. Using radio classification as a delineator, we confirm, and find additional evidence, that significant changes in flux density can occur in steep spectrum and lobe-dominated objects as well as in compact, flat-spectrum objects. We find that statistically the time-averaged total flux density spectra steepen when longer time windows are included, which we attribute to a selection effect in the source sample. We have identified preferred orientations of the electric vector of the polarized emission (EVPA) in an unbiased manner in several sources, including several QSOs which have exhibited large variations in total flux while maintaining stable EVPAs, and compared these with orientations of the flow direction indicated by VLB morphology. We have looked for systematic, monotonic changes in EVPA which might be expected in the emission from a precessing jet, but none were identified. A Scargle periodogram analysis found no strong evidence for periodicity in any of the sample sources. We thank the NSF for grants AST-8815678, AST-9120224, AST-9421979, and AST-9900723 which provided partial support for this research. The operation of the 26-meter telescope is supported by the University of Michigan Department of Astronomy.

Gender Systematics in Telescope Time Allocation at ESO

NASA Astrophysics Data System (ADS)

Patat, F.

2016-09-01

The results of a comprehensive statistical analysis of gender systematics in the time allocation process at ESO are presented. The sample on which the study is based includes more than 13 000 Normal and Short proposals, submitted by about 3000 principal investigators (PI) over eight years. The genders of PIs, and of the panel members of the Observing Programmes Committee (OPC), were used, together with their career level, to analyse the grade distributions and the proposal success rates. Proposals submitted by female PIs show a significantly lower probability of being allocated time. The proposal success rates (defined as number of top ranked runs over requested runs) are 16.0 ± 0.6% and 22.0 ± 0.4% for females and males, respectively. To a significant extent the disparity is related to different input distributions in terms of career level. The seniority of male PIs is significantly higher than that of female PIs, with only 34% of the female PIs being professionally employed astronomers (compared to 53% for male PIs). A small, but statistically significant, gender-dependent behaviour is measured for the OPC referees: both genders show the same systematics, but they are larger for males than females. The PI female/male fraction is very close to 30/70; although far from parity, the fraction is higher than that observed, for instance, among IAU membership.

Economic and outcomes consequences of TachoSil®: a systematic review.

PubMed

Colombo, Giorgio L; Bettoni, Daria; Di Matteo, Sergio; Grumi, Camilla; Molon, Cinzia; Spinelli, Daniela; Mauro, Gaetano; Tarozzo, Alessia; Bruno, Giacomo M

2014-01-01

TachoSil(®) is a medicated sponge coated with human fibrinogen and human thrombin. It is indicated as a support treatment in adult surgery to improve hemostasis, promote tissue sealing, and support sutures when standard surgical techniques are insufficient. This review systematically analyses the international scientific literature relating to the use of TachoSil in hemostasis and as a surgical sealant, from the point of view of its economic impact. We carried out a systematic review of the PubMed literature up to November 2013. Based on the selection criteria, papers were grouped according to the following outcomes: reduction of time to hemostasis; decrease in length of hospital stay; and decrease in postoperative complications. Twenty-four scientific papers were screened, 13 (54%) of which were randomized controlled trials and included a total of 2,116 patients, 1,055 of whom were treated with TachoSil. In the clinical studies carried out in patients undergoing hepatic, cardiac, or renal surgery, the time to hemostasis obtained with TachoSil was lower (1-4 minutes) than the time measured with other techniques and hemostatic drugs, with statistically significant differences. Moreover, in 13 of 15 studies, TachoSil showed a statistically significant reduction in postoperative complications in comparison with the standard surgical procedure. The range of the observed decrease in the length of hospital stay for TachoSil patients was 2.01-3.58 days versus standard techniques, with a statistically significant difference in favor of TachoSil in eight of 15 studies. This analysis shows that TachoSil has a role as a supportive treatment in surgery to improve hemostasis and promote tissue sealing when standard techniques are insufficient, with a consequent decrease in postoperative complications and hospital costs.

Early Fungicidal Activity as a Candidate Surrogate Endpoint for All-Cause Mortality in Cryptococcal Meningitis: A Systematic Review of the Evidence.

PubMed

Montezuma-Rusca, Jairo M; Powers, John H; Follmann, Dean; Wang, Jing; Sullivan, Brigit; Williamson, Peter R

2016-01-01

Cryptococcal meningitis (CM) is a leading cause of HIV-associated mortality. In clinical trials evaluating treatments for CM, biomarkers of early fungicidal activity (EFA) in cerebrospinal fluid (CSF) have been proposed as candidate surrogate endpoints for all- cause mortality (ACM). However, there has been no systematic evaluation of the group-level or trial-level evidence for EFA as a candidate surrogate endpoint for ACM. We conducted a systematic review of randomized trials in treatment of CM to evaluate available evidence for EFA measured as culture negativity at 2 weeks/10 weeks and slope of EFA as candidate surrogate endpoints for ACM. We performed sensitivity analysis on superiority trials and high quality trials as determined by Cochrane measures of trial bias. Twenty-seven trials including 2854 patients met inclusion criteria. Mean ACM was 15.8% at 2 weeks and 27.0% at 10 weeks with no overall significant difference between test and control groups. There was a statistically significant group-level correlation between average EFA and ACM at 10 weeks but not at 2 weeks. There was also no statistically significant group-level correlation between CFU culture negativity at 2weeks/10weeks or average EFA slope at 10 weeks. A statistically significant trial-level correlation was identified between EFA slope and ACM at 2 weeks, but is likely misleading, as there was no treatment effect on ACM. Mortality remains high in short time periods in CM clinical trials. Using published data and Institute of Medicine criteria, evidence for use of EFA as a surrogate endpoint for ACM is insufficient and could provide misleading results from clinical trials. ACM should be used as a primary endpoint evaluating treatments for cryptococcal meningitis.

Modeling Systematicity and Individuality in Nonlinear Second Language Development: The Case of English Grammatical Morphemes

ERIC Educational Resources Information Center

Murakami, Akira

2016-01-01

This article introduces two sophisticated statistical modeling techniques that allow researchers to analyze systematicity, individual variation, and nonlinearity in second language (L2) development. Generalized linear mixed-effects models can be used to quantify individual variation and examine systematic effects simultaneously, and generalized…

Data analysis and systematic studies for the He-6 experiment

NASA Astrophysics Data System (ADS)

Bagdasarova, Yelena; Bailey, Kevin; Flechard, Xavier; Garcia, Alejandro; Hong, Ran; Leredde, Aranud; Mueller, Peter; Naviliat-Cuncic, Oscar; O'Connor, Tom P.; Sternberg, Matthew; Storm, Derek; Swanson, Erik; Wauters, Frederik; Zumwalt, David

2015-10-01

The He-6 experiment at the University of Washington aims to precisely measure the beta-neutrino angular correlation (aβν) in the beta decay of He-6, a parameter that is particularly sensitive to tensor-like currents in the electroweak interaction. The experiment is based on a coincidence detection of the beta and recoil ion emitted from laser trapped He-6 and seeks to ultimately measure aβν to the 0 . 1 % level. Monte-carlo simulations of the decay and detection scheme are essential to analyze the data and have been extensively used to quantify the effects of systematic uncertainties. Major efforts have been put in to limit their contributions to less than 1 % of aβν, the first goal of the experiment. This set of data will guide further improvements of the experiment towards the 0 . 1 % level measurement of aβν. The data analysis procedures and the current status of the experiment, including the achieved and projected systematic and statistical uncertainties, will be presented. This work is supported by DOE, Office of Nuclear Physics, under Contract Nos. DE-AC02-06CH11357 and DE-FG02-97ER41020. Done...processed 665 records...13:57:12

Implications of pleiotropy: challenges and opportunities for mining Big Data in biomedicine.

PubMed

Yang, Can; Li, Cong; Wang, Qian; Chung, Dongjun; Zhao, Hongyu

2015-01-01

Pleiotropy arises when a locus influences multiple traits. Rich GWAS findings of various traits in the past decade reveal many examples of this phenomenon, suggesting the wide existence of pleiotropic effects. What underlies this phenomenon is the biological connection among seemingly unrelated traits/diseases. Characterizing the molecular mechanisms of pleiotropy not only helps to explain the relationship between diseases, but may also contribute to novel insights concerning the pathological mechanism of each specific disease, leading to better disease prevention, diagnosis and treatment. However, most pleiotropic effects remain elusive because their functional roles have not been systematically examined. A systematic investigation requires availability of qualified measurements at multilayered biological processes (e.g., transcription and translation). The rise of Big Data in biomedicine, such as high-quality multi-omics data, biomedical imaging data and electronic medical records of patients, offers us an unprecedented opportunity to investigate pleiotropy. There will be a great need of computationally efficient and statistically rigorous methods for integrative analysis of these Big Data in biomedicine. In this review, we outline many opportunities and challenges in methodology developments for systematic analysis of pleiotropy, and highlight its implications on disease prevention, diagnosis and treatment.

Propranolol for the treatment of anxiety disorders: Systematic review and meta-analysis.

PubMed

Steenen, Serge A; van Wijk, Arjen J; van der Heijden, Geert J M G; van Westrhenen, Roos; de Lange, Jan; de Jongh, Ad

2016-02-01

The effects of propranolol in the treatment of anxiety disorders have not been systematically evaluated previously. The aim was to conduct a systematic review and meta-analysis of randomised controlled trials, addressing the efficacy of oral propranolol versus placebo or other medication as a treatment for alleviating either state or trait anxiety in patients suffering from anxiety disorders. Eight studies met the inclusion criteria. These studies concerned panic disorder with or without agoraphobia (four studies, total n = 130), specific phobia (two studies, total n = 37), social phobia (one study, n = 16), and posttraumatic stress disorder (PTSD) (one study, n = 19). Three out of four panic disorder trials qualified for pooled analyses. These meta-analyses found no statistically significant differences between the efficacy of propranolol and benzodiazepines regarding the short-term treatment of panic disorder with or without agoraphobia. Also, no evidence was found for effects of propranolol on PTSD symptom severity through inhibition of memory reconsolidation. In conclusion, the quality of evidence for the efficacy of propranolol at present is insufficient to support the routine use of propranolol in the treatment of any of the anxiety disorders. © The Author(s) 2015.

Novel keyword co-occurrence network-based methods to foster systematic reviews of scientific literature.

PubMed

Radhakrishnan, Srinivasan; Erbis, Serkan; Isaacs, Jacqueline A; Kamarthi, Sagar

2017-01-01

Systematic reviews of scientific literature are important for mapping the existing state of research and highlighting further growth channels in a field of study, but systematic reviews are inherently tedious, time consuming, and manual in nature. In recent years, keyword co-occurrence networks (KCNs) are exploited for knowledge mapping. In a KCN, each keyword is represented as a node and each co-occurrence of a pair of words is represented as a link. The number of times that a pair of words co-occurs in multiple articles constitutes the weight of the link connecting the pair. The network constructed in this manner represents cumulative knowledge of a domain and helps to uncover meaningful knowledge components and insights based on the patterns and strength of links between keywords that appear in the literature. In this work, we propose a KCN-based approach that can be implemented prior to undertaking a systematic review to guide and accelerate the review process. The novelty of this method lies in the new metrics used for statistical analysis of a KCN that differ from those typically used for KCN analysis. The approach is demonstrated through its application to nano-related Environmental, Health, and Safety (EHS) risk literature. The KCN approach identified the knowledge components, knowledge structure, and research trends that match with those discovered through a traditional systematic review of the nanoEHS field. Because KCN-based analyses can be conducted more quickly to explore a vast amount of literature, this method can provide a knowledge map and insights prior to undertaking a rigorous traditional systematic review. This two-step approach can significantly reduce the effort and time required for a traditional systematic literature review. The proposed KCN-based pre-systematic review method is universal. It can be applied to any scientific field of study to prepare a knowledge map.

Novel keyword co-occurrence network-based methods to foster systematic reviews of scientific literature

PubMed Central

Isaacs, Jacqueline A.

2017-01-01

Systematic reviews of scientific literature are important for mapping the existing state of research and highlighting further growth channels in a field of study, but systematic reviews are inherently tedious, time consuming, and manual in nature. In recent years, keyword co-occurrence networks (KCNs) are exploited for knowledge mapping. In a KCN, each keyword is represented as a node and each co-occurrence of a pair of words is represented as a link. The number of times that a pair of words co-occurs in multiple articles constitutes the weight of the link connecting the pair. The network constructed in this manner represents cumulative knowledge of a domain and helps to uncover meaningful knowledge components and insights based on the patterns and strength of links between keywords that appear in the literature. In this work, we propose a KCN-based approach that can be implemented prior to undertaking a systematic review to guide and accelerate the review process. The novelty of this method lies in the new metrics used for statistical analysis of a KCN that differ from those typically used for KCN analysis. The approach is demonstrated through its application to nano-related Environmental, Health, and Safety (EHS) risk literature. The KCN approach identified the knowledge components, knowledge structure, and research trends that match with those discovered through a traditional systematic review of the nanoEHS field. Because KCN-based analyses can be conducted more quickly to explore a vast amount of literature, this method can provide a knowledge map and insights prior to undertaking a rigorous traditional systematic review. This two-step approach can significantly reduce the effort and time required for a traditional systematic literature review. The proposed KCN-based pre-systematic review method is universal. It can be applied to any scientific field of study to prepare a knowledge map. PMID:28328983

The Effects of Perioperative Music Interventions in Pediatric Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PubMed Central

van der Heijden, Marianne J. E.; Oliai Araghi, Sadaf; van Dijk, Monique; Jeekel, Johannes; Hunink, M. G. Myriam

2015-01-01

Objective Music interventions are widely used, but have not yet gained a place in guidelines for pediatric surgery or pediatric anesthesia. In this systematic review and meta-analysis we examined the effects of music interventions on pain, anxiety and distress in children undergoing invasive surgery. Data Sources We searched 25 electronic databases from their first available date until October 2014. Study Selection Included were all randomized controlled trials with a parallel group, crossover or cluster design that included pediatric patients from 1 month to 18 years old undergoing minimally invasive or invasive surgical procedures, and receiving either live music therapy or recorded music. Data Extraction and Synthesis 4846 records were retrieved from the searches, 26 full text reports were evaluated and data was extracted by two independent investigators. Main Outcome Measures Pain was measured with the Visual Analogue Scale, the Coloured Analogue Scale and the Facial Pain Scale. Anxiety and distress were measured with an emotional index scale (not validated), the Spielberger short State Trait Anxiety Inventory and a Facial Affective Scale. Results Three RCTs were eligible for inclusion encompassing 196 orthopedic, cardiac and day surgery patients (age of 1 day to 18 years) receiving either live music therapy or recorded music. Overall a statistically significant positive effect was demonstrated on postoperative pain (SMD -1.07; 95%CI-2.08; -0.07) and on anxiety and distress (SMD -0.34 95% CI -0.66; -0.01 and SMD -0.50; 95% CI -0.84; - 0.16. Conclusions and Relevance This systematic review and meta-analysis indicates that music interventions may have a statistically significant effect in reducing post-operative pain, anxiety and distress in children undergoing a surgical procedure. Evidence from this review and other reviews suggests music therapy may be considered for clinical use. PMID:26247769

The Association between the Use of Proton Pump Inhibitors and the Risk of Hypomagnesemia: A Systematic Review and Meta-Analysis

PubMed Central

Park, Chan Hyuk; Kim, Eun Hye; Roh, Yun Ho; Kim, Ha Yan; Lee, Sang Kil

2014-01-01

Background 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. Methods 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 I 2 statistics. Results 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, I 2 = 98.0%). Conclusions PPI use may increase the risk of hypomagnesemia. However, significant heterogeneity among the included studies prevented us from reaching a definitive conclusion. PMID:25394217

Differential gene expression detection and sample classification using penalized linear regression models.

PubMed

Wu, Baolin

2006-02-15

Differential gene expression detection and sample classification using microarray data have received much research interest recently. Owing to the large number of genes p and small number of samples n (p > n), microarray data analysis poses big challenges for statistical analysis. An obvious problem owing to the 'large p small n' is over-fitting. Just by chance, we are likely to find some non-differentially expressed genes that can classify the samples very well. The idea of shrinkage is to regularize the model parameters to reduce the effects of noise and produce reliable inferences. Shrinkage has been successfully applied in the microarray data analysis. The SAM statistics proposed by Tusher et al. and the 'nearest shrunken centroid' proposed by Tibshirani et al. are ad hoc shrinkage methods. Both methods are simple, intuitive and prove to be useful in empirical studies. Recently Wu proposed the penalized t/F-statistics with shrinkage by formally using the (1) penalized linear regression models for two-class microarray data, showing good performance. In this paper we systematically discussed the use of penalized regression models for analyzing microarray data. We generalize the two-class penalized t/F-statistics proposed by Wu to multi-class microarray data. We formally derive the ad hoc shrunken centroid used by Tibshirani et al. using the (1) penalized regression models. And we show that the penalized linear regression models provide a rigorous and unified statistical framework for sample classification and differential gene expression detection.

Ketamine as a novel treatment for major depressive disorder and bipolar depression: a systematic review and quantitative meta-analysis.

PubMed

Lee, Ellen E; Della Selva, Megan P; Liu, Anson; Himelhoch, Seth

2015-01-01

Given the significant disability, morbidity and mortality associated with depression, the promising recent trials of ketamine highlight a novel intervention. A meta-analysis was conducted to assess the efficacy of ketamine in comparison with placebo for the reduction of depressive symptoms in patients who meet criteria for a major depressive episode. Two electronic databases were searched in September 2013 for English-language studies that were randomized placebo-controlled trials of ketamine treatment for patients with major depressive disorder or bipolar depression and utilized a standardized rating scale. Studies including participants receiving electroconvulsive therapy and adolescent/child participants were excluded. Five studies were included in the quantitative meta-analysis. The quantitative meta-analysis showed that ketamine significantly reduced depressive symptoms. The overall effect size at day 1 was large and statistically significant with an overall standardized mean difference of 1.01 (95% confidence interval 0.69-1.34) (P<.001), with the effects sustained at 7 days postinfusion. The heterogeneity of the studies was low and not statistically significant, and the funnel plot showed no publication bias. The large and statistically significant effect of ketamine on depressive symptoms supports a promising, new and effective pharmacotherapy with rapid onset, high efficacy and good tolerability. Copyright © 2015. Published by Elsevier Inc.

Prevalence and predictors of khat chewing among Ethiopian university students: A systematic review and meta-analysis.

PubMed

Gebrie, Alemu; Alebel, Animut; Zegeye, Abriham; Tesfaye, Bekele

2018-01-01

Khat chewing has become a common practice among university students in developing countries like Ethiopia. It has a potential effect on physical, mental, social and cognitive aspects of student functioning. In Ethiopia, study findings regarding the prevalence of khat chewing were highly dispersed and inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled prevalence of khat chewing and its predictors among Ethiopian university students. A systematic review and meta-analysis was conducted to assess the prevalence and predictors of khat chewing among university students in Ethiopia. We searched literature from the databases of PubMed, Google Scholar, Science Direct, and the Cochrane Library. A total of 24 Ethiopian studies reporting the prevalence of khat chewing among university students were included. Data were extracted using a standardized data extraction format prepared in Microsoft Excel and the analysis was done using STATA 14 statistical software. To assess heterogeneity, the Cochrane Q test statistics and I2 test were used. Since the included studies exhibit high heterogeneity, a random effect meta-analysis model was computed to estimate the pooled prevalence of khat chewing. Moreover, the association between predictor variables, and khat chewing practice were examined. The meta-analysis of 24 studies revealed that the pooled prevalence of khat chewing among university students in Ethiopia was 23.22% (95% CI: 19.5, 27.0). In the subgroup analysis, the highest prevalence was observed in Oromia region (31.6%; 95CI: 21.2, 41.9) whereas the lowest prevalence was observed in Amhara region (18.1%; 95%CI: 12.4, 23.8). Being male OR: 2.76 (95% CI 1.64, 4.63), family khat chewing practice OR: 2.91 (95% CI 1.06, 7.98), friend khat chewing habit OR: 4.74 (95% CI 3.48, 13.06), alcohol drinking OR: 7.06 (95% CI 5.65, 8.82) and cigarette smoking habit OR: 15.11 (95% CI 8.96, 25.51) were found to be predictors of khat chewing. The study found that the prevalence of khat chewing among university students was quite common, with slightly more than 1 in 5 students engaging in the use of this substance. Being male, family khat chewing practice, friend's khat chewing habit, alcohol drinking, and cigarette smoking were found to be predictors of khat chewing practice among university students.

The effect of antenatal education in small classes on obstetric and psycho-social outcomes: a systematic review and meta-analysis protocol.

PubMed

Brixval, Carina Sjöberg; Axelsen, Solveig Forberg; Andersen, Stig Krøger; Due, Pernille; Koushede, Vibeke

2014-02-13

The aims of antenatal education contain both outcomes related to pregnancy, birth and parenthood. Both content and methods of antenatal education have changed over time without evidence of effects on relevant outcomes. The effect of antenatal education in groups, with participation of a small number of participants, may differ from the effect of other forms of antenatal education. The latest Cochrane review, assessed as up-to-date in 2007, concluded that the effect of antenatal education for childbirth or parenthood or both remains largely unknown. This systematic review and meta-analysis aims to assess the effects of antenatal education in small groups on obstetric as well as psycho-social outcomes. Eligible studies include individually randomized as well as cluster-randomized trials irrespective of language, publication year, publication type, and publication status. Only interventions carried out in the Western world will be considered in this review. We will search the databases Medline, EMBASE, CENTRAL, CINAHL, Web of Science, and PsycINFO using relevant search terms. Two independent review authors will extract data and assess risk of bias. Results will be presented as structured summaries of the included trials. A meta-analysis will be conducted. We will assess heterogeneity by using both the Chi-squared test and the I-squared statistic, and conduct subgroup analysis separately for various intervention types. In healthcare systems with limited resources evidence of the effectiveness of services provided is important for decision making, and there is a need for policy makers to implement changes in healthcare systems based on scientific evidence. The effectiveness of antenatal education in small classes is still questioned. Therefore an up-to-date systematic review is needed.This systematic review protocol was registered within the International Prospective Register of Systematic Reviews (PROSPERO) as number CRD42013004319.

Child-Staff Ratios in Early Childhood Education and Care Settings and Child Outcomes: A Systematic Review and Meta-Analysis.

PubMed

Perlman, Michal; Fletcher, Brooke; Falenchuk, Olesya; Brunsek, Ashley; McMullen, Evelyn; Shah, Prakesh S

2017-01-01

Child-staff ratios are a key quality indicator in early childhood education and care (ECEC) programs. Better ratios are believed to improve child outcomes by increasing opportunities for individual interactions and educational instruction from staff. The purpose of this systematic review, and where possible, meta-analysis, was to evaluate the association between child-staff ratios in preschool ECEC programs and children's outcomes. Searches of Medline, PsycINFO, ERIC, websites of large datasets and reference sections of all retrieved articles were conducted up to July 3, 2015. Cross-sectional or longitudinal studies that evaluated the relationship between child-staff ratios in ECEC classrooms serving preschool aged children and child outcomes were independently identified by two reviewers. Data were independently extracted from included studies by two raters and differences between raters were resolved by consensus. Searches revealed 29 eligible studies (31 samples). Child-staff ratios ranged from 5 to 14.5 preschool-aged children per adult with a mean of 8.65. All 29 studies were included in the systematic review. However, the only meta-analysis that could be conducted was based on three studies that explored associations between ratios and children's receptive language. Results of this meta-analysis were not significant. Results of the qualitative systematic review revealed few significant relationships between child-staff ratios and child outcomes construed broadly. Thus, the available literature reveal few, if any, relationships between child-staff ratios in preschool ECEC programs and children's developmental outcomes. Substantial heterogeneity in the assessment of ratios, outcomes measured, and statistics used to capture associations limited quantitative synthesis. Other methodological limitations of the research integrated in this synthesis are discussed.

Child-Staff Ratios in Early Childhood Education and Care Settings and Child Outcomes: A Systematic Review and Meta-Analysis

PubMed Central

Perlman, Michal; Fletcher, Brooke; Falenchuk, Olesya; Brunsek, Ashley; McMullen, Evelyn; Shah, Prakesh S.

2017-01-01

Child-staff ratios are a key quality indicator in early childhood education and care (ECEC) programs. Better ratios are believed to improve child outcomes by increasing opportunities for individual interactions and educational instruction from staff. The purpose of this systematic review, and where possible, meta-analysis, was to evaluate the association between child-staff ratios in preschool ECEC programs and children’s outcomes. Searches of Medline, PsycINFO, ERIC, websites of large datasets and reference sections of all retrieved articles were conducted up to July 3, 2015. Cross-sectional or longitudinal studies that evaluated the relationship between child-staff ratios in ECEC classrooms serving preschool aged children and child outcomes were independently identified by two reviewers. Data were independently extracted from included studies by two raters and differences between raters were resolved by consensus. Searches revealed 29 eligible studies (31 samples). Child-staff ratios ranged from 5 to 14.5 preschool-aged children per adult with a mean of 8.65. All 29 studies were included in the systematic review. However, the only meta-analysis that could be conducted was based on three studies that explored associations between ratios and children’s receptive language. Results of this meta-analysis were not significant. Results of the qualitative systematic review revealed few significant relationships between child-staff ratios and child outcomes construed broadly. Thus, the available literature reveal few, if any, relationships between child-staff ratios in preschool ECEC programs and children’s developmental outcomes. Substantial heterogeneity in the assessment of ratios, outcomes measured, and statistics used to capture associations limited quantitative synthesis. Other methodological limitations of the research integrated in this synthesis are discussed. PMID:28103288

Vitamin D Treatment for the Prevention of Falls in Older Adults: Systematic Review and Meta-Analysis

PubMed Central

Kalyani, Rita Rastogi; Stein, Brady; Valiyil, Ritu; Manno, Rebecca; Maynard, Janet W.; Crews, Deidra

2010-01-01

Objectives To systematically review and quantitatively synthesize the effect of vitamin D therapy on fall prevention in older adults. Design Systematic review and meta-analysis. Setting MEDLINE, CINAHL,Web of Science, EMBASE, Cochrane Library, LILACS, bibliographies of selected articles, and previous systematic reviews through February 2009 were searched for eligible studies. Participants Older adults (aged ≥60 years) who participated in randomized controlled trials that investigated the effectiveness of vitamin D therapy in the prevention of falls and used an explicit fall definition. Measurements Two authors independently extracted data including study characteristics, quality assessment, and outcomes. The I2 statistic was used to assess heterogeneity in a randomeffects model. Results Of 1,679 potentially relevant articles, 10 studies met inclusion criteria. In pooled analysis, vitamin D therapy (200-1000IU) reduced falls by 14% (relative risk [RR] 0.86;95% confidence interval 0.79-0.93;I2=7%) compared to calcium or placebo; number needed to treat=15. The following subgroups had significant fall reductions: community-dwelling (age<80 years), adjunctive calcium supplementation, no history of fractures/falls, duration>6 months, cholecalciferol, and dose≥800 IU. Meta-regression demonstrated no linear association of vitamin D dose or duration with treatment effect. Post-hoc analysis, including 7 additional studies (17 total) without explicit fall definitions, yielded smaller benefit (RR 0.92,0.87-0.98) and more heterogeneity (I2=36%) but found significant intergroup differences favoring adjunctive calcium versus none (p=0.001). Conclusion Vitamin D treatment effectively reduces the risk of falls in older adults. Future studies should investigate whether particular populations or treatment regimens may have greater benefit. PMID:20579169

Practice patterns and outcomes associated with early sedation depth in mechanically ventilated patients: a systematic review protocol.

PubMed

Stephens, Robert J; Dettmer, Matthew R; Roberts, Brian W; Fowler, Susan A; Fuller, Brian M

2017-06-09

Mechanical ventilation is a commonly performed intervention in critically ill patients. Frequently, these patients experience deep sedation early in their clinical course. Emerging data suggest that the practice of early deep sedation may negatively impact patient outcomes. The purpose of this review is to assess the world's literature to describe and determine the impact of early deep sedation on the outcomes of mechanically ventilated patients. Randomised controlled trials and non-randomised studies will be eligible for inclusion in this systematic review. With the assistance of a medical librarian, we will comprehensively search MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews and Effects, and Cochrane Database of Systematic Reviews for peer-reviewed literature. Grey literature from appropriate professional society conferences, held from 2010 to 2017, will be reviewed manually. Two authors will independently review all search results, and disagreements will be resolved through arbitration by a third author. If appropriate, meta-analysis will be used for quantitative analysis of the data. Heterogeneity between studies will be assessed using the I 2 statistic. The proposed systematic review will not collect data that are associated with individual patients and does not require ethical approval. Results of this study will contribute to the understanding of early sedation, identify future research targets and guide early care in mechanically ventilated patients. This systematic review has been registered in the international prospective register of systematic reviews (PROSPERO #CRD42017057264). © 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.

Meta-analytic approaches to determine gender differences in the age-incidence characteristics of schizophrenia and related psychoses.

PubMed

Jackson, Dan; Kirkbride, James; Croudace, Tim; Morgan, Craig; Boydell, Jane; Errazuriz, Antonia; Murray, Robin M; Jones, Peter B

2013-03-01

A recent systematic review and meta-analysis of the incidence and prevalence of schizophrenia and other psychoses in England investigated the variation in the rates of psychotic disorders. However, some of the questions of interest, and the data collected to answer these, could not be adequately addressed using established meta-analysis techniques. We developed a novel statistical method, which makes combined use of fractional polynomials and meta-regression. This was used to quantify the evidence of gender differences and a secondary peak onset in women, where the outcome of interest is the incidence of schizophrenia. Statistically significant and epidemiologically important effects were obtained using our methods. Our analysis is based on data from four studies that provide 50 incidence rates, stratified by age and gender. We describe several variations of our method, in particular those that might be used where more data is available, and provide guidance for assessing the model fit. Copyright © 2013 John Wiley & Sons, Ltd.

Data Acquisition and Preprocessing in Studies on Humans: What Is Not Taught in Statistics Classes?

PubMed

Zhu, Yeyi; Hernandez, Ladia M; Mueller, Peter; Dong, Yongquan; Forman, Michele R

2013-01-01

The aim of this paper is to address issues in research that may be missing from statistics classes and important for (bio-)statistics students. In the context of a case study, we discuss data acquisition and preprocessing steps that fill the gap between research questions posed by subject matter scientists and statistical methodology for formal inference. Issues include participant recruitment, data collection training and standardization, variable coding, data review and verification, data cleaning and editing, and documentation. Despite the critical importance of these details in research, most of these issues are rarely discussed in an applied statistics program. One reason for the lack of more formal training is the difficulty in addressing the many challenges that can possibly arise in the course of a study in a systematic way. This article can help to bridge this gap between research questions and formal statistical inference by using an illustrative case study for a discussion. We hope that reading and discussing this paper and practicing data preprocessing exercises will sensitize statistics students to these important issues and achieve optimal conduct, quality control, analysis, and interpretation of a study.

The significance of OLGA and OLGIM staging systems in the risk assessment of gastric cancer: a systematic review and meta-analysis.

PubMed

Yue, Hu; Shan, Liu; Bin, Lv

2018-02-19

Despite extensive research on the criteria for the assessment of gastric cancer risk using the Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastritis/Intestinal-Metaplasia Assessment (OLGIM) systems, no comprehensive overview or systematic summary on their use is currently available. To perform a systematic review and meta-analysis to assess the efficacy of the OLGA and OLGIM staging systems in evaluating gastric cancer risk. We searched various databases, including PubMed, EMBASE, Medline, and Cochrane's library, for articles published before March 2017 on the association between OLGA/OLGIM stages and risk of gastric cancer. Statistical analysis was performed using RevMan 5.30 and Stata 14.0, with the odds ratio, risk ratio, and 95% confidence interval as the effect measures. A meta-analysis of six case-control studies and two cohort studies, comprising 2700 subjects, was performed. The meta-analysis of prospective case-control studies demonstrated a significant association between the OLGA/OLGIM stages III/IV and gastric cancer. The Newcastle-Ottawa Scale (NOS) score reflected heterogeneity in the case-control studies on OLGA. Subgroup analysis of high-quality (NOS score ≥ 5) studies showed an association between OLGA stage III/IV and increased risk of gastric cancer; the association was also high in the remaining study with low NOS score. The association between higher stages of gastritis defined by OLGA and risk of gastric cancer was significant. This correlation implies that close and frequent monitoring of such high-risk patients is necessary to facilitate timely diagnosis of gastric cancer.

Poor methodological quality and reporting standards of systematic reviews in burn care management.

PubMed

Wasiak, Jason; Tyack, Zephanie; Ware, Robert; Goodwin, Nicholas; Faggion, Clovis M

2017-10-01

The methodological and reporting quality of burn-specific systematic reviews has not been established. The aim of this study was to evaluate the methodological quality of systematic reviews in burn care management. Computerised searches were performed in Ovid MEDLINE, Ovid EMBASE and The Cochrane Library through to February 2016 for systematic reviews relevant to burn care using medical subject and free-text terms such as 'burn', 'systematic review' or 'meta-analysis'. Additional studies were identified by hand-searching five discipline-specific journals. Two authors independently screened papers, extracted and evaluated methodological quality using the 11-item A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool and reporting quality using the 27-item Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Characteristics of systematic reviews associated with methodological and reporting quality were identified. Descriptive statistics and linear regression identified features associated with improved methodological quality. A total of 60 systematic reviews met the inclusion criteria. Six of the 11 AMSTAR items reporting on 'a priori' design, duplicate study selection, grey literature, included/excluded studies, publication bias and conflict of interest were reported in less than 50% of the systematic reviews. Of the 27 items listed for PRISMA, 13 items reporting on introduction, methods, results and the discussion were addressed in less than 50% of systematic reviews. Multivariable analyses showed that systematic reviews associated with higher methodological or reporting quality incorporated a meta-analysis (AMSTAR regression coefficient 2.1; 95% CI: 1.1, 3.1; PRISMA regression coefficient 6·3; 95% CI: 3·8, 8·7) were published in the Cochrane library (AMSTAR regression coefficient 2·9; 95% CI: 1·6, 4·2; PRISMA regression coefficient 6·1; 95% CI: 3·1, 9·2) and included a randomised control trial (AMSTAR regression coefficient 1·4; 95%CI: 0·4, 2·4; PRISMA regression coefficient 3·4; 95% CI: 0·9, 5·8). The methodological and reporting quality of systematic reviews in burn care requires further improvement with stricter adherence by authors to the PRISMA checklist and AMSTAR tool. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Precise measurement of the half-life of the Fermi {beta} decay of {sup 26}Al{sup m}

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

Scott, Rebecca J.; Thompson, Maxwell N.; Rassool, Roger P.

2011-08-15

State-of-the-art signal digitization and analysis techniques have been used to measure the half-life of the Fermi {beta} decay of {sup 26}Al{sup m}. The half-life was determined to be 6347.8 {+-} 2.5 ms. This new datum contributes to the experimental testing of the conserved-vector-current hypothesis and the required unitarity of the Cabibbo-Kobayashi-Maskawa matrix: two essential components of the standard model. Detailed discussion of the experimental techniques and data analysis and a thorough investigation of the statistical and systematic uncertainties are presented.

A combined pre-clinical meta-analysis and randomized confirmatory trial approach to improve data validity for therapeutic target validation.

PubMed

Kleikers, Pamela W M; Hooijmans, Carlijn; Göb, Eva; Langhauser, Friederike; Rewell, Sarah S J; Radermacher, Kim; Ritskes-Hoitinga, Merel; Howells, David W; Kleinschnitz, Christoph; Schmidt, Harald H H W

2015-08-27

Biomedical research suffers from a dramatically poor translational success. For example, in ischemic stroke, a condition with a high medical need, over a thousand experimental drug targets were unsuccessful. Here, we adopt methods from clinical research for a late-stage pre-clinical meta-analysis (MA) and randomized confirmatory trial (pRCT) approach. A profound body of literature suggests NOX2 to be a major therapeutic target in stroke. Systematic review and MA of all available NOX2(-/y) studies revealed a positive publication bias and lack of statistical power to detect a relevant reduction in infarct size. A fully powered multi-center pRCT rejects NOX2 as a target to improve neurofunctional outcomes or achieve a translationally relevant infarct size reduction. Thus stringent statistical thresholds, reporting negative data and a MA-pRCT approach can ensure biomedical data validity and overcome risks of bias.

Angular filter refractometry analysis using simulated annealing [An improved method for characterizing plasma density profiles using angular filter refractometry

DOE PAGES

Angland, P.; Haberberger, D.; Ivancic, S. T.; ...

2017-10-30

Here, a new method of analysis for angular filter refractometry images was developed to characterize laser-produced, long-scale-length plasmas using an annealing algorithm to iterative converge upon a solution. Angular filter refractometry (AFR) is a novel technique used to characterize the density pro files of laser-produced, long-scale-length plasmas. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on a minimization of themore » $$\\chi$$2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in average uncertainty in the density profile of 5-10% in the region of interest.« less

Angular filter refractometry analysis using simulated annealing [An improved method for characterizing plasma density profiles using angular filter refractometry

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

Angland, P.; Haberberger, D.; Ivancic, S. T.

Here, a new method of analysis for angular filter refractometry images was developed to characterize laser-produced, long-scale-length plasmas using an annealing algorithm to iterative converge upon a solution. Angular filter refractometry (AFR) is a novel technique used to characterize the density pro files of laser-produced, long-scale-length plasmas. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on a minimization of themore » $$\\chi$$2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in average uncertainty in the density profile of 5-10% in the region of interest.« less

Low-dose ionizing radiation increases the mortality risk of solid cancers in nuclear industry workers: A meta-analysis

PubMed Central

Qu, Shu-Gen; Gao, Jin; Tang, Bo; Yu, Bo; Shen, Yue-Ping; Tu, Yu

2018-01-01

Low-dose ionizing radiation (LDIR) may increase the mortality of solid cancers in nuclear industry workers, but only few individual cohort studies exist, and the available reports have low statistical power. The aim of the present study was to focus on solid cancer mortality risk from LDIR in the nuclear industry using standard mortality ratios (SMRs) and 95% confidence intervals. A systematic literature search through the PubMed and Embase databases identified 27 studies relevant to this meta-analysis. There was statistical significance for total, solid and lung cancers, with meta-SMR values of 0.88, 0.80, and 0.89, respectively. There was evidence of stochastic effects by IR, but more definitive conclusions require additional analyses using standardized protocols to determine whether LDIR increases the risk of solid cancer-related mortality. PMID:29725540

Malignant pleural effusions and the role of talc poudrage and talc slurry: a systematic review and meta-analysis

PubMed Central

Mummadi, Srinivas; Kumbam, Anusha; Hahn, Peter Y.

2015-01-01

Background: Malignant Pleural Effusion (MPE) is common with advanced malignancy. Palliative care with minimal adverse events is the cornerstone of management. Although talc pleurodesis plays an important role in treatment, the best modality of talc application remains controversial.   Objective: To compare rates of successful pleurodesis, rates of respiratory and non-respiratory complications between thoracoscopic talc insufflation/poudrage (TTI) and talc slurry (TS).  Data sources and study selection: MEDLINE (PubMed, OVID),  EBM Reviews (Cochrane database of Systematic Reviews, ACP Journal Club, DARE, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, Health Technology Assessment and NHS Economic Evaluation Database), EMBASE and Scopus. Randomized controlled trials published between 01/01/1980 - 10/1/2014 and comparing the two strategies were selected.  Results: Twenty-eight potential studies were identified of which 24 studies were further excluded, leaving four studies. No statistically significant difference in the probability of successful pleurodesis was observed between TS and TTI groups (RR 1.06; 95 % CI 0.99-1.14; Q statistic, 4.84). There was a higher risk of post procedural respiratory complications in the TTI group compared to the TS group (RR 1.91, 95% CI= 1.24-2.93, Q statistic 3.15). No statistically significant difference in the incidence of non-respiratory complications between the TTI group and the TS group was observed (RR 0.88, 95% CI= 0.72-1.07, Q statistic 4.61). Conclusions: There is no difference in success rates of pleurodesis based on patient centered outcomes between talc poudrage and talc slurry treatments.  Respiratory complications are more common with talc poudrage via thoracoscopy. PMID:25878773

SPReM: Sparse Projection Regression Model For High-dimensional Linear Regression *

PubMed Central

Sun, Qiang; Zhu, Hongtu; Liu, Yufeng; Ibrahim, Joseph G.

2014-01-01

The aim of this paper is to develop a sparse projection regression modeling (SPReM) framework to perform multivariate regression modeling with a large number of responses and a multivariate covariate of interest. We propose two novel heritability ratios to simultaneously perform dimension reduction, response selection, estimation, and testing, while explicitly accounting for correlations among multivariate responses. Our SPReM is devised to specifically address the low statistical power issue of many standard statistical approaches, such as the Hotelling’s T2 test statistic or a mass univariate analysis, for high-dimensional data. We formulate the estimation problem of SPREM as a novel sparse unit rank projection (SURP) problem and propose a fast optimization algorithm for SURP. Furthermore, we extend SURP to the sparse multi-rank projection (SMURP) by adopting a sequential SURP approximation. Theoretically, we have systematically investigated the convergence properties of SURP and the convergence rate of SURP estimates. Our simulation results and real data analysis have shown that SPReM out-performs other state-of-the-art methods. PMID:26527844

Effect of intraoperative neuromonitoring on recurrent laryngeal nerve palsy rates after thyroid surgery--a meta-analysis.

PubMed

Zheng, Shixing; Xu, Zhiwen; Wei, Yuanyuan; Zeng, Manli; He, Jinnian

2013-08-01

Though intraoperative nerve monitoring (IONM) during thyroid surgery has gained universal acceptance for localizing and identifying the recurrent laryngeal nerve (RLN), its role in reducing the rate of RLN injury remains controversial. In order to assess the effect of IONM during thyroid surgery, its value in reducing the incidence of RLN palsy was systematically evaluated. Studies were evaluated for inclusion in this analysis by researching PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the references of included studies. The initial screening of article titles and abstracts was independently performed by five reviewers based on the research protocol criteria. Each article was then read in detail and discussed before inclusion in the meta-analysis. Data were independently extracted, including the level of evidence, number of at-risk nerves, allocation method, baseline equivalence between groups, definitions of transient and permanent vocal fold palsy, systematic application of electrodes, etc. The meta-analysis was then performed. Odds ratios were pooled using a random effects model. Five randomized clinical trials and 12 comparative trials evaluating 36,487 at-risk nerves were included. Statistically significant differences in terms of total recurrent laryngeal nerve palsy (3.37% with intraoperative nerve monitoring [IONM] vs. 3.76% without IONM [OR: 0.74; 95% confidence interval [CI]: 0.59-0.92]) and transient recurrent laryngeal nerve palsy (2.56% with IONM vs. 2.71% without IONM [OR: 0.80; 95% CI: 0.65-0.99]) were identified. The persistent incidence of recurrent laryngeal nerve palsy was 0.78% for IONM versus 0.96% for nerve identification alone (OR: 0.80; 95% CI: 0.62-1.03). Based on this meta-analysis, statistically significant differences were determined in terms of the incidences of total and transient recurrent laryngeal nerve palsy after using IONM versus recurrent laryngeal nerve identification alone during thyroidectomy. However, no statistically significant differences were identified regarding the incidence of persistent recurrent laryngeal nerve palsy between groups. Copyright © 2012. Published by Elsevier B.V.

Analysis of nonintervention studies: technical supplement.

PubMed

Aickin, Mikel

2012-01-01

Methods for analyzing data in nonintervention clinical studies are substantially different from those that are appropriate for randomized clinical trials. Although the latter methods are well known, the former are not. A systematic approach for dealing with statistical confounding in nonintervention research has been developed over the past 30 to 40 years, and the essence of this theory constitutes the contents of this article. An accompanying, less technical article explains the implications of these results for clinical research.

GnRH agonist for final oocyte maturation in GnRH antagonist co-treated IVF/ICSI treatment cycles: Systematic review and meta-analysis

PubMed Central

Youssef, M.A.F.; Abdelmoty, Hatem I.; Ahmed, Mohamed A.S.; Elmohamady, Maged

2015-01-01

Final oocyte maturation in GnRH antagonist co-treated IVF/ICSI cycles can be triggered with HCG or a GnRH agonist. We conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the efficacy and safety of the final oocyte maturation trigger in GnRH antagonist co-treated cycles. Outcome measures were ongoing pregnancy rate (OPR) and ovarian hyperstimulation syndrome (OHSS) incidence. Searches: were conducted in MEDLINE, EMBASE, Science Direct, Cochrane Library, and databases of abstracts. There was a statistically significant difference against the GnRH agonist for OPR in fresh autologous cycles (n = 1024) with an odd ratio (OR) of 0.69 (95% CI: 0.52–0.93). In oocyte-donor cycles (n = 342) there was no evidence of a difference (OR: 0.91; 95% CI: 0.59–1.40). There was a statistically significant difference in favour of GnRH agonist regarding the incidence of OHSS in fresh autologous cycles (OR: 0.06; 95% CI: 0.01–0.33) and donor cycles respectively (OR: 0.06; 95% CI: 0.01–0.27). In conclusion GnRH agonist trigger for final oocyte maturation trigger in GnRH antagonist cycles is safer but less efficient than HCG. PMID:26257931

Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis.

PubMed

Yi, Jianru; Li, Meile; Li, Yu; Li, Xiaobing; Zhao, Zhihe

2016-11-21

The aim of this study was to compare the external apical root resorption (EARR) in patients receiving fixed orthodontic treatment with self-ligating or conventional brackets. Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets were identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the included studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two investigators independently. The original outcome underwent statistical pooling by using Review Manager 5. Seven studies were included in the systematic review, out of which, five studies were statistically pooled in meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly lower than that in the conventional bracket group (SMD -0.31; 95% CI: -0.60--0.01). No significant differences in other incisors were observed between self-ligating and conventional brackets. Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing the EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating brackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be confirmed by more high-quality studies.

Statistical detection of geographic clusters of resistant Escherichia coli in a regional network with WHONET and SaTScan

PubMed Central

Park, Rachel; O'Brien, Thomas F.; Huang, Susan S.; Baker, Meghan A.; Yokoe, Deborah S.; Kulldorff, Martin; Barrett, Craig; Swift, Jamie; Stelling, John

2016-01-01

Objectives While antimicrobial resistance threatens the prevention, treatment, and control of infectious diseases, systematic analysis of routine microbiology laboratory test results worldwide can alert new threats and promote timely response. This study explores statistical algorithms for recognizing geographic clustering of multi-resistant microbes within a healthcare network and monitoring the dissemination of new strains over time. Methods Escherichia coli antimicrobial susceptibility data from a three-year period stored in WHONET were analyzed across ten facilities in a healthcare network utilizing SaTScan's spatial multinomial model with two models for defining geographic proximity. We explored geographic clustering of multi-resistance phenotypes within the network and changes in clustering over time. Results Geographic clustering identified from both latitude/longitude and non-parametric facility groupings geographic models were similar, while the latter was offers greater flexibility and generalizability. Iterative application of the clustering algorithms suggested the possible recognition of the initial appearance of invasive E. coli ST131 in the clinical database of a single hospital and subsequent dissemination to others. Conclusion Systematic analysis of routine antimicrobial resistance susceptibility test results supports the recognition of geographic clustering of microbial phenotypic subpopulations with WHONET and SaTScan, and iterative application of these algorithms can detect the initial appearance in and dissemination across a region prompting early investigation, response, and containment measures. PMID:27530311

Efficacy and safety of local steroids for urethra strictures: a systematic review and meta-analysis.

PubMed

Zhang, Kaile; Qi, Er; Zhang, Yumeng; Sa, Yinglong; Fu, Qiang

2014-08-01

Local steroids have been used as an adjuvant therapy to patients undergoing internal urethrotomy (IU) in treating urethral strictures. Whether this technique is effective and safe is still controversial. The aim of this study is to determine the efficacy and safety of local steroids as applied with the IU procedure. A systematic review of the literature was performed by searching Medline, Embase, Cochrane Library Databases, and the Web of Science. We included only prospective randomized, controlled trials that compared the efficacy and safety between IU procedures with applied local steroids and those without. Eight studies were found eligible for further analysis. In total, 203 patients undergoing IU were treated with steroid injection or catheter lubrication. Time to recurrence is statistically significant (mean: 10.14 and 5.07 months, P<0.00001).The number of patients with recurrent stricture formation significantly decreased at different follow-up time points (P=0.05).No statistically significant differences were found between the recurrence rates, adverse effects, and success rates of second IUs in patients with applied local steroids and those without. The use of local steroids with IU seems to prolong time to stricture recurrence but does not seem to affect the high stricture recurrence rate following IU. When local steroids are applied with complementary intention, the disease control outcomes are encouraging. Further robust comparative effectiveness studies are now required.

The association of hyperglycemia and diabetes mellitus and the risk of chemotherapy-induced neutropenia among cancer patients: A systematic review with meta-analysis.

PubMed

Alenzi, Ebtihag O; Kelley, George A

2017-01-01

Conduct a systematic review with meta-analysis to determine the association between incident chemotherapy-induced neutropenia (CIN) and either diabetes mellitus (DM) or hyperglycemia in patients with cancer. Observational studies in cancer patients of any age receiving chemotherapy and having diabetes or hyperglycemia either during or before chemotherapy induction were included. Studies were retrieved by searching four databases (PubMed, EBSCO, ProQuest, and Cochrane) and cross-referencing. The metric for combining studies was the odds ratio (OR). Results were pooled using a random-effects model, while heterogeneity and inconsistency were assessed using the Q and I 2 statistic, respectively. Potential small-study effects were assessed using the funnel plot. Ten studies met the criteria for inclusion. Overall, the odds of having CIN were 32% higher among cancer patients with either DM or hyperglycemia compared with those without DM or hyperglycemia (OR=1.32, 95% CI, 1.06-1.64). Statistically significant heterogeneity and inconsistency were found (Q=33.15, p<0.05, I 2 =72.9%). Funnel plot asymmetry reflecting potential small-study effects was observed. Diabetes mellitus and hyperglycemia may be associated with an increased risk for CIN among cancer patients. However, additional well-designed studies are needed before any final and definitive recommendations can be made. Copyright © 2017 Elsevier Inc. All rights reserved.

Racism as a determinant of health: a protocol for conducting a systematic review and meta-analysis.

PubMed

Paradies, Yin; Priest, Naomi; Ben, Jehonathan; Truong, Mandy; Gupta, Arpana; Pieterse, Alex; Kelaher, Margaret; Gee, Gilbert

2013-09-23

Racism is increasingly recognized as a key determinant of health. A growing body of epidemiological evidence shows strong associations between self-reported racism and poor health outcomes across diverse minority groups in developed countries. While the relationship between racism and health has received increasing attention over the last two decades, a comprehensive meta-analysis focused on the health effects of racism has yet to be conducted. The aim of this review protocol is to provide a structure from which to conduct a systematic review and meta-analysis of studies that assess the relationship between racism and health. This research will consist of a systematic review and meta-analysis. Studies will be considered for review if they are empirical studies reporting quantitative data on the association between racism and health for adults and/or children of all ages from any racial/ethnic/cultural groups. Outcome measures will include general health and well-being, physical health, mental health, healthcare use and health behaviors. Scientific databases (for example, Medline) will be searched using a comprehensive search strategy and reference lists will be manually searched for relevant studies. In addition, use of online search engines (for example, Google Scholar), key websites, and personal contact with experts will also be undertaken. Screening of search results and extraction of data from included studies will be independently conducted by at least two authors, including assessment of inter-rater reliability. Studies included in the review will be appraised for quality using tools tailored to each study design. Summary statistics of study characteristics and findings will be compiled and findings synthesized in a narrative summary as well as a meta-analysis. This review aims to examine associations between reported racism and health outcomes. This comprehensive and systematic review and meta-analysis of empirical research will provide a rigorous and reliable evidence base for future research, policy and practice, including information on the extent of available evidence for a range of racial/ethnic minority groups.

An evidence-based approach to globally assess the covariate-dependent effect of the MTHFR single nucleotide polymorphism rs1801133 on blood homocysteine: a systematic review and meta-analysis.

PubMed

Jin, Huifeng; Cheng, Haojie; Chen, Wei; Sheng, Xiaoming; Levy, Mark A; Brown, Mark J; Tian, Junqiang

2018-05-01

The single nucleotide polymorphism of the gene 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T (or rs1801133) is the most established genetic factor that increases plasma total homocysteine (tHcy) and consequently results in hyperhomocysteinemia. Yet, given the limited penetrance of this genetic variant, it is necessary to individually predict the risk of hyperhomocysteinemia for an rs1801133 carrier. We hypothesized that variability in this genetic risk is largely due to the presence of factors (covariates) that serve as effect modifiers, confounders, or both, such as folic acid (FA) intake, and aimed to assess this risk in the complex context of these covariates. We systematically extracted from published studies the data on tHcy, rs1801133, and any previously reported rs1801133 covariates. The resulting metadata set was first used to analyze the covariates' modifying effect by meta-regression and other statistical means. Subsequently, we controlled for this modifying effect by genotype-stratifying tHcy data and analyzed the variability in the risk resulting from the confounding of covariates. The data set contains data on 36 rs1801133 covariates that were collected from 114,799 participants and 256 qualified studies, among which 6 covariates (sex, age, race, FA intake, smoking, and alcohol consumption) are the most frequently informed and therefore included for statistical analysis. The effect of rs1801133 on tHcy exhibits significant variability that can be attributed to effect modification as well as confounding by these covariates. Via statistical modeling, we predicted the covariate-dependent risk of tHcy elevation and hyperhomocysteinemia in a systematic manner. We showed an evidence-based approach that globally assesses the covariate-dependent effect of rs1801133 on tHcy. The results should assist clinicians in interpreting the rs1801133 data from genetic testing for their patients. Such information is also important for the public, who increasingly receive genetic data from commercial services without interpretation of its clinical relevance. This study was registered at Research Registry with the registration number reviewregistry328.

Ledipasvir + Sofosbuvir for Liver Transplant Recipients With Recurrent Hepatitis C: A Systematic Review and Meta-analysis.

PubMed

Liao, H-T; Tan, P; Huang, J-W; Yuan, K-F

2017-10-01

Studies focusing on the efficacy and safety of ledipasvir (LDV) + sofosbuvir (SOF) therapy in liver transplant (LT) recipients with hepatitis C virus (HCV) recurrence are still limited. Therefore, the aim of our work was to perform a systematic review and meta-analysis to evaluate outcome data of LDV + SOF therapy in LT recipients. Multiple databases were systematically searched for eligible studies. We included studies reporting sustained virological response 12 weeks after treatment (SVR12) and treatment-related adverse events (AEs) in LT recipients treated with LDV + SOF ± ribavirin (RBV) for HCV recurrence. All statistical analyses were conducted by using R version 3.3.1 (The R Foundation for Statistical Computing, Vienna, Austria). Twelve studies with a total of 994 LT recipients were included, most of which were diagnosed with HCV genotype 1 infection. The overall SVR12 reached 96.3% (95% confidence interval [CI]: 94.9%-97.5%) and no significant heterogeneity was observed (Q statistic = 10.63, P = .47; I 2  = 0%). No difference was found in SVR12 between treatments for 12 weeks and 24 weeks (P = .18). Patients treated with LDV + SOF + RBV (n = 525) exhibited an SVR12 rate of 95.1% (95% CI 92.8%-96.6%), which showed no difference from the findings in the LDV + SOF treatment group (n = 314) with an SVR12 reaching 94.9% (95% CI 91.5%-97.0%; P = .92). There was a tendency for a higher SVR12 in patients without cirrhosis than those with cirrhosis (P < .05). The most common AEs were listed as following: anemia 41.9% (n = 203 of 484), fatigue 39.1% (n = 207 of 530), headache 24.2% (n = 128 of 530), nausea 21.9% (n = 106 of 484), and diarrhea 19.0% (n = 92 of 484). LDV + SOF-based treatment is highly effective and well tolerated in LT recipients with HCV reinfection. Copyright © 2017 Elsevier Inc. All rights reserved.

Laparoscopic lavage versus surgical resection for acute diverticulitis with generalised peritonitis: a systematic review and meta-analysis.

PubMed

Cirocchi, R; Di Saverio, S; Weber, D G; Taboła, R; Abraha, I; Randolph, J; Arezzo, A; Binda, G A

2017-02-01

This systematic review and meta-analysis investigates current evidence on the therapeutic role of laparoscopic lavage in the management of diverticular peritonitis. A systematic review of the literature was performed on PubMed until June 2016, according to preferred reporting items for systematic reviews and meta-analyses guidelines. All randomised controlled trials comparing laparoscopic lavage with surgical resection, irrespective of anastomosis or stoma formation, were analysed. After assessment of titles and full text, 3 randomised trials fulfilled the inclusion criteria. Overall the quality of evidence was low because of serious concerns regarding the risk of bias and imprecision. In the laparoscopic lavage group, there was a statistically significant higher rate of postoperative intra-abdominal abscess (RR 2.54, 95% CI 1.34-4.83), a lower rate of postoperative wound infection (RR 0.10, 95% CI 0.02-0.51), and a shorter length of postoperative hospital stay during index admission (WMD = -2.03, 95% CI -2.59 to -1.47). There were no statistically significant differences in terms of postoperative mortality at index admission or within 30 days from intervention in all Hinchey stages and in Hinchey stage III, postoperative mortality at 12 months, surgical reintervention at index admission or within 30-90 days from index intervention, stoma rate at 12 months, or adverse events within 90 days of any Clavien-Dindo grade. The surgical reintervention rate at 12 months from index intervention was significantly lower in the laparoscopic lavage group (RR 0.57, 95% CI 0.38-0.86), but these data included emergency reintervention and planned intervention (stoma reversal). This systematic review and meta-analysis did not demonstrate any significant difference between laparoscopic peritoneal lavage and traditional surgical resection in patients with peritonitis from perforated diverticular disease, in terms of postoperative mortality and early reoperation rate. Laparoscopic lavage was associated with a lower rate of stoma formation. However, the finding of a significantly higher rate of postoperative intra-abdominal abscess in patients who underwent laparoscopic lavage compared to those who underwent surgical resection is of concern. Since the aim of surgery in patients with peritonitis is to treat the sepsis, if one technique is associated with more postoperative abscesses, then the technique is ineffective. Even so, laparoscopic lavage does not appear fundamentally inferior to traditional surgical resection and this technique may achieve reasonable outcomes with minimal invasiveness.

Publication bias in dermatology systematic reviews and meta-analyses.

PubMed

Atakpo, Paul; Vassar, Matt

2016-05-01

Systematic reviews and meta-analyses in dermatology provide high-level evidence for clinicians and policy makers that influence clinical decision making and treatment guidelines. One methodological problem with systematic reviews is the under representation of unpublished studies. This problem is due in part to publication bias. Omission of statistically non-significant data from meta-analyses may result in overestimation of treatment effect sizes which may lead to clinical consequences. Our goal was to assess whether systematic reviewers in dermatology evaluate and report publication bias. Further, we wanted to conduct our own evaluation of publication bias on meta-analyses that failed to do so. Our study considered systematic reviews and meta-analyses from ten dermatology journals from 2006 to 2016. A PubMed search was conducted, and all full-text articles that met our inclusion criteria were retrieved and coded by the primary author. 293 articles were included in our analysis. Additionally, we formally evaluated publication bias in meta-analyses that failed to do so using trim and fill and cumulative meta-analysis by precision methods. Publication bias was mentioned in 107 articles (36.5%) and was formally evaluated in 64 articles (21.8%). Visual inspection of a funnel plot was the most common method of evaluating publication bias. Publication bias was present in 45 articles (15.3%), not present in 57 articles (19.5%) and not determined in 191 articles (65.2%). Using the trim and fill method, 7 meta-analyses (33.33%) showed evidence of publication bias. Although the trim and fill method only found evidence of publication bias in 7 meta-analyses, the cumulative meta-analysis by precision method found evidence of publication bias in 15 meta-analyses (71.4%). Many of the reviews in our study did not mention or evaluate publication bias. Further, of the 42 articles that stated following PRISMA reporting guidelines, 19 (45.2%) evaluated for publication bias. In comparison to other studies, we found that systematic reviews in dermatology were less likely to evaluate for publication bias. Evaluating and reporting the likelihood of publication bias should be standard practice in systematic reviews when appropriate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sham transcranial electrical stimulation and its effects on corticospinal excitability: a systematic review and meta-analysis.

PubMed

Dissanayaka, Thusharika D; Zoghi, Maryam; Farrell, Michael; Egan, Gary F; Jaberzadeh, Shapour

2018-02-23

Sham stimulation is used in randomized controlled trials (RCTs) to assess the efficacy of active stimulation and placebo effects. It should mimic the characteristics of active stimulation to achieve blinding integrity. The present study was a systematic review and meta-analysis of the published literature to identify the effects of sham transcranial electrical stimulation (tES) - including anodal and cathodal transcranial direct current stimulation (a-tDCS, c-tDCS), transcranial alternating current stimulation (tACS), transcranial random noise stimulation (tRNS) and transcranial pulsed current stimulation (tPCS) - on corticospinal excitability (CSE), compared to baseline in healthy individuals. Electronic databases - PubMed, CINAHL, Scopus, Science Direct and MEDLINE (Ovid) - were searched for RCTs of tES from 1990 to March 2017. Thirty RCTs were identified. Using a random-effects model, meta-analysis of a-tDCS, c-tDCS, tACS, tRNS and tPCS studies showed statistically non-significant pre-post effects of sham interventions on CSE. This review found evidence for statically non-significant effects of sham tES on CSE.

Systematic review and meta-analysis of the role of mental training in the acquisition of technical skills in surgery.

PubMed

Rao, Ahsan; Tait, Ian; Alijani, Afshin

2015-09-01

Mental training is rehearsal of mental imagery without physically performing the task. The aim of the study was to perform systematic review and meta-analysis on all the available data to evaluate the role of mental training in the acquisition of surgical technical skills. The following search databases were used: EMBASE, MEDLINE, Web of Science, Clinicaltrials.gov.uk, SIGN guidelines, NICE guidelines, and Cochrane review register. Meta-analysis was performed using Revman 5.2 statistical software. There were a total of 9 randomized controlled trials with 474 participants, of which 189 participants received mental training. Five randomized controlled trials concluded positive impact of mental training. Mental training group did not show any significant improvement in overall performance of the task carried in each study (P = .06). Mental training can be used as an important supplementary tool in learning surgical skills when run in parallel with physical training and applied to trainees with some experience of the skill. Copyright © 2015 Elsevier Inc. All rights reserved.

A multilevel meta-analysis of single-case and small-n research on interventions for reducing challenging behavior in persons with intellectual disabilities.

PubMed

Heyvaert, M; Maes, B; Van den Noortgate, W; Kuppens, S; Onghena, P

2012-01-01

The effectiveness of different interventions for challenging behavior (CB) in persons with intellectual disabilities (ID) was reviewed by means of a two-phase study. First, a systematic review of 137 meta-analyses and reviews on group-study interventions for CB in persons with ID was conducted. Based on this review, hypotheses concerning the effectiveness of divergent interventions for CB and concerning the impact of variables moderating treatment effectiveness were systematically generated. Second, these hypotheses were tested by means of a multilevel meta-analysis of single-case and small-n research. Two hundred and eighty-five studies reporting on 598 individuals were examined. The average treatment effect was large and statistically significant. However, this effect varied significantly over the included studies and participants. Compared to the meta-analyses and reviews focusing on group-studies in this research domain, the results of the present multilevel meta-analysis of single-case and small-n intervention research provided more detailed knowledge on which specific CB and intervention components moderate the interventions' effectiveness. Copyright © 2011 Elsevier Ltd. All rights reserved.

Shear Recovery Accuracy in Weak-Lensing Analysis with the Elliptical Gauss-Laguerre Method

NASA Astrophysics Data System (ADS)

Nakajima, Reiko; Bernstein, Gary

2007-04-01

We implement the elliptical Gauss-Laguerre (EGL) galaxy-shape measurement method proposed by Bernstein & Jarvis and quantify the shear recovery accuracy in weak-lensing analysis. This method uses a deconvolution fitting scheme to remove the effects of the point-spread function (PSF). The test simulates >107 noisy galaxy images convolved with anisotropic PSFs and attempts to recover an input shear. The tests are designed to be immune to statistical (random) distributions of shapes, selection biases, and crowding, in order to test more rigorously the effects of detection significance (signal-to-noise ratio [S/N]), PSF, and galaxy resolution. The systematic error in shear recovery is divided into two classes, calibration (multiplicative) and additive, with the latter arising from PSF anisotropy. At S/N > 50, the deconvolution method measures the galaxy shape and input shear to ~1% multiplicative accuracy and suppresses >99% of the PSF anisotropy. These systematic errors increase to ~4% for the worst conditions, with poorly resolved galaxies at S/N simeq 20. The EGL weak-lensing analysis has the best demonstrated accuracy to date, sufficient for the next generation of weak-lensing surveys.

Systematic reviews of surgical procedures in children: quantity, coverage and quality.

PubMed

McGee, Richard G; Craig, Jonathan C; Rogerson, Thomas E; Webster, Angela C

2013-04-01

Systematic reviews have the potential to map those areas where children are under-represented in surgical research. We aimed to describe and evaluate the quantity, coverage and the quality of conduct and reporting of systematic reviews of surgical procedures in children. We searched four biomedical databases, a systematic review register, reference lists and conducted hand searching to identify relevant reviews. Two reviewers worked independently to critically appraise included studies and abstract data. We assessed reporting quality using the preferred reporting items for systematic reviews and meta-analysis statement and methodological quality using the Assessment of Multiple SysTemAtic Reviews tool. Fifteen systematic reviews were identified, representing 0.01% of all paediatric surgical citations in MEDLINE and Embase. Thirteen of the reviews were Cochrane reviews, and most reviews (12/15) addressed subspecialty interests such as otorhinolaryngology. The median number of included trials per systematic review was four (interquartile range 1 to 9.5), the median number of primary outcomes was 5.5 (interquartile range 3.5 to 7.5). In general, reporting and methodological quality was good although there were several omissions, particularly around completeness of reporting of statistical methods used, and utilisation of quality assessments in analyses. Outcomes were often not clearly defined and descriptions of procedures lacked sufficient detail to determine the similarities and differences among surgical procedures within the contributing trials. Systematic reviews of surgical procedures in children are rarely published. To improve the evidence base and guide research agendas, more systematic reviews should be conducted, using standard guidelines for conduct and reporting. © 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

An Applied Statistics Course for Systematics and Ecology PhD Students

ERIC Educational Resources Information Center

Ojeda, Mario Miguel; Sosa, Victoria

2002-01-01

Statistics education is under review at all educational levels. Statistical concepts, as well as the use of statistical methods and techniques, can be taught in at least two contrasting ways. Specifically, (1) teaching can be theoretically and mathematically oriented, or (2) it can be less mathematically oriented being focused, instead, on…

Assigning statistical significance to proteotypic peptides via database searches

PubMed Central

Alves, Gelio; Ogurtsov, Aleksey Y.; Yu, Yi-Kuo

2011-01-01

Querying MS/MS spectra against a database containing only proteotypic peptides reduces data analysis time due to reduction of database size. Despite the speed advantage, this search strategy is challenged by issues of statistical significance and coverage. The former requires separating systematically significant identifications from less confident identifications, while the latter arises when the underlying peptide is not present, due to single amino acid polymorphisms (SAPs) or post-translational modifications (PTMs), in the proteotypic peptide libraries searched. To address both issues simultaneously, we have extended RAId’s knowledge database to include proteotypic information, utilized RAId’s statistical strategy to assign statistical significance to proteotypic peptides, and modified RAId’s programs to allow for consideration of proteotypic information during database searches. The extended database alleviates the coverage problem since all annotated modifications, even those occurred within proteotypic peptides, may be considered. Taking into account the likelihoods of observation, the statistical strategy of RAId provides accurate E-value assignments regardless whether a candidate peptide is proteotypic or not. The advantage of including proteotypic information is evidenced by its superior retrieval performance when compared to regular database searches. PMID:21055489

Estimation of integral curves from high angular resolution diffusion imaging (HARDI) data.

PubMed

Carmichael, Owen; Sakhanenko, Lyudmila

2015-05-15

We develop statistical methodology for a popular brain imaging technique HARDI based on the high order tensor model by Özarslan and Mareci [10]. We investigate how uncertainty in the imaging procedure propagates through all levels of the model: signals, tensor fields, vector fields, and fibers. We construct asymptotically normal estimators of the integral curves or fibers which allow us to trace the fibers together with confidence ellipsoids. The procedure is computationally intense as it blends linear algebra concepts from high order tensors with asymptotical statistical analysis. The theoretical results are illustrated on simulated and real datasets. This work generalizes the statistical methodology proposed for low angular resolution diffusion tensor imaging by Carmichael and Sakhanenko [3], to several fibers per voxel. It is also a pioneering statistical work on tractography from HARDI data. It avoids all the typical limitations of the deterministic tractography methods and it delivers the same information as probabilistic tractography methods. Our method is computationally cheap and it provides well-founded mathematical and statistical framework where diverse functionals on fibers, directions and tensors can be studied in a systematic and rigorous way.

Estimation of integral curves from high angular resolution diffusion imaging (HARDI) data

PubMed Central

Carmichael, Owen; Sakhanenko, Lyudmila

2015-01-01

We develop statistical methodology for a popular brain imaging technique HARDI based on the high order tensor model by Özarslan and Mareci [10]. We investigate how uncertainty in the imaging procedure propagates through all levels of the model: signals, tensor fields, vector fields, and fibers. We construct asymptotically normal estimators of the integral curves or fibers which allow us to trace the fibers together with confidence ellipsoids. The procedure is computationally intense as it blends linear algebra concepts from high order tensors with asymptotical statistical analysis. The theoretical results are illustrated on simulated and real datasets. This work generalizes the statistical methodology proposed for low angular resolution diffusion tensor imaging by Carmichael and Sakhanenko [3], to several fibers per voxel. It is also a pioneering statistical work on tractography from HARDI data. It avoids all the typical limitations of the deterministic tractography methods and it delivers the same information as probabilistic tractography methods. Our method is computationally cheap and it provides well-founded mathematical and statistical framework where diverse functionals on fibers, directions and tensors can be studied in a systematic and rigorous way. PMID:25937674

Human cytomegalovirus and Epstein-Barr virus in etiopathogenesis of apical periodontitis: a systematic review.

PubMed

Jakovljevic, Aleksandar; Andric, Miroslav

2014-01-01

During the last decade, a hypothesis has been established that human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) may be implicated in the pathogenesis of apical periodontitis. The aim of this review was to analyze the available evidence that indicates that HCMV and EBV can actually contribute to the pathogenesis of periapical lesions and to answer the following focused question: is there a relationship between HCMV and EBV DNA and/or RNA detection and the clinical features of human periapical lesions? The literature search covered MEDLINE, Science Citation Index Expanded (SCIexpanded), Scopus, and The Cochrane Library database. Quantitative statistical analysis was performed on the pooled data of HCMV and EBV messenger RNA transcripts in tissues of symptomatic and asymptomatic periapical lesions. The electronic database search yielded 48 hits from PubMed, 197 hits from Scopus, 40 hits from Web of Science, and 1 from the Cochrane Library. Seventeen cross-sectional studies have been included in the final review. The pooled results from quantitative systematic method analysis showed no statistically significant relationship between the presence of HCMV and EBV messenger RNA transcripts (P = .083 and P = .306, respectively) and the clinical features of apical periodontitis. The findings of HCMV and EBV transcripts in apical periodontitis were controversial among the included studies. Herpesviruses were common in symptomatic and large-size periapical lesions, but such results failed to reach statistical significance. Further studies, including those based on an experimental animal model, should provide more data on herpesviruses as a factor in the pathogenesis of periapical inflammation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

Meta-analysis of the efficacy and safety of combined surgery in the management of eyes with coexisting cataract and open angle glaucoma.

PubMed

Jiang, Nan; Zhao, Gui-Qiu; Lin, Jing; Hu, Li-Ting; Che, Cheng-Ye; Wang, Qian; Xu, Qiang; Li, Cui; Zhang, Jie

2018-01-01

To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma. We performed a systematic search of the related literature in the Cochrane Library, PubMed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction (IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre- to post-operation, and the secondary efficacy evaluations were performed by odds ratio (OR) and 95% confidence interval (CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using RevMan software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi 2 test and the I 2 measure. Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification. Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.

Does restoration of focal lumbar lordosis for single level degenerative spondylolisthesis result in better patient-reported clinical outcomes? A systematic literature review.

PubMed

Rhee, Chanseok; Visintini, Sarah; Dunning, Cynthia E; Oxner, William M; Glennie, R Andrew

2017-10-01

It is controversial whether the surgical restoration of sagittal balance and spinopelvic angulation in a single level lumbar degenerative spondylolisthesis results in clinical improvements. The purpose of this study to systematically review the available literature to determine whether the surgical correction of malalignment in lumbar degenerative spondylolisthesis correlates with improvements in patient-reported clinical outcomes. Literature searches were performed via Ovid Medline, Embase, CENTRAL and Web of Science using search terms "lumbar," "degenerative/spondylolisthesis" and "surgery/surgical/surgeries/fusion". This resulted in 844 articles and after reviewing the abstracts and full-texts, 13 articles were included for summary and final analysis. There were two Level II articles, four Level III articles and five Level IV articles. Most commonly used patient-reported outcome measures (PROMs) were Oswestery disability index (ODI) and visual analogue scale (VAS). Four articles were included for the final statistical analysis. There was no statistically significant difference between the patient groups who achieved successful surgical correction of malalignment and those who did not for either ODI (mean difference -0.94, CI -8.89-7.00) or VAS (mean difference 1.57, CI -3.16-6.30). Two studies assessed the efficacy of manual reduction of lumbar degenerative spondylolisthesis and their clinical outcomes after the operation, and there was no statistically significant improvement. Overall, the restoration of focal lumbar lordosis and restoration of sagittal balance for single-level lumbar degenerative spondylolisthesis does not seem to yield clinical improvements but well-powered studies on this specific topic is lacking in the current literature. Future well-powered studies are needed for a more definitive conclusion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevalence of peritonitis and mortality in patients treated with continuous ambulatory peritoneal dialysis (CAPD) in Africa: a protocol for a systematic review and meta-analysis.

PubMed

Moloi, Mothusi Walter; Kajawo, Shepherd; Noubiap, Jean Jacques; Mbah, Ikechukwu O; Ekrikpo, Udeme; Kengne, Andre Pascal; Bello, Aminu K; Okpechi, Ikechi G

2018-05-24

Continuous ambulatory peritoneal dialysis (CAPD) is the ideal modality for renal replacement therapy in most African settings given that it is relatively cheaper than haemodialysis (HD) and does not require in-centre care. CAPD is, however, not readily utilised as it is often complicated by peritonitis leading to high rates of technique failure. The objective of this study is to assess the prevalence of CAPD-related peritonitis and all-cause mortality in patients treated with CAPD in Africa. We will search PubMed, EMBASE, SCOPUS, Africa Journal Online and Google Scholar for studies conducted in Africa from 1 January 1980 to 30 June 2017 with no language restrictions. Eligible studies will include cross-sectional, prospective observational and cohort studies of patients treated with CAPD. Two authors will independently screen, select studies, extract data and conduct risk of bias assessment. Data consistently reported across studies will be pooled using random-effects meta-analysis. Heterogeneity will be evaluated using Cochrane's Q statistic and quantified using I 2 statistics. Graphical and formal statistical tests will be used to assess for publication bias. Ethical approval will not be needed for this study as data used will be extracted from already published studies. Results of this review will be published in a peer-reviewed journal and presented at conferences. The Preferred Reporting Items for Systematic reviews and Meta-Analyses for Protocols 2015 (PRISMA-P 2015) framework guided the development of this protocol. CRD42017072966. © 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.

[Basic concepts for network meta-analysis].

PubMed

Catalá-López, Ferrán; Tobías, Aurelio; Roqué, Marta

2014-12-01

Systematic reviews and meta-analyses have long been fundamental tools for evidence-based clinical practice. Initially, meta-analyses were proposed as a technique that could improve the accuracy and the statistical power of previous research from individual studies with small sample size. However, one of its main limitations has been the fact of being able to compare no more than two treatments in an analysis, even when the clinical research question necessitates that we compare multiple interventions. Network meta-analysis (NMA) uses novel statistical methods that incorporate information from both direct and indirect treatment comparisons in a network of studies examining the effects of various competing treatments, estimating comparisons between many treatments in a single analysis. Despite its potential limitations, NMA applications in clinical epidemiology can be of great value in situations where there are several treatments that have been compared against a common comparator. Also, NMA can be relevant to a research or clinical question when many treatments must be considered or when there is a mix of both direct and indirect information in the body of evidence. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

PubMed Central

Smith, Justin D.

2013-01-01

This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have precluded widespread implementation and acceptance of the SCED as a viable complementary methodology to the predominant group design. This article includes a description of the research design, measurement, and analysis domains distinctive to the SCED; a discussion of the results within the framework of contemporary standards and guidelines in the field; and a presentation of updated benchmarks for key characteristics (e.g., baseline sampling, method of analysis), and overall, it provides researchers and reviewers with a resource for conducting and evaluating SCED research. The results of the systematic review of 409 studies suggest that recently published SCED research is largely in accordance with contemporary criteria for experimental quality. Analytic method emerged as an area of discord. Comparison of the findings of this review with historical estimates of the use of statistical analysis indicates an upward trend, but visual analysis remains the most common analytic method and also garners the most support amongst those entities providing SCED standards. Although consensus exists along key dimensions of single-case research design and researchers appear to be practicing within these parameters, there remains a need for further evaluation of assessment and sampling techniques and data analytic methods. PMID:22845874

Should in-line filters be used in peripheral intravenous catheters to prevent infusion-related phlebitis? A systematic review of randomized controlled trials.

PubMed

Niël-Weise, Barbara S; Stijnen, Theo; van den Broek, Peterhans J

2010-06-01

In this systematic review, we assessed the effect of in-line filters on infusion-related phlebitis associated with peripheral IV catheters. The study was designed as a systematic review and meta-analysis of randomized controlled trials. We used MEDLINE and the Cochrane Controlled Trial Register up to August 10, 2009. Two reviewers independently assessed trial quality and extracted data. Data on phlebitis were combined when appropriate, using a random-effects model. The impact of the risk of phlebitis in the control group (baseline risk) on the effect of in-line filters was studied by using meta-regression based on the bivariate meta-analysis model. The quality of the evidence was determined by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method. Eleven trials (1633 peripheral catheters) were included in this review to compare the effect of in-line filters on the incidence of phlebitis in hospitalized patients. Baseline risks across trials ranged from 23% to 96%. Meta-analysis of all trials showed that in-line filters reduced the risk of infusion-related phlebitis (relative risk, 0.66; 95% confidence interval, 0.43-1.00). This benefit, however, is very uncertain, because the trials had serious methodological shortcomings and meta-analysis revealed marked unexplained statistical heterogeneity (P < 0.0000, I(2) = 90.4%). The estimated benefit did not depend on baseline risk. In-line filters in peripheral IV catheters cannot be recommended routinely, because evidence of their benefit is uncertain.

Homeopathy for allergic rhinitis: protocol for a systematic review

PubMed Central

2014-01-01

Background Allergic rhinitis is a global health problem that is often treated with homeopathy. The objective of this review will be to evaluate the effectiveness of homeopathic treatment of allergic rhinitis. Methods/Design The authors will conduct a systematic review. We will search Medline, CENTRAL, CINAHL, EMBASE, AMED, CAM-Quest, Google Scholar and reference lists of identified studies up to December 2013. The review will include randomized controlled trials that evaluate homeopathic treatment of allergic rhinitis. Studies with participants of all ages, with acute or chronic comorbidities will be included. Patients with immunodeficiency will not be included. The diagnosis will be based on the published guidelines of diagnosis and classification. Studies of all homeopathy modalities (clinical, complex and classical homeopathy, and isopathy) will be included. We will include trials with both active controls (conventional therapy, standard care) and placebo controls. The primary outcomes are: an improvement of global symptoms recorded in validated daily or weekly diaries and any scores from validated visual analogue scales; the total Quality of Life Score (such as the Juniper RQLQ);individual symptoms scores which include any appropriate measures of nasal obstruction, runny nose, sneezing, itching, and eye symptoms; and number of days requiring medication. Secondary outcomes selected will include serum immunoglobin E (IgE) levels, individual ocular symptoms, adverse events, and the use of rescue medication. Treatment effects will be measured by calculating the mean difference and the standardized mean difference with 95% confidence interval (CI) for continuous data. Risk ratio or, if feasible, odds ratio will be calculated with 95% CI for dichotomous data. After assessing clinical and statistical heterogeneity, meta-analysis will be performed, if appropriate. The individual participant will be the unit of analysis. Descriptive information on missing data will be included about participants missing due to drop out, whether there was intention to treat or per protocol analysis and missing statistics. A number of subgroups, homeopathic potency, age groups, and types of allergic rhinitis (seasonal or perennial) will be analyzed. Sensitivity analysis will be performed to explore the impact of risk of bias on overall treatment effect. Systematic review registration PROSPERO CRD42013006741 PMID:24913155

Treatment of missing data in follow-up studies of randomised controlled trials: A systematic review of the literature.

PubMed

Sullivan, Thomas R; Yelland, Lisa N; Lee, Katherine J; Ryan, Philip; Salter, Amy B

2017-08-01

After completion of a randomised controlled trial, an extended follow-up period may be initiated to learn about longer term impacts of the intervention. Since extended follow-up studies often involve additional eligibility restrictions and consent processes for participation, and a longer duration of follow-up entails a greater risk of participant attrition, missing data can be a considerable threat in this setting. As a potential source of bias, it is critical that missing data are appropriately handled in the statistical analysis, yet little is known about the treatment of missing data in extended follow-up studies. The aims of this review were to summarise the extent of missing data in extended follow-up studies and the use of statistical approaches to address this potentially serious problem. We performed a systematic literature search in PubMed to identify extended follow-up studies published from January to June 2015. Studies were eligible for inclusion if the original randomised controlled trial results were also published and if the main objective of extended follow-up was to compare the original randomised groups. We recorded information on the extent of missing data and the approach used to treat missing data in the statistical analysis of the primary outcome of the extended follow-up study. Of the 81 studies included in the review, 36 (44%) reported additional eligibility restrictions and 24 (30%) consent processes for entry into extended follow-up. Data were collected at a median of 7 years after randomisation. Excluding 28 studies with a time to event primary outcome, 51/53 studies (96%) reported missing data on the primary outcome. The median percentage of randomised participants with complete data on the primary outcome was just 66% in these studies. The most common statistical approach to address missing data was complete case analysis (51% of studies), while likelihood-based analyses were also well represented (25%). Sensitivity analyses around the missing data mechanism were rarely performed (25% of studies), and when they were, they often involved unrealistic assumptions about the mechanism. Despite missing data being a serious problem in extended follow-up studies, statistical approaches to addressing missing data were often inadequate. We recommend researchers clearly specify all sources of missing data in follow-up studies and use statistical methods that are valid under a plausible assumption about the missing data mechanism. Sensitivity analyses should also be undertaken to assess the robustness of findings to assumptions about the missing data mechanism.

Periprocedural effects of statins on the incidence of contrast-induced acute kidney injury: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Cheungpasitporn, Wisit; Thongprayoon, Charat; Kittanamongkolchai, Wonngarm; Edmonds, Peter J; O'Corragain, Oisin A; Srivali, Narat; Ungprasert, Patompong; Erickson, Stephen B

2015-05-01

The reports on the efficacy of statins for the prevention of contrast-induced acute kidney injury (CIAKI) remain controversial. The objective of this meta-analysis was to assess the effect of statins for the prevention of CIAKI. Comprehensive literature searches for randomized controlled trials (RCTs) of periprocedural statin treatment for prevention of CIAKI were performed using MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials Systematic Reviews and clinicaltrials.gov from inception until May 2014. The primary outcome was the incidence of CIAKI. Thirteen prospective RCTs were included in our analysis. Of 5803 patients with contrast exposures, 304 patients (5.2%) had CIAKI. Patients in the statin group had an overall lower incidence of CIAKI (3.6%) compared to the control group (6.9%). Intravenous (IV) fluid hydration was used in both groups of all included studies for prevention of CIAKI. There was a significant protective effect of periprocedural statins on the incidence of CIAKI when compared to the control group [risk ratios (RRs): 0.49; 95% CI: 0.37-0.66, I(2) of 25%]. Our study demonstrates a statistically significant protective effect of statin treatment during procedures with contrast exposures. This finding suggests the use of statins in addition to standard IV crystalloid hydration may be beneficial in the prevention of CIAKI.

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

Using a Systematic Conceptual Model for a Process Evaluation of a Middle School Obesity Risk-Reduction Nutrition Curriculum Intervention: Choice, Control & Change

PubMed Central

Lee, Heewon; Contento, Isobel R.; Koch, Pamela

2012-01-01

Objective To use and review a conceptual model of process evaluation and to examine the implementation of a nutrition education curriculum, Choice, Control & Change, designed to promote dietary and physical activity behaviors that reduce obesity risk. Design A process evaluation study based on a systematic conceptual model. Setting Five middle schools in New York City. Participants 562 students in 20 classes and their science teachers (n=8). Main Outcome Measures Based on the model, teacher professional development, teacher implementation, and student reception were evaluated. Also measured were teacher characteristics, teachers’ curriculum evaluation, and satisfaction with teaching the curriculum. Analysis Descriptive statistics and Spearman’s Rho Correlation for quantitative analysis and content analysis for qualitative data were used. Results Mean score of the teacher professional development evaluation was 4.75 on a 5-point scale. Average teacher implementation rate was 73%, and student reception rate was 69%. Ongoing teacher support was highly valued by teachers. Teachers’ satisfaction with teaching the curriculum was highly correlated with students’ satisfaction (p <.05). Teachers’ perception of amount of student work was negatively correlated with implementation and with student satisfaction (p<.05). Conclusions and implications Use of a systematic conceptual model and comprehensive process measures improves understanding of the implementation process and helps educators to better implement interventions as designed. PMID:23321021

Precision determination of the πN scattering lengths and the charged πNN coupling constant

NASA Astrophysics Data System (ADS)

Ericson, T. E. O.; Loiseau, B.; Thomas, A. W.

2000-01-01

We critically evaluate the isovector GMO sumrule for the charged πNN coupling constant using recent precision data from π-p and π-d atoms and with careful attention to systematic errors. From the π-d scattering length we deduce the pion-proton scattering lengths 1/2(aπ-p + aπ-n) = (-20 +/- 6(statistic)+/-10 (systematic) .10-4m-1πc and 1/2(aπ-p - aπ-n) = (903 +/- 14) . 10-4m-1πc. From this a direct evaluation gives g2c(GMO)/4π = 14.20 +/- 0.07 (statistic)+/-0.13(systematic) or f2c/4π = 0.0786 +/- 0.0008.

Prevalence and determinants of anemia among pregnant women in Ethiopia; a systematic review and meta-analysis.

PubMed

Kassa, Getachew Mullu; Muche, Achenef Asmamaw; Berhe, Abadi Kidanemariam; Fekadu, Gedefaw Abeje

2017-01-01

Anemia during pregnancy is one of the most common indirect obstetric cause of maternal mortality in developing countries. It is responsible for poor maternal and fetal outcomes. A limited number of studies were conducted on anemia during pregnancy in Ethiopia, and they present inconsistent findings. Therefore, this review was undertaken to summarize the findings conducted in several parts of the country and present the national level of anemia among pregnant women in Ethiopia. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed for this systematic review and meta-analysis. The databases used were; PUBMED, Cochrane Library, Google Scholar, CINAHL, and African Journals Online. Search terms used were; anemia, pregnancy related anemia and Ethiopia. Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) was used for critical appraisal of studies. The meta-analysis was conducted using STATA 14 software. The pooled Meta logistic regression was computed to present the pooled prevalence and relative risks (RRs) of the determinate factors with 95% confidence interval (CI). Twenty studies were included in the meta-analysis with a total of 10, 281 pregnant women. The pooled prevalence of anemia among pregnant women in Ethiopia was 31.66% (95% CI (26.20, 37.11)). Based on the pooled prevalence of the subgroup analysis result, the lowest prevalence of anemia among pregnant women was observed in Amhara region, 15.89% (95% CI (8.82, 22.96)) and the highest prevalence was in Somali region, 56.80% (95% CI (52.76, 60.84)). Primigravid (RR: 0.61 (95% CI: 0.53, 0.71)) and urban women (RR: 0.73 (95% CI: 0.60, 0.88)) were less likely to develop anemia. On the other hand, mothers with short pregnancy interval (RR: 2.14 (95% CI: 1.67, 2.74)) and malaria infection during pregnancy (RR: 1.94 (95% CI: 1.33, 2.82)) had higher risk to develop anemia. Almost one-third of pregnant women in Ethiopia were anemic. Statistically significant association was observed between anemia during pregnancy and residence, gravidity, pregnancy interval, and malaria infection during pregnancy. Regions with higher anemia prevalence among pregnant women should be given due emphasis. The concerned body should intervene on the identified factors to reduce the high prevalence of anemia among pregnant women.

Cost-effectiveness research in cancer therapy: a systematic review of literature trends, methods and the influence of funding

PubMed Central

Al-Badriyeh, Daoud; Alameri, Marwah; Al-Okka, Randa

2017-01-01

Objective To perform a first-time analysis of the cost-effectiveness (CE) literature on chemotherapies, of all types, in cancer, in terms of trends and change over time, including the influence of industry funding. Design Systematic review. Setting A wide range of cancer-related research settings within healthcare, including health systems, hospitals and medical centres. Participants All literature comparative CE research of drug-based cancer therapies in the period 1986 to 2015. Primary and secondary outcome measures Primary outcomes are the literature trends in relation to journal subject category, authorship, research design, data sources, funds and consultation involvement. An additional outcome measure is the association between industry funding and study outcomes. Analysis Descriptive statistics and the χ2, Fisher exact or Somer's D tests were used to perform non-parametric statistics, with a p value of <0.05 as the statistical significance measure. Results Total 574 publications were analysed. The drug-related CE literature expands over time, with increased publishing in the healthcare sciences and services journal subject category (p<0.001). The retrospective data collection in studies increased over time (p<0.001). The usage of prospective data, however, has been decreasing (p<0.001) in relation to randomised clinical trials (RCTs), but is unchanging for non-RCT studies. The industry-sponsored CE studies have especially been increasing (p<0.001), in contrast to those sponsored by other sources. While paid consultation involvement grew throughout the years, the declaration of funding for this is relatively limited. Importantly, there is evidence that industry funding is associated with favourable result to the sponsor (p<0.001). Conclusions This analysis demonstrates clear trends in how the CE cancer research is presented to the practicing community, including in relation to journals, study designs, authorship and consultation, together with increased financial sponsorship by pharmaceutical industries, which may be more influencing study outcomes than other funding sources. PMID:28131999

The Cognitive Effects of Antidepressants in Major Depressive Disorder: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

PubMed Central

Rosenblat, Joshua D; Kakar, Ron

2016-01-01

Background: Cognitive dysfunction is often present in major depressive disorder (MDD). Several clinical trials have noted a pro-cognitive effect of antidepressants in MDD. The objective of the current systematic review and meta-analysis was to assess the pooled efficacy of antidepressants on various domains of cognition in MDD. Methods: Trials published prior to April 15, 2015, were identified through searching the Cochrane Central Register of Controlled Trials, PubMed, Embase, PsychINFO, Clinicaltrials.gov, and relevant review articles. Data from randomized clinical trials assessing the cognitive effects of antidepressants were pooled to determine standard mean differences (SMD) using a random-effects model. Results: Nine placebo-controlled randomized trials (2 550 participants) evaluating the cognitive effects of vortioxetine (n = 728), duloxetine (n = 714), paroxetine (n = 23), citalopram (n = 84), phenelzine (n = 28), nortryptiline (n = 32), and sertraline (n = 49) were identified. Antidepressants had a positive effect on psychomotor speed (SMD 0.16; 95% confidence interval [CI] 0.05–0.27; I2 = 46%) and delayed recall (SMD 0.24; 95% CI 0.15–0.34; I2 = 0%). The effect on cognitive control and executive function did not reach statistical significance. Of note, after removal of vortioxetine from the analysis, statistical significance was lost for psychomotor speed. Eight head-to-head randomized trials comparing the effects of selective serotonin reuptake inhibitors (SSRIs; n = 371), selective serotonin and norepinephrine reuptake inhibitors (SNRIs; n = 25), tricyclic antidepressants (TCAs; n = 138), and norepinephrine and dopamine reuptake inhibitors (NDRIs; n = 46) were identified. No statistically significant difference in cognitive effects was found when pooling results from head-to-head trials of SSRIs, SNRIs, TCAs, and NDRIs. Significant limitations were the heterogeneity of results, limited number of studies, and small sample sizes. Conclusions: Available evidence suggests that antidepressants have a significant positive effect on psychomotor speed and delayed recall. PMID:26209859

Moisture Forecast Bias Correction in GEOS DAS

NASA Technical Reports Server (NTRS)

Dee, D.

1999-01-01

Data assimilation methods rely on numerous assumptions about the errors involved in measuring and forecasting atmospheric fields. One of the more disturbing of these is that short-term model forecasts are assumed to be unbiased. In case of atmospheric moisture, for example, observational evidence shows that the systematic component of errors in forecasts and analyses is often of the same order of magnitude as the random component. we have implemented a sequential algorithm for estimating forecast moisture bias from rawinsonde data in the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The algorithm is designed to remove the systematic component of analysis errors and can be easily incorporated in an existing statistical data assimilation system. We will present results of initial experiments that show a significant reduction of bias in the GEOS DAS moisture analyses.

Hurricane Katrina-linked environmental injustice: race, class, and place differentials in attitudes.

PubMed

Adeola, Francis O; Picou, J Steven

2017-04-01

Claims of environmental injustice, human neglect, and racism dominated the popular and academic literature after Hurricane Katrina struck the United States in August 2005. A systematic analysis of environmental injustice from the perspective of the survivors remains scanty or nonexistent. This paper presents, therefore, a systematic empirical analysis of the key determinants of Katrina-induced environmental injustice attitudes among survivors in severely affected parishes (counties) in Louisiana and Mississippi three years into the recovery process. Statistical models based on a random sample of survivors were estimated, with the results revealing significant predictors such as age, children in household under 18, education, homeownership, and race. The results further indicate that African-Americans were more likely to perceive environmental injustice following Katrina than their white counterparts. Indeed, the investigation reveals that there are substantial racial gaps in measures of environmental injustice. The theoretical, methodological, and applied policy implications of these findings are discussed. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

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.

Mindfulness-based interventions for binge eating: a systematic review and meta-analysis.

PubMed

Godfrey, Kathryn M; Gallo, Linda C; Afari, Niloofar

2015-04-01

Mindfulness-based interventions are increasingly used to treat binge eating. The effects of these interventions have not been reviewed comprehensively. This systematic review and meta-analysis sought to summarize the literature on mindfulness-based interventions and determine their impact on binge eating behavior. PubMED, Web of Science, and PsycINFO were searched using keywords binge eating, overeating, objective bulimic episodes, acceptance and commitment therapy, dialectical behavior therapy, mindfulness, meditation, mindful eating. Of 151 records screened, 19 studies met inclusion criteria. Most studies showed effects of large magnitude. Results of random effects meta-analyses supported large or medium-large effects of these interventions on binge eating (within-group random effects mean Hedge's g = -1.12, 95 % CI -1.67, -0.80, k = 18; between-group mean Hedge's g = -0.70, 95 % CI -1.16, -0.24, k = 7). However, there was high statistical heterogeneity among the studies (within-group I(2) = 93 %; between-group I(2) = 90 %). Limitations and future research directions are discussed.

Prospects of studies on violence, adolescence and cortisol: a systematic literature review.

PubMed

Lugarinho, Leonardo Planel; Avanci, Joviana Quintes; Pinto, Liana Wernersbach

2017-04-01

Violence has a negative impact on adolescents and affects their quality of life. It causes stress and requires the victim's adaptive capacity, which can cause psychological and biological changes. Hormone cortisol levels have been used as stress biomarker in several studies. This paper aims to perform a systematic literature review of publications on cortisol and violence involving teenagers from 2000 to 2013. Descriptors "cortisol", "violence" and "adolescent" were used in both English and Portuguese in this review, which included bibliographic databases PubMed/Medline, Lilacs, BVS and SciELO. Twelve papers were analyzed. Most studies involve participants from the United States, of both genders and without a control group. Different types of violence are studied, especially family violence, victimization or testimony. All studies used saliva to measure cortisol and no standard methodology was used for the analysis. Most studies (83.3%) found a statistically significant association between cortisol levels and exposure to violence. Results regarding gender, type of violence, socioeconomic status or cortisol analysis methods are not yet uniform.

In-line calibration of Raman systems for analysis of gas mixtures of hydrogen isotopologues with sub-percent accuracy.

PubMed

Schlösser, Magnus; Seitz, Hendrik; Rupp, Simone; Herwig, Philipp; Alecu, Catalin Gabriel; Sturm, Michael; Bornschein, Beate

2013-03-05

Highly accurate, in-line, and real-time composition measurements of gases are mandatory in many processing applications. The quantitative analysis of mixtures of hydrogen isotopologues (H2, D2, T2, HD, HT, and DT) is of high importance in such fields as DT fusion, neutrino mass measurements using tritium β-decay or photonuclear experiments where HD targets are used. Raman spectroscopy is a favorable method for these tasks. In this publication we present a method for the in-line calibration of Raman systems for the nonradioactive hydrogen isotopologues. It is based on precise volumetric gas mixing of the homonuclear species H2/D2 and a controlled catalytic production of the heteronuclear species HD. Systematic effects like spurious exchange reactions with wall materials and others are considered with care during the procedure. A detailed discussion of statistical and systematic uncertainties is presented which finally yields a calibration accuracy of better than 0.4%.

Got power? A systematic review of sample size adequacy in health professions education research.

PubMed

Cook, David A; Hatala, Rose

2015-03-01

Many education research studies employ small samples, which in turn lowers statistical power. We re-analyzed the results of a meta-analysis of simulation-based education to determine study power across a range of effect sizes, and the smallest effect that could be plausibly excluded. We systematically searched multiple databases through May 2011, and included all studies evaluating simulation-based education for health professionals in comparison with no intervention or another simulation intervention. Reviewers working in duplicate abstracted information to calculate standardized mean differences (SMD's). We included 897 original research studies. Among the 627 no-intervention-comparison studies the median sample size was 25. Only two studies (0.3%) had ≥80% power to detect a small difference (SMD > 0.2 standard deviations) and 136 (22%) had power to detect a large difference (SMD > 0.8). 110 no-intervention-comparison studies failed to find a statistically significant difference, but none excluded a small difference and only 47 (43%) excluded a large difference. Among 297 studies comparing alternate simulation approaches the median sample size was 30. Only one study (0.3%) had ≥80% power to detect a small difference and 79 (27%) had power to detect a large difference. Of the 128 studies that did not detect a statistically significant effect, 4 (3%) excluded a small difference and 91 (71%) excluded a large difference. In conclusion, most education research studies are powered only to detect effects of large magnitude. For most studies that do not reach statistical significance, the possibility of large and important differences still exists.

Constraining sterile neutrinos with AMANDA and IceCube atmospheric neutrino data

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

Esmaili, Arman; Peres, O.L.G.; Halzen, Francis, E-mail: aesmaili@ifi.unicamp.br, E-mail: halzen@icecube.wisc.edu, E-mail: orlando@ifi.unicamp.br

2012-11-01

We demonstrate that atmospheric neutrino data accumulated with the AMANDA and the partially deployed IceCube experiments constrain the allowed parameter space for a hypothesized fourth sterile neutrino beyond the reach of a combined analysis of all other experiments, for Δm{sup 2}{sub 41}∼<1 eV{sup 2}. Although the IceCube data wins the statistics in the analysis, the advantage of a combined analysis of AMANDA and IceCube data is the partial remedy of yet unknown instrumental systematic uncertainties. We also illustrate the sensitivity of the completed IceCube detector, that is now taking data, to the parameter space of 3+1 model.

The Effectiveness of Psychosocial Interventions Delivered by Teachers in Schools: A Systematic Review and Meta-Analysis.

PubMed

Franklin, Cynthia; Kim, Johnny S; Beretvas, Tasha S; Zhang, Anao; Guz, Samantha; Park, Sunyoung; Montgomery, Katherine; Chung, Saras; Maynard, Brandy R

2017-09-01

The growing mental health needs of students within schools have resulted in teachers increasing their involvement in the delivery of school-based, psychosocial interventions. Current research reports mixed findings concerning the effectiveness of psychosocial interventions delivered by teachers for mental health outcomes. This article presents a systematic review and meta-analysis that examined the effectiveness of school-based psychosocial interventions delivered by teachers on internalizing and externalizing outcomes and the moderating factors that influence treatment effects on these outcomes. Nine electronic databases, major journals, and gray literature (e.g., websites, conference abstract) were searched and field experts were contacted to locate additional studies. Twenty-four studies that met the study inclusion criteria were coded into internalizing or externalizing outcomes and further analyzed using robust variance estimation in meta-regression. Both publication and risk of bias of studies were further assessed. The results showed statistically significant reductions in students' internalizing outcomes (d = .133, 95% CI [.002, .263]) and no statistical significant effect for externalizing outcomes (d = .15, 95% CI [-.037, .066]). Moderator analysis with meta-regression revealed that gender (%male, b = -.017, p < .05), race (% Caucasian, b = .002, p < .05), and the tier of intervention (b = .299, p = .06) affected intervention effectiveness. This study builds on existing literature that shows that teacher-delivered Tier 1 interventions are effective interventions but also adds to this literature by showing that interventions are more effective with internalizing outcomes than on the externalizing outcomes. Moderator analysis also revealed treatments were more effective with female students for internalizing outcomes and more effective with Caucasian students for externalizing outcomes.

A systematic review and meta-analysis of ketamine for the prevention of persistent post-surgical pain.

PubMed

McNicol, E D; Schumann, R; Haroutounian, S

2014-11-01

While post-operative pain routinely resolves, persistent post-surgical pain (PPSP) is common in certain surgeries; it causes disability, lowers quality of life and has economic consequences. The objectives of this systematic review and meta-analysis were to evaluate the effectiveness of ketamine in reducing the prevalence and severity of PPSP and to assess safety associated with its use. We searched the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE through December 2012 for articles in any language. We included randomized, controlled trials in adults in which ketamine was administered perioperatively via any route. Seventeen studies, the majority of which administered ketamine intravenously, met all inclusion criteria. The overall risk of developing PPSP was not significantly reduced at any time point in the ketamine group vs. placebo, nor did comparisons of pain severity scores reach statistical significance. Sensitivity analysis of exclusively intravenous ketamine studies included in this meta-analysis demonstrated statistically significant reductions in risk of developing PPSP at 3 and 6 months (P = 0.01 and P = 0.04, respectively). Adverse event rates were similar between ketamine and placebo groups. The study data from our review are heterogeneous and demonstrate efficacy of intravenously administered ketamine only in comparison with placebo. Highly variable timing and dosing of ketamine in these studies suggest that no unifying effective regimen has emerged. Future research should focus on clinically relevant outcomes, should stratify patients with pre-existing pain and possible central sensitization and should enroll sufficiently large numbers to account for loss to follow-up in long-term studies. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Bond strength of universal adhesives: A systematic review and meta-analysis.

PubMed

Rosa, Wellington Luiz de Oliveira da; Piva, Evandro; Silva, Adriana Fernandes da

2015-07-01

A systematic review was conducted to determine whether the etch-and-rinse or self-etching mode is the best protocol for dentin and enamel adhesion by universal adhesives. This report followed the PRISMA Statement. A total of 10 articles were included in the meta-analysis. Two reviewers performed a literature search up to October 2014 in eight databases: PubMed, Web of Science, Scopus, BBO, SciELO, LILACS, IBECS and The Cochrane Library. In vitro studies evaluating the bond strength of universal adhesives to dentin and/or enamel by the etch-and-rinse and self-etch strategies were eligible to be selected. Statistical analyses were conducted using RevMan 5.1 (The Cochrane Collaboration, Copenhagen, Denmark). A global comparison was performed with random-effects models at a significance level of p<0.05. The analysis of dentin micro-tensile bond strength showed no statistically significant difference between the etch-and-rinse and self-etch strategies for mild universal adhesives (p≥0.05). However, for the ultra-mild All-Bond Universal adhesive, the etch-and-rinse strategy was significantly different than the self-etch mode in terms of dentin micro-tensile bond strength, as well as in the global analysis of enamel micro-tensile and micro-shear bond strength (p≤0.05). The enamel bond strength of universal adhesives is improved with prior phosphoric acid etching. However, this effect was not evident for dentin with the use of mild universal adhesives with the etch-and-rinse strategy. Selective enamel etching prior to the application of a mild universal adhesive is an advisable strategy for optimizing bonding. Copyright © 2015 Elsevier Ltd. All rights reserved.

HICOSMO: cosmology with a complete sample of galaxy clusters - II. Cosmological results

NASA Astrophysics Data System (ADS)

Schellenberger, G.; Reiprich, T. H.

2017-10-01

The X-ray bright, hot gas in the potential well of a galaxy cluster enables systematic X-ray studies of samples of galaxy clusters to constrain cosmological parameters. HIFLUGCS consists of the 64 X-ray brightest galaxy clusters in the Universe, building up a local sample. Here, we utilize this sample to determine, for the first time, individual hydrostatic mass estimates for all the clusters of the sample and, by making use of the completeness of the sample, we quantify constraints on the two interesting cosmological parameters, Ωm and σ8. We apply our total hydrostatic and gas mass estimates from the X-ray analysis to a Bayesian cosmological likelihood analysis and leave several parameters free to be constrained. We find Ωm = 0.30 ± 0.01 and σ8 = 0.79 ± 0.03 (statistical uncertainties, 68 per cent credibility level) using our default analysis strategy combining both a mass function analysis and the gas mass fraction results. The main sources of biases that we correct here are (1) the influence of galaxy groups (incompleteness in parent samples and differing behaviour of the Lx-M relation), (2) the hydrostatic mass bias, (3) the extrapolation of the total mass (comparing various methods), (4) the theoretical halo mass function and (5) other physical effects (non-negligible neutrino mass). We find that galaxy groups introduce a strong bias, since their number density seems to be over predicted by the halo mass function. On the other hand, incorporating baryonic effects does not result in a significant change in the constraints. The total (uncorrected) systematic uncertainties (∼20 per cent) clearly dominate the statistical uncertainties on cosmological parameters for our sample.

The role of AMH and its receptor SNP in the pathogenesis of PCOS.

PubMed

Wang, Fang; Niu, Wen-Bin; Kong, Hui-Juan; Guo, Yi-Hong; Sun, Ying-Pu

2017-01-05

The etiology of polycystic ovaries syndrome (PCOS) is unknown. Studies probing the role of genetic variants of anti-Mullerian hormone (AMH) and its type II receptor (AMHR2) in the pathogenesis of PCOS have yielded inconsistent results. Thus, we performed a systematic review and meta-analysis to determine the role of genetic variants of AMH/AMHR2 in the pathogenesis of PCOS. A systematic search of electronic databases was performed. Statistical analysis was performed using the Comprehensive Meta-Analysis software (Version 3). Pooled Odds Ratios (OR) (95% confidence intervals) were determined to assess the association between genetic variants of AMH/AMHR2 and PCOS. Five studies, involving a total of 2042 PCOS cases and 1071 controls, were included in the meta-analysis. Single nucleotide polymorphisms of AMH and AMHR2 did not appear to confer a heightened risk for PCOS (OR: 0.954, 95% CI: 0.848-1.073; P = 0.435; and OR: 1.074, 95% CI: 0.875-1.318; P = 0.494, respectively). In this study, genetic variants of AMH or AMHR2 were not found to be associated with a higher risk for PCOS. Copyright © 2016. Published by Elsevier Ireland Ltd.

Does cell phone use increase the chances of parotid gland tumor development? A systematic review and meta-analysis.

PubMed

de Siqueira, Elisa Carvalho; de Souza, Fabrício Tinoco Alvim; Gomez, Ricardo Santiago; Gomes, Carolina Cavalieri; de Souza, Renan Pedra

2017-08-01

Prior epidemiological studies had examined the association between cell phone use and the development of tumors in the parotid glands. However, there is no consensus about the question of whether cell phone use is associated with increased risk of tumors in the parotid glands. We performed a meta-analysis to evaluate the existing literature about the mean question and to determine their statistical significance. Primary association studies. Papers that associated cell phone use and parotid gland tumors development were included, with no restrictions regarding publication date, language, and place of publication. Systematic literature search using PubMed, SciELO and Embase followed by meta-analysis. Initial screening included 37 articles, and three were included in meta-analysis. Using three independent samples including 5087 subjects from retrospective case-control studies, cell phone use seems to be associated with greater odds (1.28, 95%- confidence interval: 1.09-1.51) to develop salivary gland tumor. Results should be read with caution due to the limited number of studies available and their retrospective design. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Systematic review finds that study data not published in full text articles have unclear impact on meta-analyses results in medical research.

PubMed

Schmucker, Christine M; Blümle, Anette; Schell, Lisa K; Schwarzer, Guido; Oeller, Patrick; Cabrera, Laura; von Elm, Erik; Briel, Matthias; Meerpohl, Joerg J

2017-01-01

A meta-analysis as part of a systematic review aims to provide a thorough, comprehensive and unbiased statistical summary of data from the literature. However, relevant study results could be missing from a meta-analysis because of selective publication and inadequate dissemination. If missing outcome data differ systematically from published ones, a meta-analysis will be biased with an inaccurate assessment of the intervention effect. As part of the EU-funded OPEN project (www.open-project.eu) we conducted a systematic review that assessed whether the inclusion of data that were not published at all and/or published only in the grey literature influences pooled effect estimates in meta-analyses and leads to different interpretation. Systematic review of published literature (methodological research projects). Four bibliographic databases were searched up to February 2016 without restriction of publication year or language. Methodological research projects were considered eligible for inclusion if they reviewed a cohort of meta-analyses which (i) compared pooled effect estimates of meta-analyses of health care interventions according to publication status of data or (ii) examined whether the inclusion of unpublished or grey literature data impacts the result of a meta-analysis. Seven methodological research projects including 187 meta-analyses comparing pooled treatment effect estimates according to different publication status were identified. Two research projects showed that published data showed larger pooled treatment effects in favour of the intervention than unpublished or grey literature data (Ratio of ORs 1.15, 95% CI 1.04-1.28 and 1.34, 95% CI 1.09-1.66). In the remaining research projects pooled effect estimates and/or overall findings were not significantly changed by the inclusion of unpublished and/or grey literature data. The precision of the pooled estimate was increased with narrower 95% confidence interval. Although we may anticipate that systematic reviews and meta-analyses not including unpublished or grey literature study results are likely to overestimate the treatment effects, current empirical research shows that this is only the case in a minority of reviews. Therefore, currently, a meta-analyst should particularly consider time, effort and costs when adding such data to their analysis. Future research is needed to identify which reviews may benefit most from including unpublished or grey data.

Systematic review finds that study data not published in full text articles have unclear impact on meta-analyses results in medical research

PubMed Central

Blümle, Anette; Schell, Lisa K.; Schwarzer, Guido; Oeller, Patrick; Cabrera, Laura; von Elm, Erik; Briel, Matthias; Meerpohl, Joerg J.

2017-01-01

Background A meta-analysis as part of a systematic review aims to provide a thorough, comprehensive and unbiased statistical summary of data from the literature. However, relevant study results could be missing from a meta-analysis because of selective publication and inadequate dissemination. If missing outcome data differ systematically from published ones, a meta-analysis will be biased with an inaccurate assessment of the intervention effect. As part of the EU-funded OPEN project (www.open-project.eu) we conducted a systematic review that assessed whether the inclusion of data that were not published at all and/or published only in the grey literature influences pooled effect estimates in meta-analyses and leads to different interpretation. Methods and findings Systematic review of published literature (methodological research projects). Four bibliographic databases were searched up to February 2016 without restriction of publication year or language. Methodological research projects were considered eligible for inclusion if they reviewed a cohort of meta-analyses which (i) compared pooled effect estimates of meta-analyses of health care interventions according to publication status of data or (ii) examined whether the inclusion of unpublished or grey literature data impacts the result of a meta-analysis. Seven methodological research projects including 187 meta-analyses comparing pooled treatment effect estimates according to different publication status were identified. Two research projects showed that published data showed larger pooled treatment effects in favour of the intervention than unpublished or grey literature data (Ratio of ORs 1.15, 95% CI 1.04–1.28 and 1.34, 95% CI 1.09–1.66). In the remaining research projects pooled effect estimates and/or overall findings were not significantly changed by the inclusion of unpublished and/or grey literature data. The precision of the pooled estimate was increased with narrower 95% confidence interval. Conclusions Although we may anticipate that systematic reviews and meta-analyses not including unpublished or grey literature study results are likely to overestimate the treatment effects, current empirical research shows that this is only the case in a minority of reviews. Therefore, currently, a meta-analyst should particularly consider time, effort and costs when adding such data to their analysis. Future research is needed to identify which reviews may benefit most from including unpublished or grey data. PMID:28441452

Systematic and statistical uncertainties in simulated r-process abundances due to uncertain nuclear masses

DOE PAGES

Surman, Rebecca; Mumpower, Matthew; McLaughlin, Gail

2017-02-27

Unknown nuclear masses are a major source of nuclear physics uncertainty for r-process nucleosynthesis calculations. Here we examine the systematic and statistical uncertainties that arise in r-process abundance predictions due to uncertainties in the masses of nuclear species on the neutron-rich side of stability. There is a long history of examining systematic uncertainties by the application of a variety of different mass models to r-process calculations. Here we expand upon such efforts by examining six DFT mass models, where we capture the full impact of each mass model by updating the other nuclear properties — including neutron capture rates, β-decaymore » lifetimes, and β-delayed neutron emission probabilities — that depend on the masses. Unlike systematic effects, statistical uncertainties in the r-process pattern have just begun to be explored. Here we apply a global Monte Carlo approach, starting from the latest FRDM masses and considering random mass variations within the FRDM rms error. Here, we find in each approach that uncertain nuclear masses produce dramatic uncertainties in calculated r-process yields, which can be reduced in upcoming experimental campaigns.« less

Systematic and statistical uncertainties in simulated r-process abundances due to uncertain nuclear masses

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

Surman, Rebecca; Mumpower, Matthew; McLaughlin, Gail

Unknown nuclear masses are a major source of nuclear physics uncertainty for r-process nucleosynthesis calculations. Here we examine the systematic and statistical uncertainties that arise in r-process abundance predictions due to uncertainties in the masses of nuclear species on the neutron-rich side of stability. There is a long history of examining systematic uncertainties by the application of a variety of different mass models to r-process calculations. Here we expand upon such efforts by examining six DFT mass models, where we capture the full impact of each mass model by updating the other nuclear properties — including neutron capture rates, β-decaymore » lifetimes, and β-delayed neutron emission probabilities — that depend on the masses. Unlike systematic effects, statistical uncertainties in the r-process pattern have just begun to be explored. Here we apply a global Monte Carlo approach, starting from the latest FRDM masses and considering random mass variations within the FRDM rms error. Here, we find in each approach that uncertain nuclear masses produce dramatic uncertainties in calculated r-process yields, which can be reduced in upcoming experimental campaigns.« less

Post Second World War immigration from Balkan countries to Turkey.

PubMed

Kirisci, K

1995-01-01

"Although there are some works, both in English and Turkish, that have studied migration into the Ottoman empire from the Balkans during the 19th century...it is difficult to find any systematic and comprehensive literature that examines the period since the establishment of the Turkish Republic.... This article aims at filling some of this gap....[The article offers] an analysis of the size and causes of migration from the Balkans to Turkey since the end of the Second World War. The statistics for tables used in this article, unless stated otherwise, have been obtained from the General Directorate of Village Works in Ankara, which is responsible for keeping the statistical records on immigrants arriving in Turkey." excerpt

Dynamic Quantitative Trait Locus Analysis of Plant Phenomic Data.

PubMed

Li, Zitong; Sillanpää, Mikko J

2015-12-01

Advanced platforms have recently become available for automatic and systematic quantification of plant growth and development. These new techniques can efficiently produce multiple measurements of phenotypes over time, and introduce time as an extra dimension to quantitative trait locus (QTL) studies. Functional mapping utilizes a class of statistical models for identifying QTLs associated with the growth characteristics of interest. A major benefit of functional mapping is that it integrates information over multiple timepoints, and therefore could increase the statistical power for QTL detection. We review the current development of computationally efficient functional mapping methods which provide invaluable tools for analyzing large-scale timecourse data that are readily available in our post-genome era. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effectiveness of School-Based Teen Pregnancy Prevention Programs in the USA: a Systematic Review and Meta-Analysis.

PubMed

Marseille, Elliot; Mirzazadeh, Ali; Biggs, M Antonia; P Miller, Amanda; Horvath, Hacsi; Lightfoot, Marguerita; Malekinejad, Mohsen; Kahn, James G

2018-05-01

School-based programs have been a mainstay of youth pregnancy prevention efforts in the USA. We conducted a systematic review and meta-analysis to assess their effectiveness. Eligible studies evaluated the effect on pregnancy rates of programs delivered in elementary, middle, or high schools in the USA and Canada, published between January 1985 and September 2016. The primary outcome was pregnancy; secondary outcomes were delay in sexual initiation, condom use, and oral contraception use. Randomized controlled trials (RCTs) and non-RCTs with comparator groups were eligible. We developed a comprehensive search strategy, applied to major bibliographic databases, article bibliographies, gray literature, and contact with authors. We calculated risk ratios (RR) with 95% confidence intervals (CI) for each outcome and pooled data in random effects meta-analysis. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess evidence quality. Ten RCTs and 11 non-RCTs conducted from 1984 to 2016 yielded 30 unique pooled comparisons for pregnancy, of which 24 were not statistically significant. Six showed statistically significant changes in pregnancy rates: two with increased risk (RR 1.30, 95% CI 1.02-1.65; and RR 1.39, 95% CI 1.10-1.75) and four with decreased risk ranging from RR 0.56, 95% CI 0.41-0.77, to RR 0.75, 95% CI 0.58-0.96. All studies were at high risk of bias, and the quality of evidence was low or very low. Identified evidence indicated no consistent difference in rates of pregnancies between intervention recipients and controls.

Do scores on three commonly used measures of critical thinking correlate with academic success of health professions trainees? A systematic review and meta-analysis.

PubMed

Ross, David; Loeffler, Kim; Schipper, Shirley; Vandermeer, Ben; Allan, G Michael

2013-05-01

To determine whether the three commonly used measures of critical thinking correlate with academic success of medical professionals in training. The search for English-language articles (from 1980 to 2011) used Medline, Embase, Scopus, Cochrane Library on Ovid, Proquest Dissertations, Health and Psychosocial Instruments, PsychINFO, and references of included articles. Studies comparing critical thinking with academic success among medical professionals were included. Two authors performed study selection independently, with disagreement resolved by consensus. Two authors independently abstracted data on study characteristics, quality, and outcomes, with disagreement resolved by a third author. Critical thinking tests studied were the California Critical Thinking Skills Test (CCTST), California Critical Thinking Disposition Inventory (CCTDI), and Watson-Glaser Critical Thinking Appraisal. Correlation coefficients were pooled in meta-analysis. The search identified 557 studies: 52 met inclusion for systematic review, 41 of which were meta-analyzed. Critical thinking was positively correlated with academic success, r=0.31 (95% confidence intervals [CI] 0.26, 0.35), with a moderate statistical heterogeneity (I=67%). In subgroup analysis, only student type had statistical significance for correlation, although bias was likely due to low numbers for some student types. In direct comparison, using studies that employed two critical thinking tests, the CCTDI (r=0.23, 95% CI 0.15, 0.30) was significantly inferior (P<.001) to the CCTST (r=0.39, 95% CI 0.33, 0.45). Critical thinking was moderately correlated with academic success of medical professionals in training. The CCTDI was inferior to the CCTST in correlating with academic success.

Pathogenesis-based treatments in primary Sjogren's syndrome using artificial intelligence and advanced machine learning techniques: a systematic literature review.

PubMed

Foulquier, Nathan; Redou, Pascal; Le Gal, Christophe; Rouvière, Bénédicte; Pers, Jacques-Olivier; Saraux, Alain

2018-05-17

Big data analysis has become a common way to extract information from complex and large datasets among most scientific domains. This approach is now used to study large cohorts of patients in medicine. This work is a review of publications that have used artificial intelligence and advanced machine learning techniques to study physio pathogenesis-based treatments in pSS. A systematic literature review retrieved all articles reporting on the use of advanced statistical analysis applied to the study of systemic autoimmune diseases (SADs) over the last decade. An automatic bibliography screening method has been developed to perform this task. The program called BIBOT was designed to fetch and analyze articles from the pubmed database using a list of keywords and Natural Language Processing approaches. The evolution of trends in statistical approaches, sizes of cohorts and number of publications over this period were also computed in the process. In all, 44077 abstracts were screened and 1017 publications were analyzed. The mean number of selected articles was 101.0 (S.D. 19.16) by year, but increased significantly over the time (from 74 articles in 2008 to 138 in 2017). Among them only 12 focused on pSS but none of them emphasized on the aspect of pathogenesis-based treatments. To conclude, medicine progressively enters the era of big data analysis and artificial intelligence, but these approaches are not yet used to describe pSS-specific pathogenesis-based treatment. Nevertheless, large multicentre studies are investigating this aspect with advanced algorithmic tools on large cohorts of SADs patients.

Recent progress in the studies of neutron-rich and high-$Z$ systems within the covariant density functional theory

DOE PAGES

Afanasjev, Anatoli V.; Agbemava, S. E.; Ray, D.; ...

2017-01-01

Here, the analysis of statistical and systematic uncertainties and their propagation to nuclear extremes has been performed. Two extremes of nuclear landscape (neutron-rich nuclei and superheavy nuclei) have been investigated. For the first extreme, we focus on the ground state properties. For the second extreme, we pay a particular attention to theoretical uncertainties in the description of fission barriers of superheavy nuclei and their evolution on going to neutron-rich nuclei.

Statistical Optimization of 1,3-Propanediol (1,3-PD) Production from Crude Glycerol by Considering Four Objectives: 1,3-PD Concentration, Yield, Selectivity, and Productivity.

PubMed

Supaporn, Pansuwan; Yeom, Sung Ho

2018-04-30

This study investigated the biological conversion of crude glycerol generated from a commercial biodiesel production plant as a by-product to 1,3-propanediol (1,3-PD). Statistical analysis was employed to derive a statistical model for the individual and interactive effects of glycerol, (NH 4 ) 2 SO 4 , trace elements, pH, and cultivation time on the four objectives: 1,3-PD concentration, yield, selectivity, and productivity. Optimum conditions for each objective with its maximum value were predicted by statistical optimization, and experiments under the optimum conditions verified the predictions. In addition, by systematic analysis of the values of four objectives, optimum conditions for 1,3-PD concentration (49.8 g/L initial glycerol, 4.0 g/L of (NH 4 ) 2 SO 4 , 2.0 mL/L of trace element, pH 7.5, and 11.2 h of cultivation time) were determined to be the global optimum culture conditions for 1,3-PD production. Under these conditions, we could achieve high 1,3-PD yield (47.4%), 1,3-PD selectivity (88.8%), and 1,3-PD productivity (2.1/g/L/h) as well as high 1,3-PD concentration (23.6 g/L).

Implementation of statistical process control for proteomic experiments via LC MS/MS.

PubMed

Bereman, Michael S; Johnson, Richard; Bollinger, James; Boss, Yuval; Shulman, Nick; MacLean, Brendan; Hoofnagle, Andrew N; MacCoss, Michael J

2014-04-01

Statistical process control (SPC) is a robust set of tools that aids in the visualization, detection, and identification of assignable causes of variation in any process that creates products, services, or information. A tool has been developed termed Statistical Process Control in Proteomics (SProCoP) which implements aspects of SPC (e.g., control charts and Pareto analysis) into the Skyline proteomics software. It monitors five quality control metrics in a shotgun or targeted proteomic workflow. None of these metrics require peptide identification. The source code, written in the R statistical language, runs directly from the Skyline interface, which supports the use of raw data files from several of the mass spectrometry vendors. It provides real time evaluation of the chromatographic performance (e.g., retention time reproducibility, peak asymmetry, and resolution), and mass spectrometric performance (targeted peptide ion intensity and mass measurement accuracy for high resolving power instruments) via control charts. Thresholds are experiment- and instrument-specific and are determined empirically from user-defined quality control standards that enable the separation of random noise and systematic error. Finally, Pareto analysis provides a summary of performance metrics and guides the user to metrics with high variance. The utility of these charts to evaluate proteomic experiments is illustrated in two case studies.

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

Mediastinal lymph node dissection versus mediastinal lymph node sampling for early stage non-small cell lung cancer: a systematic review and meta-analysis.

PubMed

Huang, Xiongfeng; Wang, Jianmin; Chen, Qiao; Jiang, Jielin

2014-01-01

This systematic review and meta-analysis aimed to evaluate the overall survival, local recurrence, distant metastasis, and complications of mediastinal lymph node dissection (MLND) versus mediastinal lymph node sampling (MLNS) in stage I-IIIA non-small cell lung cancer (NSCLC) patients. A systematic search of published literature was conducted using the main databases (MEDLINE, PubMed, EMBASE, and Cochrane databases) to identify relevant randomized controlled trials that compared MLND vs. MLNS in NSCLC patients. Methodological quality of included randomized controlled trials was assessed according to the criteria from the Cochrane Handbook for Systematic Review of Interventions (Version 5.1.0). Meta-analysis was performed using The Cochrane Collaboration's Review Manager 5.3. The results of the meta-analysis were expressed as hazard ratio (HR) or risk ratio (RR), with their corresponding 95% confidence interval (CI). We included results reported from six randomized controlled trials, with a total of 1,791 patients included in the primary meta-analysis. Compared to MLNS in NSCLC patients, there was no statistically significant difference in MLND on overall survival (HR = 0.77, 95% CI 0.55 to 1.08; P = 0.13). In addition, the results indicated that local recurrence rate (RR = 0.93, 95% CI 0.68 to 1.28; P = 0.67), distant metastasis rate (RR = 0.88, 95% CI 0.74 to 1.04; P = 0.15), and total complications rate (RR = 1.10, 95% CI 0.67 to 1.79; P = 0.72) were similar, no significant difference found between the two groups. Results for overall survival, local recurrence rate, and distant metastasis rate were similar between MLND and MLNS in early stage NSCLC patients. There was no evidence that MLND increased complications compared with MLNS. Whether or not MLND is superior to MLNS for stage II-IIIA remains to be determined.

Methods for detecting, quantifying, and adjusting for dissemination bias in meta-analysis are described.

PubMed

Mueller, Katharina Felicitas; Meerpohl, Joerg J; Briel, Matthias; Antes, Gerd; von Elm, Erik; Lang, Britta; Motschall, Edith; Schwarzer, Guido; Bassler, Dirk

2016-12-01

To systematically review methodological articles which focus on nonpublication of studies and to describe methods of detecting and/or quantifying and/or adjusting for dissemination in meta-analyses. To evaluate whether the methods have been applied to an empirical data set for which one can be reasonably confident that all studies conducted have been included. We systematically searched Medline, the Cochrane Library, and Web of Science, for methodological articles that describe at least one method of detecting and/or quantifying and/or adjusting for dissemination bias in meta-analyses. The literature search retrieved 2,224 records, of which we finally included 150 full-text articles. A great variety of methods to detect, quantify, or adjust for dissemination bias were described. Methods included graphical methods mainly based on funnel plot approaches, statistical methods, such as regression tests, selection models, sensitivity analyses, and a great number of more recent statistical approaches. Only few methods have been validated in empirical evaluations using unpublished studies obtained from regulators (Food and Drug Administration, European Medicines Agency). We present an overview of existing methods to detect, quantify, or adjust for dissemination bias. It remains difficult to advise which method should be used as they are all limited and their validity has rarely been assessed. Therefore, a thorough literature search remains crucial in systematic reviews, and further steps to increase the availability of all research results need to be taken. Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring the Efficacy and Limitations of Shock-cooling Models: New Analysis of Type II Supernovae Observed by the Kepler Mission

NASA Astrophysics Data System (ADS)

Rubin, Adam; Gal-Yam, Avishay

2017-10-01

Modern transient surveys have begun discovering and following supernovae (SNe) shortly after first light—providing systematic measurements of the rise of Type II SNe. We explore how analytic models of early shock-cooling emission from core-collapse SNe can constrain the progenitor’s radius, explosion velocity, and local host extinction. We simulate synthetic photometry in several realistic observing scenarios; assuming the models describe the typical explosions well, we find that ultraviolet observations can constrain the progenitor’s radius to a statistical uncertainty of ±10%-15%, with a systematic uncertainty of ±20%. With these observations the local host extinction (A V ) can be constrained to a factor of two and the shock velocity to ±5% with a systematic uncertainty of ±10%. We also reanalyze the SN light curves presented by Garnavich et al. (2016) and find that KSN 2011a can be fit by a blue supergiant model with a progenitor radius of {R}s< 7.7+8.8({stat})+1.9({sys}) {R}⊙ , while KSN 2011d can be fit with a red supergiant model with a progenitor radius of {R}s={111}-21({stat)-1({sys})}+89({stat)+49({sys})} {R}⊙ . Our results do not agree with those of Garnavich et al. Moreover, we re-evaluate their claims and find that there is no statistically significant evidence for a shock-breakout flare in the light curve of KSN 2011d.

Systematic literature review shows that appetite rating does not predict energy intake.

PubMed

Holt, Guy M; Owen, Lauren J; Till, Sophie; Cheng, Yanying; Grant, Vicky A; Harden, Charlotte J; Corfe, Bernard M

2017-11-02

Ratings of appetite are commonly used to assess appetite modification following an intervention. Subjectively rated appetite is a widely employed proxy measure for energy intake (EI), measurement of which requires greater time and resources. However, the validity of appetite as a reliable predictor of EI has not yet been reviewed systematically. This literature search identified studies that quantified both appetite ratings and EI. Outcomes were predefined as: (1) agreement between self-reported appetite scores and EI; (2) no agreement between self-reported appetitescores and EI. The presence of direct statistical comparison between the endpoints, intervention type and study population were also recorded. 462 papers were included in this review. Appetite scores failed to correspond with EI in 51.3% of the total studies. Only 6% of all studies evaluated here reported a direct statistical comparison between appetite scores and EI. χ 2 analysis demonstrated that any relationship between EI and appetite was independent of study type stratification by age, gender or sample size. The very substantive corpus reviewed allows us to conclude that self-reported appetite ratings of appetite do not reliably predict EI. Caution should be exercised when drawing conclusions based from self-reported appetite scores in relation to prospective EI.

Cervical lacerations in planned versus labor cerclage removal: a systematic review.

PubMed

Simonazzi, Giuliana; Curti, Alessandra; Bisulli, Maria; Seravalli, Viola; Saccone, Gabriele; Berghella, Vincenzo

2015-10-01

The aim of this study was to evaluate the incidence of cervical lacerations with cerclage removal planned before labor compared to after the onset of labor by a systematic review of published studies. Searches were performed in electronic databases from inception of each database to November 2014. We identified all studies reporting the rate of cervical lacerations and the timing of cerclage removal (either before or after the onset of labor). The primary outcome was the incidence of spontaneous and clinically significant intrapartum cervical lacerations (i.e. lacerations requiring suturing). Six studies, which met the inclusion criteria, were included in the analysis. The overall incidence of cervical lacerations was 8.9% (32/359). There were 23/280 (6.4%) cervical lacerations in the planned removal group, and 9/79 (11.4%) in the removal after labor group (odds ratio 0.70, 95% confidence interval 0.31-1.57). In summary, planned removal of cerclage before labor was not shown to be associated with statistically significant reduction in the incidence of cervical lacerations. However, since that our data probably did not reach statistical significance because of a type II error, further studies are needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

THE IDENTIFICATION OF THE X-RAY COUNTERPART TO PSR J2021+4026

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

Weisskopf, Martin C.; Elsner, Ronald F.; O'Dell, Stephen L.

2011-12-10

We report the probable identification of the X-ray counterpart to the {gamma}-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer and timing analysis with the Fermi satellite. Given the statistical and systematic errors, the positions determined by both satellites are coincident. The X-ray source position is R.A. 20{sup h}21{sup m}30.{sup s}733, decl. +40 Degree-Sign 26'46.''04 (J2000) with an estimated uncertainty of 1.''3 combined statistical and systematic error. Moreover, both the X-ray to {gamma}-ray and the X-ray to optical flux ratios are sensible assuming a neutron star origin for the X-ray flux. The X-ray sourcemore » has no cataloged infrared-to-visible counterpart and, through new observations, we set upper limits to its optical emission of i' > 23.0 mag and r' > 25.2 mag. The source exhibits an X-ray spectrum with most likely both a power law and a thermal component. We also report on the X-ray and visible light properties of the 43 other sources detected in our Chandra observation.« less

The Identification Of The X-Ray Counterpart To PSR J2021+4026

DOE PAGES

Weisskopf, Martin C.; Romani, Roger W.; Razzano, Massimiliano; ...

2011-11-23

We report the probable identification of the X-ray counterpart to the γ-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray Observatory ACIS and timing analysis with the Fermi satellite. Given the statistical and systematic errors, the positions determined by both satellites are coincident. The X-ray source position is R.A. 20h21m30s.733, Decl. +40°26'46.04" (J2000) with an estimated uncertainty of 1."3 combined statistical and systematic error. Moreover, both the X-ray to γ-ray and the X-ray to optical flux ratios are sensible assuming a neutron star origin for the X-ray flux. The X-ray source has no cataloged infrared-to-visible counterpart and, through newmore » observations, we set upper limits to its optical emission of i' > 23.0 mag and r' > 25.2 mag. The source exhibits an X-ray spectrum with most likely both a powerlaw and a thermal component. We also report on the X-ray and visible light properties of the 43 other sources detected in our Chandra observation.« less

Irradiated patients and survival rate of dental implants: A systematic review and meta-analysis.

PubMed

Smith Nobrega, Adhara; Santiago, Joel Ferreira; de Faria Almeida, Daniel Augusto; Dos Santos, Daniela Micheline; Pellizzer, Eduardo Piza; Goiato, Marcelo Coelho

2016-12-01

Radiotherapy has been considered a contraindication for rehabilitation with dental implants because it can change the survival rate of implants. Nevertheless, the installation of implants in irradiated patients has been used with varying success. The purpose of this systematic review was to compare the success rate of implants placed in irradiated human bone tissue with that of implants placed in nonirradiated areas. Searches were performed in the EMBASE, Cochrane, and PubMed/Medline databases up to December 2013 to identify clinical trials addressing the subject. This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The relative risks of implant failure and survival curves were calculated considering a confidence interval of 95%. Heterogeneity was analyzed by using a funnel chart. A total of 40 studies involving 2220 participants and 9231 dental implants were selected. The survival curve of the studies indicated a survival rate of 84.3% for implants installed in irradiated bone tissue. The meta-analysis indicated statistically significant differences (P<.001) between item success rates of implants placed in irradiated areas and those of implants placed in nonirradiated areas. Dental implants installed in the irradiated area of an oral cavity have a high survival rate, but strict monitoring is needed to prevent complications, thereby reducing possible failures. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Low energy peripheral scaling in nucleon-nucleon scattering and uncertainty quantification

NASA Astrophysics Data System (ADS)

Ruiz Simo, I.; Amaro, J. E.; Ruiz Arriola, E.; Navarro Pérez, R.

2018-03-01

We analyze the peripheral structure of the nucleon-nucleon interaction for LAB energies below 350 MeV. To this end we transform the scattering matrix into the impact parameter representation by analyzing the scaled phase shifts (L + 1/2) δ JLS (p) and the scaled mixing parameters (L + 1/2)ɛ JLS (p) in terms of the impact parameter b = (L + 1/2)/p. According to the eikonal approximation, at large angular momentum L these functions should become an universal function of b, independent on L. This allows to discuss in a rather transparent way the role of statistical and systematic uncertainties in the different long range components of the two-body potential. Implications for peripheral waves obtained in chiral perturbation theory interactions to fifth order (N5LO) or from the large body of NN data considered in the SAID partial wave analysis are also drawn from comparing them with other phenomenological high-quality interactions, constructed to fit scattering data as well. We find that both N5LO and SAID peripheral waves disagree more than 5σ with the Granada-2013 statistical analysis, more than 2σ with the 6 statistically equivalent potentials fitting the Granada-2013 database and about 1σ with the historical set of 13 high-quality potentials developed since the 1993 Nijmegen analysis.

Systematic Biases in Parameter Estimation of Binary Black-Hole Mergers

NASA Technical Reports Server (NTRS)

Littenberg, Tyson B.; Baker, John G.; Buonanno, Alessandra; Kelly, Bernard J.

2012-01-01

Parameter estimation of binary-black-hole merger events in gravitational-wave data relies on matched filtering techniques, which, in turn, depend on accurate model waveforms. Here we characterize the systematic biases introduced in measuring astrophysical parameters of binary black holes by applying the currently most accurate effective-one-body templates to simulated data containing non-spinning numerical-relativity waveforms. For advanced ground-based detectors, we find that the systematic biases are well within the statistical error for realistic signal-to-noise ratios (SNR). These biases grow to be comparable to the statistical errors at high signal-to-noise ratios for ground-based instruments (SNR approximately 50) but never dominate the error budget. At the much larger signal-to-noise ratios expected for space-based detectors, these biases will become large compared to the statistical errors but are small enough (at most a few percent in the black-hole masses) that we expect they should not affect broad astrophysical conclusions that may be drawn from the data.

Cervical screening programmes: can automation help? Evidence from systematic reviews, an economic analysis and a simulation modelling exercise applied to the UK.

PubMed

Willis, B H; Barton, P; Pearmain, P; Bryan, S; Hyde, C

2005-03-01

To assess the effectiveness and cost-effectiveness of adding automated image analysis to cervical screening programmes. Searching of all major electronic databases to the end of 2000 was supplemented by a detailed survey for unpublished UK literature. Four systematic reviews were conducted according to recognised guidance. The review of 'clinical effectiveness' included studies assessing reproducibility and impact on health outcomes and processes in addition to evaluations of test accuracy. A discrete event simulation model was developed, although the economic evaluation ultimately relied on a cost-minimisation analysis. The predominant finding from the systematic reviews was the very limited amount of rigorous primary research. None of the included studies refers to the only commercially available automated image analysis device in 2002, the AutoPap Guided Screening (GS) System. The results of the included studies were debatably most compatible with automated image analysis being equivalent in test performance to manual screening. Concerning process, there was evidence that automation does lead to reductions in average slide processing times. In the PRISMATIC trial this was reduced from 10.4 to 3.9 minutes, a statistically significant and practically important difference. The economic evaluation tentatively suggested that the AutoPap GS System may be efficient. The key proviso is that credible data become available to support that the AutoPap GS System has test performance and processing times equivalent to those obtained for PAPNET. The available evidence is still insufficient to recommend implementation of automated image analysis systems. The priority for action remains further research, particularly the 'clinical effectiveness' of the AutoPap GS System. Assessing the cost-effectiveness of introducing automation alongside other approaches is also a priority.

Main Clinical Outcomes of Feldspathic Porcelain and Glass-Ceramic Laminate Veneers: A Systematic Review and Meta-Analysis of Survival and Complication Rates.

PubMed

Morimoto, Susana; Albanesi, Rafael Borges; Sesma, Newton; Agra, Carlos Martins; Braga, Mariana Minatel

2016-01-01

The aim of this study was to perform a systematic review and meta-analysis based on clinical trials that evaluated the main outcomes of glass-ceramic and feldspathic porcelain laminate veneers. A systematic search was carried out in Cochrane and PubMed databases. From the selected studies, the survival rates for porcelain and glass-ceramic veneers were extracted, as were complication rates of clinical outcomes: debonding, fracture/chipping, secondary caries, endodontic problems, severe marginal discoloration, and influence of incisal coverage and enamel/dentin preparation. The Cochran Q test and the I(2) statistic were used to evaluate heterogeneity. Out of the 899 articles initially identified, 13 were included for analysis. Metaregression analysis showed that the types of ceramics and follow-up periods had no influence on failure rate. The estimated overall cumulative survival rate was 89% (95% CI: 84% to 94%) in a median follow-up period of 9 years. The estimated survival for glass-ceramic was 94% (95% CI: 87% to 100%), and for feldspathic porcelain veneers, 87% (95% CI: 82% to 93%). The meta-analysis showed rates for the following events: debonding: 2% (95% CI: 1% to 4%); fracture/chipping: 4% (95% CI: 3% to 6%); secondary caries: 1% (95% CI: 0% to 3%); severe marginal discoloration: 2% (95% CI: 1% to 10%); endodontic problems: 2% (95% CI: 1% to 3%); and incisal coverage odds ratio: 1.25 (95% CI: 0.33 to 4.73). It was not possible to perform meta-analysis of the influence of enamel/dentin preparation on failure rates. Glass-ceramic and porcelain laminate veneers have high survival rates. Fracture/ chipping was the most frequent complication, providing evidence that ceramic veneers are a safe treatment option that preserve tooth structure.

Evidence from prospective cohort studies does not support current dietary fat guidelines: a systematic review and meta-analysis.

PubMed

Harcombe, Zoë; Baker, Julien S; Davies, Bruce

2017-12-01

National dietary guidelines were introduced in 1977 and 1983, by the US and UK governments to reduce coronary heart disease (CHD) mortality by reducing dietary fat intake. Our 2016 systematic review examined the epidemiological evidence available to the dietary committees at the time; we found no support for the recommendations to restrict dietary fat. The present investigation extends our work by re-examining the totality of epidemiological evidence currently available relating to dietary fat guidelines. A systematic review and meta-analysis of prospective cohort studies currently available, which examined the relationship between dietary fat, serum cholesterol and the development of CHD, were undertaken. Across 7 studies, involving 89 801 participants (94% male), there were 2024 deaths from CHD during the mean follow-up of 11.9±5.6 years. The death rate from CHD was 2.25%. Eight data sets were suitable for inclusion in meta-analysis; all excluded participants with previous heart disease. Risk ratios (RRs) from meta-analysis were not statistically significant for CHD deaths and total or saturated fat consumption. The RR from meta-analysis for total fat intake and CHD deaths was 1.04 (95% CI 0.98 to 1.10). The RR from meta-analysis for saturated fat intake and CHD deaths was 1.08 (95% CI 0.94 to 1.25). Epidemiological evidence to date found no significant difference in CHD mortality and total fat or saturated fat intake and thus does not support the present dietary fat guidelines. The evidence per se lacks generalisability for population-wide guidelines. 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/.

Global Overexpression of ET-1 Decreases Blood Pressure - A Systematic Review and Meta-Analysis of ET-1 Transgenic Mice.

PubMed

Lu, Yong Ping; Tsuprykov, Oleg; Vignon-Zellweger, Nicolas; Heiden, Susi; Hocher, Berthold

2016-01-01

ET-1 has independent effects on blood pressure regulation in vivo, it is involved in tubular water and salt excretion, promotes constriction of smooth muscle cells, modulates sympathetic nerve activity, and activates the liberation of nitric oxide. To determine the net effect of these partially counteracting mechanisms on blood pressure, a systematic meta-analysis was performed. Based on the principles of Cochrane systematic reviews, we searched in major literature databases - MEDLINE (PubMed), Embase, Google Scholar, and the China Biological Medicine Database (CBM-disc) - for articles relevant to the topic of the blood pressure phenotype of endothelin-1 transgenic (ET-1+/+) mice from January 1, 1988 to March 31, 2016. Review Manager Version 5.0 (Rev-Man 5.0) software was applied for statistical analysis. In total thirteen studies reported blood pressure data. The meta-analysis of blood pressure data showed that homozygous ET-1 transgenic mice (ET-1+/+ mice) had a significantly lower blood pressure as compared to WT mice (mean difference: -2.57 mmHg, 95% CI: -4.98∼ -0.16, P = 0.04), with minimal heterogeneity (P = 0.86). A subgroup analysis of mice older than 6 months revealed that the blood pressure difference between ET-1+/+ mice and WT mice was even more pronounced (mean difference: -6.19 mmHg, 95% CI: -10.76∼ -1.62, P = 0.008), with minimal heterogeneity (P = 0.91). This meta-analysis provides robust evidence that global ET-1 overexpression in mice lowers blood pressure in an age-dependent manner. Older ET-1+/+ mice have a somewhat more pronounced reduction of blood pressure. © 2016 The Author(s) Published by S. Karger AG, Basel.

What is the effectiveness of the negative pressure wound therapy (NPWT) in patients treated with open abdomen technique? A systematic review and meta-analysis.

PubMed

Cirocchi, Roberto; Birindelli, Arianna; Biffl, Walter L; Mutafchiyski, Ventsislav; Popivanov, Georgi; Chiara, Osvaldo; Tugnoli, Gregorio; Di Saverio, Salomone

2016-09-01

The open abdomen technique may be used in critically ill patients to manage abdominal injury, reduce the septic complications, and prevent the abdominal compartment syndrome. Many different techniques have been proposed and multiple studies have been conducted, but the best method of temporary abdominal closure has not been determined yet. Recently, new randomized and nonrandomized controlled trials have been published on this topic. We aimed to perform an up-to-date systematic review on the management of open abdomen, including the most recent published randomized and nonrandomized controlled trials, to compare negative pressure wound therapy (NPWT) with no NPWT and define if one technique has better outcomes than the other with regard to primary fascial closure, postoperative 30-day mortality and morbidity, enteroatmospheric fistulae, abdominal abscess, bleeding, and length of stay. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the Cochrane Handbook for Systematic Reviews of Interventions, an online literature research (until July 1, 2015) was performed on MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, and Cochrane Library databases. The MeSH terms and free words used "vacuum assisted closure" "vac;", "open abdomen", "damage control surgery", and "temporary abdominal closure". No language restriction was made. The initial systematic literature search yielded 452 studies. After a careful assessment of the titles and of the full text was obtained, eight articles fulfilled inclusion criteria. We analyzed 1,225 patients, of whom 723 (59%) underwent NPWT and 502 (41%) did not undergo NPWT, and performed four subgroups: VAC versus Bogota bag technique (two studies, 106 participants), VAC versus mesh-foil laparostomy (two studies, 159 participants), VAC versus laparostomy (adhesive impermeable with midline zip) (one study, 106 participants), and NPWT versus no NPWT techniques (three studies, 854 participants) in which it is not possible to perform an analysis of the different types of treatment. Comparing the NPWT group and the group without NPWT, there was no statistically significant difference in fascial closure (63.5% vs 69.5%; odds ratio [OR], 0.74; 95% confidence interval [CI], 0.27-2.06; p = 0.57), postoperative 30-day overall morbidity (p = 0.19), postoperative enteroatmospheric fistulae rate (2.1% vs 5.8%; OR, 0.63; 95% CIs, 0.12-3.15; p = 0.57), in the postoperative bleeding rate (5.7% vs 14.9%; OR, 0.58; 95% CIs, 0.05-6.84; p = 0.87), and postoperative abdominal abscess rate (2.4% vs 5.6%; OR, 0.42; 95% CI, 0.13-1.34; p = 0.14). On the other hand, statistical significance was found between the NPWT group and the group without NPWT in the postoperative mortality rate (28.5% vs 41.4%; OR, 0.46; 95% CI, 0.23-0.91; p = 0.03) and in the length of stay in the intensive care unit (mean difference, -4.53; 95% CI, -5.46 to 3.60; p < 0.00001). The limitations of the present analysis might be related to the lack of randomized controlled trials, so there is a risk of selection bias favoring NPWT. For several outcomes, there were few studies, confidence intervals were wide, and inconsistency was high, suggesting that although there were no statistically significant differences between the groups, there was insufficient evidence to show that the outcomes were similar. We can conclude from the current available data that NPWT seems to be associated with a trend toward better outcomes compared to the use of no NPWT. It does reflect the evidence presented in the current systematic review; however, the data should be interpreted with substantial caution given a number of weaknesses (in particular, the lack of statistical significance and heterogeneity between studies, i.e., small sample size of the included studies, high variability between studies). We highlight the need for randomized controlled trials having homogeneous inclusion criteria to assess the use of NPWT for the management of open abdomen. Systemic review/meta-analysis, level III.

Language of publication restrictions in systematic reviews gave different results depending on whether the intervention was conventional or complementary.

PubMed

Pham, Ba'; Klassen, Terry P; Lawson, Margaret L; Moher, David

2005-08-01

To assess whether language of publication restrictions impact the estimates of an intervention's effectiveness, whether such impact is similar for conventional medicine and complementary medicine interventions, and whether the results are influenced by publication bias and statistical heterogeneity. We set out to examine the extent to which including reports of randomized controlled trials (RCTs) in languages other than English (LOE) influences the results of systematic reviews, using a broad dataset of 42 language-inclusive systematic reviews, involving 662 RCTs, including both conventional medicine (CM) and complementary and alternative medicine (CAM) interventions. For CM interventions, language-restricted systematic reviews, compared with language-inclusive ones, did not introduce biased results, in terms of estimates of intervention effectiveness (random effects ration of odds rations ROR=1.02; 95% CI=0.83-1.26). For CAM interventions, however, language-restricted systematic reviews resulted in a 63% smaller protective effect estimate than language-inclusive reviews (random effects ROR=1.63; 95% CI=1.03-2.60). Language restrictions do not change the results of CM systematic reviews but do substantially alter the results of CAM systematic reviews. These findings are robust even after sensitivity analyses, and do not appear to be influenced by statistical heterogeneity and publication bias.

Advanced imaging technologies increase detection of dysplasia and neoplasia in patients with Barrett's esophagus: a meta-analysis and systematic review.

PubMed

Qumseya, Bashar J; Wang, Haibo; Badie, Nicole; Uzomba, Rosemary N; Parasa, Sravanthi; White, Donna L; Wolfsen, Herbert; Sharma, Prateek; Wallace, Michael B

2013-12-01

US guidelines recommend surveillance of patients with Barrett's esophagus (BE) to detect dysplasia. BE conventionally is monitored via white-light endoscopy (WLE) and a collection of random biopsy specimens. However, this approach does not definitively or consistently detect areas of dysplasia. Advanced imaging technologies can increase the detection of dysplasia and cancer. We investigated whether these imaging technologies can increase the diagnostic yield for the detection of neoplasia in patients with BE, compared with WLE and analysis of random biopsy specimens. We performed a systematic review, using Medline and Embase, to identify relevant peer-review studies. Fourteen studies were included in the final analysis, with a total of 843 patients. Our metameter (estimate) of interest was the paired-risk difference (RD), defined as the difference in yield of the detection of dysplasia or cancer using advanced imaging vs WLE. The estimated paired-RD and 95% confidence interval (CI) were obtained using random-effects models. Heterogeneity was assessed by means of the Q statistic and the I(2) statistic. An exploratory meta-regression was performed to look for associations between the metameter and potential confounders or modifiers. Overall, advanced imaging techniques increased the diagnostic yield for detection of dysplasia or cancer by 34% (95% CI, 20%-56%; P < .0001). A subgroup analysis showed that virtual chromoendoscopy significantly increased the diagnostic yield (RD, 0.34; 95% CI, 0.14-0.56; P < .0001). The RD for chromoendoscopy was 0.35 (95% CI, 0.13-0.56; P = .0001). There was no significant difference between virtual chromoendoscopy and chromoendoscopy, based on Student t test analysis (P = .45). Based on a meta-analysis, advanced imaging techniques such as chromoendoscopy or virtual chromoendoscopy significantly increase the diagnostic yield for identification of dysplasia or cancer in patients with BE. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Towards application of rule learning to the meta-analysis of clinical data: an example of the metabolic syndrome.

PubMed

Wojtusiak, Janusz; Michalski, Ryszard S; Simanivanh, Thipkesone; Baranova, Ancha V

2009-12-01

Systematic reviews and meta-analysis of published clinical datasets are important part of medical research. By combining results of multiple studies, meta-analysis is able to increase confidence in its conclusions, validate particular study results, and sometimes lead to new findings. Extensive theory has been built on how to aggregate results from multiple studies and arrive to the statistically valid conclusions. Surprisingly, very little has been done to adopt advanced machine learning methods to support meta-analysis. In this paper we describe a novel machine learning methodology that is capable of inducing accurate and easy to understand attributional rules from aggregated data. Thus, the methodology can be used to support traditional meta-analysis in systematic reviews. Most machine learning applications give primary attention to predictive accuracy of the learned knowledge, and lesser attention to its understandability. Here we employed attributional rules, the special form of rules that are relatively easy to interpret for medical experts who are not necessarily trained in statistics and meta-analysis. The methodology has been implemented and initially tested on a set of publicly available clinical data describing patients with metabolic syndrome (MS). The objective of this application was to determine rules describing combinations of clinical parameters used for metabolic syndrome diagnosis, and to develop rules for predicting whether particular patients are likely to develop secondary complications of MS. The aggregated clinical data was retrieved from 20 separate hospital cohorts that included 12 groups of patients with present liver disease symptoms and 8 control groups of healthy subjects. The total of 152 attributes were used, most of which were measured, however, in different studies. Twenty most common attributes were selected for the rule learning process. By applying the developed rule learning methodology we arrived at several different possible rulesets that can be used to predict three considered complications of MS, namely nonalcoholic fatty liver disease (NAFLD), simple steatosis (SS), and nonalcoholic steatohepatitis (NASH).

Back schools for the treatment of chronic low back pain: possibility of benefit but no convincing evidence after 47 years of research—systematic review and meta-analysis

PubMed Central

Straube, Sebastian; Harden, Markus; Schröder, Heiko; Arendacka, Barbora; Fan, Xiangning; Moore, R. Andrew; Friede, Tim

2016-01-01

Abstract Back schools are interventions that comprise exercise and education components. We aimed to systematically review the randomized controlled trial evidence on back schools for the treatment of chronic low back pain. By searching MEDLINE, Embase, and Cochrane Central as well as bibliographies, we identified 31 studies for inclusion in our systematic review and 5 of these for inclusion in meta-analyses. Meta-analyses for pain scores and functional outcomes revealed statistical superiority of back schools vs no intervention for some comparisons but not others. No meta-analysis was feasible for the comparison of back schools vs other active treatments. Adverse events were poorly reported so that no reliable conclusions regarding the safety of back schools can be drawn, although some limited reassurance in this regard may be derived from the fact that few adverse events and no serious adverse events were reported in the back school groups in the studies that did report on safety. Overall, the evidence base for the use of back schools to treat chronic low back pain is weak; in nearly a half-century since back schools were first trialled, no unequivocal evidence of benefit has emerged. PMID:27257858

Back schools for the treatment of chronic low back pain: possibility of benefit but no convincing evidence after 47 years of research-systematic review and meta-analysis.

PubMed

Straube, Sebastian; Harden, Markus; Schröder, Heiko; Arendacka, Barbora; Fan, Xiangning; Moore, R Andrew; Friede, Tim

2016-10-01

Back schools are interventions that comprise exercise and education components. We aimed to systematically review the randomized controlled trial evidence on back schools for the treatment of chronic low back pain. By searching MEDLINE, Embase, and Cochrane Central as well as bibliographies, we identified 31 studies for inclusion in our systematic review and 5 of these for inclusion in meta-analyses. Meta-analyses for pain scores and functional outcomes revealed statistical superiority of back schools vs no intervention for some comparisons but not others. No meta-analysis was feasible for the comparison of back schools vs other active treatments. Adverse events were poorly reported so that no reliable conclusions regarding the safety of back schools can be drawn, although some limited reassurance in this regard may be derived from the fact that few adverse events and no serious adverse events were reported in the back school groups in the studies that did report on safety. Overall, the evidence base for the use of back schools to treat chronic low back pain is weak; in nearly a half-century since back schools were first trialled, no unequivocal evidence of benefit has emerged.

Interventions to improve adherence to tuberculosis treatment: systematic review and meta-analysis.

PubMed

Müller, A M; Osório, C S; Silva, D R; Sbruzzi, G; de Tarso, P; Dalcin, Roth

2018-07-01

One of the most serious problems in tuberculosis (TB) control is non-adherence to treatment. Several strategies have been developed to improve adherence and increase the cure rate. To systematically review interventions to improve adherence to anti-tuberculosis treatment. We performed a systematic review and meta-analysis of 22 randomised clinical trials (RCTs) to ascertain whether providing directly observed treatment, short-course (DOTS), financial incentives, food incentives and/or patient education/counselling improved adherence to anti-tuberculosis treatment. The primary outcome was cure rate; secondary outcomes were default and mortality rates. Sources used were Medline (accessed via PubMed), Cochrane Central, LILACS (Literatura Latino Americana em Ciências da Saúde, Latin American and Caribbean Health Sciences Literature) and Embase from inception to October 2015. A significant increase in cure rates, by 18% with DOTS and by 16% with patient education and counselling, was observed. In addition, the default rate decreased by 49% with DOTS, by 26% with financial incentives and by 13% with patient education and counselling. There was no statistically significant reduction in mortality rates with these interventions. Use of DOTS and patient education/counselling significantly improved cure rates; DOTS, patient education/counselling and financial incentives led to a reduction in the default rate.

Coronectomy of impacted mandibular third molars: A meta-analysis and systematic review of the literature

PubMed Central

Cervera-Espert*, Juan; Pérez-Martínez*, Sara; Cervera-Ballester, Juan; Penarrocha-Oltra, David

2016-01-01

Background Coronectomy is an alternative to complete removal of an impacted mandibular third molar. Most authors have recommended coronectomy to prevent damage to the inferior alveolar nerve during surgical extraction of lower third molars. The present study offers a systematic review and metaanalysis of the coronectomy technique. Material and Methods A systematic review and meta-analysis was performed based on a PubMed and Cochrane databases search for articles published from 2014 and involving coronectomy of mandibular third molars located near the inferior alveolar nerve canal, with a minimum of 10 cases and a minimum follow-up period of 6 months. After application of the inclusion and exclusion criteria, a total of 12 articles were included in the study. Results and Discussion Coronectomy results in significantly lesser loss of sensitivity of the inferior alveolar nerve and prevents the occurrence of dry socket. No statistically significant differences were observed in the incidence of pain and infection between coronectomy and complete surgical extraction. After coronectomy, the remaining tooth fragment migrates an average of 2 mm within two years. Conclusions Coronectomy is indicated when the mandibular third molar is in contact with the inferior alveolar nerve and complete removal of the tooth may cause nerve damage. Key words:Coronectomy, included third molar, inferior alveolar nerve injury. PMID:27031064

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.

Medial Tibial Stress Syndrome in Active Individuals: A Systematic Review and Meta-analysis of Risk Factors

PubMed Central

Reinking, Mark F.; Austin, Tricia M.; Richter, Randy R.; Krieger, Mary M.

2016-01-01

Context: Medial tibial stress syndrome (MTSS) is a common condition in active individuals and presents as diffuse pain along the posteromedial border of the tibia. Objective: To use cross-sectional, case-control, and cohort studies to identify significant MTSS risk factors. Data Sources: Bibliographic databases (PubMed, Scopus, CINAHL, SPORTDiscus, EMBASE, EBM Reviews, PEDRo), grey literature, electronic search of full text of journals, manual review of reference lists, and automatically executed PubMed MTSS searches were utilized. All searches were conducted between 2011 and 2015. Study Selection: Inclusion criteria were determined a priori and included original research with participants’ pain diffuse, located in the posterior medial tibial region, and activity related. Study Design: Systematic review with meta-analysis. Level of evidence: Level 4. Data Extraction: Titles and abstracts were reviewed to eliminate citations that did not meet the criteria for inclusion. Study characteristics identified a priori were extracted for data analysis. Statistical heterogeneity was examined using the I2 index and Cochran Q test, and a random-effects model was used to calculate the meta-analysis when 2 or more studies examined a risk factor. Two authors independently assessed study quality. Results: Eighty-three articles met the inclusion criteria, and 22 articles included risk factor data. Of the 27 risk factors that were in 2 or more studies, 5 risk factors showed a significant pooled effect and low statistical heterogeneity, including female sex (odds ratio [OR], 2.35; CI, 1.58-3.50), increased weight (standardized mean difference [SMD], 0.24; CI, 0.03-0.45), higher navicular drop (SMD, 0.44; CI, 0.21-0.67), previous running injury (OR, 2.18; CI, 1.00-4.72), and greater hip external rotation with the hip in flexion (SMD, 0.44; CI, 0.23-0.65). The remaining risk factors had a nonsignificant pooled effect or significant pooled effect with high statistical heterogeneity. Conclusion: Female sex, increased weight, higher navicular drop, previous running injury, and greater hip external rotation with the hip in flexion are risk factors for the development of MTSS. PMID:27729482

Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves.

PubMed

Guyot, Patricia; Ades, A E; Ouwens, Mario J N M; Welton, Nicky J

2012-02-01

The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers. The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.

Diagnostic potential of real-time elastography (RTE) and shear wave elastography (SWE) to differentiate benign and malignant thyroid nodules: A systematic review and meta-analysis.

PubMed

Hu, Xiangdong; Liu, Yujiang; Qian, Linxue

2017-10-01

Real-time elastography (RTE) and shear wave elastography (SWE) are noninvasive and easily available imaging techniques that measure the tissue strain, and it has been reported that the sensitivity and the specificity of elastography were better in differentiating between benign and malignant thyroid nodules than conventional technologies. Relevant articles were searched in multiple databases; the comparison of elasticity index (EI) was conducted with the Review Manager 5.0. Forest plots of the sensitivity and specificity and SROC curve of RTE and SWE were performed with STATA 10.0 software. In addition, sensitivity analysis and bias analysis of the studies were conducted to examine the quality of articles; and to estimate possible publication bias, funnel plot was used and the Egger test was conducted. Finally 22 articles which eventually satisfied the inclusion criteria were included in this study. After eliminating the inefficient, benign and malignant nodules were 2106 and 613, respectively. The meta-analysis suggested that the difference of EI between benign and malignant nodules was statistically significant (SMD = 2.11, 95% CI [1.67, 2.55], P < .00001). The overall sensitivities of RTE and SWE were roughly comparable, whereas the difference of specificities between these 2 methods was statistically significant. In addition, statistically significant difference of AUC between RTE and SWE was observed between RTE and SWE (P < .01). The specificity of RTE was statistically higher than that of SWE; which suggests that compared with SWE, RTE may be more accurate on differentiating benign and malignant thyroid nodules.

Systematic analysis of coding and noncoding DNA sequences using methods of statistical linguistics

NASA Technical Reports Server (NTRS)

Mantegna, R. N.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Peng, C. K.; Simons, M.; Stanley, H. E.

1995-01-01

We compare the statistical properties of coding and noncoding regions in eukaryotic and viral DNA sequences by adapting two tests developed for the analysis of natural languages and symbolic sequences. The data set comprises all 30 sequences of length above 50 000 base pairs in GenBank Release No. 81.0, as well as the recently published sequences of C. elegans chromosome III (2.2 Mbp) and yeast chromosome XI (661 Kbp). We find that for the three chromosomes we studied the statistical properties of noncoding regions appear to be closer to those observed in natural languages than those of coding regions. In particular, (i) a n-tuple Zipf analysis of noncoding regions reveals a regime close to power-law behavior while the coding regions show logarithmic behavior over a wide interval, while (ii) an n-gram entropy measurement shows that the noncoding regions have a lower n-gram entropy (and hence a larger "n-gram redundancy") than the coding regions. In contrast to the three chromosomes, we find that for vertebrates such as primates and rodents and for viral DNA, the difference between the statistical properties of coding and noncoding regions is not pronounced and therefore the results of the analyses of the investigated sequences are less conclusive. After noting the intrinsic limitations of the n-gram redundancy analysis, we also briefly discuss the failure of the zeroth- and first-order Markovian models or simple nucleotide repeats to account fully for these "linguistic" features of DNA. Finally, we emphasize that our results by no means prove the existence of a "language" in noncoding DNA.

Analysis of statistical and standard algorithms for detecting muscle onset with surface electromyography.

PubMed

Tenan, Matthew S; Tweedell, Andrew J; Haynes, Courtney A

2017-01-01

The timing of muscle activity is a commonly applied analytic method to understand how the nervous system controls movement. This study systematically evaluates six classes of standard and statistical algorithms to determine muscle onset in both experimental surface electromyography (EMG) and simulated EMG with a known onset time. Eighteen participants had EMG collected from the biceps brachii and vastus lateralis while performing a biceps curl or knee extension, respectively. Three established methods and three statistical methods for EMG onset were evaluated. Linear envelope, Teager-Kaiser energy operator + linear envelope and sample entropy were the established methods evaluated while general time series mean/variance, sequential and batch processing of parametric and nonparametric tools, and Bayesian changepoint analysis were the statistical techniques used. Visual EMG onset (experimental data) and objective EMG onset (simulated data) were compared with algorithmic EMG onset via root mean square error and linear regression models for stepwise elimination of inferior algorithms. The top algorithms for both data types were analyzed for their mean agreement with the gold standard onset and evaluation of 95% confidence intervals. The top algorithms were all Bayesian changepoint analysis iterations where the parameter of the prior (p0) was zero. The best performing Bayesian algorithms were p0 = 0 and a posterior probability for onset determination at 60-90%. While existing algorithms performed reasonably, the Bayesian changepoint analysis methodology provides greater reliability and accuracy when determining the singular onset of EMG activity in a time series. Further research is needed to determine if this class of algorithms perform equally well when the time series has multiple bursts of muscle activity.

Gene flow analysis method, the D-statistic, is robust in a wide parameter space.

PubMed

Zheng, Yichen; Janke, Axel

2018-01-08

We evaluated the sensitivity of the D-statistic, a parsimony-like method widely used to detect gene flow between closely related species. This method has been applied to a variety of taxa with a wide range of divergence times. However, its parameter space and thus its applicability to a wide taxonomic range has not been systematically studied. Divergence time, population size, time of gene flow, distance of outgroup and number of loci were examined in a sensitivity analysis. The sensitivity study shows that the primary determinant of the D-statistic is the relative population size, i.e. the population size scaled by the number of generations since divergence. This is consistent with the fact that the main confounding factor in gene flow detection is incomplete lineage sorting by diluting the signal. The sensitivity of the D-statistic is also affected by the direction of gene flow, size and number of loci. In addition, we examined the ability of the f-statistics, [Formula: see text] and [Formula: see text], to estimate the fraction of a genome affected by gene flow; while these statistics are difficult to implement to practical questions in biology due to lack of knowledge of when the gene flow happened, they can be used to compare datasets with identical or similar demographic background. The D-statistic, as a method to detect gene flow, is robust against a wide range of genetic distances (divergence times) but it is sensitive to population size. The D-statistic should only be applied with critical reservation to taxa where population sizes are large relative to branch lengths in generations.

Extraction of the proton radius from electron-proton scattering data

DOE PAGES

Lee, Gabriel; Arrington, John R.; Hill, Richard J.

2015-07-27

We perform a new analysis of electron-proton scattering data to determine the proton electric and magnetic radii, enforcing model-independent constraints from form factor analyticity. A wide-ranging study of possible systematic effects is performed. An improved analysis is developed that rebins data taken at identical kinematic settings and avoids a scaling assumption of systematic errors with statistical errors. Employing standard models for radiative corrections, our improved analysis of the 2010 Mainz A1 Collaboration data yields a proton electric radius r E = 0.895(20) fm and magnetic radius r M = 0.776(38) fm. A similar analysis applied to world data (excluding Mainzmore » data) implies r E = 0.916(24) fm and r M = 0.914(35) fm. The Mainz and world values of the charge radius are consistent, and a simple combination yields a value r E = 0.904(15) fm that is 4σ larger than the CREMA Collaboration muonic hydrogen determination. The Mainz and world values of the magnetic radius differ by 2.7σ, and a simple average yields r M = 0.851(26) fm. As a result, the circumstances under which published muonic hydrogen and electron scattering data could be reconciled are discussed, including a possible deficiency in the standard radiative correction model which requires further analysis.« less

Systematic Review and Meta-Analysis of a Proprietary Alpha-Amylase Inhibitor from White Bean (Phaseolus vulgaris L.) on Weight and Fat Loss in Humans

PubMed Central

Udani, Jay; Tan, Ollie; Molina, Jhanna

2018-01-01

The aim of this meta-analysis was to examine the evidence for the effectiveness of a proprietary alpha-amylase inhibitor from white bean (Phaseolus vulgaris L.) supplementation interventions in humans on modification of body weight and fat mass. A systematic literature search was performed using three databases: PubMed, the Cochrane collaboration, and Google Scholar. In addition, the manufacturer was contacted for internal unpublished data, and finally, the reference section of relevant original research and review papers were mined for additional studies. Eleven studies were selected for the meta-analysis of weight loss (a total of 573 subjects), and three studies for the meta-analysis of body fat reduction (a total of 110 subjects), as they fulfilled the inclusion criteria. Phaseolus vulgaris supplementation showed an average effect on weight loss difference of −1.08 kg (95% CI (confidence interval), −0.42 kg to −1.16 kg, p < 0.00001), and the average effect on body fat reduction was 3.26 kg (95% CI, −2.35 kg to −4.163 kg, p = 0.02). This meta-analysis found statistically significant effects of Phaseolus vulgaris supplementation on body weight and body fat. PMID:29677119

Systematic Review and Meta-Analysis of a Proprietary Alpha-Amylase Inhibitor from White Bean (Phaseolus vulgaris L.) on Weight and Fat Loss in Humans.

PubMed

Udani, Jay; Tan, Ollie; Molina, Jhanna

2018-04-20

The aim of this meta-analysis was to examine the evidence for the effectiveness of a proprietary alpha-amylase inhibitor from white bean ( Phaseolus vulgaris L.) supplementation interventions in humans on modification of body weight and fat mass. A systematic literature search was performed using three databases: PubMed, the Cochrane collaboration, and Google Scholar. In addition, the manufacturer was contacted for internal unpublished data, and finally, the reference section of relevant original research and review papers were mined for additional studies. Eleven studies were selected for the meta-analysis of weight loss (a total of 573 subjects), and three studies for the meta-analysis of body fat reduction (a total of 110 subjects), as they fulfilled the inclusion criteria. Phaseolus vulgaris supplementation showed an average effect on weight loss difference of −1.08 kg (95% CI (confidence interval), −0.42 kg to −1.16 kg, p < 0.00001), and the average effect on body fat reduction was 3.26 kg (95% CI, −2.35 kg to −4.163 kg, p = 0.02). This meta-analysis found statistically significant effects of Phaseolus vulgaris supplementation on body weight and body fat.

The effectiveness of external sensory cues in improving functional performance in individuals with Parkinson's disease: a systematic review with meta-analysis.

PubMed

Cassimatis, Constantine; Liu, Karen P Y; Fahey, Paul; Bissett, Michelle

2016-09-01

A systematic review with meta-analysis was performed to investigate the effect external sensory cued therapy on activities of daily living (ADL) performance that include walking and daily tasks such as dressing for individuals with Parkinson's disease (PD). A detailed computer-aided search of the literature was applied to MEDLINE, Cumulative Index to Nursing and Allied Health Literature, EMBASE and PubMed. Studies investigating the effects of external sensory cued therapy on ADL performance for individuals with PD in all stages of disease progression were collected. Relevant articles were critically reviewed and study results were synthesized by two independent researchers. A data-analysis method was used to extract data from selected articles. A meta-analysis was carried out for all randomized-controlled trials. Six studies with 243 individuals with PD were included in this review. All six studies yielded positive findings in favour of external sensory cues. The meta-analysis showed that external sensory cued therapy improved statistically after treatment (P=0.011) and at follow-up (P<0.001) for ADL performance. The results of this review provided evidence of an improvement in ADL performance in general in individuals with PD. It is recommended that clinicians incorporate external sensory into a training programme focused on improving daily task performance.

An Overview of Interrater Agreement on Likert Scales for Researchers and Practitioners

PubMed Central

O'Neill, Thomas A.

2017-01-01

Applications of interrater agreement (IRA) statistics for Likert scales are plentiful in research and practice. IRA may be implicated in job analysis, performance appraisal, panel interviews, and any other approach to gathering systematic observations. Any rating system involving subject-matter experts can also benefit from IRA as a measure of consensus. Further, IRA is fundamental to aggregation in multilevel research, which is becoming increasingly common in order to address nesting. Although, several technical descriptions of a few specific IRA statistics exist, this paper aims to provide a tractable orientation to common IRA indices to support application. The introductory overview is written with the intent of facilitating contrasts among IRA statistics by critically reviewing equations, interpretations, strengths, and weaknesses. Statistics considered include rwg, rwg*, r′wg, rwg(p), average deviation (AD), awg, standard deviation (Swg), and the coefficient of variation (CVwg). Equations support quick calculation and contrasting of different agreement indices. The article also includes a “quick reference” table and three figures in order to help readers identify how IRA statistics differ and how interpretations of IRA will depend strongly on the statistic employed. A brief consideration of recommended practices involving statistical and practical cutoff standards is presented, and conclusions are offered in light of the current literature. PMID:28553257

Inference on network statistics by restricting to the network space: applications to sexual history data.

PubMed

Goyal, Ravi; De Gruttola, Victor

2018-01-30

Analysis of sexual history data intended to describe sexual networks presents many challenges arising from the fact that most surveys collect information on only a very small fraction of the population of interest. In addition, partners are rarely identified and responses are subject to reporting biases. Typically, each network statistic of interest, such as mean number of sexual partners for men or women, is estimated independently of other network statistics. There is, however, a complex relationship among networks statistics; and knowledge of these relationships can aid in addressing concerns mentioned earlier. We develop a novel method that constrains a posterior predictive distribution of a collection of network statistics in order to leverage the relationships among network statistics in making inference about network properties of interest. The method ensures that inference on network properties is compatible with an actual network. Through extensive simulation studies, we also demonstrate that use of this method can improve estimates in settings where there is uncertainty that arises both from sampling and from systematic reporting bias compared with currently available approaches to estimation. To illustrate the method, we apply it to estimate network statistics using data from the Chicago Health and Social Life Survey. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Independent Component Analysis applied to Ground-based observations

NASA Astrophysics Data System (ADS)

Martins-Filho, Walter; Griffith, Caitlin; Pearson, Kyle; Waldmann, Ingo; Alvarez-Candal, Alvaro; Zellem, Robert Thomas

2018-01-01

Transit measurements of Jovian-sized exoplanetary atmospheres allow one to study the composition of exoplanets, largely independent of the planet’s temperature profile. However, measurements of hot-Jupiter transits must archive a level of accuracy in the flux to determine the spectral modulation of the exoplanetary atmosphere. To accomplish this level of precision, we need to extract systematic errors, and, for ground-based measurements, the effects of Earth’s atmosphere, from signal due to the exoplanet, which is several orders of magnitude smaller. The effects of the terrestrial atmosphere and some of the time-dependent systematic errors of ground-based transit measurements are treated mainly by dividing the host star by a reference star at each wavelength and time step of the transit. Recently, Independent Component Analysis (ICA) have been used to remove systematics effects from the raw data of space-based observations (Waldmann, 2014, 2012; Morello et al., 2016, 2015). ICA is a statistical method born from the ideas of the blind-source separations studies, which can be used to de-trend several independent source signals of a data set (Hyvarinen and Oja, 2000). This technique requires no additional prior knowledge of the data set. In addition, this technique has the advantage of requiring no reference star. Here we apply the ICA to ground-based photometry of the exoplanet XO-2b recorded by the 61” Kuiper Telescope and compare the results of the ICA to those of a previous analysis from Zellem et al. (2015), which does not use ICA. We also simulate the effects of various conditions (concerning the systematic errors, noise and the stability of object on the detector) to determine the conditions under which an ICA can be used with high precision to extract the light curve of exoplanetary photometry measurements

Role of the ultrasonographic 'whirlpool sign' in intestinal volvulus: a systematic review and meta-analysis.

PubMed

Enyuma, Callistus O A; Adam, Ahmed; Aigbodion, Sunday J; McDowall, Jared; Gerber, Louis; Buchanan, Sean; Laher, Abdullah E

2018-05-08

Intestinal volvulus is a potentially life-threatening condition that occurs when loops of bowel twist around its supporting mesentery and associated vasculature. Clinicians often rely on various radiological investigations for prompt diagnosis to avoid complications such as bowel infarction. This review assesses the clinical reliability of the ultrasonographic whirlpool sign (WS) in the diagnosis of intestinal volvulus. In adherence with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) statement, a systematic search of BMJ Best Practice, Cochrane Database of Systematic Reviews, EMBASE, Google Scholar, PubMed, Scopus and Web of Science databases was performed (August 2017), using relevant search terms. Selected studies were ranked for quality and relevance using the CASP (Critical Appraisal Skills Program) tool. Sixteen articles (1640 participants) were assessed. The mean and median sample size was 102.5 (SD ± 192.23) and 28 (range 7-770), respectively. The WS was positive in 212 of 255 (83.1%) patients with intestinal volvulus. Meta-analysis of the studies that provided sufficient data resulted in a pooled sensitivity and specificity of 87.42% (95% confidence interval (CI): 81.05-92.25) and 98.63% (95% CI: 97.88-99.18), respectively, with an estimated summary effect of 5.28 (95% CI: 4.47-6.08, P < 0.001). There was negligible inter-study heterogeneity, which was suggested by an I 2 statistic of 0% (95% CI: 0.00-76.34) and a τ 2 parameter of 0 (95% CI: 0.00-5.35). Though the pooled sensitivity was less than ideal (87.42%), this review and meta-analysis nevertheless supports the reliability of the ultrasonographic WS as an acceptable indicator of intestinal volvulus. © 2018 Royal Australasian College of Surgeons.

Systematic review and meta-analysis of metal versus plastic stents for preoperative biliary drainage in resectable periampullary or pancreatic head tumors.

PubMed

Crippa, S; Cirocchi, R; Partelli, S; Petrone, M C; Muffatti, F; Renzi, C; Falconi, M; Arcidiacono, P G

2016-09-01

Preoperative biliary drainage (PBD) with stenting increases complications compared with surgery without PBD. Metallic stents are considered superior to plastic stents when considering stent-related complications. Aim of the present systematic review and meta-analysis is to compare the rate of endoscopic re-intervention before surgery and postoperative outcomes of metal versus plastic stents in patients with resectable periampullary or pancreatic head neoplasms. We conducted a bibliographic research using the National Library of Medicine's PubMed database, including both randomized controlled trials (RCTs) and non-RCTs. Quantitative synthesis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Statistical heterogeneity was assessed using the I(2) tests. One RCT and four non-RCTs were selected, including 704 patients. Of these, 202 patients (29.5%) were treated with metal stents and 502 (70.5%) with plastic stents. The majority of patients (86.4%) had pancreatic cancer. The rate of endoscopic re-intervention after preoperative biliary drainage was significantly lower in the metal stent (3.4%) than in the plastic stent (14.8%) group (p < 0.0001). The rate of postoperative pancreatic fistula was significantly lower in the meta stent group as well (5.1% versus 11.8%, p = 0.04). The rate of post-operative surgical complications and of - post-operative mortality did not differ between the two groups. Although the present systematic review and meta-analysis demonstrates that metal stent are more effective than plastic stents for PBD in patients with resectable periampullary tumors, randomized controlled trials are needed in order to confirm these data with a higher level of evidence. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hypertrophic Effects of Concentric vs. Eccentric Muscle Actions: A Systematic Review and Meta-analysis.

PubMed

Schoenfeld, Brad J; Ogborn, Dan I; Vigotsky, Andrew D; Franchi, Martino V; Krieger, James W

2017-09-01

Schoenfeld, BJ, Ogborn, DI, Vigotsky, AD, Franchi, MV, and Krieger, JW. Hypertrophic effects of concentric vs. eccentric muscle actions: A systematic review and meta-analysis. J Strength Cond Res 31(9): 2599-2608, 2017-Controversy exists as to whether different dynamic muscle actions produce divergent hypertrophic responses. The purpose of this paper was to conduct a systematic review and meta-analysis of randomized controlled trials comparing the hypertrophic effects of concentric vs. eccentric training in healthy adults after regimented resistance training (RT). Studies were deemed eligible for inclusion if they met the following criteria: (a) were an experimental trial published in an English-language refereed journal; (b) directly compared concentric and eccentric actions without the use of external implements (i.e., blood pressure cuffs) and all other RT variables equivalent; (c) measured morphologic changes using biopsy, imaging (magnetic resonance imaging, computerized tomography, or ultrasound), bioelectrical impedance, and/or densitometry; (d) had a minimum duration of 6 weeks; and (e) used human participants without musculoskeletal injury or any health condition that could directly, or through the medications associated with the management of said condition, be expected to impact the hypertrophic response to resistance exercise. A systematic literature search determined that 15 studies met inclusion criteria. Results showed that eccentric muscle actions resulted in a greater effect size (ES) compared with concentric actions, but results did not reach statistical significance (ES difference = 0.25 ± 0.13; 95% confidence interval: -0.03 to 0.52; p = 0.076). The mean percent change in muscle growth across studies favored eccentric compared with concentric actions (10.0% vs. 6.8, respectively). The findings indicate the importance of including eccentric and concentric actions in a hypertrophy-oriented RT program, as both have shown to be effective in increasing muscle hypertrophy.

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

Associations between socioeconomic factors and proinflammatory cytokines in children, adolescents and young adults: a systematic review protocol

PubMed Central

Fredman, Nick John; Duque, Gustavo; Duckham, Rachel Louise; Green, Darci

2018-01-01

Introduction There is now substantial evidence of a social gradient in bone health. Social stressors, related to socioeconomic status, are suggested to produce an inflammatory response marked by increased levels of proinflammatory cytokines. Here we focus on the particular role in the years before the achievement of peak bone mass, encompassing childhood, adolescence and young adulthood. An examination of such associations will help explain how social factors such as occupation, level of education and income may affect later-life bone disorders. This paper presents the protocol for a systematic review of existing literature regarding associations between socioeconomic factors and proinflammatory cytokines in those aged 6–30 years. Methods and analysis We will conduct a systematic search of PubMed, OVID and CINAHL databases to identify articles that examine associations between socioeconomic factors and levels of proinflammatory cytokines, known to influence bone health, during childhood, adolescence or young adulthood. The findings of this review have implications for the equitable development of peak bone mass regardless of socioeconomic factors. Two independent reviewers will determine the eligibility of studies according to predetermined criteria, and studies will be assessed for methodological quality using a published scoring system. Should statistical heterogeneity be non-significant, we will conduct a meta-analysis; however, if heterogeneity prevent numerical syntheses, we will undertake a best-evidence analysis to determine whether socioeconomic differences exist in the levels of proinflammatory cytokines from childhood through to young adulthood. Ethics and dissemination This study will be a systematic review of published data, and thus ethics approval is not required. In addition to peer-reviewed publication, these findings will be presented at professional conferences in national and international arenas. PMID:29490962

Using Real-Life Data When Teaching Statistics: Student Perceptions of this Strategy in an Introductory Statistics Course

ERIC Educational Resources Information Center

Neumann, David L.; Hood, Michelle; Neumann, Michelle M.

2013-01-01

Many teachers of statistics recommend using real-life data during class lessons. However, there has been little systematic study of what effect this teaching method has on student engagement and learning. The present study examined this question in a first-year university statistics course. Students (n = 38) were interviewed and their reflections…

Assessing the statistical significance of the achieved classification error of classifiers constructed using serum peptide profiles, and a prescription for random sampling repeated studies for massive high-throughput genomic and proteomic studies.

PubMed

Lyons-Weiler, James; Pelikan, Richard; Zeh, Herbert J; Whitcomb, David C; Malehorn, David E; Bigbee, William L; Hauskrecht, Milos

2005-01-01

Peptide profiles generated using SELDI/MALDI time of flight mass spectrometry provide a promising source of patient-specific information with high potential impact on the early detection and classification of cancer and other diseases. The new profiling technology comes, however, with numerous challenges and concerns. Particularly important are concerns of reproducibility of classification results and their significance. In this work we describe a computational validation framework, called PACE (Permutation-Achieved Classification Error), that lets us assess, for a given classification model, the significance of the Achieved Classification Error (ACE) on the profile data. The framework compares the performance statistic of the classifier on true data samples and checks if these are consistent with the behavior of the classifier on the same data with randomly reassigned class labels. A statistically significant ACE increases our belief that a discriminative signal was found in the data. The advantage of PACE analysis is that it can be easily combined with any classification model and is relatively easy to interpret. PACE analysis does not protect researchers against confounding in the experimental design, or other sources of systematic or random error. We use PACE analysis to assess significance of classification results we have achieved on a number of published data sets. The results show that many of these datasets indeed possess a signal that leads to a statistically significant ACE.

Inadvertent P-hacking among trials and systematic reviews of the effect of progestogens in pregnancy? A systematic review and meta-analysis.

PubMed

Prior, M; Hibberd, R; Asemota, N; Thornton, J G

2017-06-01

Progestogens have been evaluated in numerous trials and meta-analyses, many of which concluded they were effective. However, two large trials PROMISE and OPPTIMUM have recently concluded that progesterone was ineffective. This raises the possibility that earlier studies and reviews had been biased by either selective publication or selective choice of outcomes, so called "P-hacking". To compare the findings all progestogen trials and systematic reviews with those of trials with pre-registered primary outcomes which avoided selective outcome reporting. Search of PubMed, the Cochrane Library and trial registries. Registration PROSPERO CRD42016035303. Systematic reviews of randomised trials comparing progestogen with placebo in pregnancy and the individual trials included in those reviews. The subset of trials reporting a pre-registered primary outcome were compared with the totality of trials and reviews. For reviews all outcomes were included. For individual trials all outcomes reported in the systematic reviews were included. For the comparison group we recorded the registered primary outcome from trials that were either registered before they started, or registered during the recruitment phase and also double blind. Nineteen of twenty-nine meta-analyses concluded that progestogens were effective. Twenty-two trials reported their pre-registered primary outcomes. There was no effect of progesterone on primary registered dichotomous outcome RR 1.00 (95% CI 0.94-1.07). Only one of the 22 showed a nominally statistically significant benefit. When evaluated in registered double-blind trials with analysis restricted to predefined primary outcomes, progestational agents in pregnancy are ineffective. Progestogens to prevent pregnancy loss, an example of P-hacking. © 2017 Royal College of Obstetricians and Gynaecologists.

Fitting and Phenomenology in Type IA Supernova Cosmology: Generalized Likelihood Analyses for Multiple Evolving Populations and Observations of Near-Infrared Lightcurves Including Host Galaxy Properties

NASA Astrophysics Data System (ADS)

Ponder, Kara A.

In the late 1990s, Type Ia supernovae (SNeIa) led to the discovery that the Universe is expanding at an accelerating rate due to dark energy. Since then, many different tracers of acceleration have been used to characterize dark energy, but the source of cosmic acceleration has remained a mystery. To better understand dark energy, future surveys such as the ground-based Large Synoptic Survey Telescope and the space-based Wide-Field Infrared Survey Telescope will collect thousands of SNeIa to use as a primary dark energy probe. These large surveys will be systematics limited, which makes it imperative for our insight regarding systematics to dramatically increase over the next decade for SNeIa to continue to contribute to precision cosmology. I approach this problem by improving statistical methods in the likelihood analysis and collecting near infrared (NIR) SNeIa with their host galaxies to improve the nearby data set and search for additional systematics. Using more statistically robust methods to account for systematics within the likelihood function can increase accuracy in cosmological parameters with a minimal precision loss. Though a sample of at least 10,000 SNeIa is necessary to confirm multiple populations of SNeIa, the bias in cosmology is ˜ 2 sigma with only 2,500 SNeIa. This work focused on an example systematic (host galaxy correlations), but it can be generalized for any systematic that can be represented by a distribution of multiple Gaussians. The SweetSpot survey gathered 114 low-redshift, NIR SNeIa that will act as a crucial anchor sample for the future high redshift surveys. NIR observations are not as affected by dust contamination, which may lead to increased understanding of systematics seen in optical wavelengths. We obtained spatially resolved spectra for 32 SweetSpot host galaxies to test for local host galaxy correlations. For the first time, we probe global host galaxy correlations with NIR brightnesses from the current literature sample of SNeIa with host galaxy data from publicly available catalogs. We find inconclusive evidence that more massive galaxies host SNeIa that are brighter in the NIR than SNeIa hosted in less massive galaxies.

The application of knowledge synthesis methods in agri-food public health: recent advancements, challenges and opportunities.

PubMed

Young, Ian; Waddell, Lisa; Sanchez, Javier; Wilhelm, Barbara; McEwen, Scott A; Rajić, Andrijana

2014-03-01

Knowledge synthesis refers to the integration of findings from individual research studies on a given topic or question into the global knowledge base. The application of knowledge synthesis methods, particularly systematic reviews and meta-analysis, has increased considerably in the agri-food public health sector over the past decade and this trend is expected to continue. The objectives of our review were: (1) to describe the most promising knowledge synthesis methods and their applicability in agri-food public health, and (2) to summarize the recent advancements, challenges, and opportunities in the use of systematic review and meta-analysis methods in this sector. We performed a structured review of knowledge synthesis literature from various disciplines to address the first objective, and used comprehensive insights and experiences in applying these methods in the agri-food public health sector to inform the second objective. We describe five knowledge synthesis methods that can be used to address various agri-food public health questions or topics under different conditions and contexts. Scoping reviews describe the main characteristics and knowledge gaps in a broad research field and can be used to evaluate opportunities for prioritizing focused questions for related systematic reviews. Structured rapid reviews are streamlined systematic reviews conducted within a short timeframe to inform urgent decision-making. Mixed-method and qualitative reviews synthesize diverse sources of contextual knowledge (e.g. socio-cognitive, economic, and feasibility considerations). Systematic reviews are a structured and transparent method used to summarize and synthesize literature on a clearly-defined question, and meta-analysis is the statistical combination of data from multiple individual studies. We briefly describe and discuss key advancements in the use of systematic reviews and meta-analysis, including: risk-of-bias assessments; an overall quality-of-evidence approach; engagement of stakeholders; Bayesian, multivariate, and network meta-analysis; and synthesis of diagnostic test accuracy studies. We also highlight several challenges and opportunities in the conduct of systematic reviews (e.g. inclusion of grey literature, minimizing language bias, and optimizing search strategies) and meta-analysis (e.g. inclusion of observational studies and approaches to address the insufficient reporting of data and significant heterogeneity). Many of these developments have yet to be comprehensively applied and evaluated in an agri-food public health context, and more research is needed in this area. There is a need to strengthen knowledge synthesis capacity and infrastructure at the regional, national, and international levels in this sector to ensure that the best available knowledge is used to inform future decision-making about agri-food public health issues. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Deformation-induced spatiotemporal fluctuation, evolution and localization of strain fields in a bulk metallic glass

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

Wu, Yuan; Bei, Hongbin; Wang, Yanli

Deformation behavior and local strain evolutions upon loading and unloading of a bulk metallic glass (BMG) were systematically investigated by in situ digital image correlation (DIC). Distinct fluctuations and irreversible local strains were observed before the onset of macroscopic yielding. Statistical analysis shows that these fluctuations might be related to intrinsic structural heterogeneities, and that the evolution history and characteristics of local strain fields play an important role in the subsequent initiation of shear bands. Effects of sample size, pre-strain, and loading conditions were systematically analyzed in terms of the probability distributions of the resulting local strain fields. It ismore » found that a higher degree of local shear strain heterogeneity corresponds to a more ductile stressestrain curve. Implications of these findings are discussed for the design of new materials.« less

Running coupling constant from lattice studies of gluon and ghost propagators

NASA Astrophysics Data System (ADS)

Cucchieri, A.; Mendes, T.

2004-12-01

We present a numerical study of the running coupling constant in four-dimensional pure-SU(2) lattice gauge theory. The running coupling is evaluated by fitting data for the gluon and ghost propagators in minimal Landau gauge. Following Refs. [1, 2], the fitting formulae are obtained by a simultaneous integration of the β function and of a function coinciding with the anomalous dimension of the propagator in the momentum subtraction scheme. We consider these formulae at three and four loops. The fitting method works well, especially for the ghost case, for which statistical error and hyper-cubic effects are very small. Our present result for ΛMS is 200-40+60 MeV, where the error is purely systematic. We are currently extending this analysis to five loops in order to reduce this systematic error.

Systematic search for major genes in schizophrenia: Methodological issues and results from chromosome 12

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

Dawson, E.; Powell, J.F.; Sham, P.

1995-10-09

We describe a method of systematically searching for major genes in disorders of unknown mode of inheritance, using linkage analysis. Our method is designed to minimize the probability of missing linkage due to inadequate exploration of data. We illustrate this method with the results of a search for a locus for schizophrenia on chromosome 12 using 22 highly polymorphic markers in 23 high density pedigrees. The markers span approximately 85-90% of the chromosome and are on average 9.35 cM apart. We have analysed the data using the most plausible current genetic models and allowing for the presence of genetic heterogeneity.more » None of the markers was supportive of linkage and the distribution of the heterogeneity statistics was in accordance with the null hypothesis. 53 refs., 2 figs., 4 tabs.« less

Deformation-induced spatiotemporal fluctuation, evolution and localization of strain fields in a bulk metallic glass

DOE PAGES

Wu, Yuan; Bei, Hongbin; Wang, Yanli; ...

2015-05-16

Deformation behavior and local strain evolutions upon loading and unloading of a bulk metallic glass (BMG) were systematically investigated by in situ digital image correlation (DIC). Distinct fluctuations and irreversible local strains were observed before the onset of macroscopic yielding. Statistical analysis shows that these fluctuations might be related to intrinsic structural heterogeneities, and that the evolution history and characteristics of local strain fields play an important role in the subsequent initiation of shear bands. Effects of sample size, pre-strain, and loading conditions were systematically analyzed in terms of the probability distributions of the resulting local strain fields. It ismore » found that a higher degree of local shear strain heterogeneity corresponds to a more ductile stressestrain curve. Implications of these findings are discussed for the design of new materials.« less

The use of GRADE approach in systematic reviews of animal studies.

PubMed

Wei, Dang; Tang, Kun; Wang, Qi; Estill, Janne; Yao, Liang; Wang, Xiaoqin; Chen, Yaolong; Yang, Kehu

2016-03-15

The application of GRADE (Grading of Recommendations Assessment, Development and Evaluation) in SR of animal studies can promote the translation from bench to bedside. We aim to explore the use of GRADE in systematic reviews of animal studies. We used a theoretical analysis method to explore the use of GRADE in SR of animal studies and applied in a SR of animal studies. Meanwhile, we presented and discussed our results in two international conferences. Five downgrade factors were considered as follows in systematic reviews of animal studies: 1) Risk of bias: the SYRCLE tool can be used for assessing the risk of bias of animal studies. 2) Indirectness: we can assess indirectness in systematic reviews of animal studies from the PICO. 3) Inconsistency: similarity of point estimates, extent of overlap of confidence intervals and statistical heterogeneity are also suitable to evaluate inconsistency of evidence from animal studies. 4) Imprecision: optimal information size (OIS) and 95% confidence intervals (CIs) are also suitable for systematic reviews of animal studies, like those of clinical trials. 5) Publication bias: we need to consider publication bias comprehensively through the qualitative and quantitative methods. The methods about the use of GRADE in systematic review of animal studies are explicit. However, the principle about GRADE in developing the policy based on the evidence from animal studies when there is an emergency of public health. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Effectiveness of acupuncture for cancer pain: protocol for an umbrella review and meta-analyses of controlled trials

PubMed Central

He, Yihan; Liu, Yihong; May, Brian H; Zhang, Anthony Lin; Zhang, Haibo; Lu, ChuanJian; Yang, Lihong; Guo, Xinfeng; Xue, Charlie Changli

2017-01-01

Introduction The National Comprehensive Cancer Network guidelines for adult cancer pain indicate that acupuncture and related therapies may be valuable additions to pharmacological interventions for pain management. Of the systematic reviews related to this topic, some concluded that acupuncture was promising for alleviating cancer pain, while others argued that the evidence was insufficient to support its effectiveness. Methods and analysis This review will consist of three components: (1) synthesis of findings from existing systematic reviews; (2) updated meta-analyses of randomised clinical trials and (3) analyses of results of other types of clinical studies. We will search six English and four Chinese biomedical databases, dissertations and grey literature to identify systematic reviews and primary clinical studies. Two reviewers will screen results of the literature searches independently to identify included reviews and studies. Data from included articles will be abstracted for assessment, analysis and summary. Two assessors will appraise the quality of systematic reviews using Assessment of Multiple Systematic Reviews; assess the randomised controlled trials using the Cochrane Collaboration’s risk of bias tool and other types of studies according to the Newcastle-Ottawa Scale. We will use ‘summary of evidence’ tables to present evidence from existing systematic reviews and meta-analyses. Using the primary clinical studies, we will conduct meta-analysis for each outcome, by grouping studies based on the type of acupuncture, the comparator and the specific type of pain. Sensitivity analyses are planned according to clinical factors, acupuncture method, methodological characteristics and presence of statistical heterogeneity as applicable. For the non-randomised studies, we will tabulate the characteristics, outcome measures and the reported results of each study. Consistencies and inconsistencies in evidence will be investigated and discussed. Finally, we will use the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the quality of the overall evidence. Ethics and dissemination There are no ethical considerations associated with this review. The findings will be disseminated in peer-reviewed journals or conference presentations. PROSPERO registration number CRD42017064113. PMID:29229658

Clinical and economic impact of antibiotic resistance in developing countries: A systematic review and meta-analysis.

PubMed

Founou, Raspail Carrel; Founou, Luria Leslie; Essack, Sabiha Yusuf

2017-01-01

Despite evidence of the high prevalence of antibiotic resistant infections in developing countries, studies on the clinical and economic impact of antibiotic resistance (ABR) to inform interventions to contain its emergence and spread are limited. The aim of this study was to analyze the published literature on the clinical and economic implications of ABR in developing countries. A systematic search was carried out in Medline via PubMed and Web of Sciences and included studies published from January 01, 2000 to December 09, 2016. All papers were considered and a quality assessment was performed using the Newcastle-Ottawa quality assessment scale (NOS). Of 27 033 papers identified, 40 studies met the strict inclusion and exclusion criteria and were finally included in the qualitative and quantitative analysis. Mortality was associated with resistant bacteria, and statistical significance was evident with an odds ratio (OR) 2.828 (95%CI, 2.231-3.584; p = 0.000). ESKAPE pathogens was associated with the highest risk of mortality and with high statistical significance (OR 3.217; 95%CIs; 2.395-4.321; p = 0.001). Eight studies showed that ABR, and especially antibiotic-resistant ESKAPE bacteria significantly increased health care costs. ABR is associated with a high mortality risk and increased economic costs with ESKAPE pathogens implicated as the main cause of increased mortality. Patients with non-communicable disease co-morbidities were identified as high-risk populations.

Clinical and economic impact of antibiotic resistance in developing countries: A systematic review and meta-analysis

PubMed Central

Founou, Luria Leslie; Essack, Sabiha Yusuf

2017-01-01

Introduction Despite evidence of the high prevalence of antibiotic resistant infections in developing countries, studies on the clinical and economic impact of antibiotic resistance (ABR) to inform interventions to contain its emergence and spread are limited. The aim of this study was to analyze the published literature on the clinical and economic implications of ABR in developing countries. Methods A systematic search was carried out in Medline via PubMed and Web of Sciences and included studies published from January 01, 2000 to December 09, 2016. All papers were considered and a quality assessment was performed using the Newcastle-Ottawa quality assessment scale (NOS). Results Of 27 033 papers identified, 40 studies met the strict inclusion and exclusion criteria and were finally included in the qualitative and quantitative analysis. Mortality was associated with resistant bacteria, and statistical significance was evident with an odds ratio (OR) 2.828 (95%CI, 2.231–3.584; p = 0.000). ESKAPE pathogens was associated with the highest risk of mortality and with high statistical significance (OR 3.217; 95%CIs; 2.395–4.321; p = 0.001). Eight studies showed that ABR, and especially antibiotic-resistant ESKAPE bacteria significantly increased health care costs. Conclusion ABR is associated with a high mortality risk and increased economic costs with ESKAPE pathogens implicated as the main cause of increased mortality. Patients with non-communicable disease co-morbidities were identified as high-risk populations. PMID:29267306

A systematic review of complication and recurrence rates of musculocutaneous, fasciocutaneous, and perforator-based flaps for treatment of pressure sores.

PubMed

Sameem, Mojib; Au, Michael; Wood, Thomas; Farrokhyar, Forough; Mahoney, James

2012-07-01

Management of pressure sores poses a significant reconstructive challenge for plastic surgeons. Currently, there is no consensus on whether musculocutaneous, fasciocutaneous, or perforator-based flaps provide superior results for treating pressure sores. The following databases were searched: Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, LILACS (January of 1950 to November of 2010), MEDLINE (January of 1950 to November of 2010), and EMBASE (January of 1980 to November of 2010). Only articles reporting on the use of musculocutaneous, fasciocutaneous, and perforator-based flaps were included. The primary study outcomes were complication and recurrence rates. Fifty-five articles were included in the final analysis (kappa = 0.78). From this total, 28 were categorized as pertaining to musculocutaneous flaps, 13 studied fasciocutaneous flaps, and 14 evaluated perforator-based flaps. The authors' review revealed recurrence and complication rates of 8.9 and 18.6 percent, respectively, following reconstruction with musculocutaneous flaps, 11.2 and 11.7 percent following reconstruction with fasciocutaneous flaps, and 5.6 and 19.6 percent following reconstruction with perforator-based flaps. Overall, statistical analysis revealed no significant difference in complication or recurrence rates among these three techniques. The authors' review revealed that there was no statistically significant difference with regard to recurrence or complication rates among musculocutaneous, fasciocutaneous, or perforator-based flaps. This suggests that surgeons performing such reconstructive procedures may choose to consider the advantages of a specific approach rather than the complication and recurrence rates. Therapeutic, IV.

The analgesic effect of wound infiltration with local anaesthetics after breast surgery: a qualitative systematic review.

PubMed

Byager, N; Hansen, M S; Mathiesen, O; Dahl, J B

2014-04-01

Wound infiltration with local anaesthetics is commonly used during breast surgery in an attempt to reduce post-operative pain and opioid consumption. The aim of this review was to evaluate the effect of wound infiltration with local anaesthetics compared with a control group on post-operative pain after breast surgery. A systematic review was performed by searching PubMed, Google Scholar, the Cochrane database and Embase for randomised, blinded, controlled trials of wound infiltration with local anaesthetics for post-operative pain relief in female adults undergoing breast surgery. The analgesic effect was evaluated in a qualitative analysis by assessment of significant difference between groups (P < 0.05) in pain scores and supplemental analgesic consumption. Ten trials including 699 patients were included in the final analysis. Three trials investigated mastectomy, four trials partial or segmental mastectomy, and three trials breast reduction, excision of benign lump and unspecified breast surgery, respectively. Six trials demonstrated a small and short-lasting, but statistically significant reduction of post-operative pain scores, and four trials observed a statistically significant reduction in post-operative, supplemental opioid consumption that was, however, of limited clinical relevance. Wound infiltration with local anaesthetics may have a modest analgesic effect in the first few hours after surgery. Pain after breast surgery is, however, generally mild to moderate, and other non-invasive analgesic methods may be preferable in this surgical population. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Mining protein loops using a structural alphabet and statistical exceptionality

PubMed Central

2010-01-01

Background Protein loops encompass 50% of protein residues in available three-dimensional structures. These regions are often involved in protein functions, e.g. binding site, catalytic pocket... However, the description of protein loops with conventional tools is an uneasy task. Regular secondary structures, helices and strands, have been widely studied whereas loops, because they are highly variable in terms of sequence and structure, are difficult to analyze. Due to data sparsity, long loops have rarely been systematically studied. Results We developed a simple and accurate method that allows the description and analysis of the structures of short and long loops using structural motifs without restriction on loop length. This method is based on the structural alphabet HMM-SA. HMM-SA allows the simplification of a three-dimensional protein structure into a one-dimensional string of states, where each state is a four-residue prototype fragment, called structural letter. The difficult task of the structural grouping of huge data sets is thus easily accomplished by handling structural letter strings as in conventional protein sequence analysis. We systematically extracted all seven-residue fragments in a bank of 93000 protein loops and grouped them according to the structural-letter sequence, named structural word. This approach permits a systematic analysis of loops of all sizes since we consider the structural motifs of seven residues rather than complete loops. We focused the analysis on highly recurrent words of loops (observed more than 30 times). Our study reveals that 73% of loop-lengths are covered by only 3310 highly recurrent structural words out of 28274 observed words). These structural words have low structural variability (mean RMSd of 0.85 Å). As expected, half of these motifs display a flanking-region preference but interestingly, two thirds are shared by short (less than 12 residues) and long loops. Moreover, half of recurrent motifs exhibit a significant level of amino-acid conservation with at least four significant positions and 87% of long loops contain at least one such word. We complement our analysis with the detection of statistically over-represented patterns of structural letters as in conventional DNA sequence analysis. About 30% (930) of structural words are over-represented, and cover about 40% of loop lengths. Interestingly, these words exhibit lower structural variability and higher sequential specificity, suggesting structural or functional constraints. Conclusions We developed a method to systematically decompose and study protein loops using recurrent structural motifs. This method is based on the structural alphabet HMM-SA and not on structural alignment and geometrical parameters. We extracted meaningful structural motifs that are found in both short and long loops. To our knowledge, it is the first time that pattern mining helps to increase the signal-to-noise ratio in protein loops. This finding helps to better describe protein loops and might permit to decrease the complexity of long-loop analysis. Detailed results are available at http://www.mti.univ-paris-diderot.fr/publication/supplementary/2009/ACCLoop/. PMID:20132552

Mining protein loops using a structural alphabet and statistical exceptionality.

PubMed

Regad, Leslie; Martin, Juliette; Nuel, Gregory; Camproux, Anne-Claude

2010-02-04

Protein loops encompass 50% of protein residues in available three-dimensional structures. These regions are often involved in protein functions, e.g. binding site, catalytic pocket... However, the description of protein loops with conventional tools is an uneasy task. Regular secondary structures, helices and strands, have been widely studied whereas loops, because they are highly variable in terms of sequence and structure, are difficult to analyze. Due to data sparsity, long loops have rarely been systematically studied. We developed a simple and accurate method that allows the description and analysis of the structures of short and long loops using structural motifs without restriction on loop length. This method is based on the structural alphabet HMM-SA. HMM-SA allows the simplification of a three-dimensional protein structure into a one-dimensional string of states, where each state is a four-residue prototype fragment, called structural letter. The difficult task of the structural grouping of huge data sets is thus easily accomplished by handling structural letter strings as in conventional protein sequence analysis. We systematically extracted all seven-residue fragments in a bank of 93000 protein loops and grouped them according to the structural-letter sequence, named structural word. This approach permits a systematic analysis of loops of all sizes since we consider the structural motifs of seven residues rather than complete loops. We focused the analysis on highly recurrent words of loops (observed more than 30 times). Our study reveals that 73% of loop-lengths are covered by only 3310 highly recurrent structural words out of 28274 observed words). These structural words have low structural variability (mean RMSd of 0.85 A). As expected, half of these motifs display a flanking-region preference but interestingly, two thirds are shared by short (less than 12 residues) and long loops. Moreover, half of recurrent motifs exhibit a significant level of amino-acid conservation with at least four significant positions and 87% of long loops contain at least one such word. We complement our analysis with the detection of statistically over-represented patterns of structural letters as in conventional DNA sequence analysis. About 30% (930) of structural words are over-represented, and cover about 40% of loop lengths. Interestingly, these words exhibit lower structural variability and higher sequential specificity, suggesting structural or functional constraints. We developed a method to systematically decompose and study protein loops using recurrent structural motifs. This method is based on the structural alphabet HMM-SA and not on structural alignment and geometrical parameters. We extracted meaningful structural motifs that are found in both short and long loops. To our knowledge, it is the first time that pattern mining helps to increase the signal-to-noise ratio in protein loops. This finding helps to better describe protein loops and might permit to decrease the complexity of long-loop analysis. Detailed results are available at http://www.mti.univ-paris-diderot.fr/publication/supplementary/2009/ACCLoop/.

The cognitive profile of myotonic dystrophy type 1: A systematic review and meta-analysis.

PubMed

Okkersen, Kees; Buskes, Melanie; Groenewoud, Johannes; Kessels, Roy P C; Knoop, Hans; van Engelen, Baziel; Raaphorst, Joost

2017-10-01

To examine the cognitive profile of patients with myotonic dystrophy type 1 (DM1) on the basis of a systematic review and meta-analysis of the literature. Embase, Medline and PsycInfo were searched for studies reporting ≥1 neuropsychological test in both DM1 patients and healthy controls. Search, data extraction and risk of bias analysis were independently performed by two authors to minimize error. Neuropsychological tests were categorized into 12 cognitive domains and effect sizes (Hedges' g) were calculated for each domain and for tests administered in ≥5 studies. DM1 participants demonstrated a significantly worse performance compared to controls in all cognitive domains. Effect sizes ranged from -.33 (small) for verbal memory to -1.01 (large) for visuospatial perception. Except for the domains global cognition, intelligence and social cognition, wide confidence intervals (CIs) were associated with moderate to marked statistical heterogeneity that necessitates careful interpretation of results. Out of the individual tests, the Rey-Osterrieth complex figure-copy (both non-verbal memory and visuoconstruction) showed consistent impairment with acceptable heterogeneity. In DM1 patients, cognitive deficits may include a variable combination of global cognitive impairment with involvement across different domains, including social cognition, memory and visuospatial functioning. Although DM1 is a heterogeneous disorder, our study shows that meta-analysis is feasible, contributes to the understanding of brain involvement and may direct bedside testing. The protocol for this study has been registered in PROSPERO (International prospective register of systematic reviews) under ID: 42016037415. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of advanced life support versus basic life support on the mortality rates of patients with trauma in prehospital settings: a study protocol for a systematic review and meta-analysis

PubMed Central

Kondo, Yutaka; Fukuda, Tatsuma; Uchimido, Ryo; Hifumi, Toru; Hayashida, Kei

2017-01-01

Introduction Advanced life support (ALS) is thought to be associated with improved survival in prehospital trauma care when compared with basic life support (BLS). However, evidence on the benefits of prehospital ALS for patients with trauma is controversial. Therefore, we aim to clarify if ALS improves mortality in patients with trauma when compared with BLS by conducting a systematic review and meta-analysis of the recent literature. Methods and analysis We will perform searches in PubMed, Embase and the Cochrane Central Register of Controlled Trials for published observational studies, controlled before-and-after studies, randomised controlled trials and other controlled trials conducted in humans and published until March 2017. We will screen search results, assess study selection, extract data and assess the risk of bias in duplicate; disagreements will be resolved through discussions. Data from clinically homogeneous studies will be pooled using a random-effects meta-analysis, heterogeneity of effects will be assessed using the χ2 test of homogeneity, and any observed heterogeneity will be quantified using the I2 statistic. Last, the Grading of Recommendations Assessment, Development and Evaluation approach will be used to rate the quality of the evidence. Ethics and dissemination Our study does not require ethical approval as it is based on findings of previously published articles. Results will be disseminated through publication in a peer-reviewed journal, presentations at relevant conferences and publications for patient information. Trial registration number PROSPERO (International Prospective Register of Systematic Reviews) registration number CRD42017054389. PMID:29061611

Colloids versus crystalloids in objective-guided fluid therapy, systematic review and meta-analysis. Too early or too late to draw conclusions.

PubMed

Ripollés, Javier; Espinosa, Ángel; Casans, Rubén; Tirado, Ana; Abad, Alfredo; Fernández, Cristina; Calvo, José

2015-01-01

Several clinical trials on Goal directed fluid therapy (GDFT) were carried out, many of those using colloids in order to optimize the preload. After the decision of European Medicines Agency, there is such controversy regarding its use, benefits, and possible contribution to renal failure. The objective of this systematic review and meta-analysis is to compare the use of last-generation colloids, derived from corn, with crystalloids in GDFT to determine associated complications and mortality. A bibliographic research was carried out in MEDLINE PubMed, EMBASE and Cochrane Library, corroborating randomized clinical trials where crystalloids are compared to colloids in GDFT for major non-cardiac surgery in adults. One hundred thirty references were found and among those 38 were selected and 29 analyzed; of these, six were included for systematic review and meta-analysis, including 390 patients. It was observed that the use of colloids is not associated with the increase of complications, but rather with a tendency to a higher mortality (RR [95% CI] 3.87 [1.121-13.38]; I(2)=0.0%; p=0.635). Because of the limitations of this meta-analysis due to the small number of randomized clinical trials and patients included, the results should be taken cautiously, and the performance of new randomized clinical trials is proposed, with enough statistical power, comparing balanced and unbalanced colloids to balanced and unbalanced crystalloids, following the protocols of GDFT, considering current guidelines and suggestions made by groups of experts. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Is chronic toxoplasmosis a risk factor for diabetes mellitus? A systematic review and meta-analysis of case-control studies.

PubMed

Majidiani, Hamidreza; Dalvand, Sahar; Daryani, Ahmad; Galvan-Ramirez, Ma de la Luz; Foroutan-Rad, Masoud

The global protozoan parasite, Toxoplasma gondii, infects many warm-blooded animals and humans by employing different transmission routes. There have been some recent studies on the probable relevance of infectious agents and diabetes. Therefore, we conducted a systematic review and meta-analysis to identify the possible association between chronic toxoplasmosis and diabetes mellitus. This study was conducted following the general methodology recommended for systematic reviews and meta-analysis. Nine English literature databases (Google scholar, PubMed, Scopus, Web of science, Science Direct, Ovid, ProQuest, IngentaConnect, and Wiley Online Library) were searched, up to January 2016. Random effects model was used to determine odds ratios and their 95% confidence intervals. Our review resulted in a total of seven publications meeting the inclusion criteria. Because of significant heterogeneity, we estimated a common OR by a random effects model at 1.10 (95% CI=0.13-9.57) with p=0.929 and 2.39 (95% CI=1.20-4.75) with p=0.013 for type 1 and type 2 diabetes mellitus, respectively. Despite the limitations such as low number of studies, this meta-analysis suggests chronic toxoplasmosis as a possible risk factor for type 2 DM. However, based on random effects model no statistically significant association was observed between T. gondii and type 1 DM. It is highly recommended for researchers to carry out more accurate studies aiming to better understand this association. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Prevalence and predictors of khat chewing among Ethiopian university students: A systematic review and meta-analysis

PubMed Central

Alebel, Animut; Zegeye, Abriham; Tesfaye, Bekele

2018-01-01

Background Khat chewing has become a common practice among university students in developing countries like Ethiopia. It has a potential effect on physical, mental, social and cognitive aspects of student functioning. In Ethiopia, study findings regarding the prevalence of khat chewing were highly dispersed and inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled prevalence of khat chewing and its predictors among Ethiopian university students. Method A systematic review and meta-analysis was conducted to assess the prevalence and predictors of khat chewing among university students in Ethiopia. We searched literature from the databases of PubMed, Google Scholar, Science Direct, and the Cochrane Library. A total of 24 Ethiopian studies reporting the prevalence of khat chewing among university students were included. Data were extracted using a standardized data extraction format prepared in Microsoft Excel and the analysis was done using STATA 14 statistical software. To assess heterogeneity, the Cochrane Q test statistics and I2 test were used. Since the included studies exhibit high heterogeneity, a random effect meta-analysis model was computed to estimate the pooled prevalence of khat chewing. Moreover, the association between predictor variables, and khat chewing practice were examined. Results The meta-analysis of 24 studies revealed that the pooled prevalence of khat chewing among university students in Ethiopia was 23.22% (95% CI: 19.5, 27.0). In the subgroup analysis, the highest prevalence was observed in Oromia region (31.6%; 95CI: 21.2, 41.9) whereas the lowest prevalence was observed in Amhara region (18.1%; 95%CI: 12.4, 23.8). Being male OR: 2.76 (95% CI 1.64, 4.63), family khat chewing practice OR: 2.91 (95% CI 1.06, 7.98), friend khat chewing habit OR: 4.74 (95% CI 3.48, 13.06), alcohol drinking OR: 7.06 (95% CI 5.65, 8.82) and cigarette smoking habit OR: 15.11 (95% CI 8.96, 25.51) were found to be predictors of khat chewing. Conclusion The study found that the prevalence of khat chewing among university students was quite common, with slightly more than 1 in 5 students engaging in the use of this substance. Being male, family khat chewing practice, friend’s khat chewing habit, alcohol drinking, and cigarette smoking were found to be predictors of khat chewing practice among university students. PMID:29649253

Rational-Emotive Therapy versus Systematic Desensitization: A Comment on Moleski and Tosi.

ERIC Educational Resources Information Center

Atkinson, Leslie

1983-01-01

Questioned the statistical analyses of the Moleski and Tosi investigation of rational-emotive therapy versus systematic desensitization. Suggested means for lowering the error rate through a more efficient experimental design. Recommended a reanalysis of the original data. (LLL)

Effectiveness of the management of major depressive episodes/disorder in adults with comorbid chronic physical diseases: a protocol for a systematic review and meta-analysis.

PubMed

Martínez, Pablo; Castro, Ariel; Alonso, Diego; Vöhringer, Paul A; Rojas, Graciela

2017-07-20

Depression is a global-scale public health problem, and a significant association has been established between depression and chronic physical diseases. This growing comorbidity poses a challenge to healthcare systems. We aim to assess the effectiveness of the management of major depressive episodes/disorder in adults with comorbid chronic physical diseases. We will conduct a systematic review and meta-analysis of randomised clinical trials. Two databases MEDLINE and Cochrane Library (Cochrane Database for Systematic Reviews and CENTRAL), as well as the reference lists of the included articles, will be searched for studies either in English or Spanish with published results within the 2005-2015 period. Studies must fulfil the following conditions: (1) participants aged 18 years or older, diagnosed as having a major depressive episodes/disorder according to standardised criteria and chronic physical diseases; (2)interventions (be it pharmacological, psychological, psychosocial or a combination) must be compared with control conditions (other 'active' intervention, treatment as usual, waiting list or placebo); (3)and must report reduction in depressive symptoms after treatment, response to treatment, remission of major depressive episodes/disorder and significant improvement in quality of life. Data extraction, risk of bias evaluation, results summarisation and quality of the evidence (GRADE) will be performed as recommended by the Cochrane Collaboration. A qualitative synthesis and a random effects meta-analysis will be carried out. Effect sizes will be calculated (relative risk and Cohen's d), I 2 and Q statistics will be employed to study heterogeneity and publication bias analysis will be performed. Subgroup analyses and meta-regression will be carried out. Results are expected to be published in specialised peer-reviewed journals (preferred topics: Mental Health, Psychology, Psychiatry and/or Systematic Reviews) and dissemination activities will be targeted to all the healthcare providers. International Prospective Register of Systematic Reviews (CRD42016029166) submitted on 11 January 2016. © 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.

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