A Review of Meta-Analyses in Education: Methodological Strengths and Weaknesses

ERIC Educational Resources Information Center

Ahn, Soyeon; Ames, Allison J.; Myers, Nicholas D.

2012-01-01

The current review addresses the validity of published meta-analyses in education that determines the credibility and generalizability of study findings using a total of 56 meta-analyses published in education in the 2000s. Our objectives were to evaluate the current meta-analytic practices in education, identify methodological strengths and…

Meta-analysis of magnitudes, differences and variation in evolutionary parameters.

PubMed

Morrissey, M B

2016-10-01

Meta-analysis is increasingly used to synthesize major patterns in the large literatures within ecology and evolution. Meta-analytic methods that do not account for the process of observing data, which we may refer to as 'informal meta-analyses', may have undesirable properties. In some cases, informal meta-analyses may produce results that are unbiased, but do not necessarily make the best possible use of available data. In other cases, unbiased statistical noise in individual reports in the literature can potentially be converted into severe systematic biases in informal meta-analyses. I first present a general description of how failure to account for noise in individual inferences should be expected to lead to biases in some kinds of meta-analysis. In particular, informal meta-analyses of quantities that reflect the dispersion of parameters in nature, for example, the mean absolute value of a quantity, are likely to be generally highly misleading. I then re-analyse three previously published informal meta-analyses, where key inferences were of aspects of the dispersion of values in nature, for example, the mean absolute value of selection gradients. Major biological conclusions in each original informal meta-analysis closely match those that could arise as artefacts due to statistical noise. I present alternative mixed-model-based analyses that are specifically tailored to each situation, but where all analyses may be implemented with widely available open-source software. In each example meta-re-analysis, major conclusions change substantially. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Grey literature in meta-analyses.

PubMed

Conn, Vicki S; Valentine, Jeffrey C; Cooper, Harris M; Rantz, Marilyn J

2003-01-01

In meta-analysis, researchers combine the results of individual studies to arrive at cumulative conclusions. Meta-analysts sometimes include "grey literature" in their evidential base, which includes unpublished studies and studies published outside widely available journals. Because grey literature is a source of data that might not employ peer review, critics have questioned the validity of its data and the results of meta-analyses that include it. To examine evidence regarding whether grey literature should be included in meta-analyses and strategies to manage grey literature in quantitative synthesis. This article reviews evidence on whether the results of studies published in peer-reviewed journals are representative of results from broader samplings of research on a topic as a rationale for inclusion of grey literature. Strategies to enhance access to grey literature are addressed. The most consistent and robust difference between published and grey literature is that published research is more likely to contain results that are statistically significant. Effect size estimates of published research are about one-third larger than those of unpublished studies. Unfunded and small sample studies are less likely to be published. Yet, importantly, methodological rigor does not differ between published and grey literature. Meta-analyses that exclude grey literature likely (a) over-represent studies with statistically significant findings, (b) inflate effect size estimates, and (c) provide less precise effect size estimates than meta-analyses including grey literature. Meta-analyses should include grey literature to fully reflect the existing evidential base and should assess the impact of methodological variations through moderator analysis.

Exploring changes over time and characteristics associated with data retrieval across individual participant data meta-analyses: systematic review

PubMed Central

Marson, Anthony G; Davie, Becky; Reynolds, Sally; Williams, Lisa; Smith, Catrin Tudur

2017-01-01

Abstract Objective To investigate whether the success rate of retrieving individual participant data (IPD) for use in IPD meta-analyses has increased over time, and to explore the characteristics associated with IPD retrieval. Design Systematic review of published IPD meta-analyses, supplemented by a reflection of the Cochrane Epilepsy Group’s 20 years’ experience of requesting IPD. Data sources Medline, CENTRAL, Scopus, Web of Science, CINAHL Plus, and PsycINFO. Eligibility criteria for study selection IPD meta-analyses of studies of all designs and all clinical areas published in English. Results 760 IPD meta-analyses which identified studies by systematic methods that had been published between 1987 and 2015 were included. Only 188 (25%) of these IPD meta-analyses retrieved 100% of the eligible IPD for analysis, with 324 (43%) of these IPD meta-analyses retrieving 80% or more of relevant IPD. There is insufficient evidence to suggest that IPD retrieval rates have improved over time. IPD meta-analyses that included only randomised trials, had an authorship policy, included fewer eligible participants, and were conducted outside of the Cochrane Database of Systematic Reviews were associated with a high or complete IPD retrieval rate. There was no association between the source of funding of the IPD meta-analyses and IPD retrieval rate. The IPD retrieval rate of the Cochrane Epilepsy Group has declined from 83% (up to 2005) to 65% (between 2012 and 2015) and the reported reasons for lack of data availability have changed in recent years. Conclusions IPD meta-analyses are considered to be the “gold standard” for the synthesis of data from clinical research studies; however, only 25% of published IPD meta-analyses have had access to all IPD. PMID:28381561

Meta-analysis to determine the effects of plant disease management measures: review and case studies on soybean and apple.

PubMed

Ngugi, Henry K; Esker, Paul D; Scherm, Harald

2011-01-01

The continuing exponential increase in scientific knowledge, the growing availability of large databases containing raw or partially annotated information, and the increased need to document impacts of large-scale research and funding programs provide a great incentive for integrating and adding value to previously published (or unpublished) research through quantitative synthesis. Meta-analysis has become the standard for quantitative evidence synthesis in many disciplines, offering a broadly accepted and statistically powerful framework for estimating the magnitude, consistency, and homogeneity of the effect of interest across studies. Here, we review previous and current uses of meta-analysis in plant pathology with a focus on applications in epidemiology and disease management. About a dozen formal meta-analyses have been published in the plant pathological literature in the past decade, and several more are currently in progress. Three broad research questions have been addressed, the most common being the comparative efficacy of chemical treatments for managing disease and reducing yield loss across environments. The second most common application has been the quantification of relationships between disease intensity and yield, or between different measures of disease, across studies. Lastly, meta-analysis has been applied to assess factors affecting pathogen-biocontrol agent interactions or the effectiveness of biological control of plant disease or weeds. In recent years, fixed-effects meta-analysis has been largely replaced by random- (or mixed-) effects analysis owing to the statistical benefits associated with the latter and the wider availability of computer software to conduct these analyses. Another recent trend has been the more common use of multivariate meta-analysis or meta-regression to analyze the impacts of study-level independent variables (moderator variables) on the response of interest. The application of meta-analysis to practical problems in epidemiology and disease management is illustrated with case studies from our work on Phakopsora pachyrhizi on soybean and Erwinia amylovora on apple. We show that although meta-analyses are often used to corroborate and validate general conclusions drawn from more traditional, qualitative reviews, they can also reveal new patterns and interpretations not obvious from individual studies.

A meta-analysis but not a systematic review: an evaluation of the Global BMI Mortality Collaboration.

PubMed

Flegal, Katherine M; Ioannidis, John P A

2017-08-01

Meta-analyses of individual participant data (MIPDs) offer many advantages and are considered the highest level of evidence. However, MIPDs can be seriously compromised when they are not solidly founded upon a systematic review. These data-intensive collaborative projects may be led by experts who already have deep knowledge of the literature in the field and of the results of published studies and how these results vary based on different analytical approaches. If investigators tailor the searches, eligibility criteria, and analysis plan of the MIPD, they run the risk of reaching foregone conclusions. We exemplify this potential bias in a MIPD on the association of body mass index with mortality conducted by a collaboration of outstanding and extremely knowledgeable investigators. Contrary to a previous meta-analysis of group data that used a systematic review approach, the MIPD did not seem to use a formal search: it considered 239 studies, of which the senior author was previously aware of at least 238, and it violated its own listed eligibility criteria to include those studies and exclude other studies. It also preferred an analysis plan that was also known to give a specific direction of effects in already published results of most of the included evidence. MIPDs where results of constituent studies are already largely known need safeguards to their validity. These may include careful systematic searches, adherence to the Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data guidelines, and exploration of the robustness of results with different analyses. They should also avoid selective emphasis on foregone conclusions based on previously known results with specific analytical choices. Copyright © 2017 Elsevier Inc. All rights reserved.

The prevalence of pathological gambling among college students: a meta-analytic synthesis, 2005-2013.

PubMed

Nowak, Donald E; Aloe, Ariel M

2014-12-01

The problem of gambling addiction can be especially noteworthy among college and university students, many of whom have the resources, proximity, free time, and desire to become involved in the myriad options of gambling now available. Although limited attention has been paid specifically to college student gambling in the body of literature, there have been two published meta-analyses estimating the prevalence of probable pathological gambling among college students. This present study aims to be the third, presenting an up-to-date proportion of those students exhibiting gambling pathology, and is the first to include international studies from outside the United States and Canada. The purpose of this study was to use the most up-to-date meta-analytical procedures to synthesize the rates of probable pathological gambling for college and university students worldwide. A thorough literature review and coding procedure resulted in 19 independent data estimates retrieved from 18 studies conducted between 2005 and 2013. To synthesize the studies, a random effects model for meta-analysis was applied. The estimated proportion of probable pathological gamblers among the over 13,000 college students surveyed was computed at 10.23%, considerably higher than either of the two previously published meta-analyses, and more than double the rate reported in the first meta-analysis of this type published in 1999. Implications and recommendations for future practice in dealing with college students and gambling addiction are outlined and described for both administrators and mental health professionals.

Does the inclusion of grey literature influence estimates of intervention effectiveness reported in meta-analyses?

PubMed

McAuley, L; Pham, B; Tugwell, P; Moher, D

2000-10-07

The inclusion of only a subset of all available evidence in a meta-analysis may introduce biases and threaten its validity; this is particularly likely if the subset of included studies differ from those not included, which may be the case for published and grey literature (unpublished studies, with limited distribution). We set out to examine whether exclusion of grey literature, compared with its inclusion in meta-analysis, provides different estimates of the effectiveness of interventions assessed in randomised trials. From a random sample of 135 meta-analyses, we identified and retrieved 33 publications that included both grey and published primary studies. The 33 publications contributed 41 separate meta-analyses from several disease areas. General characteristics of the meta-analyses and associated studies and outcome data at the trial level were collected. We explored the effects of the inclusion of grey literature on the quantitative results using logistic-regression analyses. 33% of the meta-analyses were found to include some form of grey literature. The grey literature, when included, accounts for between 4.5% and 75% of the studies in a meta-analysis. On average, published work, compared with grey literature, yielded significantly larger estimates of the intervention effect by 15% (ratio of odds ratios=1.15 [95% CI 1.04-1.28]). Excluding abstracts from the analysis further compounded the exaggeration (1.33 [1.10-1.60]). The exclusion of grey literature from meta-analyses can lead to exaggerated estimates of intervention effectiveness. In general, meta-analysts should attempt to identify, retrieve, and include all reports, grey and published, that meet predefined inclusion criteria.

More female patients and fewer stimuli per session are associated with the short-term antidepressant properties of repetitive transcranial magnetic stimulation (rTMS): a meta-analysis of 54 sham-controlled studies published between 1997–2013

PubMed Central

Kedzior, Karina Karolina; Azorina, Valeriya; Reitz, Sarah Kim

2014-01-01

Background Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) appears to have short-term antidepressant properties. The aim of the current study was to update our previous meta-analysis and to investigate factors associated with the antidepressant properties of rTMS. Method Following a systematic literature search conducted in Medline and PsycInfo, N=14 sham-controlled, parallel design studies (published after 2008 to August 2013) that had utilized rTMS of the DLPFC in major depression were included in the current meta-analysis. The sensitivity and moderator analyses also included data from N=40 studies (published in 1997–2008) from our previous meta-analysis. The effect size (Cohen’s d) in each study was the standardized difference in mean depression scores (on Hamilton Depression Rating Scale, Beck Depression Inventory, Montgomery Åsberg Depression Rating Scale) from baseline to final (after last session) in rTMS compared to sham groups. Results According to a random-effects model with inverse-variance weights, depression scores were significantly reduced after rTMS compared to sham in studies published from 2008–2013 based on N=659 patients (overall mean weighted d=−0.42, 95% confidence interval: −0.66, −0.18, P=0.001). Combining studies from our past and current meta-analyses (published in 1997–2013; N=54) revealed that depression was significantly reduced after left-fast (>1 Hz), right-slow (≤1 Hz), and bilateral (or sequential) rTMS of DLPFC compared to sham. Significant antidepressant properties of rTMS were observed in studies with patients who were treatment resistant, unipolar (or bipolar), non-psychotic, medication-free (or started on antidepressants concurrently with rTMS). According to univariate meta-regressions, depression scores were significantly lower in studies with more female patients and fewer stimuli per session. There was little evidence that publication bias occurred in the analysis. Conclusion According to this study, the largest meta-analysis to date, short-term antidepressant properties of rTMS are independent of concurrent antidepressants and might depend on sex and the number of stimuli per session. PMID:24855360

Modelling multiple sources of dissemination bias in meta-analysis.

PubMed

Bowden, Jack; Jackson, Dan; Thompson, Simon G

2010-03-30

Asymmetry in the funnel plot for a meta-analysis suggests the presence of dissemination bias. This may be caused by publication bias through the decisions of journal editors, by selective reporting of research results by authors or by a combination of both. Typically, study results that are statistically significant or have larger estimated effect sizes are more likely to appear in the published literature, hence giving a biased picture of the evidence-base. Previous statistical approaches for addressing dissemination bias have assumed only a single selection mechanism. Here we consider a more realistic scenario in which multiple dissemination processes, involving both the publishing authors and journals, are operating. In practical applications, the methods can be used to provide sensitivity analyses for the potential effects of multiple dissemination biases operating in meta-analysis.

Meta-analyses of animal studies: an introduction of a valuable instrument to further improve healthcare.

PubMed

Hooijmans, Carlijn R; IntHout, Joanna; Ritskes-Hoitinga, Merel; Rovers, Maroeska M

2014-01-01

In research aimed at improving human health care, animal studies still play a crucial role, despite political and scientific efforts to reduce preclinical experimentation in laboratory animals. In animal studies, the results and their interpretation are not always straightforward, as no single study is executed perfectly in all steps. There are several possible sources of bias, and many animal studies are replicates of studies conducted previously. Use of meta-analysis to combine the results of studies may lead to more reliable conclusions and a reduction of unnecessary duplication of animal studies. In addition, due to the more exploratory nature of animal studies as compared to clinical trials, meta-analyses of animal studies have greater potential in exploring possible sources of heterogeneity. There is an abundance of literature on how to perform meta-analyses on clinical data. Animal studies, however, differ from clinical studies in some aspects, such as the diversity of animal species studied, experimental design, and study characteristics. In this paper, we will discuss the main principles and practices for meta-analyses of experimental animal studies. © The Author 2014. Published by Oxford University Press.

Supplemental Vitamins and Minerals for CVD Prevention and Treatment.

PubMed

Jenkins, David J A; Spence, J David; Giovannucci, Edward L; Kim, Young-In; Josse, Robert; Vieth, Reinhold; Blanco Mejia, Sonia; Viguiliouk, Effie; Nishi, Stephanie; Sahye-Pudaruth, Sandhya; Paquette, Melanie; Patel, Darshna; Mitchell, Sandy; Kavanagh, Meaghan; Tsirakis, Tom; Bachiri, Lina; Maran, Atherai; Umatheva, Narmada; McKay, Taylor; Trinidad, Gelaine; Bernstein, Daniel; Chowdhury, Awad; Correa-Betanzo, Julieta; Del Principe, Gabriella; Hajizadeh, Anisa; Jayaraman, Rohit; Jenkins, Amy; Jenkins, Wendy; Kalaichandran, Ruben; Kirupaharan, Geithayini; Manisekaran, Preveena; Qutta, Tina; Shahid, Ramsha; Silver, Alexis; Villegas, Cleo; White, Jessica; Kendall, Cyril W C; Pichika, Sathish C; Sievenpiper, John L

2018-06-05

The authors identified individual randomized controlled trials from previous meta-analyses and additional searches, and then performed meta-analyses on cardiovascular disease outcomes and all-cause mortality. The authors assessed publications from 2012, both before and including the U.S. Preventive Service Task Force review. Their systematic reviews and meta-analyses showed generally moderate- or low-quality evidence for preventive benefits (folic acid for total cardiovascular disease, folic acid and B-vitamins for stroke), no effect (multivitamins, vitamins C, D, β-carotene, calcium, and selenium), or increased risk (antioxidant mixtures and niacin [with a statin] for all-cause mortality). Conclusive evidence for the benefit of any supplement across all dietary backgrounds (including deficiency and sufficiency) was not demonstrated; therefore, any benefits seen must be balanced against possible risks. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Methodology and reporting of meta-analyses in the neurosurgical literature.

PubMed

Klimo, Paul; Thompson, Clinton J; Ragel, Brian T; Boop, Frederick A

2014-04-01

Neurosurgeons are inundated with vast amounts of new clinical research on a daily basis, making it difficult and time-consuming to keep up with the latest literature. Meta-analysis is an extension of a systematic review that employs statistical techniques to pool the data from the literature in order to calculate a cumulative effect size. This is done to answer a clearly defined a priori question. Despite their increasing popularity in the neurosurgery literature, meta-analyses have not been scrutinized in terms of reporting and methodology. The authors performed a literature search using PubMed/MEDLINE to locate all meta-analyses that have been published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Accepted checklists for reporting (PRISMA) and methodology (AMSTAR) were applied to each meta-analysis, and the number of items within each checklist that were satisfactorily fulfilled was recorded. The authors sought to answer 4 specific questions: Are meta-analyses improving 1) with time; 2) when the study met their definition of a meta-analysis; 3) when clinicians collaborated with a potential expert in meta-analysis; and 4) when the meta-analysis was the only focus of the paper? Seventy-two meta-analyses were published in the JNS Publishing Group journals and Neurosurgery between 1990 and 2012. The number of published meta-analyses has increased dramatically in the last several years. The most common topics were vascular, and most were based on observational studies. Only 11 papers were prepared using an established checklist. The average AMSTAR and PRISMA scores (proportion of items satisfactorily fulfilled divided by the total number of eligible items in the respective instrument) were 31% and 55%, respectively. Major deficiencies were identified, including the lack of a comprehensive search strategy, study selection and data extraction, assessment of heterogeneity, publication bias, and study quality. Almost one-third of the papers did not meet our basic definition of a meta-analysis. The quality of reporting and methodology was better 1) when the study met our definition of a meta-analysis; 2) when one or more of the authors had experience or expertise in conducting a meta-analysis; 3) when the meta-analysis was not conducted alongside an evaluation of the authors' own data; and 4) in more recent studies. Reporting and methodology of meta-analyses in the neurosurgery literature is excessively variable and overall poor. As these papers are being published with increasing frequency, neurosurgical journals need to adopt a clear definition of a meta-analysis and insist that they be created using checklists for both reporting and methodology. Standardization will ensure high-quality publications.

Meta-analyses with industry involvement are massively published and report no caveats for antidepressants.

PubMed

Ebrahim, Shanil; Bance, Sheena; Athale, Abha; Malachowski, Cindy; Ioannidis, John P A

2016-02-01

To identify the impact of industry involvement in the publication and interpretation of meta-analyses of antidepressant trials in depression. Using MEDLINE, we identified all meta-analyses evaluating antidepressants for depression published in January 2007-March 2014. We extracted data pertaining to author affiliations, conflicts of interest, and whether the conclusion of the abstract included negative statements on whether the antidepressant(s) were effective or safe. We identified 185 eligible meta-analyses. Fifty-four meta-analyses (29%) had authors who were employees of the assessed drug manufacturer, and 147 (79%) had some industry link (sponsorship or authors who were industry employees and/or had conflicts of interest). Only 58 meta-analyses (31%) had negative statements in the concluding statement of the abstract. Meta-analyses including an author who were employees of the manufacturer of the assessed drug were 22-fold less likely to have negative statements about the drug than other meta-analyses [1/54 (2%) vs. 57/131 (44%); P < 0.001]. There is a massive production of meta-analyses of antidepressants for depression authored by or linked to the industry, and they almost never report any caveats about antidepressants in their abstracts. Our findings add a note of caution for meta-analyses with ties to the manufacturers of the assessed products. Copyright © 2016 Elsevier Inc. All rights reserved.

Night shift work and breast cancer risk: what do the meta-analyses tell us?

PubMed

Pahwa, Manisha; Labrèche, France; Demers, Paul A

2018-05-22

Objectives This paper aims to compare results, assess the quality, and discuss the implications of recently published meta-analyses of night shift work and breast cancer risk. Methods A comprehensive search was conducted for meta-analyses published from 2007-2017 that included at least one pooled effect size (ES) for breast cancer associated with any night shift work exposure metric and were accompanied by a systematic literature review. Pooled ES from each meta-analysis were ascertained with a focus on ever/never exposure associations. Assessments of heterogeneity and publication bias were also extracted. The AMSTAR 2 checklist was used to evaluate quality. Results Seven meta-analyses, published from 2013-2016, collectively included 30 cohort and case-control studies spanning 1996-2016. Five meta-analyses reported pooled ES for ever/never night shift work exposure; these ranged from 0.99 [95% confidence interval (CI) 0.95-1.03, N=10 cohort studies) to 1.40 (95% CI 1.13-1.73, N=9 high quality studies). Estimates for duration, frequency, and cumulative night shift work exposure were scant and mostly not statistically significant. Meta-analyses of cohort, Asian, and more fully-adjusted studies generally resulted in lower pooled ES than case-control, European, American, or minimally-adjusted studies. Most reported statistically significant between-study heterogeneity. Publication bias was not evident in any of the meta-analyses. Only one meta-analysis was strong in critical quality domains. Conclusions Fairly consistent elevated pooled ES were found for ever/never night shift work and breast cancer risk, but results for other shift work exposure metrics were inconclusive. Future evaluations of shift work should incorporate high quality meta-analyses that better appraise individual study quality.

How can my research paper be useful for future meta-analyses on forest restoration practices?

Treesearch

Enrique Andivia; Pedro Villar‑Salvador; Juan A. Oliet; Jaime Puertolas; R. Kasten Dumroese

2018-01-01

Statistical meta-analysis is a powerful and useful tool to quantitatively synthesize the information conveyed in published studies on a particular topic. It allows identifying and quantifying overall patterns and exploring causes of variation. The inclusion of published works in meta-analyses requires, however, a minimum quality standard of the reported data and...

False-positive findings in Cochrane meta-analyses with and without application of trial sequential analysis: an empirical review.

PubMed

Imberger, Georgina; Thorlund, Kristian; Gluud, Christian; Wetterslev, Jørn

2016-08-12

Many published meta-analyses are underpowered. We explored the role of trial sequential analysis (TSA) in assessing the reliability of conclusions in underpowered meta-analyses. We screened The Cochrane Database of Systematic Reviews and selected 100 meta-analyses with a binary outcome, a negative result and sufficient power. We defined a negative result as one where the 95% CI for the effect included 1.00, a positive result as one where the 95% CI did not include 1.00, and sufficient power as the required information size for 80% power, 5% type 1 error, relative risk reduction of 10% or number needed to treat of 100, and control event proportion and heterogeneity taken from the included studies. We re-conducted the meta-analyses, using conventional cumulative techniques, to measure how many false positives would have occurred if these meta-analyses had been updated after each new trial. For each false positive, we performed TSA, using three different approaches. We screened 4736 systematic reviews to find 100 meta-analyses that fulfilled our inclusion criteria. Using conventional cumulative meta-analysis, false positives were present in seven of the meta-analyses (7%, 95% CI 3% to 14%), occurring more than once in three. The total number of false positives was 14 and TSA prevented 13 of these (93%, 95% CI 68% to 98%). In a post hoc analysis, we found that Cochrane meta-analyses that are negative are 1.67 times more likely to be updated (95% CI 0.92 to 2.68) than those that are positive. We found false positives in 7% (95% CI 3% to 14%) of the included meta-analyses. Owing to limitations of external validity and to the decreased likelihood of updating positive meta-analyses, the true proportion of false positives in meta-analysis is probably higher. TSA prevented 93% of the false positives (95% CI 68% to 98%). 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/

Quantitative assessment of the association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and digestive system cancer risk.

PubMed

Wang, J; Yang, S; Guo, F H; Mao, X; Zhou, H; Dong, Y Q; Wang, Z M; Luo, F

2015-11-13

The angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been reported to be associated with digestive system cancer; however, the results from previous studies have been conflicting. The present study aimed to investigate the association between the ACE I/D polymorphism and the risk of digestive system cancer using a meta-analysis of previously published studies. Databases were systematically searched to identify relevant studies published prior to December 2014. We estimated the pooled OR with its 95%CI to assess the association. The meta-analysis consisted of thirteen case-control studies that included 2557 patients and 4356 healthy controls. Meta-analysis results based on all the studies showed no significant association between the ACE I/D polymorphism and the risk of digestive system cancer (DD vs II: OR = 0.85, 95%CI = 0.59-1.24; DI vs II: OR = 0.94, 95%CI = 0.78-1.15; dominant model: OR = 0.96, 95%CI = 0.81- 1.15; recessive model: OR = 1.06, 95%CI = 0.76-1.48). Subgroup analyses by race and cancer type did not detect an association between the ACE I/D polymorphism and digestive system cancer risk. However, when the analyses were restricted to smaller studies (N < 500 patients), the summary OR of DI vs II was 0.80 (95%CI = 0.66-0.97). Our analyses detected a possibility of publication bias with a misestimate of the true association by smaller studies. Overall, meta-analysis results suggest the ACE I/D polymorphism might not be associated with susceptibility to digestive system cancer. Further large and well-designed studies are needed to confirm these conclusions.

Empirical evidence about inconsistency among studies in a pair-wise meta-analysis.

PubMed

Rhodes, Kirsty M; Turner, Rebecca M; Higgins, Julian P T

2016-12-01

This paper investigates how inconsistency (as measured by the I 2 statistic) among studies in a meta-analysis may differ, according to the type of outcome data and effect measure. We used hierarchical models to analyse data from 3873 binary, 5132 continuous and 880 mixed outcome meta-analyses within the Cochrane Database of Systematic Reviews. Predictive distributions for inconsistency expected in future meta-analyses were obtained, which can inform priors for between-study variance. Inconsistency estimates were highest on average for binary outcome meta-analyses of risk differences and continuous outcome meta-analyses. For a planned binary outcome meta-analysis in a general research setting, the predictive distribution for inconsistency among log odds ratios had median 22% and 95% CI: 12% to 39%. For a continuous outcome meta-analysis, the predictive distribution for inconsistency among standardized mean differences had median 40% and 95% CI: 15% to 73%. Levels of inconsistency were similar for binary data measured by log odds ratios and log relative risks. Fitted distributions for inconsistency expected in continuous outcome meta-analyses using mean differences were almost identical to those using standardized mean differences. The empirical evidence on inconsistency gives guidance on which outcome measures are most likely to be consistent in particular circumstances and facilitates Bayesian meta-analysis with an informative prior for heterogeneity. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.

Methodological quality is underrated in systematic reviews and meta-analyses in health psychology.

PubMed

Oliveras, Isabel; Losilla, Josep-Maria; Vives, Jaume

2017-06-01

In this paper, we compile and describe the main approaches proposed in the literature to include methodological quality (MQ) or risk of bias (RoB) into research synthesis. We also meta-review how the RoB of observational primary studies is being assessed and to what extent the results are incorporated in the conclusions of research synthesis. Electronic databases were searched for systematic reviews or meta-analyses related to health and clinical psychology. A random sample of 90 reviews published between January 2010 and May 2016 was examined. A total of 46 reviews (51%) performed a formal assessment of the RoB of primary studies. Only 17 reviews (19%) linked the outcomes of quality assessment with the results of the review. According to the previous literature, our results corroborate the lack of guidance to incorporate the RoB assessment in the results of systematic reviews and meta-analyses. Our recommendation is to appraise MQ according to domains of RoB to rate the degree of credibility of the results of a research synthesis, as well as subgroup analysis or meta-regression as analytical methods to incorporate the quality assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Hypnotic Enhancement of Cognitive-Behavioral Weight Loss Treatments--Another Meta-reanalysis.

ERIC Educational Resources Information Center

Kirsch, Irving

1996-01-01

In a meta-analysis of the effect of adding hypnosis to cognitive-behavioral treatments for weight reduction, additional data were obtained from authors of two previous studies, and computational inaccuracies in the previous meta-analyses were corrected. Discusses findings. Correlational analyses indicated that the benefits of hypnosis increased…

Understanding differences in results from literature-based and individual patient meta-analyses: an example from meta-analyses of observational data.

PubMed

Poppe, Katrina K; Doughty, Robert N; Yu, Cheuk-Man; Quintana, Miguel; Møller, Jacob E; Klein, Allan L; Gamble, Greg D; Dini, Frank L; Whalley, Gillian A

2011-04-14

Meta-analyses are increasingly used to summarise observational data however a literature meta-analysis (LMA) may give different results to the corresponding individual patient meta-analysis (IPMA). This study compares the published results of equivalent LMAs and IPMAs, highlighting factors that can affect the results and therefore impact on clinical interpretation of meta-analyses. Univariate results from published meta-analyses of prospective observational outcome data were compared, as were the number of studies, patients and length of follow-up. The absolute difference in survival was calculated. The association between severe diastolic dysfunction (RFP) and death post acute myocardial infarction (AMI) and in chronic heart failure (HF) were used as clinical examples. The IPMA hazard ratio was lower that the LMA odds ratio: AMI hazard ratio 2.67 (95% confidence interval 2.23 to 3.20), odds ratio 4.10 (3.38 to 4.99); HF hazard ratio 2.42 (2.06 to 2.83), odds ratio 4.36 (3.60 to 5.04). The IPMAs contained most of the studies from the LMAs as well as additional unpublished data, and a longer length of follow-up was available in the IPMAs (AMI 3.7 vs 2.6 yr, HF 4.0 vs 1.5 yr). Restricting analysis to the same studies in both the LMA and IPMA resulted in a similar difference in effect sizes between methods to those found in the published analyses. The result of a meta-analysis is affected by whether study level or individual patient data have been used, and the variant of analysis that is required. Awareness and consideration of these factors is important for clinical interpretation of meta-analyses. Copyright © 2009 Elsevier B.V. All rights reserved.

Reporting of meta-analyses of randomized controlled trials with a focus on drug safety: an empirical assessment.

PubMed

Hammad, Tarek A; Neyarapally, George A; Pinheiro, Simone P; Iyasu, Solomon; Rochester, George; Dal Pan, Gerald

2013-01-01

Due to the sparse nature of serious drug-related adverse events (AEs), meta-analyses combining data from several randomized controlled trials (RCTs) to evaluate drug safety issues are increasingly being conducted and published, influencing clinical and regulatory decision making. Evaluation of meta-analyses involves the assessment of both the individual constituent trials and the approaches used to combine them. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting framework is designed to enhance the reporting of systematic reviews and meta-analyses. However, PRISMA may not cover all critical elements useful in the evaluation of meta-analyses with a focus on drug safety particularly in the regulatory-public health setting. This work was conducted to (1) evaluate the adherence of a sample of published drug safety-focused meta-analyses to the PRISMA reporting framework, (2) identify gaps in this framework based on key aspects pertinent to drug safety, and (3) stimulate the development and validation of a more comprehensive reporting tool that incorporates elements unique to drug safety evaluation. We selected a sample of meta-analyses of RCTs based on review of abstracts from high-impact journals as well as top medical specialty journals between 2009 and 2011. We developed a preliminary reporting framework based on PRISMA with specific additional reporting elements critical for the evaluation of drug safety meta-analyses of RCTs. The reporting of pertinent elements in each meta-analysis was reviewed independently by two authors; discrepancies in the independent evaluations were resolved through discussions between the two authors. A total of 27 meta-analyses, 12 from highest impact journals, 13 from specialty medical journals, and 2 from Cochrane reviews, were identified and evaluated. The great majority (>85%) of PRISMA elements were addressed in more than half of the meta-analyses reviewed. However, the majority of meta-analyses (>60%) did not address most (>80%) of the additional reporting elements critical for the evaluation of drug safety. Some of these elements were not addressed in any of the reviewed meta-analyses. This review included a sample of meta-analyses, with a focus on drug safety, recently published in high-impact journals; therefore, we may have underestimated the extent of the reporting problem across all meta-analyses of drug safety. Furthermore, temporal trends in reporting could not be evaluated in this review because of the short time interval selected. While the majority of PRISMA elements were addressed by most studies reviewed, the majority of studies did not address most of the additional safety-related elements. These findings highlight the need for the development and validation of a drug safety reporting framework and the importance of the current initiative by the Council for International Organizations of Medical Sciences (CIOMS) to create a guidance document for drug safety information synthesis/meta-analysis, which may improve reporting, conduct, and evaluation of meta-analyses of drug safety and inform clinical and regulatory decision making.

A Tutorial on Conducting Meta-Analyses of Clinical Outcome Research.

ERIC Educational Resources Information Center

Robey, Randall R.; Dalebout, Susan D.

1998-01-01

The purpose of this tutorial is to enhance the familiarity and accessibility of meta-analyses in the domains of audiology and speech-language pathology for investigating questions of treatment efficacy and treatment effectiveness. Steps to conducting a meta-analysis are explained and an example of meta-analysis using published data is included.…

No evidential value in samples of transcranial direct current stimulation (tDCS) studies of cognition and working memory in healthy populations.

PubMed

Medina, Jared; Cason, Samuel

2017-09-01

A substantial number of studies have been published over the last decade, claiming that transcranial direct current stimulation (tDCS) can influence performance on cognitive tasks. However, there is some skepticism regarding the efficacy of tDCS, and evidence from meta-analyses are mixed. One major weakness of these meta-analyses is that they only examine outcomes in published studies. Given biases towards publishing positive results in the scientific literature, there may be a substantial "file-drawer" of unpublished negative results in the tDCS literature. Furthermore, multiple researcher degrees of freedom can also inflate published p-values. Recently, Simonsohn, Nelson and Simmons (2014) created a novel meta-analytic tool that examines the distribution of significant p-values in a literature, and compares it to expected distributions with different effect sizes. Using this tool, one can assess whether the selected studies have evidential value. Therefore, we examined a random selection of studies that used tDCS to alter performance on cognitive tasks, and tDCS studies on working memory in a recently published meta-analysis (Mancuso et al., 2016). Using a p-curve analysis, we found no evidence that the tDCS studies had evidential value (33% power or greater), with the estimate of statistical power of these studies being approximately 14% for the cognitive studies, and 5% (what would be expected from randomly generated data) for the working memory studies. It is likely that previous tDCS studies are substantially underpowered, and we provide suggestions for future research to increase the evidential value of future tDCS studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Systematic literature reviews and meta-analyses: part 6 of a series on evaluation of scientific publications.

PubMed

Ressing, Meike; Blettner, Maria; Klug, Stefanie J

2009-07-01

Because of the rising number of scientific publications, it is important to have a means of jointly summarizing and assessing different studies on a single topic. Systematic literature reviews, meta-analyses of published data, and meta-analyses of individual data (pooled reanalyses) are now being published with increasing frequency. We here describe the essential features of these methods and discuss their strengths and weaknesses. This article is based on a selective literature search. The different types of review and meta-analysis are described, the methods used in each are outlined so that they can be evaluated, and a checklist is given for the assessment of reviews and meta-analyses of scientific articles. Systematic literature reviews provide an overview of the state of research on a given topic and enable an assessment of the quality of individual studies. They also allow the results of different studies to be evaluated together when these are inconsistent. Meta-analyses additionally allow calculation of pooled estimates of an effect. The different types of review and meta-analysis are discussed with examples from the literature on one particular topic. Systematic literature reviews and meta-analyses enable the research findings and treatment effects obtained in different individual studies to be summed up and evaluated.

Meta-analysis of the effectiveness of psychological and medical treatments for binge-eating disorder (MetaBED): study protocol.

PubMed

Hilbert, Anja; Petroff, David; Herpertz, Stephan; Kersting, Anette; Pietrowsky, Reinhard; Tuschen-Caffier, Brunna; Vocks, Silja; Schmidt, Ricarda

2017-03-29

Binge-eating disorder (BED) was included as its own diagnostic entity in the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). An increasing number of treatment studies have been published, but an up-to-date comprehensive meta-analysis on diverse treatment approaches for BED is lacking. In an updated and extension of a previous meta-analysis, the goals of this study are to assess the short-term and long-term effectiveness of psychological and medical treatments for BED. We will search bibliographic databases and study registries, including manual searches for studies published before January 2016. The search strategy will include terms relating to binge eating and diverse forms of psychological and medical interventions. Language will be restricted to English. The studies included will be treatment studies, that is, randomised-controlled trials, and non-randomised and non-controlled studies, for individuals with BED (DSM-IV or DSM-5), and studies that provided a pre-treatment and at least one post-treatment or follow-up assessment of binge eating. The primary outcomes will be the number of binge-eating episodes, abstinence from binge eating and diagnosis of BED at post-treatment and/or follow-up(s), and changes from pre-treatment to post-treatment and/or follow-up(s). Likewise, as secondary outcomes, eating disorder and general psychopathology, quality of life, and body weight will be analysed and adverse events and treatment drop-out will be examined. Study search, selection and data extraction, including risk of bias assessment, will be independently performed by 2 reviewers and consensus will be sought. Moderator analyses will be conducted, and equity aspects will be considered. Sensitivity analyses will be conducted to determine the robustness of the results. Ethical approval is not required for this meta-analysis. Published in a peer-reviewed journal and disseminated electronically and in print, this meta-analysis will form the basis of the renewal of the German evidence-based S3 Guidelines of Diagnosis and Treatment of Eating Disorders, specifically BED. CRD42016043604. 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/.

Publication bias in obesity treatment trials?

PubMed

Allison, D B; Faith, M S; Gorman, B S

1996-10-01

The present investigation examined the extent of publication bias (namely the tendency to publish significant findings and file away non-significant findings) within the obesity treatment literature. Quantitative literature synthesis of four published meta-analyses from the obesity treatment literature. Interventions in these studies included pharmacological, educational, child, and couples treatments. To assess publication bias, several regression procedures (for example weighted least-squares, random-effects multi-level modeling, and robust regression methods) were used to regress effect sizes onto their standard errors, or proxies thereof, within each of the four meta-analysis. A significant positive beta weight in these analyses signified publication bias. There was evidence for publication bias within two of the four published meta-analyses, such that reviews of published studies were likely to overestimate clinical efficacy. The lack of evidence for publication bias within the two other meta-analyses might have been due to insufficient statistical power rather than the absence of selection bias. As in other disciplines, publication bias appears to exist in the obesity treatment literature. Suggestions are offered for managing publication bias once identified or reducing its likelihood in the first place.

Trends in published meta-analyses in cancer research, 2008-2013.

PubMed

Qadir, Ximena V; Clyne, Mindy; Lam, Tram Kim; Khoury, Muin J; Schully, Sheri D

2017-01-01

In order to capture trends in the contribution of epidemiology to cancer research, we describe an online meta-analysis database resource for cancer clinical and population research and illustrate trends and descriptive detail of cancer meta-analyses from 2008 through 2013. A total of 4,686 cancer meta-analyses met our inclusion criteria. During this 6-year period, a fivefold increase was observed in the yearly number of meta-analyses. Fifty-six percent of meta-analyses concerned observational studies, mostly of cancer risk, more than half of which were genetic studies. The major cancer sites were breast, colorectal, and digestive. This online database for Cancer Genomics and Epidemiology Navigator will be continuously updated to allow investigators to quickly navigate the meta-analyses emerging from cancer epidemiology studies and cancer clinical trials.

Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study.

PubMed

Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias; Salanti, Georgia

2018-02-28

To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) ("living" network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (P<0.10). Cumulative pairwise and network meta-analyses were performed for each selected comparison. Monitoring boundaries of statistical significance were constructed and the evidence against the null hypothesis was considered to be strong when the monitoring boundaries were crossed. A significance level was defined as α=5%, power of 90% (β=10%), and an anticipated treatment effect to detect equal to the final estimate from the network meta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis provided strong evidence against the null hypothesis for seven comparisons, but for an additional 10 comparisons only network meta-analysis provided strong evidence against the null hypothesis (P=0.002). The median time to strong evidence against the null hypothesis was 19 years with living network meta-analysis and 23 years with living pairwise meta-analysis (hazard ratio 2.78, 95% confidence interval 1.00 to 7.72, P=0.05). Studies directly comparing the treatments of interest continued to be published for eight comparisons after strong evidence had become evident in network meta-analysis. In comparative effectiveness research, prospectively planned living network meta-analyses produced strong evidence against the null hypothesis more often and earlier than conventional, pairwise meta-analyses. 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.

Reporting and methodological quality of meta-analyses in urological literature.

PubMed

Xia, Leilei; Xu, Jing; Guzzo, Thomas J

2017-01-01

To assess the overall quality of published urological meta-analyses and identify predictive factors for high quality. We systematically searched PubMed to identify meta-analyses published from January 1st, 2011 to December 31st, 2015 in 10 predetermined major paper-based urology journals. The characteristics of the included meta-analyses were collected, and their reporting and methodological qualities were assessed by the PRISMA checklist (27 items) and AMSTAR tool (11 items), respectively. Descriptive statistics were used for individual items as a measure of overall compliance, and PRISMA and AMSTAR scores were calculated as the sum of adequately reported domains. Logistic regression was used to identify predictive factors for high qualities. A total of 183 meta-analyses were included. The mean PRISMA and AMSTAR scores were 22.74 ± 2.04 and 7.57 ± 1.41, respectively. PRISMA item 5, protocol and registration, items 15 and 22, risk of bias across studies, items 16 and 23, additional analysis had less than 50% adherence. AMSTAR item 1, " a priori " design, item 5, list of studies and item 10, publication bias had less than 50% adherence. Logistic regression analyses showed that funding support and " a priori " design were associated with superior reporting quality, following PRISMA guideline and " a priori " design were associated with superior methodological quality. Reporting and methodological qualities of recently published meta-analyses in major paper-based urology journals are generally good. Further improvement could potentially be achieved by strictly adhering to PRISMA guideline and having " a priori " protocol.

Review and meta-analysis of genetic polymorphisms associated with exceptional human longevity.

PubMed

Revelas, Mary; Thalamuthu, Anbupalam; Oldmeadow, Christopher; Evans, Tiffany-Jane; Armstrong, Nicola J; Kwok, John B; Brodaty, Henry; Schofield, Peter R; Scott, Rodney J; Sachdev, Perminder S; Attia, John R; Mather, Karen A

2018-06-08

Many factors contribute to exceptional longevity, with genetics playing a significant role. However, to date, genetic studies examining exceptional longevity have been inconclusive. This comprehensive review seeks to determine the genetic variants associated with exceptional longevity by undertaking meta-analyses. Meta-analyses of genetic polymorphisms previously associated with exceptional longevity (85+) were undertaken. For each variant, meta-analyses were performed if there were data from at least three independent studies available, including two unpublished additional cohorts. Five polymorphisms, ACE rs4340, APOE ε2/3/4, FOXO3A rs2802292, KLOTHO KL-VS and IL6 rs1800795 were significantly associated with exceptional longevity, with the pooled effect sizes (odds ratios) ranging from 0.42 (APOE ε4) to 1.45 (FOXO3A males). In general, the observed modest effect sizes of the significant variants suggest many genes of small influence play a role in exceptional longevity, which is consistent with results for other polygenic traits. Our results also suggest that genes related to cardiovascular health may be implicated in exceptional longevity. Future studies should examine the roles of gender and ethnicity and carefully consider study design, including the selection of appropriate controls. Copyright © 2018. Published by Elsevier B.V.

Altered Brain Activity in Unipolar Depression Revisited: Meta-analyses of Neuroimaging Studies.

PubMed

Müller, Veronika I; Cieslik, Edna C; Serbanescu, Ilinca; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

2017-01-01

During the past 20 years, numerous neuroimaging experiments have investigated aberrant brain activation during cognitive and emotional processing in patients with unipolar depression (UD). The results of those investigations, however, vary considerably; moreover, previous meta-analyses also yielded inconsistent findings. To readdress aberrant brain activation in UD as evidenced by neuroimaging experiments on cognitive and/or emotional processing. Neuroimaging experiments published from January 1, 1997, to October 1, 2015, were identified by a literature search of PubMed, Web of Science, and Google Scholar using different combinations of the terms fMRI (functional magnetic resonance imaging), PET (positron emission tomography), neural, major depression, depression, major depressive disorder, unipolar depression, dysthymia, emotion, emotional, affective, cognitive, task, memory, working memory, inhibition, control, n-back, and Stroop. Neuroimaging experiments (using fMRI or PET) reporting whole-brain results of group comparisons between adults with UD and healthy control individuals as coordinates in a standard anatomic reference space and using an emotional or/and cognitive challenging task were selected. Coordinates reported to show significant activation differences between UD and healthy controls during emotional or cognitive processing were extracted. By using the revised activation likelihood estimation algorithm, different meta-analyses were calculated. Meta-analyses tested for brain regions consistently found to show aberrant brain activation in UD compared with controls. Analyses were calculated across all emotional processing experiments, all cognitive processing experiments, positive emotion processing, negative emotion processing, experiments using emotional face stimuli, experiments with a sex discrimination task, and memory processing. All meta-analyses were calculated across experiments independent of reporting an increase or decrease of activity in major depressive disorder. For meta-analyses with a minimum of 17 experiments available, separate analyses were performed for increases and decreases. In total, 57 studies with 99 individual neuroimaging experiments comprising in total 1058 patients were included; 34 of them tested cognitive and 65 emotional processing. Overall analyses across cognitive processing experiments (P > .29) and across emotional processing experiments (P > .47) revealed no significant results. Similarly, no convergence was found in analyses investigating positive (all P > .15), negative (all P > .76), or memory (all P > .48) processes. Analyses that restricted inclusion of confounds (eg, medication, comorbidity, age) did not change the results. Inconsistencies exist across individual experiments investigating aberrant brain activity in UD and replication problems across previous neuroimaging meta-analyses. For individual experiments, these inconsistencies may relate to use of uncorrected inference procedures, differences in experimental design and contrasts, or heterogeneous clinical populations; meta-analytically, differences may be attributable to varying inclusion and exclusion criteria or rather liberal statistical inference approaches.

Altered Brain Activity in Unipolar Depression Revisited Meta-analyses of Neuroimaging Studies

PubMed Central

Müller, Veronika I.; Cieslik, Edna C.; Serbanescu, Ilinca; Laird, Angela R.; Fox, Peter T.; Eickhoff, Simon B.

2017-01-01

IMPORTANCE During the past 20 years, numerous neuroimaging experiments have investigated aberrant brain activation during cognitive and emotional processing in patients with unipolar depression (UD). The results of those investigations, however, vary considerably; moreover, previous meta-analyses also yielded inconsistent findings. OBJECTIVE To readdress aberrant brain activation in UD as evidenced by neuroimaging experiments on cognitive and/or emotional processing. DATA SOURCES Neuroimaging experiments published from January 1, 1997, to October 1, 2015, were identified by a literature search of PubMed, Web of Science, and Google Scholar using different combinations of the terms fMRI (functional magnetic resonance imaging), PET (positron emission tomography), neural, major depression, depression, major depressive disorder, unipolar depression, dysthymia, emotion, emotional, affective, cognitive, task, memory, working memory, inhibition, control, n-back, and Stroop. STUDY SELECTION Neuroimaging experiments (using fMRI or PET) reporting whole-brain results of group comparisons between adults with UD and healthy control individuals as coordinates in a standard anatomic reference space and using an emotional or/and cognitive challenging task were selected. DATA EXTRACTION AND SYNTHESIS Coordinates reported to show significant activation differences between UD and healthy controls during emotional or cognitive processing were extracted. By using the revised activation likelihood estimation algorithm, different meta-analyses were calculated. MAIN OUTCOMES AND MEASURES Meta-analyses tested for brain regions consistently found to show aberrant brain activation in UD compared with controls. Analyses were calculated across all emotional processing experiments, all cognitive processing experiments, positive emotion processing, negative emotion processing, experiments using emotional face stimuli, experiments with a sex discrimination task, and memory processing. All meta-analyses were calculated across experiments independent of reporting an increase or decrease of activity in major depressive disorder. For meta-analyses with a minimum of 17 experiments available, separate analyses were performed for increases and decreases. RESULTS In total, 57 studies with 99 individual neuroimaging experiments comprising in total 1058 patients were included; 34 of them tested cognitive and 65 emotional processing. Overall analyses across cognitive processing experiments (P > .29) and across emotional processing experiments (P > .47) revealed no significant results. Similarly, no convergence was found in analyses investigating positive (all P > .15), negative (all P > .76), or memory (all P > .48) processes. Analyses that restricted inclusion of confounds (eg, medication, comorbidity, age) did not change the results. CONCLUSIONS AND RELEVANCE Inconsistencies exist across individual experiments investigating aberrant brain activity in UD and replication problems across previous neuroimaging meta-analyses. For individual experiments, these inconsistencies may relate to use of uncorrected inference procedures, differences in experimental design and contrasts, or heterogeneous clinical populations; meta-analytically, differences may be attributable to varying inclusion and exclusion criteria or rather liberal statistical inference approaches. PMID:27829086

Predictive distributions were developed for the extent of heterogeneity in meta-analyses of continuous outcome data.

PubMed

Rhodes, Kirsty M; Turner, Rebecca M; Higgins, Julian P T

2015-01-01

Estimation of between-study heterogeneity is problematic in small meta-analyses. Bayesian meta-analysis is beneficial because it allows incorporation of external evidence on heterogeneity. To facilitate this, we provide empirical evidence on the likely heterogeneity between studies in meta-analyses relating to specific research settings. Our analyses included 6,492 continuous-outcome meta-analyses within the Cochrane Database of Systematic Reviews. We investigated the influence of meta-analysis settings on heterogeneity by modeling study data from all meta-analyses on the standardized mean difference scale. Meta-analysis setting was described according to outcome type, intervention comparison type, and medical area. Predictive distributions for between-study variance expected in future meta-analyses were obtained, which can be used directly as informative priors. Among outcome types, heterogeneity was found to be lowest in meta-analyses of obstetric outcomes. Among intervention comparison types, heterogeneity was lowest in meta-analyses comparing two pharmacologic interventions. Predictive distributions are reported for different settings. In two example meta-analyses, incorporating external evidence led to a more precise heterogeneity estimate. Heterogeneity was influenced by meta-analysis characteristics. Informative priors for between-study variance were derived for each specific setting. Our analyses thus assist the incorporation of realistic prior information into meta-analyses including few studies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Intermittent catheterisation with hydrophilic and non-hydrophilic urinary catheters: systematic literature review and meta-analyses.

PubMed

Rognoni, Carla; Tarricone, Rosanna

2017-01-10

Intermittent catheterisation is the method of choice for the management of bladder dysfunctions. Different urinary catheters are available, but there is conflicting evidence on which type of catheter is best. The present study provides an objective evaluation of the clinical effectiveness of different subsets of urinary catheters. A systematic literature review was performed for published RCTs regarding hydrophilic coated and PVC (standard) catheters for intermittent catheterisation. Separate meta-analyses were conducted to combine data on frequencies of urinary tract infections (UTIs) and haematuria. Two separate analyses were performed, including or excluding reused standard catheters. Seven studies were eligible for inclusion in the review. The meta-analyses exploring UTI frequencies showed a lower risk ratio associated with hydrophilic catheters in comparison to standard ones (RR = 0.84; 95% CI, 0.75-0.94; p = 0.003). Results for the "reuse" scenario were consistent with the ones related to "single-use" scenario in terms of frequency of UTIs. The meta-analyses exploring haematuria were not able to demonstrate any statistically significant difference between hydrophilic catheters in comparison to standard ones. The findings confirm previously reported benefits of hydrophilic catheters but a broader evaluation that takes into account also patient preferences, compliance of therapy, quality of life and costs would be needed to assess the economic sustainability of these advanced devices.

Early studies reported extreme findings with large variability: a meta-epidemiologic study in the field of endocrinology.

PubMed

Wang, Zhen; Alahdab, Fares; Almasri, Jehad; Haydour, Qusay; Mohammed, Khaled; Abu Dabrh, Abd Moain; Prokop, Larry J; Alfarkh, Wedad; Lakis, Sumaya; Montori, Victor M; Murad, Mohammad Hassan

2016-04-01

To evaluate the presence of extreme findings and fluctuation in effect size in endocrinology. We systematically identified all meta-analyses published in 2014 in the field of endocrinology. Within each meta-analysis, the effect size of the primary binary outcome was compared across studies according to their order of publication. We pooled studies using the DerSimonian and Laird random-effects method. Heterogeneity was evaluated using the I(2) and tau(2). Twelve percent of the included 100 meta-analyses reported the largest effect size in the very first published study. The largest effect size occurred in the first 2 earliest studies in 31% of meta-analyses. When the effect size was the largest in the first published study, it was three times larger than the final pooled effect (ratio of rates, 3.26; 95% confidence interval: 1.80, 5.90). The largest heterogeneity measured by I(2) was observed in 18% of the included meta-analyses when combining the first 2 studies or 17% when combing the first 3 studies. In endocrinology, early studies reported extreme findings with large variability. This behavior of the evidence needs to be taken into account when used to formulate clinical policies. Copyright © 2016 Elsevier Inc. All rights reserved.

Alcohol intake and gastric cancer: Meta-analyses of published data versus individual participant data pooled analyses (StoP Project).

PubMed

Ferro, Ana; Morais, Samantha; Rota, Matteo; Pelucchi, Claudio; Bertuccio, Paola; Bonzi, Rossella; Galeone, Carlotta; Zhang, Zuo-Feng; Matsuo, Keitaro; Ito, Hidemi; Hu, Jinfu; Johnson, Kenneth C; Yu, Guo-Pei; Palli, Domenico; Ferraroni, Monica; Muscat, Joshua; Malekzadeh, Reza; Ye, Weimin; Song, Huan; Zaridze, David; Maximovitch, Dmitry; Fernández de Larrea, Nerea; Kogevinas, Manolis; Vioque, Jesus; Navarrete-Muñoz, Eva M; Pakseresht, Mohammadreza; Pourfarzi, Farhad; Wolk, Alicja; Orsini, Nicola; Bellavia, Andrea; Håkansson, Niclas; Mu, Lina; Pastorino, Roberta; Kurtz, Robert C; Derakhshan, Mohammad H; Lagiou, Areti; Lagiou, Pagona; Boffetta, Paolo; Boccia, Stefania; Negri, Eva; La Vecchia, Carlo; Peleteiro, Bárbara; Lunet, Nuno

2018-05-01

Individual participant data pooled analyses allow access to non-published data and statistical reanalyses based on more homogeneous criteria than meta-analyses based on systematic reviews. We quantified the impact of publication-related biases and heterogeneity in data analysis and presentation in summary estimates of the association between alcohol drinking and gastric cancer. We compared estimates obtained from conventional meta-analyses, using only data available in published reports from studies that take part in the Stomach Cancer Pooling (StoP) Project, with individual participant data pooled analyses including the same studies. A total of 22 studies from the StoP Project assessed the relation between alcohol intake and gastric cancer, 19 had specific data for levels of consumption and 18 according to cancer location; published reports addressing these associations were available from 18, 5 and 5 studies, respectively. The summary odds ratios [OR, (95%CI)] estimate obtained with published data for drinkers vs. non-drinkers was 10% higher than the one obtained with individual StoP data [18 vs. 22 studies: 1.21 (1.07-1.36) vs. 1.10 (0.99-1.23)] and more heterogeneous (I 2 : 63.6% vs 54.4%). In general, published data yielded less precise summary estimates (standard errors up to 2.6 times higher). Funnel plot analysis suggested publication bias. Meta-analyses of the association between alcohol drinking and gastric cancer tended to overestimate the magnitude of the effects, possibly due to publication bias. Additionally, individual participant data pooled analyses yielded more precise estimates for different levels of exposure or cancer subtypes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Knowledge Integration in Cancer: Current Landscape and Future Prospects

PubMed Central

Ioannidis, John P.A.; Schully, Sheri D.; Lam, Tram Kim; Khoury, Muin J.

2015-01-01

Knowledge integration includes knowledge management, synthesis, and translation processes. It aims to maximize the use of collected scientific information and accelerate translation of discoveries into individual and population health benefits. Accumulated evidence in cancer epidemiology constitutes a large share of the 2.7 million articles on cancer in PubMed. We examine the landscape of knowledge integration in cancer epidemiology. Past approaches have mostly used retrospective efforts of knowledge management and traditional systematic reviews and meta-analyses. Systematic searches identify 2,332 meta-analyses, about half of which are on genetics and epigenetics. Meta-analyses represent 1:89-1:1162 of published articles in various cancer subfields. Recently, there are more collaborative meta-analyses with individual-level data, including those with prospective collection of measurements [e.g., genotypes in genome-wide association studies (GWAS)]; this may help increase the reliability of inferences in the field. However, most meta-analyses are still done retrospectively with published information. There is also a flurry of candidate gene meta-analyses with spuriously prevalent "positive" results. Prospective design of large research agendas, registration of datasets, and public availability of data and analyses may improve our ability to identify knowledge gaps, maximize and accelerate translational progress or—at a minimum—recognize dead ends in a more timely fashion. PMID:23093546

Knowledge integration in cancer: current landscape and future prospects.

PubMed

Ioannidis, John P A; Schully, Sheri D; Lam, Tram Kim; Khoury, Muin J

2013-01-01

Knowledge integration includes knowledge management, synthesis, and translation processes. It aims to maximize the use of collected scientific information and accelerate translation of discoveries into individual and population health benefits. Accumulated evidence in cancer epidemiology constitutes a large share of the 2.7 million articles on cancer in PubMed. We examine the landscape of knowledge integration in cancer epidemiology. Past approaches have mostly used retrospective efforts of knowledge management and traditional systematic reviews and meta-analyses. Systematic searches identify 2,332 meta-analyses, about half of which are on genetics and epigenetics. Meta-analyses represent 1:89-1:1162 of published articles in various cancer subfields. Recently, there are more collaborative meta-analyses with individual-level data, including those with prospective collection of measurements [e.g., genotypes in genome-wide association studies (GWAS)]; this may help increase the reliability of inferences in the field. However, most meta-analyses are still done retrospectively with published information. There is also a flurry of candidate gene meta-analyses with spuriously prevalent "positive" results. Prospective design of large research agendas, registration of datasets, and public availability of data and analyses may improve our ability to identify knowledge gaps, maximize and accelerate translational progress or-at a minimum-recognize dead ends in a more timely fashion.

Review of meta-analyses evaluating surrogate endpoints for overall survival in oncology.

PubMed

Sherrill, Beth; Kaye, James A; Sandin, Rickard; Cappelleri, Joseph C; Chen, Connie

2012-01-01

Overall survival (OS) is the gold standard in measuring the treatment effect of new drug therapies for cancer. However, practical factors may preclude the collection of unconfounded OS data, and surrogate endpoints are often used instead. Meta-analyses have been widely used for the validation of surrogate endpoints, specifically in oncology. This research reviewed published meta-analyses on the types of surrogate measures used in oncology studies and examined the extent of correlation between surrogate endpoints and OS for different cancer types. A search was conducted in October 2010 to compile available published evidence in the English language for the validation of disease progression-related endpoints as surrogates of OS, based on meta-analyses. We summarize published meta-analyses that quantified the correlation between progression-based endpoints and OS for multiple advanced solid-tumor types. We also discuss issues that affect the interpretation of these findings. Progression-free survival is the most commonly used surrogate measure in studies of advanced solid tumors, and correlation with OS is reported for a limited number of cancer types. Given the increased use of crossover in trials and the availability of second-/third-line treatment options available to patients after progression, it will become increasingly more difficult to establish correlation between effects on progression-free survival and OS in additional tumor types.

Reporting and methodological quality of meta-analyses in urological literature

PubMed Central

Xu, Jing

2017-01-01

Purpose To assess the overall quality of published urological meta-analyses and identify predictive factors for high quality. Materials and Methods We systematically searched PubMed to identify meta-analyses published from January 1st, 2011 to December 31st, 2015 in 10 predetermined major paper-based urology journals. The characteristics of the included meta-analyses were collected, and their reporting and methodological qualities were assessed by the PRISMA checklist (27 items) and AMSTAR tool (11 items), respectively. Descriptive statistics were used for individual items as a measure of overall compliance, and PRISMA and AMSTAR scores were calculated as the sum of adequately reported domains. Logistic regression was used to identify predictive factors for high qualities. Results A total of 183 meta-analyses were included. The mean PRISMA and AMSTAR scores were 22.74 ± 2.04 and 7.57 ± 1.41, respectively. PRISMA item 5, protocol and registration, items 15 and 22, risk of bias across studies, items 16 and 23, additional analysis had less than 50% adherence. AMSTAR item 1, “a priori” design, item 5, list of studies and item 10, publication bias had less than 50% adherence. Logistic regression analyses showed that funding support and “a priori” design were associated with superior reporting quality, following PRISMA guideline and “a priori” design were associated with superior methodological quality. Conclusions Reporting and methodological qualities of recently published meta-analyses in major paper-based urology journals are generally good. Further improvement could potentially be achieved by strictly adhering to PRISMA guideline and having “a priori” protocol. PMID:28439452

Investigating the effect of ethnicity on IVF outcome.

PubMed

Dhillon, Rima K; Smith, Paul P; Malhas, Rosamund; Harb, Hoda M; Gallos, Ioannis D; Dowell, Ken; Fishel, Simon; Deeks, Jon J; Coomarasamy, Aravinthan

2015-09-01

Success rates for IVF among women from different ethnic groups have been inconclusive. In this study, the relationship between ethnicity and IVF outcome was investigated. Results of a cohort study analysing 13,473 first cycles were compared with the results of meta-analysed data from 16 published studies. Adjustment was made for age, body-mass index, cause of infertility, duration of infertility, previous live birth, previous spontaneous abortion and number of embryos transferred. Black and South Asian women were found to have lower live birth rates compared with White women: Black versus White (OR 0.42 [0.25 to 0.70]; P = 0.001); South Asian versus White (OR 0.80 [0.65t o 0.99]; P = 0.04). Black women had significantly lower clinical pregnancy rates compared with White women (OR 0.41 [0.25 to 9 0.67]; P < 0.001). The meta-analysed results also showed that Black and South Asian women had statistically significant reduced odds of live birth (OR 0.62 [0.55 to 0.71); P < 0.001 and OR 0.66 [0.52 to 0.85); P = 0.001, respectively). Black and South Asian women seem to have the poorest outcome, which is not explained by the commonly known confounders. Future research needs to investigate the possible explanations for this difference and improve IVF outcome for all women. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

A disease looking for innovative drugs: The case of pulmonary arterial hypertension.

PubMed

Joppi, Roberta; Gerardi, Chiara; Bertele', Vittorio; Garattini, Silvio

2018-05-25

Pulmonary arterial hypertension (PAH) is a life-threatening rare disease. Between 2001 and 2016 the European Medicines Agency (EMA) approved nine drugs to treat PAH. Considering the poor prognosis of patients with PAH it would be useful to understand whether the approved therapies can change the natural history of the disease. We assessed the therapeutic value and the quality of the evidence on medicines that have been authorized by the EMA in the 2000s. Information about drug approval was obtained from the EMA website and the European Public Assessment Reports. MedLine, Embase, and Cochrane databases were systematically searched for published randomized clinical trials and meta-analyses of the selected drugs and their combinations. At the time of approval no medicine had been proved to reduce mortality or slow the progression of the disease or to improve patients' quality of life. Recent meta-analyses concluded that, compared to placebo, active treatments reduced mortality but there was no conclusion on any preferred therapeutic option. Approvals of monotherapies in the absence of best evidence of their efficacy, have prompted the search for better efficacy of their combinations. Three meta-analyses found no advantage in survival from combinations as opposed to monotherapies. This model case confirms previous analyses that marketing authorizations granted in spite of low evidence of therapeutic efficacy not only expose patients to treatments with unknown benefit-risk profiles but also hamper post-marketing research aimed at filling the information gap. Copyright © 2018. Published by Elsevier B.V.

Optimal patient education for cancer pain: a systematic review and theory-based meta-analysis.

PubMed

Marie, N; Luckett, T; Davidson, P M; Lovell, M; Lal, S

2013-12-01

Previous systematic reviews have found patient education to be moderately efficacious in decreasing the intensity of cancer pain, but variation in results warrants analysis aimed at identifying which strategies are optimal. A systematic review and meta-analysis was undertaken using a theory-based approach to classifying and comparing educational interventions for cancer pain. The reference lists of previous reviews and MEDLINE, PsycINFO, and CENTRAL were searched in May 2012. Studies had to be published in a peer-reviewed English language journal and compare the effect on cancer pain intensity of education with usual care. Meta-analyses used standardized effect sizes (ES) and a random effects model. Subgroup analyses compared intervention components categorized using the Michie et al. (Implement Sci 6:42, 2011) capability, opportunity, and motivation behavior (COM-B) model. Fifteen randomized controlled trials met the criteria. As expected, meta-analysis identified a small-moderate ES favoring education versus usual care (ES, 0.27 [-0.47, -0.07]; P = 0.007) with substantial heterogeneity (I² = 71 %). Subgroup analyses based on the taxonomy found that interventions using "enablement" were efficacious (ES, 0.35 [-0.63, -0.08]; P = 0.01), whereas those lacking this component were not (ES, 0.18 [-0.46, 0.10]; P = 0.20). However, the subgroup effect was nonsignificant (P = 0.39), and heterogeneity was not reduced. Factoring in the variable of individualized versus non-individualized influenced neither efficacy nor heterogeneity. The current meta-analysis follows a trend in using theory to understand the mechanisms of complex interventions. We suggest that future efforts focus on interventions that target patient self-efficacy. Authors are encouraged to report comprehensive details of interventions and methods to inform synthesis, replication, and refinement.

Quality Assessment of Studies Published in Open Access and Subscription Journals: Results of a Systematic Evaluation.

PubMed

Pastorino, Roberta; Milovanovic, Sonja; Stojanovic, Jovana; Efremov, Ljupcho; Amore, Rosarita; Boccia, Stefania

2016-01-01

Along with the proliferation of Open Access (OA) publishing, the interest for comparing the scientific quality of studies published in OA journals versus subscription journals has also increased. With our study we aimed to compare the methodological quality and the quality of reporting of primary epidemiological studies and systematic reviews and meta-analyses published in OA and non-OA journals. In order to identify the studies to appraise, we listed all OA and non-OA journals which published in 2013 at least one primary epidemiologic study (case-control or cohort study design), and at least one systematic review or meta-analysis in the field of oncology. For the appraisal, we picked up the first studies published in 2013 with case-control or cohort study design from OA journals (Group A; n = 12), and in the same time period from non-OA journals (Group B; n = 26); the first systematic reviews and meta-analyses published in 2013 from OA journals (Group C; n = 15), and in the same time period from non-OA journals (Group D; n = 32). We evaluated the methodological quality of studies by assessing the compliance of case-control and cohort studies to Newcastle and Ottawa Scale (NOS) scale, and the compliance of systematic reviews and meta-analyses to Assessment of Multiple Systematic Reviews (AMSTAR) scale. The quality of reporting was assessed considering the adherence of case-control and cohort studies to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist, and the adherence of systematic reviews and meta-analyses to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) checklist. Among case-control and cohort studies published in OA and non-OA journals, we did not observe significant differences in the median value of NOS score (Group A: 7 (IQR 7-8) versus Group B: 8 (7-9); p = 0.5) and in the adherence to STROBE checklist (Group A, 75% versus Group B, 80%; p = 0.1). The results did not change after adjustment for impact factor. The compliance with AMSTAR and adherence to PRISMA checklist were comparable between systematic reviews and meta-analyses published in OA and non-OA journals (Group C, 46.0% versus Group D, 55.0%; p = 0.06), (Group C, 72.0% versus Group D, 76.0%; p = 0.1), respectively). The epidemiological studies published in OA journals in the field of oncology approach the same methodological quality and quality of reporting as studies published in non-OA journals.

Quality Assessment of Studies Published in Open Access and Subscription Journals: Results of a Systematic Evaluation

PubMed Central

Pastorino, Roberta; Milovanovic, Sonja; Stojanovic, Jovana; Efremov, Ljupcho; Amore, Rosarita; Boccia, Stefania

2016-01-01

Introduction Along with the proliferation of Open Access (OA) publishing, the interest for comparing the scientific quality of studies published in OA journals versus subscription journals has also increased. With our study we aimed to compare the methodological quality and the quality of reporting of primary epidemiological studies and systematic reviews and meta-analyses published in OA and non-OA journals. Methods In order to identify the studies to appraise, we listed all OA and non-OA journals which published in 2013 at least one primary epidemiologic study (case-control or cohort study design), and at least one systematic review or meta-analysis in the field of oncology. For the appraisal, we picked up the first studies published in 2013 with case-control or cohort study design from OA journals (Group A; n = 12), and in the same time period from non-OA journals (Group B; n = 26); the first systematic reviews and meta-analyses published in 2013 from OA journals (Group C; n = 15), and in the same time period from non-OA journals (Group D; n = 32). We evaluated the methodological quality of studies by assessing the compliance of case-control and cohort studies to Newcastle and Ottawa Scale (NOS) scale, and the compliance of systematic reviews and meta-analyses to Assessment of Multiple Systematic Reviews (AMSTAR) scale. The quality of reporting was assessed considering the adherence of case-control and cohort studies to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist, and the adherence of systematic reviews and meta-analyses to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) checklist. Results Among case-control and cohort studies published in OA and non-OA journals, we did not observe significant differences in the median value of NOS score (Group A: 7 (IQR 7–8) versus Group B: 8 (7–9); p = 0.5) and in the adherence to STROBE checklist (Group A, 75% versus Group B, 80%; p = 0.1). The results did not change after adjustment for impact factor. The compliance with AMSTAR and adherence to PRISMA checklist were comparable between systematic reviews and meta-analyses published in OA and non-OA journals (Group C, 46.0% versus Group D, 55.0%; p = 0.06), (Group C, 72.0% versus Group D, 76.0%; p = 0.1), respectively). Conclusion The epidemiological studies published in OA journals in the field of oncology approach the same methodological quality and quality of reporting as studies published in non-OA journals. PMID:27167982

The Impact of Guided Notes on Post-Secondary Student Achievement: A Meta-Analysis

ERIC Educational Resources Information Center

Larwin, Karen H.; Larwin, David A.

2013-01-01

The common practice of using of guided notes in the post-secondary classroom is not fully appreciated or understood. In an effort to add to the existing research about this phenomenon, the current investigation expands on previously published research and one previously published meta-analysis that examined the impact of guided notes on…

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

PubMed Central

2012-01-01

Background Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention. Methods Using a collection of reviews identified previously, 166 references including a meta-analysis were selected for review. At least one of the primary outcomes in each review was an adverse or unintended event. The nature of the intervention, source of funding, number of individual meta-analyses performed, number of primary studies included in the review, and use of meta-analytic methods were all recorded. Specific areas of interest relating to the methods used included the choice of outcome metric, methods of dealing with sparse events, heterogeneity, publication bias and use of individual patient data. Results The 166 included reviews were published between 1994 and 2006. Interventions included drugs and surgery among other interventions. Many of the references being reviewed included multiple meta-analyses with 44.6% (74/166) including more than ten. Randomised trials only were included in 42.2% of meta-analyses (70/166), observational studies only in 33.7% (56/166) and a mix of observational studies and trials in 15.7% (26/166). Sparse data, in the form of zero events in one or both arms where the outcome was a count of events, was found in 64 reviews of two-arm studies, of which 41 (64.1%) had zero events in both arms. Conclusions Meta-analyses of adverse events data are common and useful in terms of increasing the power to detect an association with an intervention, especially when the events are infrequent. However, with regard to existing meta-analyses, a wide variety of different methods have been employed, often with no evident rationale for using a particular approach. More specifically, the approach to dealing with zero events varies, and guidelines on this issue would be desirable. PMID:22553987

Reappraisal of previously reported meta-analyses on antibiotic prophylaxis for low-risk laparoscopic cholecystectomy: an overview of systematic reviews

PubMed Central

Matsui, Yoichi; Satoi, Sohei; Hirooka, Satoshi; Kosaka, Hisashi; Kawaura, Takayuki; Kitawaki, Tomoki

2018-01-01

Introduction Many researchers have addressed overdosage and inappropriate use of antibiotics. Many meta-analyses have investigated antibiotic prophylaxis for low-risk laparoscopic cholecystectomy with the aim of reducing unnecessary antibiotic use. Most of these meta-analyses have concluded that prophylactic antibiotics are not required for low-risk laparoscopic cholecystectomies. This study aimed to assess the validity of this conclusion by systematically reviewing these meta-analyses. Methods A systematic review was undertaken. Searches were limited to meta-analyses and systematic reviews. PubMed and Cochrane Library electronic databases were searched from inception until March 2016 using the following keyword combinations: ‘antibiotic prophylaxis’, ‘laparoscopic cholecystectomy’ and ‘systematic review or meta-analysis’. Two independent reviewers selected meta-analyses or systematic reviews evaluating prophylactic antibiotics for laparoscopic cholecystectomy. All of the randomised controlled trials (RCTs) analysed in these meta-analyses were also reviewed. Results Seven meta-analyses regarding prophylactic antibiotics for low-risk laparoscopic cholecystectomy that had examined a total of 28 RCTs were included. Review of these meta-analyses revealed 48 miscounts of the number of outcomes. Six RCTs were inappropriate for the meta-analyses; one targeted patients with acute cholecystitis, another measured inappropriate outcomes, the original source of a third was not found and the study protocols of the remaining three were not appropriate for the meta-analyses. After correcting the above miscounts and excluding the six inappropriate RCTs, pooled risk ratios (RRs) were recalculated. These showed that, contrary to what had previously been concluded, antibiotics significantly reduced the risk of postoperative infections. The rates of surgical site, distant and overall infections were all significantly reduced by antibiotic administration (RR (95% CI); 0.71 (0.51 to 0.99), 0.37 (0.19 to 0.73), 0.50 (0.34 to 0.75), respectively). Conclusions Prophylactic antibiotics reduce the incidence of postoperative infections after elective laparoscopic cholecystectomy. PMID:29549197

A Quantitative Assessment of the Reporting Quality of Herbal Medicine Research: The Road to Improvement.

PubMed

Naumann, Ken

2018-02-01

To quantify different aspects of the quality of reporting of herbal medicine clinical trials, to determine how that quality is affecting the conclusions of meta-analyses, and to target areas for improvement in future herbal medicine research reporting. The Electronic databases PubMed, Academic Search Premier, ScienceDirect, and Alt HealthWatch were searched for meta-analyses of herbal medicines in refereed journals and Cochrane Reviews in the years 2000-2004 and 2010-2014. The search was limited to meta-analyses of randomized controlled trials involving humans and published in English. Judgments and descriptions within the meta-analyses were used to report on risks of bias in the included clinical trials and the meta-analyses themselves. Out of 3264 citations, 9 journal-published meta-analyses were selected from 2000 to 2004, 116 from 2010 to 2014, and 44 Cochrane Reviews from 2010 to 2014. Across both time frames and categories of publication, <42% of the trials included in the meta-analyses described adequate randomization; <19% described concealment methods; <26% described double blinding; <29% described outcome assessment blinding, ≤53% discussed incomplete data, and <36% were nonselective in their reporting. Less than 54% of trials reported on adverse events and 64% of meta-analyses did not include a single trial with a low risk of bias. Taxonomic verification and chemical characterization of test products were infrequent in trials. Only 40% of meta-analyses considered publication bias and, of those that did, 90% found evidence for it. Cochrane Reviews were more likely than other sources to make negative conclusions of efficacy or to defer conclusions because of the absence of high quality trials. Meta-analyses of herbal medicines include a significant number of clinical trials that do not meet the recommended standards for clinical trial reporting. This quantitative assessment identified significant publication bias and other bias risks that may be due to inadequate trial design or incomplete reporting of outcomes. Suggested improvements to herbal medicine clinical trial reporting are discussed.

Novel citation-based search method for scientific literature: application to meta-analyses.

PubMed

Janssens, A Cecile J W; Gwinn, M

2015-10-13

Finding eligible studies for meta-analysis and systematic reviews relies on keyword-based searching as the gold standard, despite its inefficiency. Searching based on direct citations is not sufficiently comprehensive. We propose a novel strategy that ranks articles on their degree of co-citation with one or more "known" articles before reviewing their eligibility. In two independent studies, we aimed to reproduce the results of literature searches for sets of published meta-analyses (n = 10 and n = 42). For each meta-analysis, we extracted co-citations for the randomly selected 'known' articles from the Web of Science database, counted their frequencies and screened all articles with a score above a selection threshold. In the second study, we extended the method by retrieving direct citations for all selected articles. In the first study, we retrieved 82% of the studies included in the meta-analyses while screening only 11% as many articles as were screened for the original publications. Articles that we missed were published in non-English languages, published before 1975, published very recently, or available only as conference abstracts. In the second study, we retrieved 79% of included studies while screening half the original number of articles. Citation searching appears to be an efficient and reasonably accurate method for finding articles similar to one or more articles of interest for meta-analysis and reviews.

Exercise improves depressive symptoms in older adults: An umbrella review of systematic reviews and meta-analyses.

PubMed

Catalan-Matamoros, Daniel; Gomez-Conesa, Antonia; Stubbs, Brendon; Vancampfort, Davy

2016-10-30

Late-life depression is a growing public health concern. Exercise may be of added value but the literature remains equivocal. We conducted a systematic overview of meta-analyses and an exploratory pooled analysis of previous meta-analyses to determine the effect of exercise on depression in older adults. Two independent researchers searched Pubmed, CINAHL, Cochrane Plus, PsycArticles, and PsycInfo for meta-analyses on exercise in late-life depression. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. We pooled effect sizes from previous meta-analyses of randomized controlled trials to determine the effect of exercise on depression in older adults. The systematic review yielded 3 meta-analyses. In total, 16 unique cohorts of 1487 participants were included. The quality of the three included meta-analyses was considered as "moderate" according to AMSTAR scores. No serious adverse events were reported. Compared to controls (n=583), those exercising (n=541) significantly reduced depressive symptoms. Our umbrella review indicates that exercise is safe and efficacious in reducing depressive symptoms in older people. Since exercise has many other known health benefits, it should be considered as a core intervention in the multidisciplinary treatment of older adults experiencing depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Reporting completeness and transparency of meta-analyses of depression screening tool accuracy: A comparison of meta-analyses published before and after the PRISMA statement.

PubMed

Rice, Danielle B; Kloda, Lorie A; Shrier, Ian; Thombs, Brett D

2016-08-01

Meta-analyses that are conducted rigorously and reported completely and transparently can provide accurate evidence to inform the best possible healthcare decisions. Guideline makers have raised concerns about the utility of existing evidence on the diagnostic accuracy of depression screening tools. The objective of our study was to evaluate the transparency and completeness of reporting in meta-analyses of the diagnostic accuracy of depression screening tools using the PRISMA tool adapted for diagnostic test accuracy meta-analyses. We searched MEDLINE and PsycINFO from January 1, 2005 through March 13, 2016 for recent meta-analyses in any language on the diagnostic accuracy of depression screening tools. Two reviewers independently assessed the transparency in reporting using the PRISMA tool with appropriate adaptations made for studies of diagnostic test accuracy. We identified 21 eligible meta-analyses. Twelve of 21 meta-analyses complied with at least 50% of adapted PRISMA items. Of 30 adapted PRISMA items, 11 were fulfilled by ≥80% of included meta-analyses, 3 by 50-79% of meta-analyses, 7 by 25-45% of meta-analyses, and 9 by <25%. On average, post-PRISMA meta-analyses complied with 17 of 30 items compared to 13 of 30 items pre-PRISMA. Deficiencies in the transparency of reporting in meta-analyses of the diagnostic test accuracy of depression screening tools of meta-analyses were identified. Authors, reviewers, and editors should adhere to the PRISMA statement to improve the reporting of meta-analyses of the diagnostic accuracy of depression screening tools. Copyright © 2016 Elsevier Inc. All rights reserved.

Review of meta-analyses evaluating surrogate endpoints for overall survival in oncology

PubMed Central

Sherrill, Beth; Kaye, James A; Sandin, Rickard; Cappelleri, Joseph C; Chen, Connie

2012-01-01

Overall survival (OS) is the gold standard in measuring the treatment effect of new drug therapies for cancer. However, practical factors may preclude the collection of unconfounded OS data, and surrogate endpoints are often used instead. Meta-analyses have been widely used for the validation of surrogate endpoints, specifically in oncology. This research reviewed published meta-analyses on the types of surrogate measures used in oncology studies and examined the extent of correlation between surrogate endpoints and OS for different cancer types. A search was conducted in October 2010 to compile available published evidence in the English language for the validation of disease progression-related endpoints as surrogates of OS, based on meta-analyses. We summarize published meta-analyses that quantified the correlation between progression-based endpoints and OS for multiple advanced solid-tumor types. We also discuss issues that affect the interpretation of these findings. Progression-free survival is the most commonly used surrogate measure in studies of advanced solid tumors, and correlation with OS is reported for a limited number of cancer types. Given the increased use of crossover in trials and the availability of second-/third-line treatment options available to patients after progression, it will become increasingly more difficult to establish correlation between effects on progression-free survival and OS in additional tumor types. PMID:23109809

Model-driven meta-analyses for informing health care: a diabetes meta-analysis as an exemplar.

PubMed

Brown, Sharon A; Becker, Betsy Jane; García, Alexandra A; Brown, Adama; Ramírez, Gilbert

2015-04-01

A relatively novel type of meta-analysis, a model-driven meta-analysis, involves the quantitative synthesis of descriptive, correlational data and is useful for identifying key predictors of health outcomes and informing clinical guidelines. Few such meta-analyses have been conducted and thus, large bodies of research remain unsynthesized and uninterpreted for application in health care. We describe the unique challenges of conducting a model-driven meta-analysis, focusing primarily on issues related to locating a sample of published and unpublished primary studies, extracting and verifying descriptive and correlational data, and conducting analyses. A current meta-analysis of the research on predictors of key health outcomes in diabetes is used to illustrate our main points. © The Author(s) 2014.

MODEL-DRIVEN META-ANALYSES FOR INFORMING HEALTH CARE: A DIABETES META-ANALYSIS AS AN EXEMPLAR

PubMed Central

Brown, Sharon A.; Becker, Betsy Jane; García, Alexandra A.; Brown, Adama; Ramírez, Gilbert

2015-01-01

A relatively novel type of meta-analysis, a model-driven meta-analysis, involves the quantitative synthesis of descriptive, correlational data and is useful for identifying key predictors of health outcomes and informing clinical guidelines. Few such meta-analyses have been conducted and thus, large bodies of research remain unsynthesized and uninterpreted for application in health care. We describe the unique challenges of conducting a model-driven meta-analysis, focusing primarily on issues related to locating a sample of published and unpublished primary studies, extracting and verifying descriptive and correlational data, and conducting analyses. A current meta-analysis of the research on predictors of key health outcomes in diabetes is used to illustrate our main points. PMID:25142707

[Comparison of simple pooling and bivariate model used in meta-analyses of diagnostic test accuracy published in Chinese journals].

PubMed

Huang, Yuan-sheng; Yang, Zhi-rong; Zhan, Si-yan

2015-06-18

To investigate the use of simple pooling and bivariate model in meta-analyses of diagnostic test accuracy (DTA) published in Chinese journals (January to November, 2014), compare the differences of results from these two models, and explore the impact of between-study variability of sensitivity and specificity on the differences. DTA meta-analyses were searched through Chinese Biomedical Literature Database (January to November, 2014). Details in models and data for fourfold table were extracted. Descriptive analysis was conducted to investigate the prevalence of the use of simple pooling method and bivariate model in the included literature. Data were re-analyzed with the two models respectively. Differences in the results were examined by Wilcoxon signed rank test. How the results differences were affected by between-study variability of sensitivity and specificity, expressed by I2, was explored. The 55 systematic reviews, containing 58 DTA meta-analyses, were included and 25 DTA meta-analyses were eligible for re-analysis. Simple pooling was used in 50 (90.9%) systematic reviews and bivariate model in 1 (1.8%). The remaining 4 (7.3%) articles used other models pooling sensitivity and specificity or pooled neither of them. Of the reviews simply pooling sensitivity and specificity, 41(82.0%) were at the risk of wrongly using Meta-disc software. The differences in medians of sensitivity and specificity between two models were both 0.011 (P<0.001, P=0.031 respectively). Greater differences could be found as I2 of sensitivity or specificity became larger, especially when I2>75%. Most DTA meta-analyses published in Chinese journals(January to November, 2014) combine the sensitivity and specificity by simple pooling. Meta-disc software can pool the sensitivity and specificity only through fixed-effect model, but a high proportion of authors think it can implement random-effect model. Simple pooling tends to underestimate the results compared with bivariate model. The greater the between-study variance is, the more likely the simple pooling has larger deviation. It is necessary to increase the knowledge level of statistical methods and software for meta-analyses of DTA data.

Fluoxetine: a review on evidence based medicine

PubMed Central

Rossi, Andrea; Barraco, Alessandra; Donda, Pietro

2004-01-01

Background Fluoxetine was the first molecule of a new generation of antidepressants, the Selective Serotonin Re-uptake Inhibitors (SSRIs). It is recurrently the paradigm for the development of any new therapy in the treatment of depression. Many controlled studies and meta-analyses were performed on Fluoxetine, to improve the understanding of its real impact in the psychiatric area. The main objective of this review is to assess the quality and the results reported in the meta-analyses published on Fluoxetine. Methods Published articles on Medline, Embase and Cochrane databases reporting meta-analyses were used as data sources for this review. Articles found in the searches were reviewed by 2 independent authors, to assess if these were original meta-analyses. Only data belonging to the most recent and comprehensive meta-analytic studies were included in this review. Results Data, based on a group of 9087 patients, who were included in 87 different randomized clinical trials, confirms that fluoxetine is safe and effective in the treatment of depression from the first week of therapy. Fluoxetine's main advantage over previously available antidepressants (TCAs) was its favorable safety profile, that reduced the incidence of early drop-outs and improved patient's compliance, associated with a comparable efficacy on depressive symptoms. In these patients, Fluoxetine has proven to be more effective than placebo from the first week of therapy. Fluoxetine has shown to be safe and effective in the elderly population, as well as during pregnancy. Furthermore, it was not associated with an increased risk of suicide in the overall evaluation of controlled clinical trials. The meta-analysis available on the use of Fluoxetine in the treatment of bulimia nervosa shows that the drug is as effective as other agents with fewer patients dropping out of treatment. Fluoxetine has demonstrated to be as effective as chlomipramine in the treatment of Obsessive-Compulsive-Disorder (OCD). Conclusion Fluoxetine can be considered a drug successfully used in several diseases for its favorable safety/efficacy ratio. As the response rate of mentally ill patients is strictly related to each patient's personal characteristics, any new drug in this area, will have to be developed under these considerations. PMID:14962351

Effects of Interventions on Survival in Acute Respiratory Distress Syndrome: an Umbrella Review of 159 Published Randomized Trials and 29 Meta-analyses

PubMed Central

Tonelli, Adriano R.; Zein, Joe; Adams, Jacob; Ioannidis, John P.A.

2014-01-01

Purpose Multiple interventions have been tested in acute respiratory distress syndrome (ARDS). We examined the entire agenda of published randomized controlled trials (RCTs) in ARDS that reported on mortality and of respective meta-analyses. Methods We searched PubMed, the Cochrane Library and Web of Knowledge until July 2013. We included RCTs in ARDS published in English. We excluded trials of newborns and children; and those on short-term interventions, ARDS prevention or post-traumatic lung injury. We also reviewed all meta-analyses of RCTs in this field that addressed mortality. Treatment modalities were grouped in five categories: mechanical ventilation strategies and respiratory care, enteral or parenteral therapies, inhaled / intratracheal medications, nutritional support and hemodynamic monitoring. Results We identified 159 published RCTs of which 93 had overall mortality reported (n= 20,671 patients) - 44 trials (14,426 patients) reported mortality as a primary outcome. A statistically significant survival benefit was observed in 8 trials (7 interventions) and two trials reported an adverse effect on survival. Among RTCs with >50 deaths in at least 1 treatment arm (n=21), 2 showed a statistically significant mortality benefit of the intervention (lower tidal volumes and prone positioning), 1 showed a statistically significant mortality benefit only in adjusted analyses (cisatracurium) and 1 (high-frequency oscillatory ventilation) showed a significant detrimental effect. Across 29 meta-analyses, the most consistent evidence was seen for low tidal volumes and prone positioning in severe ARDS. Conclusions There is limited supportive evidence that specific interventions can decrease mortality in ARDS. While low tidal volumes and prone positioning in severe ARDS seem effective, most sporadic findings of interventions suggesting reduced mortality are not corroborated consistently in large-scale evidence including meta-analyses. PMID:24667919

Systematic overview and critical appraisal of meta-analyses of interventions in intensive care medicine.

PubMed

Koster, T M; Wetterslev, J; Gluud, C; Keus, F; van der Horst, I C C

2018-05-24

Meta-analysed intervention effect estimates are perceived to represent the highest level of evidence. However, such effects and the randomized clinical trials which are included in them need critical appraisal before the effects can be trusted. Critical appraisal of a predefined set of all meta-analyses on interventions in intensive care medicine to assess their quality and assessed the risks of bias in those meta-analyses having the best quality. We conducted a systematic search to select all meta-analyses of randomized clinical trials on interventions used in intensive care medicine. Selected meta-analyses were critically appraised for basic scientific criteria, (1) presence of an available protocol, (2) report of a full search strategy, and (3) use of any bias risk assessment of included trials. All meta-analyses which qualified these criteria were scrutinized by full "Risk of Bias in Systematic Reviews" ROBIS evaluation of 4 domains of risks of bias, and a "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" PRISMA evaluation. We identified 467 meta-analyses. A total of 56 meta-analyses complied with these basic scientific criteria. We scrutinized the risks of bias in the 56 meta-analyses by full ROBIS evaluation and a PRISMA evaluation. Only 4 meta-analyses scored low risk of bias in all the 4 ROBIS domains and 41 meta-analyses reported all 27 items of the PRISMA checklist. In contrast with what might be perceived as the highest level of evidence only 0.9% of all meta-analyses were judged to have overall low risk of bias. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration

PubMed Central

Liberati, Alessandro; Altman, Douglas G; Tetzlaff, Jennifer; Mulrow, Cynthia; Gøtzsche, Peter C; Ioannidis, John P A; Clarke, Mike; Devereaux, P J; Kleijnen, Jos; Moher, David

2009-01-01

Systematic reviews and meta-analyses are essential to summarise evidence relating to efficacy and safety of healthcare interventions accurately and reliably. The clarity and transparency of these reports, however, are not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (quality of reporting of meta-analysis) statement—a reporting guideline published in 1999—there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realising these issues, an international group that included experienced authors and methodologists developed PRISMA (preferred reporting items for systematic reviews and meta-analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this explanation and elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA statement, this document, and the associated website (www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses. PMID:19622552

Grey literature in meta-analyses of randomized trials of health care interventions.

PubMed

Hopewell, S; McDonald, S; Clarke, M; Egger, M

2007-04-18

The inclusion of grey literature (i.e. literature that has not been formally published) in systematic reviews may help to overcome some of the problems of publication bias, which can arise due to the selective availability of data. To review systematically research studies, which have investigated the impact of grey literature in meta-analyses of randomized trials of health care interventions. We searched the Cochrane Methodology Register (The Cochrane Library Issue 3, 2005), MEDLINE (1966 to 20 May 2005), the Science Citation Index (June 2005) and contacted researchers who may have carried out relevant studies. A study was considered eligible for this review if it compared the effect of the inclusion and exclusion of grey literature on the results of a cohort of meta-analyses of randomized trials. Data were extracted from each report independently by two reviewers. The main outcome measure was an estimate of the impact of trials from the grey literature on the pooled effect estimates of the meta-analyses. Information was also collected on the area of health care, the number of meta-analyses, the number of trials, the number of trial participants, the year of publication of the trials, the language and country of publication of the trials, the number and type of grey and published literature, and methodological quality. Five studies met the inclusion criteria. All five studies showed that published trials showed an overall greater treatment effect than grey trials. This difference was statistically significant in one of the five studies. Data could be combined for three of the five studies. This showed that, on average, published trials showed a 9% greater treatment effect than grey trials (ratio of odds ratios for grey versus published trials 1.09; 95% CI 1.03-1.16). Overall there were more published trials included in the meta-analyses than grey trials (median 224 (IQR 108-365) versus 45(IQR 40-102)). Published trials had more participants on average. The most common types of grey literature were abstracts (55%) and unpublished data (30%). There is limited evidence to show whether grey trials are of poorer methodological quality than published trials. This review shows that published trials tend to be larger and show an overall greater treatment effect than grey trials. This has important implications for reviewers who need to ensure they identify grey trials, in order to minimise the risk of introducing bias into their review.

Publication Bias in Special Education Meta-Analyses

ERIC Educational Resources Information Center

Gage, Nicholas A.; Cook, Bryan G.; Reichow, Brian

2017-01-01

Publication bias involves the disproportionate representation of studies with large and significant effects in the published research. Among other problems, publication bias results in inflated omnibus effect sizes in meta-analyses, giving the impression that interventions have stronger effects than they actually do. Although evidence suggests…

Point-of-sale tobacco promotion and youth smoking: a meta-analysis.

PubMed

Robertson, Lindsay; Cameron, Claire; McGee, Rob; Marsh, Louise; Hoek, Janet

2016-12-01

Previous systematic reviews have found consistent evidence of a positive association between exposure to point-of-sale (POS) tobacco promotion and increased smoking and smoking susceptibility among children and adolescents. No meta-analysis has been conducted on these studies to date. Systematic literature searches were carried out to identify all quantitative observational studies that examined the relationship between POS tobacco promotion and individual-level smoking and smoking-related cognitions among children and adolescents, published between January 1990 and June 2014. Random-effects meta-analyses were used. Subgroup analyses were conducted according to extent of tobacco POS advertising environment in the study environment. Sensitivity analyses were performed according to study size and quality. 13 studies met the inclusion criteria; 11 reported data for behavioural outcomes, 6 for cognitive outcomes (each of these assessed smoking susceptibility). The studies were cross-sectional, with the exception of 2 cohort studies. For the behavioural outcomes, the pooled OR was 1.61 (95% CI 1.33 to 1.96) and for smoking susceptibility the pooled OR was 1.32 (95% CI 1.09 to 1.61). Children and adolescents more frequently exposed to POS tobacco promotion have around 1.6 times higher odds of having tried smoking and around 1.3 times higher odds of being susceptible to future smoking, compared with those less frequently exposed. Together with the available evaluations of POS display bans, the results strongly indicate that legislation banning tobacco POS promotion will effectively reduce smoking among young people. 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/.

The Influence of Judgment Calls on Meta-Analytic Findings.

PubMed

Tarrahi, Farid; Eisend, Martin

2016-01-01

Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions.

A framework for the meta-analysis of Bland-Altman studies based on a limits of agreement approach.

PubMed

Tipton, Elizabeth; Shuster, Jonathan

2017-10-15

Bland-Altman method comparison studies are common in the medical sciences and are used to compare a new measure to a gold-standard (often costlier or more invasive) measure. The distribution of these differences is summarized by two statistics, the 'bias' and standard deviation, and these measures are combined to provide estimates of the limits of agreement (LoA). When these LoA are within the bounds of clinically insignificant differences, the new non-invasive measure is preferred. Very often, multiple Bland-Altman studies have been conducted comparing the same two measures, and random-effects meta-analysis provides a means to pool these estimates. We provide a framework for the meta-analysis of Bland-Altman studies, including methods for estimating the LoA and measures of uncertainty (i.e., confidence intervals). Importantly, these LoA are likely to be wider than those typically reported in Bland-Altman meta-analyses. Frequently, Bland-Altman studies report results based on repeated measures designs but do not properly adjust for this design in the analysis. Meta-analyses of Bland-Altman studies frequently exclude these studies for this reason. We provide a meta-analytic approach that allows inclusion of estimates from these studies. This includes adjustments to the estimate of the standard deviation and a method for pooling the estimates based upon robust variance estimation. An example is included based on a previously published meta-analysis. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Survey of the Methods and Reporting Practices in Published Meta-analyses of Test Performance: 1987 to 2009

ERIC Educational Resources Information Center

Dahabreh, Issa J.; Chung, Mei; Kitsios, Georgios D.; Terasawa, Teruhiko; Raman, Gowri; Tatsioni, Athina; Tobar, Annette; Lau, Joseph; Trikalinos, Thomas A.; Schmid, Christopher H.

2013-01-01

We performed a survey of meta-analyses of test performance to describe the evolution in their methods and reporting. Studies were identified through MEDLINE (1966-2009), reference lists, and relevant reviews. We extracted information on clinical topics, literature review methods, quality assessment, and statistical analyses. We reviewed 760…

Meta-epidemiologic study showed frequent time trends in summary estimates from meta-analyses of diagnostic accuracy studies.

PubMed

Cohen, Jérémie F; Korevaar, Daniël A; Wang, Junfeng; Leeflang, Mariska M; Bossuyt, Patrick M

2016-09-01

To evaluate changes over time in summary estimates from meta-analyses of diagnostic accuracy studies. We included 48 meta-analyses from 35 MEDLINE-indexed systematic reviews published between September 2011 and January 2012 (743 diagnostic accuracy studies; 344,015 participants). Within each meta-analysis, we ranked studies by publication date. We applied random-effects cumulative meta-analysis to follow how summary estimates of sensitivity and specificity evolved over time. Time trends were assessed by fitting a weighted linear regression model of the summary accuracy estimate against rank of publication. The median of the 48 slopes was -0.02 (-0.08 to 0.03) for sensitivity and -0.01 (-0.03 to 0.03) for specificity. Twelve of 96 (12.5%) time trends in sensitivity or specificity were statistically significant. We found a significant time trend in at least one accuracy measure for 11 of the 48 (23%) meta-analyses. Time trends in summary estimates are relatively frequent in meta-analyses of diagnostic accuracy studies. Results from early meta-analyses of diagnostic accuracy studies should be considered with caution. Copyright © 2016 Elsevier Inc. All rights reserved.

Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review

PubMed Central

Kirksey, Meghan A.; Haskins, Stephen C.; Cheng, Jennifer; Liu, Spencer S.

2015-01-01

Background The use of peripheral nerve blocks for anesthesia and postoperative analgesia has increased significantly in recent years. Adjuvants are frequently added to local anesthetics to prolong analgesia following peripheral nerve blockade. Numerous randomized controlled trials and meta-analyses have examined the pros and cons of the use of various individual adjuvants. Objectives To systematically review adjuvant-related randomized controlled trials and meta-analyses and provide clinical recommendations for the use of adjuvants in peripheral nerve blocks. Methods Randomized controlled trials and meta-analyses that were published between 1990 and 2014 were included in the initial bibliographic search, which was conducted using Medline/PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Only studies that were published in English and listed block analgesic duration as an outcome were included. Trials that had already been published in the identified meta-analyses and included adjuvants not in widespread use and published without an Investigational New Drug application or equivalent status were excluded. Results Sixty one novel clinical trials and meta-analyses were identified and included in this review. The clinical trials reported analgesic duration data for the following adjuvants: buprenorphine (6), morphine (6), fentanyl (10), epinephrine (3), clonidine (7), dexmedetomidine (7), dexamethasone (7), tramadol (8), and magnesium (4). Studies of perineural buprenorphine, clonidine, dexamethasone, dexmedetomidine, and magnesium most consistently demonstrated prolongation of peripheral nerve blocks. Conclusions Buprenorphine, clonidine, dexamethasone, magnesium, and dexmedetomidine are promising agents for use in prolongation of local anesthetic peripheral nerve blocks, and further studies of safety and efficacy are merited. However, caution is recommended with use of any perineural adjuvant, as none have Food and Drug Administration approval, and concerns for side effects and potential toxicity persist. PMID:26355598

Systematic reviews and meta-analyses on treatment of asthma: critical evaluation

PubMed Central

Jadad, Alejandro R; Moher, Michael; Browman, George P; Booker, Lynda; Sigouin, Christopher; Fuentes, Mario; Stevens, Robert

2000-01-01

Objective To evaluate the clinical, methodological, and reporting aspects of systematic reviews and meta-analyses on the treatment of asthma and to compare those published by the Cochrane Collaboration with those published in paper based journals. Design Analysis of studies identified from Medline, CINAHL, HealthSTAR, EMBASE, Cochrane Library, personal collections, and reference lists. Studies Articles describing a systematic review or a meta-analysis of the treatment of asthma that were published as a full report, in any language or format, in a peer reviewed journal or the Cochrane Library. Main outcome measures General characteristics of studies reviewed and methodological characteristics (sources of articles; language restrictions; format, design, and publication status of studies included; type of data synthesis; and methodological quality). Results 50 systematic reviews and meta-analyses were included. More than half were published in the past two years. Twelve reviews were published in the Cochrane Library and 38 were published in 22 peer reviewed journals. Forced expiratory volume in one second was the most frequently used outcome, but few reviews evaluated the effect of treatment on costs or patient preferences. Forty reviews were judged to have serious or extensive flaws. All six reviews associated with industry were in this group. Seven of the 10 most rigorous reviews were published in the Cochrane Library. Conclusions Most reviews published in peer reviewed journals or funded by industry have serious methodological flaws that limit their value to guide decisions. Cochrane reviews are more rigorous and better reported than those published in peer reviewed journals. PMID:10688558

The Treatment of Restless Legs Syndrome and Periodic Limb Movement Disorder in Adults—An Update for 2012: Practice Parameters with an Evidence-Based Systematic Review and Meta-Analyses

PubMed Central

Aurora, R. Nisha; Kristo, David A.; Bista, Sabin R.; Rowley, James A.; Zak, Rochelle S.; Casey, Kenneth R.; Lamm, Carin I.; Tracy, Sharon L.; Rosenberg, Richard S.

2012-01-01

A systematic literature review and meta-analyses (where appropriate) were performed to update the previous AASM practice parameters on the treatments, both dopaminergic and other, of RLS and PLMD. A considerable amount of literature has been published since these previous reviews were performed, necessitating an update of the corresponding practice parameters. Therapies with a STANDARD level of recommendation include pramipexole and ropinirole. Therapies with a GUIDELINE level of recommendation include levodopa with dopa decarboxylase inhibitor, opioids, gabapentin enacarbil, and cabergoline (which has additional caveats for use). Therapies with an OPTION level of recommendation include carbamazepine, gabapentin, pregabalin, clonidine, and for patients with low ferritin levels, iron supplementation. The committee recommends a STANDARD AGAINST the use of pergolide because of the risks of heart valve damage. Therapies for RLS secondary to ESRD, neuropathy, and superficial venous insufficiency are discussed. Lastly, therapies for PLMD are reviewed. However, it should be mentioned that because PLMD therapy typically mimics RLS therapy, the primary focus of this review is therapy for idiopathic RLS. Citation: Aurora RN; Kristo DA; Bista SR; Rowley JA: Zak RS; Casey KR; Lamm CI; Tracy SL; Rosenberg RS. The treatment of restless legs syndrome and periodic limb movement disorder in adults—an update for 2012: practice parameters with an evidence-based systematic review and meta-analyses. SLEEP 2012;35(8):1039-1062. PMID:22851801

Interpretive analysis of 85 systematic reviews suggests that narrative syntheses and meta-analyses are incommensurate in argumentation.

PubMed

Melendez-Torres, G J; O'Mara-Eves, A; Thomas, J; Brunton, G; Caird, J; Petticrew, M

2017-03-01

Using Toulmin's argumentation theory, we analysed the texts of systematic reviews in the area of workplace health promotion to explore differences in the modes of reasoning embedded in reports of narrative synthesis as compared with reports of meta-analysis. We used framework synthesis, grounded theory and cross-case analysis methods to analyse 85 systematic reviews addressing intervention effectiveness in workplace health promotion. Two core categories, or 'modes of reasoning', emerged to frame the contrast between narrative synthesis and meta-analysis: practical-configurational reasoning in narrative synthesis ('what is going on here? What picture emerges?') and inferential-predictive reasoning in meta-analysis ('does it work, and how well? Will it work again?'). Modes of reasoning examined quality and consistency of the included evidence differently. Meta-analyses clearly distinguished between warrant and claim, whereas narrative syntheses often presented joint warrant-claims. Narrative syntheses and meta-analyses represent different modes of reasoning. Systematic reviewers are likely to be addressing research questions in different ways with each method. It is important to consider narrative synthesis in its own right as a method and to develop specific quality criteria and understandings of how it is carried out, not merely as a complement to, or second-best option for, meta-analysis. © 2016 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. © 2016 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd.

Agreement between the results of meta-analyses from case reports and from clinical studies regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I who initiated enzyme replacement therapy in adult age: An example of case reports meta-analyses as an useful tool for evidence-based medicine in rare diseases.

PubMed

Sampayo-Cordero, Miguel; Miguel-Huguet, Bernat; Pardo-Mateos, Almudena; Moltó-Abad, Marc; Muñoz-Delgado, Cecilia; Pérez-López, Jordi

2018-02-01

Case reports might have a prominent role in the rare diseases field, due to the small number of patients affected by one such disease. A previous systematic review regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I (MPS-I) who initiated enzyme replacement therapy (ERT) in adult age has been published. The review included a meta-analysis of 19 clinical studies and the description of eleven case reports. It was of interest to perform a meta-analysis of those case reports to explore the role of such meta-analyses as a tool for evidence-based medicine in rare diseases. The study included all case reports with standard treatment regimen. Primary analysis was the percentage of case reports showing an improvement in a specific outcome. Only when that percentage was statistically higher than 5%, the improvement was confirmed as such. The outcomes that accomplished this criterion were ranked and compared to the GRADE criteria obtained by those same outcomes in the previous meta-analysis of clinical studies. There were three outcomes that had a significant improvement: Urine glycosaminoglycans, liver volume and 6-minute walking test. Positive and negative predictive values, sensitivity and specificity for the results of the meta-analysis of case reports as compared to that of clinical studies were 100%, 88.9%, 75% and 100%, respectively. Accordingly, absolute (Rho=0.82, 95%CI: 0.47 to 0.95) and relative agreement (Kappa=0.79, 95%CI: 0.593 to 0.99) between the number of case reports with improvement in a specific outcome and the GRADE evidence score for that outcome were good. Sensitivity analysis showed that agreement between the meta-analysis of case reports and that of the clinical studies were good only when using a strong confirmatory strategy for outcome improvement in case reports. We found an agreement between the results of meta-analyses from case reports and from clinical studies in the efficacy of laronidase therapy in patients with MPS-I who initiated ERT in adult age. This agreement suggests that combining case reports quantitatively, rather than analyzing them separately or qualitatively, may improve conclusions in the field of rare diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

The PRISMA Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions: Explanation and Elaboration

PubMed Central

Liberati, Alessandro; Altman, Douglas G.; Tetzlaff, Jennifer; Mulrow, Cynthia; Gøtzsche, Peter C.; Ioannidis, John P. A.; Clarke, Mike; Devereaux, P. J.; Kleijnen, Jos; Moher, David

2009-01-01

Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement—a reporting guideline published in 1999—there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this Explanation and Elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA Statement, this document, and the associated Web site (http://www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses. PMID:19621070

Using aggregate data to estimate the standard error of a treatment-covariate interaction in an individual patient data meta-analysis.

PubMed

Kovalchik, Stephanie A; Cumberland, William G

2012-05-01

Subgroup analyses are important to medical research because they shed light on the heterogeneity of treatment effectts. A treatment-covariate interaction in an individual patient data (IPD) meta-analysis is the most reliable means to estimate how a subgroup factor modifies a treatment's effectiveness. However, owing to the challenges in collecting participant data, an approach based on aggregate data might be the only option. In these circumstances, it would be useful to assess the relative efficiency and power loss of a subgroup analysis without patient-level data. We present methods that use aggregate data to estimate the standard error of an IPD meta-analysis' treatment-covariate interaction for regression models of a continuous or dichotomous patient outcome. Numerical studies indicate that the estimators have good accuracy. An application to a previously published meta-regression illustrates the practical utility of the methodology. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies of educational interventions and outcomes in diabetic adults: a meta-analysis revisited.

PubMed

Brown, S A

1990-12-01

This paper reports a follow-up of previous meta-analysis research conducted by the author on the effects of diabetes patient education on patient outcomes. An expanded sample of studies and psychological outcome variables were added to the previously studied variables of patient knowledge, self-care behaviors (compliance and skill performance) and metabolic control. The purpose was to determine: (1) the effects of patient education on specific outcome variables; and (2) the relationships between effects of education and characteristics of the studies and/or subjects. Following an extensive literature search, a total of 82 studies were found which met the inclusion criteria for this analysis; 68% were published and 32% were unpublished. Homogeneity analyses of specific patient outcome variables yielded the following results: knowledge effects ranged from 0.49 to 1.05; self-care behavior effects from 0.17 to 0.57, with insulin injection and weight loss associated with the smallest effect sizes; metabolic control from 0.16 to 0.41; and psychological outcomes 0.27. Mean age of the subjects was negatively correlated with knowledge and cholesterol, indicating that the older the mean age of the subjects, the lower the effects of patient education on these variables. Findings of this meta-analysis on the expanded data set were consistent with the previous meta-analysis and lend support to the effectiveness of diabetes patient education in improving patient outcomes.

Financial ties and concordance between results and conclusions in meta-analyses: retrospective cohort study.

PubMed

Yank, Veronica; Rennie, Drummond; Bero, Lisa A

2007-12-08

To determine whether financial ties to one drug company are associated with favourable results or conclusions in meta-analyses on antihypertensive drugs. Retrospective cohort study. Meta-analyses published up to December 2004 that were not duplicates and evaluated the effects of antihypertensive drugs compared with any comparator on clinical end points in adults. Financial ties were categorised as one drug company compared with all others. The main outcomes were the results and conclusions of meta-analyses, with both outcomes separately categorised as being favourable or not favourable towards the study drug. We also collected data on characteristics of meta-analyses that the literature suggested might be associated with favourable results or conclusions. 124 meta-analyses were included in the study, 49 (40%) of which had financial ties to one drug company. On univariate logistic regression analyses, meta-analyses of better methodological quality were more likely to have favourable results (odds ratio 1.16, 95% confidence interval 1.07 to 1.27). Although financial ties to one drug company were not associated with favourable results, such ties constituted the only characteristic significantly associated with favourable conclusions (4.09, 1.30 to 12.83). When controlling for other characteristics of meta-analyses in multiple logistic regression analyses, meta-analyses that had financial ties to one drug company remained more likely to report favourable conclusions (5.11, 1.54 to 16.92). Meta-analyses on antihypertensive drugs and with financial ties to one drug company are not associated with favourable results but are associated with favourable conclusions.

Suicide by occupation: systematic review and meta-analysis.

PubMed

Milner, Allison; Spittal, Matthew J; Pirkis, Jane; LaMontagne, Anthony D

2013-12-01

Previous research has shown that those employed in certain occupations, such as doctors and farmers, have an elevated risk of suicide, yet little research has sought to synthesise these findings across working-age populations. To summarise published research in this area through systematic review and meta-analysis. Random effects meta-analyses were used to calculate a pooled risk of suicide across occupational skill-level groups. Thirty-four studies were included in the meta-analysis. Elementary professions (e.g. labourers and cleaners) were at elevated risk compared with the working-age population (rate ratio (RR) = 1.84, 95% CI 1.46-2.33), followed by machine operators and deck crew (RR = 1.78, 95% CI 1.22-2.60) and agricultural workers (RR = 1.64, 95% CI 1.19-2.28). Results suggested a stepwise gradient in risk, with the lowest skilled occupations being at greater risk of suicide than the highest skill-level group. This is the first comprehensive meta-analytical review of suicide and occupation. There is a need for future studies to investigate explanations for the observed skill-level differences, particularly in people employed in lower skill-level groups.

How individual participant data meta-analyses have influenced trial design, conduct, and analysis.

PubMed

Tierney, Jayne F; Pignon, Jean-Pierre; Gueffyier, Francois; Clarke, Mike; Askie, Lisa; Vale, Claire L; Burdett, Sarah

2015-11-01

To demonstrate how individual participant data (IPD) meta-analyses have impacted directly on the design and conduct of trials and highlight other advantages IPD might offer. Potential examples of the impact of IPD meta-analyses on trials were identified at an international workshop, attended by individuals with experience in the conduct of IPD meta-analyses and knowledge of trials in their respective clinical areas. Experts in the field who did not attend were asked to provide any further examples. We then examined relevant trial protocols, publications, and Web sites to verify the impacts of the IPD meta-analyses. A subgroup of workshop attendees sought further examples and identified other aspects of trial design and conduct that may inform IPD meta-analyses. We identified 52 examples of IPD meta-analyses thought to have had a direct impact on the design or conduct of trials. After screening relevant trial protocols and publications, we identified 28 instances where IPD meta-analyses had clearly impacted on trials. They have influenced the selection of comparators and participants, sample size calculations, analysis and interpretation of subsequent trials, and the conduct and analysis of ongoing trials, sometimes in ways that would not possible with systematic reviews of aggregate data. We identified additional potential ways that IPD meta-analyses could be used to influence trials. IPD meta-analysis could be better used to inform the design, conduct, analysis, and interpretation of trials. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studies.

PubMed

Li, Xue; Meng, Xiangrui; Timofeeva, Maria; Tzoulaki, Ioanna; Tsilidis, Konstantinos K; Ioannidis, John PA; Campbell, Harry; Theodoratou, Evropi

2017-06-07

Objective  To map the diverse health outcomes associated with serum uric acid (SUA) levels. Design  Umbrella review. Data sources  Medline, Embase, Cochrane Database of Systematic Reviews, and screening of citations and references. Eligibility criteria  Systematic reviews and meta-analyses of observational studies that examined associations between SUA level and health outcomes, meta-analyses of randomised controlled trials that investigated health outcomes related to SUA lowering treatment, and Mendelian randomisation studies that explored the causal associations of SUA level with health outcomes. Results  57 articles reporting 15 systematic reviews and144 meta-analyses of observational studies (76 unique outcomes), 8 articles reporting 31 meta-analyses of randomised controlled trials (20 unique outcomes), and 36 articles reporting 107 Mendelian randomisation studies (56 unique outcomes) met the eligibility criteria. Across all three study types, 136 unique health outcomes were reported. 16 unique outcomes in meta-analyses of observational studies had P<10 -6 , 8 unique outcomes in meta-analyses of randomised controlled trials had P<0.001, and 4 unique outcomes in Mendelian randomisation studies had P<0.01. Large between study heterogeneity was common (80% and 45% in meta-analyses of observational studies and of randomised controlled trials, respectively). 42 (55%) meta-analyses of observational studies and 7 (35%) meta-analyses of randomised controlled trials showed evidence of small study effects or excess significance bias. No associations from meta-analyses of observational studies were classified as convincing; five associations were classified as highly suggestive (increased risk of heart failure, hypertension, impaired fasting glucose or diabetes, chronic kidney disease, coronary heart disease mortality with high SUA levels). Only one outcome from randomised controlled trials (decreased risk of nephrolithiasis recurrence with SUA lowering treatment) had P<0.001, a 95% prediction interval excluding the null, and no large heterogeneity or bias. Only one outcome from Mendelian randomisation studies (increased risk of gout with high SUA levels) presented convincing evidence. Hypertension and chronic kidney disease showed concordant evidence in meta-analyses of observational studies, and in some (but not all) meta-analyses of randomised controlled trials with respective intermediate or surrogate outcomes, but they were not statistically significant in Mendelian randomisation studies. Conclusion  Despite a few hundred systematic reviews, meta-analyses, and Mendelian randomisation studies exploring 136 unique health outcomes, convincing evidence of a clear role of SUA level only exists for gout and nephrolithiasis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

PubMed

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

2016-11-14

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

Methodologic quality of meta-analyses and systematic reviews on the Mediterranean diet and cardiovascular disease outcomes: a review.

PubMed

Huedo-Medina, Tania B; Garcia, Marissa; Bihuniak, Jessica D; Kenny, Anne; Kerstetter, Jane

2016-03-01

Several systematic reviews/meta-analyses published within the past 10 y have examined the associations of Mediterranean-style diets (MedSDs) on cardiovascular disease (CVD) risk. However, these reviews have not been evaluated for satisfying contemporary methodologic quality standards. This study evaluated the quality of recent systematic reviews/meta-analyses on MedSD and CVD risk outcomes by using an established methodologic quality scale. The relation between review quality and impact per publication value of the journal in which the article had been published was also evaluated. To assess compliance with current standards, we applied a modified version of the Assessment of Multiple Systematic Reviews (AMSTARMedSD) quality scale to systematic reviews/meta-analyses retrieved from electronic databases that had met our selection criteria: 1) used systematic or meta-analytic procedures to review the literature, 2) examined MedSD trials, and 3) had MedSD interventions independently or combined with other interventions. Reviews completely satisfied from 8% to 75% of the AMSTARMedSD items (mean ± SD: 31.2% ± 19.4%), with those published in higher-impact journals having greater quality scores. At a minimum, 60% of the 24 reviews did not disclose full search details or apply appropriate statistical methods to combine study findings. Only 5 of the reviews included participant or study characteristics in their analyses, and none evaluated MedSD diet characteristics. These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on CVD risk do not fully comply with contemporary methodologic quality standards. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects CVD risk or how these effects may be modified by the participant or MedSD characteristics. To clarify the associations between MedSD and CVD risk, future meta-analyses and systematic reviews should not only follow methodologic quality standards but also include more statistical modeling results when data allow. © 2016 American Society for Nutrition.

The Empirical Review of Meta-Analysis Published in Korea

ERIC Educational Resources Information Center

Park, Sunyoung; Hong, Sehee

2016-01-01

Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication…

The Success of Linear Bootstrapping Models: Decision Domain-, Expertise-, and Criterion-Specific Meta-Analysis

PubMed Central

Kaufmann, Esther; Wittmann, Werner W.

2016-01-01

The success of bootstrapping or replacing a human judge with a model (e.g., an equation) has been demonstrated in Paul Meehl’s (1954) seminal work and bolstered by the results of several meta-analyses. To date, however, analyses considering different types of meta-analyses as well as the potential dependence of bootstrapping success on the decision domain, the level of expertise of the human judge, and the criterion for what constitutes an accurate decision have been missing from the literature. In this study, we addressed these research gaps by conducting a meta-analysis of lens model studies. We compared the results of a traditional (bare-bones) meta-analysis with findings of a meta-analysis of the success of bootstrap models corrected for various methodological artifacts. In line with previous studies, we found that bootstrapping was more successful than human judgment. Furthermore, bootstrapping was more successful in studies with an objective decision criterion than in studies with subjective or test score criteria. We did not find clear evidence that the success of bootstrapping depended on the decision domain (e.g., education or medicine) or on the judge’s level of expertise (novice or expert). Correction of methodological artifacts increased the estimated success of bootstrapping, suggesting that previous analyses without artifact correction (i.e., traditional meta-analyses) may have underestimated the value of bootstrapping models. PMID:27327085

Meta-assessment of bias in science

PubMed Central

Fanelli, Daniele; Costas, Rodrigo; Ioannidis, John P. A.

2017-01-01

Numerous biases are believed to affect the scientific literature, but their actual prevalence across disciplines is unknown. To gain a comprehensive picture of the potential imprint of bias in science, we probed for the most commonly postulated bias-related patterns and risk factors, in a large random sample of meta-analyses taken from all disciplines. The magnitude of these biases varied widely across fields and was overall relatively small. However, we consistently observed a significant risk of small, early, and highly cited studies to overestimate effects and of studies not published in peer-reviewed journals to underestimate them. We also found at least partial confirmation of previous evidence suggesting that US studies and early studies might report more extreme effects, although these effects were smaller and more heterogeneously distributed across meta-analyses and disciplines. Authors publishing at high rates and receiving many citations were, overall, not at greater risk of bias. However, effect sizes were likely to be overestimated by early-career researchers, those working in small or long-distance collaborations, and those responsible for scientific misconduct, supporting hypotheses that connect bias to situational factors, lack of mutual control, and individual integrity. Some of these patterns and risk factors might have modestly increased in intensity over time, particularly in the social sciences. Our findings suggest that, besides one being routinely cautious that published small, highly-cited, and earlier studies may yield inflated results, the feasibility and costs of interventions to attenuate biases in the literature might need to be discussed on a discipline-specific and topic-specific basis. PMID:28320937

Are K-12 learners motivated in physical education? A meta-analysis.

PubMed

Chen, Senlin; Chen, Ang; Zhu, Xihe

2012-03-01

Previous studies devoted to K-12 learner motivation in physical education share a general assumption that students may lack motivation. This meta-analytic study examined published original studies (n = 79) to determine students' motivation level and the association between motivation and outcomes. Original means of motivation measures were converted and aggregated to determine motivation levels. Correlation effect sizes were calculated to determine the association between motivation and outcome measures. The analyses revealed that K-12 students are motivated regardless of the theoretical constructs used in the studies (M > 50). The correlation effect sizes (r = .20-.30, p < .05) indicate a weak association between motivation and outcome. The findings suggest a need to involve meaningful learning and pedagogy variables in motivation research.

A Meta-Analysis of the Social Communication Questionnaire: Screening for Autism Spectrum Disorder

ERIC Educational Resources Information Center

Chesnut, Steven R.; Wei, Tianlan; Barnard-Brak, Lucy; Richman, David M.

2017-01-01

The current meta-analysis examines the previous research on the utility of the Social Communication Questionnaire as a screening instrument for autism spectrum disorder. Previously published reports have highlighted the inconsistencies between Social Communication Questionnaire-screening results and formal autism spectrum disorder diagnoses. The…

Meta-analyses of the 5-HTTLPR polymorphisms and post-traumatic stress disorder.

PubMed

Navarro-Mateu, Fernando; Escámez, Teresa; Koenen, Karestan C; Alonso, Jordi; Sánchez-Meca, Julio

2013-01-01

To conduct a meta-analysis of all published genetic association studies of 5-HTTLPR polymorphisms performed in PTSD cases. Potential studies were identified through PubMed/MEDLINE, EMBASE, Web of Science databases (Web of Knowledge, WoK), PsychINFO, PsychArticles and HuGeNet (Human Genome Epidemiology Network) up until December 2011. Published observational studies reporting genotype or allele frequencies of this genetic factor in PTSD cases and in non-PTSD controls were all considered eligible for inclusion in this systematic review. Two reviewers selected studies for possible inclusion and extracted data independently following a standardized protocol. A biallelic and a triallelic meta-analysis, including the total S and S' frequencies, the dominant (S+/LL and S'+/L'L') and the recessive model (SS/L+ and S'S'/L'+), was performed with a random-effect model to calculate the pooled OR and its corresponding 95% CI. Forest plots and Cochran's Q-Statistic and I(2) index were calculated to check for heterogeneity. Subgroup analyses and meta-regression were carried out to analyze potential moderators. Publication bias and quality of reporting were also analyzed. 13 studies met our inclusion criteria, providing a total sample of 1874 patients with PTSD and 7785 controls in the biallelic meta-analyses and 627 and 3524, respectively, in the triallelic. None of the meta-analyses showed evidence of an association between 5-HTTLPR and PTSD but several characteristics (exposure to the same principal stressor for PTSD cases and controls, adjustment for potential confounding variables, blind assessment, study design, type of PTSD, ethnic distribution and Total Quality Score) influenced the results in subgroup analyses and meta-regression. There was no evidence of potential publication bias. Current evidence does not support a direct effect of 5-HTTLPR polymorphisms on PTSD. Further analyses of gene-environment interactions, epigenetic modulation and new studies with large samples and/or meta-analyses are required.

The economics of dentistry: a neglected concern.

PubMed

Shariati, Batoul; MacEntee, Michael I; Yazdizadeh, Maryam

2013-10-01

Demand for economic evaluations in health care is growing with expectations that they will help to develop regional and national policies on health and social programmes. We present here the scope, quality and content of systematic reviews and meta-analyses relating to the economics of dentistry published over the last 15 years. To review the quality and outcome of systematic reviews and meta-analyses relating to the economics of dental treatments, preventions and services. A systematic search was conducted in 14 electronic databases for systematic reviews and meta-analyses published between January 1997 and July 2011 on the economics of oral disorders and oral health care. Review papers were extracted by two independent investigators to identify the characteristics, results and quality of the reviews and to highlight gaps in knowledge about the economics of dentistry. From 3150 unique references, we found 73 systematic reviews or meta-analyses of dental economics as primary or secondary outcomes. The focus of 12 of them was on the cost or cost-effectiveness of dental prevention, 54 on treatment, five on prevention and treatment and two on delivery of dental services. However, only 12 of the systematic reviews drew conclusions from economic data, and four of them constructed an economic model from synthesized data. Overall, the quality was good in the 12 systematic reviews but poor in the original studies. There is very little helpful data published on the economics of dentistry. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

High statistical heterogeneity is more frequent in meta-analysis of continuous than binary outcomes.

PubMed

Alba, Ana C; Alexander, Paul E; Chang, Joanne; MacIsaac, John; DeFry, Samantha; Guyatt, Gordon H

2016-02-01

We compared the distribution of heterogeneity in meta-analyses of binary and continuous outcomes. We searched citations in MEDLINE and Cochrane databases for meta-analyses of randomized trials published in 2012 that reported a measure of heterogeneity of either binary or continuous outcomes. Two reviewers independently performed eligibility screening and data abstraction. We evaluated the distribution of I(2) in meta-analyses of binary and continuous outcomes and explored hypotheses explaining the difference in distributions. After full-text screening, we selected 671 meta-analyses evaluating 557 binary and 352 continuous outcomes. Heterogeneity as assessed by I(2) proved higher in continuous than in binary outcomes: the proportion of continuous and binary outcomes reporting an I(2) of 0% was 34% vs. 52%, respectively, and reporting an I(2) of 60-100% was 39% vs. 14%. In continuous but not binary outcomes, I(2) increased with larger number of studies included in a meta-analysis. Increased precision and sample size do not explain the larger I(2) found in meta-analyses of continuous outcomes with a larger number of studies. Meta-analyses evaluating continuous outcomes showed substantially higher I(2) than meta-analyses of binary outcomes. Results suggest differing standards for interpreting I(2) in continuous vs. binary outcomes may be appropriate. Copyright © 2016 Elsevier Inc. All rights reserved.

From pre-registration to publication: a non-technical primer for conducting a meta-analysis to synthesize correlational data

PubMed Central

Quintana, Daniel S.

2015-01-01

Meta-analysis synthesizes a body of research investigating a common research question. Outcomes from meta-analyses provide a more objective and transparent summary of a research area than traditional narrative reviews. Moreover, they are often used to support research grant applications, guide clinical practice, and direct health policy. The aim of this article is to provide a practical and non-technical guide for psychological scientists that outlines the steps involved in planning and performing a meta-analysis of correlational datasets. I provide a supplementary R script to demonstrate each analytical step described in the paper, which is readily adaptable for researchers to use for their analyses. While the worked example is the analysis of a correlational dataset, the general meta-analytic process described in this paper is applicable for all types of effect sizes. I also emphasize the importance of meta-analysis protocols and pre-registration to improve transparency and help avoid unintended duplication. An improved understanding this tool will not only help scientists to conduct their own meta-analyses but also improve their evaluation of published meta-analyses. PMID:26500598

From pre-registration to publication: a non-technical primer for conducting a meta-analysis to synthesize correlational data.

PubMed

Quintana, Daniel S

2015-01-01

Meta-analysis synthesizes a body of research investigating a common research question. Outcomes from meta-analyses provide a more objective and transparent summary of a research area than traditional narrative reviews. Moreover, they are often used to support research grant applications, guide clinical practice, and direct health policy. The aim of this article is to provide a practical and non-technical guide for psychological scientists that outlines the steps involved in planning and performing a meta-analysis of correlational datasets. I provide a supplementary R script to demonstrate each analytical step described in the paper, which is readily adaptable for researchers to use for their analyses. While the worked example is the analysis of a correlational dataset, the general meta-analytic process described in this paper is applicable for all types of effect sizes. I also emphasize the importance of meta-analysis protocols and pre-registration to improve transparency and help avoid unintended duplication. An improved understanding this tool will not only help scientists to conduct their own meta-analyses but also improve their evaluation of published meta-analyses.

Systematic review and meta-analysis of candidate gene association studies of lower urinary tract symptoms in men.

PubMed

Cartwright, Rufus; Mangera, Altaf; Tikkinen, Kari A O; Rajan, Prabhakar; Pesonen, Jori; Kirby, Anna C; Thiagamoorthy, Ganesh; Ambrose, Chris; Gonzalez-Maffe, Juan; Bennett, Phillip R; Palmer, Tom; Walley, Andrew; Järvelin, Marjo-Riitta; Khullar, Vik; Chapple, Chris

2014-10-01

Although family studies have shown that male lower urinary tract symptoms (LUTS) are highly heritable, no systematic review exists of genetic polymorphisms tested for association with LUTS. To systematically review and meta-analyze studies assessing candidate polymorphisms/genes tested for an association with LUTS, and to assess the strength, consistency, and potential for bias among pooled associations. A systematic search of the PubMed and HuGE databases as well as abstracts of major urologic meetings was performed through to January 2013. Case-control studies reporting genetic associations in men with LUTS were included. Reviewers independently and in duplicate screened titles, abstracts, and full texts to determine eligibility, abstracted data, and assessed the credibility of pooled associations according to the interim Venice criteria. Authors were contacted for clarifications if needed. Meta-analyses were performed for variants assessed in more than two studies. We identified 74 eligible studies containing data on 70 different genes. A total of 35 meta-analyses were performed with statistical significance in five (ACE, ELAC2, GSTM1, TERT, and VDR). The heterogeneity was high in three of these meta-analyses. The rs731236 variant of the vitamin D receptor had a protective effect for LUTS (odds ratio: 0.64; 95% confidence interval, 0.49-0.83) with moderate heterogeneity (I(2)=27.2%). No evidence for publication bias was identified. Limitations include wide-ranging phenotype definitions for LUTS and limited power in most meta-analyses to detect smaller effect sizes. Few putative genetic risk variants have been reliably replicated across populations. We found consistent evidence of a reduced risk of LUTS associated with the common rs731236 variant of the vitamin D receptor gene in our meta-analyses. Combining the results from all previous studies of genetic variants that may cause urinary symptoms in men, we found significant variants in five genes. Only one, a variant of the vitamin D receptor, was consistently protective across different populations. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Is Operative Treatment of Achilles Tendon Ruptures Superior to Nonoperative Treatment?

PubMed Central

Erickson, Brandon J.; Mascarenhas, Randy; Saltzman, Bryan M.; Walton, David; Lee, Simon; Cole, Brian J.; Bach, Bernard R.

2015-01-01

Background: Multiple meta-analyses have been published in efforts to determine whether operative or nonoperative treatment of Achilles tendon ruptures affords superior outcomes. Purpose: To perform a systematic review of overlapping meta-analyses comparing operative and nonoperative treatment of Achilles tendon ruptures to determine which meta-analyses provide the highest level of evidence for treatment recommendations. Study Design: Systematic review; Level of evidence, 3. Methods: A systematic review of the literature was performed to identify meta-analyses that fit the study inclusion criteria. Data were extracted from these meta-analyses regarding patient outcomes and reruptures. Meta-analysis quality was assessed using the Oxman-Guyatt and QUOROM (Quality of Reporting of Meta-analyses) systems. The Jadad algorithm was applied to determine the meta-analyses with the highest level of evidence. Results: Nine meta-analyses met the eligibility criteria, with all but 1 study including level 1 evidence. A total of 5842 patients were included. Seven studies found a higher rate of rerupture in the nonoperative group but a higher rate of complications in the operative group. One study found no differences in rerupture or complication rates, and 1 study found surgery decreased rerupture rates only when compared with nonoperative treatment without a functional brace. Three studies also identified an earlier return to work in the operative group. Almost all (8 of 9) of the meta-analyses had Oxman-Guyatt scores >3, indicating no major flaws. Conclusion: Operative treatment of Achilles tendon ruptures decreases rerupture rates but increases the risk for minor complications when compared with nonoperative treatment. Additionally, surgical treatment may allow earlier return to work. PMID:26665055

Implementing informative priors for heterogeneity in meta-analysis using meta-regression and pseudo data.

PubMed

Rhodes, Kirsty M; Turner, Rebecca M; White, Ian R; Jackson, Dan; Spiegelhalter, David J; Higgins, Julian P T

2016-12-20

Many meta-analyses combine results from only a small number of studies, a situation in which the between-study variance is imprecisely estimated when standard methods are applied. Bayesian meta-analysis allows incorporation of external evidence on heterogeneity, providing the potential for more robust inference on the effect size of interest. We present a method for performing Bayesian meta-analysis using data augmentation, in which we represent an informative conjugate prior for between-study variance by pseudo data and use meta-regression for estimation. To assist in this, we derive predictive inverse-gamma distributions for the between-study variance expected in future meta-analyses. These may serve as priors for heterogeneity in new meta-analyses. In a simulation study, we compare approximate Bayesian methods using meta-regression and pseudo data against fully Bayesian approaches based on importance sampling techniques and Markov chain Monte Carlo (MCMC). We compare the frequentist properties of these Bayesian methods with those of the commonly used frequentist DerSimonian and Laird procedure. The method is implemented in standard statistical software and provides a less complex alternative to standard MCMC approaches. An importance sampling approach produces almost identical results to standard MCMC approaches, and results obtained through meta-regression and pseudo data are very similar. On average, data augmentation provides closer results to MCMC, if implemented using restricted maximum likelihood estimation rather than DerSimonian and Laird or maximum likelihood estimation. The methods are applied to real datasets, and an extension to network meta-analysis is described. The proposed method facilitates Bayesian meta-analysis in a way that is accessible to applied researchers. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Transfemoral, transapical and transcatheter aortic valve implantation and surgical aortic valve replacement: a meta-analysis of direct and adjusted indirect comparisons of early and mid-term deaths.

PubMed

Ando, Tomo; Takagi, Hisato; Grines, Cindy L

2017-09-01

Clinical outcomes of transfemoral-transcatheter aortic valve implantation (TF-TAVI) versus surgical aortic valve replacement (SAVR) or transapical (TA)-TAVI are limited to a few randomized clinical trials (RCTs). Because previous meta-analyses only included a limited number of adjusted studies or several non-adjusted studies, our goal was to compare and summarize the outcomes of TF-TAVI vs SAVR and TF-TAVI vs TA-TAVI exclusively with the RCT and propensity-matched cohort studies with direct and adjusted indirect comparisons to reach more precise conclusions. We hypothesized that TF-TAVI would offer surgical candidates a better outcome compared with SAVR and TA-TAVI because of its potential for fewer myocardial injuries. A literature search was conducted through PUBMED and EMBASE through June 2016. Only RCTs and propensity-matched cohort studies were included. A direct meta-analysis of TF-TAVI vs SAVR, TA-TAVI vs SAVR and TF-TAVI vs TA-TAVI was conducted. Then, the effect size of an indirect meta-analysis was calculated from the direct meta-analysis. The effect sizes of direct and indirect meta-analyses were then combined. A random-effects model was used to calculate the hazards ratio and the odds ratio with 95% confidence intervals. Early (in-hospital or 30 days) and mid-term (≥1 year) all-cause mortality rates were assessed. Our search resulted in 4 RCTs (n = 2319) and 14 propensity-matched cohort (n = 7217) studies with 9536 patients of whom 3471, 1769 and 4296 received TF, TA and SAVR, respectively. Direct meta-analyses and combined direct and indirect meta-analyses of early and mid-term deaths with TF-TAVI and SAVR were similar. Early deaths with TF-TAVI vs TA-TAVI were comparable in direct meta-analyses (odds ratio 0.64, P = 0.35) and direct and indirect meta-analyses combined (odds ratio 0.73, P = 0.24). Mid-term deaths with TF-TAVI vs TA-TAVI were increased (hazard ratio 0.83, P = 0.07) in a direct meta-analysis and became significant after addition of the indirect meta-analysis (hazard ratio 0.78, 95% confidence interval 0.67-0.92, P = 0.003). In conclusion, TF-TAVI was associated with similar early and mid-term deaths compared with SAVR. The number of early deaths was not significantly different between TF-TAVI and TA-TAVI, whereas there were fewer mid-term deaths with TF-TAVI than with TA-TAVI. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Quality of meta-analyses in major leading gastroenterology and hepatology journals: A systematic review.

PubMed

Liu, Pengfei; Qiu, Yuanyu; Qian, Yuting; Chen, Xiao; Wang, Yiran; Cui, Jin; Zhai, Xiao

2017-01-01

To appraise the current reporting methodological quality of meta-analyses in five leading gastroenterology and hepatology journals, and to identify the variables associated with the reporting quality. We systematically searched the literature of meta-analyses in Gastroenterology, Gut, Hepatology, Journal of Hepatology (J HEPATOL) and American Journal of Gastroenterology (AM J GASTROENTEROL) from 2006 to 2008 and from 2012 to 2014. Characteristics were extracted based on the PRISMA statement and the AMSTAR tool. Country, number of patients, funding source were also revealed and descriptively reported. A total of 127 meta-analyses were enrolled in this study and were compared among journals, study years, and other characters. Compliances with the PRISMA statement and the AMSTAR checklist were 20.8 ± 4.2 out of a maximum of 27 and 7.6 ± 2.4 out of a maximum of 11, respectively. Some domains were poorly reported including describing a protocol and/or registration (item 5, 0.0%), describing methods, and giving results of additional analyses (item 16, 45.7% and item 23, 48.0%) for PRISMA and duplicating study selection and data extraction (item 2, 53.5%), and providing a list of included and excluded studies (item 5, 14.2%) for AMSTAR. Publication in recent years showed a significantly better methodological quality than those published in previous years. This study shows that methodological reporting quality of MAs in the major gastroenterology and hepatology journals has improved in recent years after the publication of the developed PRISMA statement, and it can be further improved. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Anxiety Outcomes after Physical Activity Interventions: Meta-Analysis Findings

PubMed Central

Conn, Vicki S.

2011-01-01

Background Although numerous primary studies have documented the mental health benefits of physical activity (PA), no previous quantitative synthesis has examined anxiety outcomes of interventions to increase PA. Objectives This meta-analysis integrates extant research about anxiety outcomes from interventions to increase PA among healthy adults. Method Extensive literature searching located published and unpublished PA intervention studies with anxiety outcomes. Eligible studies reported findings from interventions designed to increase PA delivered to healthy adults without anxiety disorders. Data were coded from primary studies. Random-effects meta-analytic procedures were completed. Exploratory moderator analyses using meta-analysis ANOVA and regression analogues were conducted to determine if report, methods, sample, or intervention characteristics were associated with differences in anxiety outcomes. Results Data were synthesized across 3,289 subjects from 19 eligible reports. The overall mean anxiety effect size (d-index) for two-group comparisons was 0.22 with significant heterogeneity (Q = 32.15). Exploratory moderator analyses found larger anxiety improvement effect sizes among studies that included larger samples, used random allocation of subjects to treatment and control conditions, targeted only PA behavior instead of multiple health behaviors, included supervised exercise (vs. home-based PA), used moderate or high-intensity instead of low-intensity PA, and suggested subjects exercise at a fitness facility (vs. home) following interventions. Discussion These findings document that some interventions can decrease anxiety symptoms among healthy adults. Exploratory moderator analyses suggest possible directions for future primary research to compare interventions in randomized trials to confirm causal relationships. PMID:20410849

Association between study design and citation counts of articles published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist.

PubMed

Allareddy, Veerasathpurush; Lee, Min Kyeong; Shah, Andrea; Elangovan, Satheesh; Lin, Chin-Yu

2012-01-01

The scientific community views meta-analyses and systematic reviews, in addition to well-designed randomized controlled clinical trials, as the highest echelon in the continuum of hierarchy of evidence. The objective of this study was to examine the association between different study designs and citation counts of articles published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist. All articles, excluding editorial comments, letters to the editor, commentaries, and special articles, that were published in the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist during the years 2004 and 2005 were examined in this study. The number of times an article was cited in the first 24 months after its publication was computed. The PubMed database was used to index the study design of the articles. The association between study design and citation counts was examined using the Kruskal-Wallis test. A multivariable negative binomial regression model was used to examine the association between citation count and study design along with several other confounding variables. A total of 624 articles were selected for analysis. Of these, there were 25 meta-analyses or review articles, 42 randomized clinical trials, 59 clinical trials, 48 animal studies, 64 case reports, and 386 quasiexperimental/miscellaneous study designs. The mean ± SD citation count was 1.04 ± 1.46. Nearly half of the articles (n = 311) were not cited even once during the observation period. Case reports were cited less frequently than meta-analyses or reviews (incident risk ratio, 0.37; 95% confidence interval, 0.19 to 0.72; P = .003), even after adjusting for other independent variables. Among various study designs, meta-analyses and review articles are more likely to be cited in the first 24 months after publication. This study demonstrates the importance of publishing more meta-analyses and review articles for quicker dissemination of research findings.

Epidemiology, quality, and reporting characteristics of systematic reviews and meta-analyses of nursing interventions published in Chinese journals.

PubMed

Zhang, Juxia; Wang, Jiancheng; Han, Lin; Zhang, Fengwa; Cao, Jianxun; Ma, Yuxia

2015-01-01

Systematic reviews (SRs) and meta-analyses (MAs) of nursing interventions have become increasingly popular in China. This review provides the first examination of epidemiological characteristics of these SRs as well as compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses and Assessment of Multiple Systematic Reviews guidelines. The purpose of this study was to examine epidemiologic and reporting characteristics as well as the methodologic quality of SRs and MAs of nursing interventions published in Chinese journals. Four Chinese databases were searched (the Chinese Biomedicine Literature Database, Chinese Scientific Journal Full-text Database, Chinese Journal Full-text Database, and Wanfang Database) for SRs and MAs of nursing intervention from inception through June 2013. Data were extracted into Excel (Microsoft, Redmond, WA). The Assessment of Multiple Systematic Reviews and Preferred Reporting Items for Systematic Reviews and Meta-analyses checklists were used to assess methodologic quality and reporting characteristics, respectively. A total of 144 SRs were identified, most (97.2%) of which used "systematic review" or "meta-analyses" in the titles. None of the reviews had been updated. Nearly half (41%) were written by nurses, and more than half (61%) were reported in specialist journals. The most common conditions studied were endocrine, nutritional and metabolic diseases, and neoplasms. Most (70.8%) reported information about quality assessment, whereas less than half (25%) reported assessing for publication bias. None of the reviews reported a conflict of interest. Although many SRs of nursing interventions have been published in Chinese journals, the quality of these reviews is of concern. As a potential key source of information for nurses and nursing administrators, not only were many of these reviews incomplete in the information they provided, but also some results were misleading. Improving the quality of SRs of nursing interventions conducted and published by nurses in China is urgently needed in order to increase the value of these studies. Copyright © 2015 Elsevier Inc. All rights reserved.

A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses.

PubMed

Esposito, Katherine; Maiorino, Maria Ida; Bellastella, Giuseppe; Chiodini, Paolo; Panagiotakos, Demosthenes; Giugliano, Dario

2015-08-10

To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states. A systematic review of all meta-analyses and randomised controlled trials (RCTs) that compared the Mediterranean diet with a control diet on the treatment of type 2 diabetes and prediabetic states was conducted. Electronic searches were carried out up to January 2015. Trials were included for meta-analyses if they had a control group treated with another diet, if they were of sufficient duration (at least 6 months), and if they had at least 30 participants in each arm. A random-effect model was used to pool data. Adults with or at risk for type 2 diabetes. Dietary patterns that described themselves as using a 'Mediterranean' dietary pattern. The outcomes were glycaemic control, cardiovascular risk factors and remission from the metabolic syndrome. From 2824 studies, 8 meta-analyses and 5 RCTs were eligible. A 'de novo' meta-analysis of 3 long-term (>6 months) RCTs of the Mediterranean diet and glycaemic control of diabetes favoured the Mediterranean diet as compared with lower fat diets. Another 'de novo' meta-analysis of two long-term RCTs showed a 49% increased probability of remission from the metabolic syndrome. 5 meta-analyses showed a favourable effect of the Mediterranean diet, as compared with other diets, on body weight, total cholesterol and high-density lipoprotein cholesterol. 2 meta-analyses demonstrated that higher adherence to the Mediterranean diet reduced the risk of future diabetes by 19-23%. The Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes. 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.

Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study

PubMed Central

Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias

2018-01-01

Abstract Objective To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) (“living” network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Design Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Data sources Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Eligibility criteria for study selection Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (P<0.10). Outcomes and analysis Cumulative pairwise and network meta-analyses were performed for each selected comparison. Monitoring boundaries of statistical significance were constructed and the evidence against the null hypothesis was considered to be strong when the monitoring boundaries were crossed. A significance level was defined as α=5%, power of 90% (β=10%), and an anticipated treatment effect to detect equal to the final estimate from the network meta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. Results 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis provided strong evidence against the null hypothesis for seven comparisons, but for an additional 10 comparisons only network meta-analysis provided strong evidence against the null hypothesis (P=0.002). The median time to strong evidence against the null hypothesis was 19 years with living network meta-analysis and 23 years with living pairwise meta-analysis (hazard ratio 2.78, 95% confidence interval 1.00 to 7.72, P=0.05). Studies directly comparing the treatments of interest continued to be published for eight comparisons after strong evidence had become evident in network meta-analysis. Conclusions In comparative effectiveness research, prospectively planned living network meta-analyses produced strong evidence against the null hypothesis more often and earlier than conventional, pairwise meta-analyses. PMID:29490922

Methodological quality of meta-analyses of single-case experimental studies.

PubMed

Jamshidi, Laleh; Heyvaert, Mieke; Declercq, Lies; Fernández-Castilla, Belén; Ferron, John M; Moeyaert, Mariola; Beretvas, S Natasha; Onghena, Patrick; Van den Noortgate, Wim

2017-12-28

Methodological rigor is a fundamental factor in the validity and credibility of the results of a meta-analysis. Following an increasing interest in single-case experimental design (SCED) meta-analyses, the current study investigates the methodological quality of SCED meta-analyses. We assessed the methodological quality of 178 SCED meta-analyses published between 1985 and 2015 through the modified Revised-Assessment of Multiple Systematic Reviews (R-AMSTAR) checklist. The main finding of the current review is that the methodological quality of the SCED meta-analyses has increased over time, but is still low according to the R-AMSTAR checklist. A remarkable percentage of the studies (93.80% of the included SCED meta-analyses) did not even reach the midpoint score (22, on a scale of 0-44). The mean and median methodological quality scores were 15.57 and 16, respectively. Relatively high scores were observed for "providing the characteristics of the included studies" and "doing comprehensive literature search". The key areas of deficiency were "reporting an assessment of the likelihood of publication bias" and "using the methods appropriately to combine the findings of studies". Although the results of the current review reveal that the methodological quality of the SCED meta-analyses has increased over time, still more efforts are needed to improve their methodological quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

21 CFR 814.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., reports of adverse events, or new analyses of previously submitted data (e.g., meta-analyses) if the studies, events or analyses reveal risks of a different type or greater severity or frequency than... per year. (o) Newly acquired information means data, analyses, or other information not previously...

Socioeconomic status and antisocial behaviour among children and adolescents: a systematic review and meta-analysis.

PubMed

Piotrowska, Patrycja J; Stride, Christopher B; Croft, Simone E; Rowe, Richard

2015-02-01

Previous research on the association between socioeconomic status (SES) and child and adolescent antisocial behaviour has produced mixed findings showing variation in the strength of association. This systematic review and meta-analysis aimed to summarise evidence on the relationship between socioeconomic status and broadly conceptualised antisocial behaviour, investigating variation across a range of antisocial subtypes and other potential moderators, including age, sex and informant. We identified 133 studies containing data suitable for effect size calculation, and 139 independent effect sizes were analysed (total N=339868). The global meta-analysis showed that lower family socioeconomic status was associated with higher levels of antisocial behaviour. Moderation analyses revealed this relationship was stronger where callous-unemotional traits were the outcome, and where antisocial behaviour was reported by parents or teachers rather than self-reported. The relationship between family SES and antisocial behaviour, however, was independent of higher-level constructs such as national income inequality. These results indicate that SES can be considered a robust correlate of broadly conceptualised antisocial behaviour but the strength of this relationship may depend on the antisocial subtype under investigation and the design of the study. Copyright © 2014. Published by Elsevier Ltd.

Stuttering, Induced Fluency, and Natural Fluency: A Hierarchical Series of Activation Likelihood Estimation Meta-Analyses

PubMed Central

Budde, Kristin S.; Barron, Daniel S.; Fox, Peter T.

2015-01-01

Developmental stuttering is a speech disorder most likely due to a heritable form of developmental dysmyelination impairing the function of the speech-motor system. Speech-induced brain-activation patterns in persons who stutter (PWS) are anomalous in various ways; the consistency of these aberrant patterns is a matter of ongoing debate. Here, we present a hierarchical series of coordinate-based meta-analyses addressing this issue. Two tiers of meta-analyses were performed on a 17-paper dataset (202 PWS; 167 fluent controls). Four large-scale (top-tier) meta-analyses were performed, two for each subject group (PWS and controls). These analyses robustly confirmed the regional effects previously postulated as “neural signatures of stuttering” (Brown 2005) and extended this designation to additional regions. Two smaller-scale (lower-tier) meta-analyses refined the interpretation of the large-scale analyses: 1) a between-group contrast targeting differences between PWS and controls (stuttering trait); and 2) a within-group contrast (PWS only) of stuttering with induced fluency (stuttering state). PMID:25463820

Measuring the statistical validity of summary meta-analysis and meta-regression results for use in clinical practice.

PubMed

Willis, Brian H; Riley, Richard D

2017-09-20

An important question for clinicians appraising a meta-analysis is: are the findings likely to be valid in their own practice-does the reported effect accurately represent the effect that would occur in their own clinical population? To this end we advance the concept of statistical validity-where the parameter being estimated equals the corresponding parameter for a new independent study. Using a simple ('leave-one-out') cross-validation technique, we demonstrate how we may test meta-analysis estimates for statistical validity using a new validation statistic, Vn, and derive its distribution. We compare this with the usual approach of investigating heterogeneity in meta-analyses and demonstrate the link between statistical validity and homogeneity. Using a simulation study, the properties of Vn and the Q statistic are compared for univariate random effects meta-analysis and a tailored meta-regression model, where information from the setting (included as model covariates) is used to calibrate the summary estimate to the setting of application. Their properties are found to be similar when there are 50 studies or more, but for fewer studies Vn has greater power but a higher type 1 error rate than Q. The power and type 1 error rate of Vn are also shown to depend on the within-study variance, between-study variance, study sample size, and the number of studies in the meta-analysis. Finally, we apply Vn to two published meta-analyses and conclude that it usefully augments standard methods when deciding upon the likely validity of summary meta-analysis estimates in clinical practice. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

A Systematic Summary of Systematic Reviews on the Topic of the Anterior Cruciate Ligament

PubMed Central

Anderson, Michael J.; Browning, William M.; Urband, Christopher E.; Kluczynski, Melissa A.; Bisson, Leslie J.

2016-01-01

Background: There has been a substantial increase in the amount of systematic reviews and meta-analyses published on the anterior cruciate ligament (ACL). Purpose: To quantify the number of systematic reviews and meta-analyses published on the ACL in the past decade and to provide an overall summary of this literature. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of all ACL-related systematic reviews and meta-analyses published between January 2004 and September 2014 was performed using PubMed, MEDLINE, and the Cochrane Database. Narrative reviews and non-English articles were excluded. Results: A total of 1031 articles were found, of which 240 met the inclusion criteria. Included articles were summarized and divided into 17 topics: anatomy, epidemiology, prevention, associated injuries, diagnosis, operative versus nonoperative management, graft choice, surgical technique, fixation methods, computer-assisted surgery, platelet-rich plasma, rehabilitation, return to play, outcomes assessment, arthritis, complications, and miscellaneous. Conclusion: A summary of systematic reviews on the ACL can supply the surgeon with a single source for the most up-to-date synthesis of the literature. PMID:27047983

The evaluation of meta-analysis techniques for quantifying prescribed fire effects on fuel loadings.

Treesearch

Karen E. Kopper; Donald McKenzie; David L. Peterson

2009-01-01

Models and effect-size metrics for meta-analysis were compared in four separate meta-analyses quantifying surface fuels after prescribed fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the Western United States. An aggregated data set was compiled from eight published reports that contained data from 65 fire treatment units....

Short-term Effect of Fine Particulate Matter on Children's Hospital Admissions and Emergency Department Visits for Asthma: A Systematic Review and Meta-analysis.

PubMed

Lim, Hyungryul; Kwon, Ho-Jang; Lim, Ji-Ae; Choi, Jong Hyuk; Ha, Mina; Hwang, Seung-Sik; Choi, Won-Jun

2016-07-01

No children-specified review and meta-analysis paper about the short-term effect of fine particulate matter (PM2.5) on hospital admissions and emergency department visits for asthma has been published. We calculated more precise pooled effect estimates on this topic and evaluated the variation in effect size according to the differences in study characteristics not considered in previous studies. Two authors each independently searched PubMed and EMBASE for relevant studies in March, 2016. We conducted random effect meta-analyses and mixed-effect meta-regression analyses using retrieved summary effect estimates and 95% confidence intervals (CIs) and some characteristics of selected studies. The Egger's test and funnel plot were used to check publication bias. All analyses were done using R version 3.1.3. We ultimately retrieved 26 time-series and case-crossover design studies about the short-term effect of PM2.5 on children's hospital admissions and emergency department visits for asthma. In the primary meta-analysis, children's hospital admissions and emergency department visits for asthma were positively associated with a short-term 10 μg/m3 increase in PM2.5 (relative risk, 1.048; 95% CI, 1.028 to 1.067; I2=95.7%). We also found different effect coefficients by region; the value in Asia was estimated to be lower than in North America or Europe. We strengthened the evidence on the short-term effect of PM2.5 on children's hospital admissions and emergency department visits for asthma. Further studies from other regions outside North America and Europe regions are needed for more generalizable evidence.

Social Cognitive Predictors of College Students' Academic Performance and Persistence: A Meta-Analytic Path Analysis

ERIC Educational Resources Information Center

Brown, Steven D.; Tramayne, Selena; Hoxha, Denada; Telander, Kyle; Fan, Xiaoyan; Lent, Robert W.

2008-01-01

This study tested Social Cognitive Career Theory's (SCCT) academic performance model using a two-stage approach that combined meta-analytic and structural equation modeling methodologies. Unbiased correlations obtained from a previously published meta-analysis [Robbins, S. B., Lauver, K., Le, H., Davis, D., & Langley, R. (2004). Do psychosocial…

Con: Meta-analysis: some key limitations and potential solutions.

PubMed

Esterhuizen, Tonya M; Thabane, Lehana

2016-06-01

Meta-analysis, a statistical combination of results of several trials to produce a summary effect, has been subject to criticism in the past, mainly for the reasons of poor quality of included studies, heterogeneity between studies meta-analyzed and failing to address publication bias. These limitations can cause the results to be misleading, which is important if policy and practice decisions are based on systematic reviews and meta-analyses. We elaborate on these limitations and illustrate them with examples from the nephrology literature. Finally, we present some potential solutions, notably, education in meta-analysis for evidence producers and consumers as well as the use of individual patient data for meta-analyses. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

A critical appraisal of the scientific basis of commercial genomic profiles used to assess health risks and personalize health interventions.

PubMed

Janssens, A Cecile J W; Gwinn, Marta; Bradley, Linda A; Oostra, Ben A; van Duijn, Cornelia M; Khoury, Muin J

2008-03-01

Predictive genomic profiling used to produce personalized nutrition and other lifestyle health recommendations is currently offered directly to consumers. By examining previous meta-analyses and HuGE reviews, we assessed the scientific evidence supporting the purported gene-disease associations for genes included in genomic profiles offered online. We identified seven companies that offer predictive genomic profiling. We searched PubMed for meta-analyses and HuGE reviews of studies of gene-disease associations published from 2000 through June 2007 in which the genotypes of people with a disease were compared with those of a healthy or general-population control group. The seven companies tested at least 69 different polymorphisms in 56 genes. Of the 56 genes tested, 24 (43%) were not reviewed in meta-analyses. For the remaining 32 genes, we found 260 meta-analyses that examined 160 unique polymorphism-disease associations, of which only 60 (38%) were found to be statistically significant. Even the 60 significant associations, which involved 29 different polymorphisms and 28 different diseases, were generally modest, with synthetic odds ratios ranging from 0.54 to 0.88 for protective variants and from 1.04 to 3.2 for risk variants. Furthermore, genes in cardiogenomic profiles were more frequently associated with noncardiovascular diseases than with cardiovascular diseases, and though two of the five genes of the osteogenomic profiles did show significant associations with disease, the associations were not with bone diseases. There is insufficient scientific evidence to conclude that genomic profiles are useful in measuring genetic risk for common diseases or in developing personalized diet and lifestyle recommendations for disease prevention.

Early Versus Delayed Motion After Rotator Cuff Repair: A Systematic Review of Overlapping Meta-analyses.

PubMed

Houck, Darby A; Kraeutler, Matthew J; Schuette, Hayden B; McCarty, Eric C; Bravman, Jonathan T

2017-10-01

Previous meta-analyses have been conducted to compare outcomes of early versus delayed motion after rotator cuff repair. To conduct a systematic review of overlapping meta-analyses comparing early versus delayed motion rehabilitation protocols after rotator cuff repair to determine which meta-analyses provide the best available evidence. Systematic review. A systematic review was performed by searching PubMed and Cochrane Library databases. Search terms included "rotator cuff repair," "early passive motion," "immobilization," "rehabilitation protocol," and "meta-analysis." Results were reviewed to determine study eligibility. Patient outcomes and structural healing were extracted from these meta-analyses. Meta-analysis quality was assessed using the Oxman-Guyatt and Quality of Reporting of Meta-analyses (QUOROM) systems. The Jadad decision algorithm was then used to determine which meta-analyses provided the best level of evidence. Seven meta-analyses containing a total of 5896 patients met the eligibility criteria (1 Level I evidence, 4 Level II evidence, 2 Level III evidence). None of these meta-analyses found immobilization to be superior to early motion; however, most studies suggested that early motion would increase range of motion (ROM), thereby reducing time of recovery. Three of these studies suggested that tear size contributed to the choice of rehabilitation to ensure proper healing of the shoulder. A study by Chan et al in 2014 received the highest QUOROM and Oxman-Guyatt scores, and therefore this meta-analysis appeared to have the highest level of evidence. Additionally, a study by Riboh and Garrigues in 2014 was selected as the highest quality study in this systematic review according to the Jadad decision algorithm. The current, best available evidence suggests that early motion improves ROM after rotator cuff repair but increases the risk of rotator cuff retear. Lower quality meta-analyses indicate that tear size may provide a better strategy in determining the correct rehabilitation protocol.

Large-scale meta-analysis of interleukin-1 beta and interleukin-1 receptor antagonist polymorphisms on risk of radiographic hip and knee osteoarthritis and severity of knee osteoarthritis.

PubMed

Kerkhof, H J M; Doherty, M; Arden, N K; Abramson, S B; Attur, M; Bos, S D; Cooper, C; Dennison, E M; Doherty, S A; Evangelou, E; Hart, D J; Hofman, A; Javaid, K; Kerna, I; Kisand, K; Kloppenburg, M; Krasnokutsky, S; Maciewicz, R A; Meulenbelt, I; Muir, K R; Rivadeneira, F; Samuels, J; Sezgin, M; Slagboom, E; Smith, A J P; Spector, T D; Tamm, A; Tamm, A; Uitterlinden, A G; Wheeler, M; Zhai, G; Zhang, W; van Meurs, J B J; Valdes, A M

2011-03-01

To clarify the role of common genetic variation in the Interleukin-1β (IL1B) and Interleukin-1R antagonist (IL1RN) genes on risk of knee and hip osteoarthritis (OA) and severity of knee OA by means of large-scale meta-analyses. We searched PubMed for articles assessing the role of IL1B and IL1RN polymorphisms/haplotypes on the risk of hip and/or knee OA. Novel data were included from eight unpublished studies. Meta-analyses were performed using fixed- and random-effects models with a total of 3595 hip OA and 5013 knee OA cases, and 6559 and 9132 controls respectively. The role of ILRN haplotypes on radiographic severity of knee OA was tested in 1918 cases with Kellgren-Lawrence (K/L) 1 or 2 compared to 199 cases with K/L 3 or 4. The meta-analysis of six published studies retrieved from the literature search and eight unpublished studies showed no evidence of association between common genetic variation in the IL1B or IL1RN genes and risk of hip OA or knee OA (P>0.05 for rs16944, rs1143634, rs419598 and haplotype C-G-C (rs1143634, rs16944 and rs419598) previously implicated in risk of hip OA). The C-T-A haplotype formed by rs419598, rs315952 and rs9005, previously implicated in radiographic severity of knee OA, was associated with reduced severity of knee OA (odds ratio (OR)=0.71 95%CI 0.56-0.91; P=0.006, I(2)=74%), and achieved borderline statistical significance in a random-effects model (OR=0.61 95%CI 0.35-1.06 P=0.08). Common genetic variation in the Interleukin-1 region is not associated with prevalence of hip or knee OA but our data suggest that IL1RN might have a role in severity of knee OA. Copyright © 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Additional considerations are required when preparing a protocol for a systematic review with multiple interventions.

PubMed

Chaimani, Anna; Caldwell, Deborah M; Li, Tianjing; Higgins, Julian P T; Salanti, Georgia

2017-03-01

The number of systematic reviews that aim to compare multiple interventions using network meta-analysis is increasing. In this study, we highlight aspects of a standard systematic review protocol that may need modification when multiple interventions are to be compared. We take the protocol format suggested by Cochrane for a standard systematic review as our reference and compare the considerations for a pairwise review with those required for a valid comparison of multiple interventions. We suggest new sections for protocols of systematic reviews including network meta-analyses with a focus on how to evaluate their assumptions. We provide example text from published protocols to exemplify the considerations. Standard systematic review protocols for pairwise meta-analyses need extensions to accommodate the increased complexity of network meta-analysis. Our suggested modifications are widely applicable to both Cochrane and non-Cochrane systematic reviews involving network meta-analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

Examining the Efficacy of Self-Regulated Strategy Development for Students with Emotional or Behavioral Disorders: A Meta-Analysis

ERIC Educational Resources Information Center

Losinski, Mickey; Cuenca-Carlino, Yojanna; Zablocki, Mark; Teagarden, James

2014-01-01

Two previous reviews have indicated that self-regulated strategy instruction (SRSD) is an evidence-based practice that can improve the writing skills of students with emotional and behavioral disorders. The purpose of this meta-analysis is to extend the findings and analytic methods of previous reviews by examining published studies regarding…

Correlation of human papilloma virus with oral squamous cell carcinoma in Chinese population.

PubMed

Zhou, Jingping; Tao, Detao; Tang, Daofang; Gao, Zhenlin

2015-01-01

Previous studies indicated that oral squamous cell carcinomas (OSCC) might be related to human papilloma virus (HPV) infection. However, the relationship between OSCC in a Chinese population and oral HPV infection is still unclear. In this study, we evaluate the relationship of OSCC with HPV infection in a Chinese population via a meta-analysis. The reports on HPV and OSCC in a Chinese population published between January, 1994, and October, 2015 were retrieved via CNKI/WANFANG/pubmed databases. According to the inclusion criteria, we selected 26 eligible case-control studies. After testing the heterogeneity of the studies by the Cochran Q test, the meta-analyses for HPV and HPV16 were performed using the random effects model. Quantitative meta-analyses showed that, compared with normal oral mucosa the combined odds ratio of OSCC with HPV infection were 1.98 (95% CI: 1.34-2.92). The test for overall effect showed that the P value was less than 0.05 (Z = 3.46). Forest plot analyses were seen in Figures 2 and 3. Publication bias and bias risk analysis using RevMan 5.3 software were measured indicators of the graphics of the basic symmetry. High incidences of HPV infection were found in the samples of Chinese OSCC. For the Chinese population, HPV infection elevates the risk of OSCC tumorigenesis.

When ab ≠ c - c': published errors in the reports of single-mediator models.

PubMed

Petrocelli, John V; Clarkson, Joshua J; Whitmire, Melanie B; Moon, Paul E

2013-06-01

Accurate reports of mediation analyses are critical to the assessment of inferences related to causality, since these inferences are consequential for both the evaluation of previous research (e.g., meta-analyses) and the progression of future research. However, upon reexamination, approximately 15% of published articles in psychology contain at least one incorrect statistical conclusion (Bakker & Wicherts, Behavior research methods, 43, 666-678 2011), disparities that beget the question of inaccuracy in mediation reports. To quantify this question of inaccuracy, articles reporting standard use of single-mediator models in three high-impact journals in personality and social psychology during 2011 were examined. More than 24% of the 156 models coded failed an equivalence test (i.e., ab = c - c'), suggesting that one or more regression coefficients in mediation analyses are frequently misreported. The authors cite common sources of errors, provide recommendations for enhanced accuracy in reports of single-mediator models, and discuss implications for alternative methods.

Is intramedullary fixation of displaced midshaft clavicle fracture superior to plate fixation? Evidence from a systematic review of discordant meta-analyses.

PubMed

Xu, Bin; Lin, Yongsheng; Wang, Zhihong; Cao, Junming; Yang, Yipeng; Xia, Hehuan; Zhang, Yingze

2017-07-01

An increasing number of meta-analyses comparing intramedullary fixation (IF) with plate fixation (PF) for displaced midshaft clavicle fracture have been reported, but the inconsistent results obtained might confuse decision-making. We systematically reviewed discordant meta-analyses for assisting the decision-maker in interpreting and selecting amongst discordant meta-analyses and providing surgical recommendations for displaced midshaft clavicle fracture according to currently best available evidence. Meta-analyses on IF and PF for displaced midshaft clavicle fracture were identified by searching PubMed, Emabase and the Cochrane Library. A review of meta-analysis quality and data extraction was individually conducted by two reviewers. The meta-analysis providing the best available evidence was identified using the Jadad decision algorithm. Nine studies were included, five of which were of Level-II evidence and four of which were of Level-III evidence. These meta-analyses scored from 6 to 10 according to the Assessment of Multiple Systematic Reviews instrument. With respect to the Jadad decision algorithm, the best meta-analysis was chosen depending upon publication characteristics and methodology of primary studies, language restrictions, and whether data on individual patients were analysed. A meta-analysis incorporating more randomised controlled trials was eventually selected. The best available evidence indicated that the differences between IF and PF were not significant in terms of shoulder function or the rate of treatment failure. However, IF significantly decreased the operative time and the rate of non-operative complications, especially the rate of infection. Based on the best available evidence, IF may be superior to PF for treating displaced midshaft clavicle fracture. Copyright © 2017. Published by Elsevier Ltd.

Meta-synthesis of health behavior change meta-analyses.

PubMed

Johnson, Blair T; Scott-Sheldon, Lori A J; Carey, Michael P

2010-11-01

We integrated and compared meta-analytic findings across diverse behavioral interventions to characterize how well they have achieved change in health behavior. Outcomes from 62 meta-analyses of interventions for change in health behavior were quantitatively synthesized, including 1011 primary-level investigations with 599,559 participants. Content coding suggested 6 behavioral domains: eating and physical activity, sexual behavior, addictive behaviors, stress management, female-specific screening and intervention behaviors, and behaviors involving use of health services. Behavior change interventions were efficacious (mean effect sizes = 0.08-0.45). Behavior change was more evident in more recent meta-analyses; those that sampled older interventions and literatures or sampled more published articles; those that included studies that relied on self-report, used briefer interventions, or sampled fewer, older, or female participants; and in some domains (e.g., stress management) more than others (e.g., sexual behaviors). Interventions improved health-related behaviors; however, efficacy varied as a function of participant and intervention characteristics. This meta-synthesis provides information about the efficacy of behavioral change interventions across health domains and populations; this knowledge can inform the design and development of public health interventions and future meta-analyses of these studies.

Immune-related adverse events associated with PD-1 and PD-L1 inhibitors for nonsmall cell lung cancer

PubMed Central

Sun, Xiaoying; Roudi, Raheleh; Chen, Shangya; Fan, Bin; Li, Hong Jin; Zhou, Min; Li, Xin; Li, Bin

2017-01-01

Abstract Introduction: Nonsmall cell lung cancer accounts for approximately 80% of all lung cancers, and approximately 75% of cases are diagnosed in the middle and late stages of disease. Unfortunately, limited treatment does not improve the prognosis of advanced disease. Monoclonal antibodies targeting programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) represent a new treatment paradigm for nonsmall cell lung cancer. Nevertheless, the immune-related adverse events (irAEs) associated with PD-1 and PD-L1 inhibitors are unique, and early recognition and treatment of these events are essential. Methods and Analysis: A systematic literature search will be performed using the EMBASE, MEDLINE, and Cochrane databases to identify relevant articles published in any language. Randomized clinical trials, case series, and case reports of PD-1 and PD-L1 inhibitors in the treatment of nonsmall cell lung cancer will be included. All meta-analyses will be performed using RevMan software. The quality of the studies will be evaluated using the guidelines listed in the Cochrane Handbook. If the necessary data are available, then subgroup analyses will be performed for high-, median-, and low-dose cohorts. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements will be followed until the findings of the systematic review and meta-analysis are reported. Conclusions: This will be the first systematic review and meta-analysis to describe previously reported irAEs related to PD-1 and PD-L1 inhibitors in the treatment of nonsmall cell lung cancer. PMID:29095271

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.

Meta-analysis of randomized clinical trials in the era of individual patient data sharing.

PubMed

Kawahara, Takuya; Fukuda, Musashi; Oba, Koji; Sakamoto, Junichi; Buyse, Marc

2018-06-01

Individual patient data (IPD) meta-analysis is considered to be a gold standard when the results of several randomized trials are combined. Recent initiatives on sharing IPD from clinical trials offer unprecedented opportunities for using such data in IPD meta-analyses. First, we discuss the evidence generated and the benefits obtained by a long-established prospective IPD meta-analysis in early breast cancer. Next, we discuss a data-sharing system that has been adopted by several pharmaceutical sponsors. We review a number of retrospective IPD meta-analyses that have already been proposed using this data-sharing system. Finally, we discuss the role of data sharing in IPD meta-analysis in the future. Treatment effects can be more reliably estimated in both types of IPD meta-analyses than with summary statistics extracted from published papers. Specifically, with rich covariate information available on each patient, prognostic and predictive factors can be identified or confirmed. Also, when several endpoints are available, surrogate endpoints can be assessed statistically. Although there are difficulties in conducting, analyzing, and interpreting retrospective IPD meta-analysis utilizing the currently available data-sharing systems, data sharing will play an important role in IPD meta-analysis in the future.

Stuttering, induced fluency, and natural fluency: a hierarchical series of activation likelihood estimation meta-analyses.

PubMed

Budde, Kristin S; Barron, Daniel S; Fox, Peter T

2014-12-01

Developmental stuttering is a speech disorder most likely due to a heritable form of developmental dysmyelination impairing the function of the speech-motor system. Speech-induced brain-activation patterns in persons who stutter (PWS) are anomalous in various ways; the consistency of these aberrant patterns is a matter of ongoing debate. Here, we present a hierarchical series of coordinate-based meta-analyses addressing this issue. Two tiers of meta-analyses were performed on a 17-paper dataset (202 PWS; 167 fluent controls). Four large-scale (top-tier) meta-analyses were performed, two for each subject group (PWS and controls). These analyses robustly confirmed the regional effects previously postulated as "neural signatures of stuttering" (Brown, Ingham, Ingham, Laird, & Fox, 2005) and extended this designation to additional regions. Two smaller-scale (lower-tier) meta-analyses refined the interpretation of the large-scale analyses: (1) a between-group contrast targeting differences between PWS and controls (stuttering trait); and (2) a within-group contrast (PWS only) of stuttering with induced fluency (stuttering state). Copyright © 2014 Elsevier Inc. All rights reserved.

Redundant systematic reviews on the same topic in surgery: a study protocol for a meta-epidemiological investigation.

PubMed

Katsura, Morihiro; Kuriyama, Akira; Tada, Masafumi; Yamamoto, Kazumichi; Furukawa, Toshi A

2017-08-21

We are witnessing an explosive increase in redundant and overlapping publications of systematic reviews and meta-analyses (SRs/MAs) on the same topic, which often present conflicting results and interpretations, in the current medical literature. They represent wasted efforts on the part of investigators and peer reviewers and may confuse and possibly mislead clinicians and policymakers. Here, we present a protocol for a meta-epidemiological investigation to describe how often there are overlapping SRs/MAs on the same topic, to assess the quality of these multiple publications, and to investigate the causes of discrepant results between multiple SRs/MAs in the field of major surgery. We will use MEDLINE/PubMed to identify all SRs/MAs of randomised controlled trials (RCTs) published in 2015 regarding major surgical interventions. After identifying the 'benchmark' SRs/MAs published in 2015, a process of screening in MEDLINE will be carried out to identify the previous SRs/MAs of RCTs on the same topic that were published within 5 years of the 'benchmark' SRs/MAs. We will tabulate the number of previous SRs/MAs on the same topic of RCTs, and then describe their variations in numbers of RCTs included, sample sizes, effect size estimates and other characteristics. We will also assess the differences in quality of each SR/MA using A Measurement Tool to Assess Systematic Reviews (AMSTAR) score. Finally, we will investigate the potential reasons to explain the discrepant results between multiple SRs/MAs. No formal ethical approval and informed consent are required because this study will not collect primary individual data. The intended audiences of the findings include clinicians, healthcare researchers and policymakers. We will publish our findings as a scientific report in a peer-reviewed journal. In PROSPERO CRD42017059077, March 2017. © 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.

Lipoprotein (a) as a risk factor for ischemic stroke: a meta-analysis.

PubMed

Nave, Alexander H; Lange, Kristin S; Leonards, Christopher O; Siegerink, Bob; Doehner, Wolfram; Landmesser, Ulf; Steinhagen-Thiessen, Elisabeth; Endres, Matthias; Ebinger, Martin

2015-10-01

Lipoprotein (a) [Lp(a)] harbors atherogenic potential but its role as a risk factor for ischemic stroke remains controversial. We conducted a meta-analysis to determine the relative strength of the association between Lp(a) and ischemic stroke and identify potential subgroup-specific risk differences. A systematic search using the MeSH terms "lipoproteins" OR "lipoprotein a" AND "stroke" was performed in PubMed and ScienceDirect for case-control studies from June 2006 and prospective cohort studies from April 2009 until December 20th 2014. Data from eligible papers published before these dates were reviewed and extracted from previous meta-analyses. Studies that assessed the relationship between Lp(a) levels and ischemic stroke and reported generic data-i.e. odds ratio [OR], hazard ratio, or risk ratio [RR]-were eligible for inclusion. Studies that not distinguish between ischemic and hemorrhagic stroke and transient ischemic attack were excluded. Random effects meta-analyses with mixed-effects meta-regression were performed by pooling adjusted OR or RR. A total of 20 articles comprising 90,904 subjects and 5029 stroke events were eligible for the meta-analysis. Comparing high with low Lp(a) levels, the pooled estimated OR was 1.41 (95% CI, 1.26-1.57) for case-control studies (n = 11) and the pooled estimated RR was 1.29 (95% CI, 1.06-1.58) for prospective studies (n = 9). Sex-specific differences in RR were inconsistent between case-control and prospective studies. Study populations with a mean age of ≤55 years had an increased RR compared to older study populations. Reported Lp(a) contrast levels and ischemic stroke subtype significantly contributed to the heterogeneity observed in the analyses. Elevated Lp(a) is an independent risk factor for ischemic stroke and may be especially relevant for young stroke patients. Sex-specific risk differences remain conflicting. Further studies in these subgroups may be warranted. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Genetic and Diagnostic Biomarker Development in ASD Toddlers Using Resting-State Functional MRI

DTIC Science & Technology

by the principal investigators are being mined for ASD relevant biomarkers. Structural and (constrained) functional meta-analyses of previously...ASD and typically developing (TD) individuals. These regions-of-interest will be extended through additional functional meta-analyses, network models will be created, and these models will be applied to primary ASD data .

Development and validation of MIX: comprehensive free software for meta-analysis of causal research data.

PubMed

Bax, Leon; Yu, Ly-Mee; Ikeda, Noriaki; Tsuruta, Harukazu; Moons, Karel G M

2006-10-13

Meta-analysis has become a well-known method for synthesis of quantitative data from previously conducted research in applied health sciences. So far, meta-analysis has been particularly useful in evaluating and comparing therapies and in assessing causes of disease. Consequently, the number of software packages that can perform meta-analysis has increased over the years. Unfortunately, it can take a substantial amount of time to get acquainted with some of these programs and most contain little or no interactive educational material. We set out to create and validate an easy-to-use and comprehensive meta-analysis package that would be simple enough programming-wise to remain available as a free download. We specifically aimed at students and researchers who are new to meta-analysis, with important parts of the development oriented towards creating internal interactive tutoring tools and designing features that would facilitate usage of the software as a companion to existing books on meta-analysis. We took an unconventional approach and created a program that uses Excel as a calculation and programming platform. The main programming language was Visual Basic, as implemented in Visual Basic 6 and Visual Basic for Applications in Excel 2000 and higher. The development took approximately two years and resulted in the 'MIX' program, which can be downloaded from the program's website free of charge. Next, we set out to validate the MIX output with two major software packages as reference standards, namely STATA (metan, metabias, and metatrim) and Comprehensive Meta-Analysis Version 2. Eight meta-analyses that had been published in major journals were used as data sources. All numerical and graphical results from analyses with MIX were identical to their counterparts in STATA and CMA. The MIX program distinguishes itself from most other programs by the extensive graphical output, the click-and-go (Excel) interface, and the educational features. The MIX program is a valid tool for performing meta-analysis and may be particularly useful in educational environments. It can be downloaded free of charge via http://www.mix-for-meta-analysis.info or http://sourceforge.net/projects/meta-analysis.

Sleep in patients with remitted bipolar disorders: a meta-analysis of actigraphy studies.

PubMed

Geoffroy, P A; Scott, J; Boudebesse, C; Lajnef, M; Henry, C; Leboyer, M; Bellivier, F; Etain, B

2015-02-01

Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls. A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI). Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07). This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The American Psychological Association Task Force assessment of violent video games: Science in the service of public interest.

PubMed

Calvert, Sandra L; Appelbaum, Mark; Dodge, Kenneth A; Graham, Sandra; Nagayama Hall, Gordon C; Hamby, Sherry; Fasig-Caldwell, Lauren G; Citkowicz, Martyna; Galloway, Daniel P; Hedges, Larry V

2017-01-01

A task force of experts was convened by the American Psychological Association (APA) to update the knowledge and policy about the impact of violent video game use on potential adverse outcomes. This APA Task Force on Media Violence examined the existing literature, including the meta-analyses in the field, since the last APA report on media violence in 2005. Because the most recent meta-analyses were published in 2010 and reflected work through 2009, the task force conducted a search of the published studies from 2009-2013. These recently published articles were scored and assessed by a systematic evidentiary review, followed by a meta-analysis of the high utility studies, as documented in the evidentiary review. Consistent with the literature that we reviewed, we found that violent video game exposure was associated with: an increased composite aggression score; increased aggressive behavior; increased aggressive cognitions; increased aggressive affect, increased desensitization, and decreased empathy; and increased physiological arousal. The size of the effects was similar to that in prior meta-analyses, suggesting a stable result. Our task force concluded that violent video game use is a risk factor for adverse outcomes, but found insufficient studies to examine any potential link between violent video game use and delinquency or criminal behavior. Our technical report is the basis of this article. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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

PubMed

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

2015-01-01

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

The profile of HLA-DRB1 alleles in Arabs with type 1 diabetes; meta-analyses.

PubMed

Hamzeh, A R; Nair, P; Al Ali, M T

2016-01-01

Genes from the HLA complex have a major contribution in type 1 diabetes (T1D), which results from an interplay between environmental and genetic factors. The latter can explain some of the geographic variability in T1D occurrence around the world. Of a particular importance in this regard are the HLA-DR, -DP and -DQ loci. Consequently, we aimed at elucidating the collective genetic profiles of various alleles relating to HLA-DRB1 and -DP in T1D patients throughout the Arab World using the tools of meta-analysis. As for HLA-DQA1 and DQB1 alleles; this analysis was completed and published previously (see Introduction). As a result of limited availability of relevant studies of the HLA-DP locus, only HLA-DRB1 alleles were tackled in this paper. Our study showed that significant increases in T1D risk resulted from harboring the alleles DRB1*03:01 and *04:05 (odds ratio 7.76 and 7.52, respectively). DRB1*04:01 and *04:02 were also predisposing for T1D in Arabs. Very strong evidence supported the protective effects of DRB1*10:01, *13:01, *15:02 and *16:01, with low heterogeneity and no publication bias. The results from the series of meta-analyses performed in this study help to complete the global genetic epidemiological map of T1D by providing statistically robust data from the Arab World. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

What Limits the Encoding Effect of Note-Taking? A Meta-Analytic Examination

ERIC Educational Resources Information Center

Kobayashi, K.

2005-01-01

Previous meta-analyses indicate that the overall encoding effect of note-taking is positive but modest. This meta-analysis of 57 note-taking versus no note-taking comparison studies explored what limits the encoding effect by examining the moderating influence of seven variables: intervention, schooling level, presentation mode and length, test…

Methodological Standards for Meta-Analyses and Qualitative Systematic Reviews of Cardiac Prevention and Treatment Studies: A Scientific Statement From the American Heart Association.

PubMed

Rao, Goutham; Lopez-Jimenez, Francisco; Boyd, Jack; D'Amico, Frank; Durant, Nefertiti H; Hlatky, Mark A; Howard, George; Kirley, Katherine; Masi, Christopher; Powell-Wiley, Tiffany M; Solomonides, Anthony E; West, Colin P; Wessel, Jennifer

2017-09-05

Meta-analyses are becoming increasingly popular, especially in the fields of cardiovascular disease prevention and treatment. They are often considered to be a reliable source of evidence for making healthcare decisions. Unfortunately, problems among meta-analyses such as the misapplication and misinterpretation of statistical methods and tests are long-standing and widespread. The purposes of this statement are to review key steps in the development of a meta-analysis and to provide recommendations that will be useful for carrying out meta-analyses and for readers and journal editors, who must interpret the findings and gauge methodological quality. To make the statement practical and accessible, detailed descriptions of statistical methods have been omitted. Based on a survey of cardiovascular meta-analyses, published literature on methodology, expert consultation, and consensus among the writing group, key recommendations are provided. Recommendations reinforce several current practices, including protocol registration; comprehensive search strategies; methods for data extraction and abstraction; methods for identifying, measuring, and dealing with heterogeneity; and statistical methods for pooling results. Other practices should be discontinued, including the use of levels of evidence and evidence hierarchies to gauge the value and impact of different study designs (including meta-analyses) and the use of structured tools to assess the quality of studies to be included in a meta-analysis. We also recommend choosing a pooling model for conventional meta-analyses (fixed effect or random effects) on the basis of clinical and methodological similarities among studies to be included, rather than the results of a test for statistical heterogeneity. © 2017 American Heart Association, Inc.

Network meta-analyses could be improved by searching more sources and by involving a librarian.

PubMed

Li, Lun; Tian, Jinhui; Tian, Hongliang; Moher, David; Liang, Fuxiang; Jiang, Tongxiao; Yao, Liang; Yang, Kehu

2014-09-01

Network meta-analyses (NMAs) aim to rank the benefits (or harms) of interventions, based on all available randomized controlled trials. Thus, the identification of relevant data is critical. We assessed the conduct of the literature searches in NMAs. Published NMAs were retrieved by searching electronic bibliographic databases and other sources. Two independent reviewers selected studies and five trained reviewers abstracted data regarding literature searches, in duplicate. Search method details were examined using descriptive statistics. Two hundred forty-nine NMAs were included. Eight used previous systematic reviews to identify primary studies without further searching, and five did not report any literature searches. In the 236 studies that used electronic databases to identify primary studies, the median number of databases was 3 (interquartile range: 3-5). MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were the most commonly used databases. The most common supplemental search methods included reference lists of included studies (48%), reference lists of previous systematic reviews (40%), and clinical trial registries (32%). None of these supplemental methods was conducted in more than 50% of the NMAs. Literature searches in NMAs could be improved by searching more sources, and by involving a librarian or information specialist. Copyright © 2014 Elsevier Inc. All rights reserved.

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

PubMed Central

2014-01-01

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

Comparison of Estimates between Cohort and Case-Control Studies in Meta-Analyses of Therapeutic Interventions: A Meta-Epidemiological Study.

PubMed

Lanza, Amy; Ravaud, Philippe; Riveros, Carolina; Dechartres, Agnes

2016-01-01

Observational studies are increasingly being used for assessing therapeutic interventions. Case-control studies are generally considered to have greater risk of bias than cohort studies, but we lack evidence of differences in effect estimates between the 2 study types. We aimed to compare estimates between cohort and case-control studies in meta-analyses of observational studies of therapeutic interventions by using a meta-epidemiological study. We used a random sample of meta-analyses of therapeutic interventions published in 2013 that included both cohort and case-control studies assessing a binary outcome. For each meta-analysis, the ratio of estimates (RE) was calculated by comparing the estimate in case-control studies to that in cohort studies. Then, we used random-effects meta-analysis to estimate a combined RE across meta-analyses. An RE < 1 indicated that case-control studies yielded larger estimates than cohort studies. The final analysis included 23 meta-analyses: 138 cohort and 133 case-control studies. Treatment effect estimates did not significantly differ between case-control and cohort studies (combined RE 0.97 [95% CI 0.86-1.09]). Heterogeneity was low, with between-meta-analysis variance τ2 = 0.0049. Estimates did not differ between case-control and prospective or retrospective cohort studies (RE = 1.05 [95% CI 0.96-1.15] and RE = 0.99 [95% CI, 0.83-1.19], respectively). Sensitivity analysis of studies reporting adjusted estimates also revealed no significant difference (RE = 1.03 [95% CI 0.91-1.16]). Heterogeneity was also low for these analyses. We found no significant difference in treatment effect estimates between case-control and cohort studies assessing therapeutic interventions.

Diabetes, plasma glucose and incidence of pancreatic cancer: A prospective study of 0.5 million Chinese adults and a meta-analysis of 22 cohort studies.

PubMed

Pang, Yuanjie; Kartsonaki, Christiana; Guo, Yu; Bragg, Fiona; Yang, Ling; Bian, Zheng; Chen, Yiping; Iona, Andri; Millwood, Iona Y; Lv, Jun; Yu, Canqing; Chen, Junshi; Li, Liming; Holmes, Michael V; Chen, Zhengming

2017-04-15

Diabetes is associated with an increased risk of pancreatic cancer (PC) in Western populations. Uncertainty remains, however, about the relevance of plasma glucose for PC among people without diabetes and about the associations of diabetes and high blood glucose with PC in China where the increase in diabetes prevalence has been very recent. The prospective China Kadoorie Biobank (CKB) study recruited 512,000 adults aged 30-79 years from 10 diverse areas of China during 2004-2008, recording 595 PC cases during 8 years of follow-up. Cox regression yielded adjusted hazard ratios (HRs) for PC associated with diabetes (previously diagnosed or screen-detected) and, among those without previously diagnosed diabetes, with levels of random plasma glucose (RPG). These were further meta-analysed with 22 published prospective studies. Overall 5.8% of CKB participants had diabetes at baseline. Diabetes was associated with almost twofold increased risk of PC (adjusted HR = 1.87, 95% CI 1.48-2.37), with excess risk higher in those with longer duration since diagnosis (p for trend = 0.01). Among those without previously diagnosed diabetes, each 1 mmol/L higher usual RPG was associated with a HR of 1.12 (1.04-1.21). In meta-analysis of CKB and 22 other studies, previously diagnosed diabetes was associated with a 52% excess risk (1.52, 1.43-1.63). Among those without diabetes, each 1 mmol/L higher blood glucose was associated with a 15% (1.15, 1.09-1.21) excess risk. In Chinese and non-Chinese populations, diabetes and higher blood glucose levels among those without diabetes are associated with an increased risk of PC. © 2017 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.

Histamine food poisonings: A systematic review and meta-analysis.

PubMed

Colombo, Fabio M; Cattaneo, Patrizia; Confalonieri, Enrica; Bernardi, Cristian

2018-05-03

The aim of this study was to assess the mean of histamine concentration in food poisoning. Systematic review and meta-analysis of reports published between 1959 and 2013. Main criteria for inclusion of studies were: all report types that present outbreaks of "histamine poisoning' or "scombroid syndrome" from food, including histamine content and type of food. Health status of people involved must be nonpathological. Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with confidence interval for the meta-mean of 422.62-2900.78 mg/kg; heterogeneity index (I2) was 100% (P < 0.0001); prediction interval was 24.12-50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication, and consumption of histamine releasing food) and histamine poisoning, were highlighted. This is the first systematic review and meta-analysis that analyzes all the available data on histamine poisoning outbreaks evaluating the histamine concentration in food involved. Histamine mean concentration in poisoning samples was fairly high. Our study suffers from some limitations, which are intrinsic of the studies included, for instance the lack of a complete anamnesis of each poisoning episode. Protocol registration: Methods were specified in advance and have been published as a protocol in PROSPERO database (18/07/2012 -CRD42012002566).

Consumption of garlic and risk of colorectal cancer: An updated meta-analysis of prospective studies

PubMed Central

Hu, Ji-Yi; Hu, Yi-Wang; Zhou, Jiao-Jiao; Zhang, Meng-Wen; Li, Dan; Zheng, Shu

2014-01-01

AIM: To conduct an updated meta-analysis of prospective studies addressing the association between garlic consumption and colorectal cancer. METHODS: Eligible cohort studies were identified by searching MEDLINE (PubMed) and screening the references of related articles published up to October 2013. Meta-analyses were conducted for colorectal cancer in relation to consumption of raw and cooked (RC) garlic and garlic supplements, separately. The summary relative risks (RR) with 95%CI were calculated using fixed-effects or random-effects model depending on the heterogeneity among studies. RESULTS: A total of 5 prospective cohort studies were identified. In contrast to the previous meta-analysis, no significant associations were found between consumption of RC garlic (RR: 1.06; 95%CI: 0.95-1.19) or garlic supplements (RR: 1.12; 95%CI: 0.96-1.31) and risk of colorectal cancer. A non-significant protective effect of garlic supplement intake against colorectal cancer was observed in females (RR: 0.84; 95%CI: 0.64-1.11), but the opposite was the case in males (RR: 1.24; 95%CI: 0.96-1.59). CONCLUSION: Consumption of RC garlic or garlic supplements is not significantly associated with reduced colorectal cancer risk. PMID:25386091

Consumption of garlic and risk of colorectal cancer: an updated meta-analysis of prospective studies.

PubMed

Hu, Ji-Yi; Hu, Yi-Wang; Zhou, Jiao-Jiao; Zhang, Meng-Wen; Li, Dan; Zheng, Shu

2014-11-07

To conduct an updated meta-analysis of prospective studies addressing the association between garlic consumption and colorectal cancer. Eligible cohort studies were identified by searching MEDLINE (PubMed) and screening the references of related articles published up to October 2013. Meta-analyses were conducted for colorectal cancer in relation to consumption of raw and cooked (RC) garlic and garlic supplements, separately. The summary relative risks (RR) with 95%CI were calculated using fixed-effects or random-effects model depending on the heterogeneity among studies. A total of 5 prospective cohort studies were identified. In contrast to the previous meta-analysis, no significant associations were found between consumption of RC garlic (RR: 1.06; 95%CI: 0.95-1.19) or garlic supplements (RR: 1.12; 95%CI: 0.96-1.31) and risk of colorectal cancer. A non-significant protective effect of garlic supplement intake against colorectal cancer was observed in females (RR: 0.84; 95%CI: 0.64-1.11), but the opposite was the case in males (RR: 1.24; 95%CI: 0.96-1.59). Consumption of RC garlic or garlic supplements is not significantly associated with reduced colorectal cancer risk.

Intrinsic disruption of white matter microarchitecture in first-episode, drug-naive major depressive disorder: A voxel-based meta-analysis of diffusion tensor imaging.

PubMed

Chen, Guangxiang; Guo, Yi; Zhu, Hongyan; Kuang, Weihong; Bi, Feng; Ai, Hua; Gu, Zhongwei; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

2017-06-02

Previous studies have demonstrated the influences of episodes and antidepressant drugs on white matter (WM) in patients with major depressive disorder (MDD). However, most diffusion tensor imaging (DTI) studies included highly heterogeneous individuals with different numbers of depressive episodes or medication status. To exclude the confounding effects of multiple episodes or medication, we conducted a quantitative voxel-based meta-analysis of fractional anisotropy (FA) in patients with first-episode, drug-naive MDD to identify the intrinsic WM alterations involved in the pathogenesis of MDD. The pooled meta-analysis revealed significant FA reductions in the body of the corpus callosum (CC), bilateral anterior limb of the internal capsule (ALIC), right inferior temporal gyrus (ITG) and right superior frontal gyrus (SFG) in MDD patients relative to healthy controls. Meta-regression analyses revealed that FA reduction in the right ALIC and right SFG was negatively correlated with symptom severity and duration of depression, respectively. Our findings provide robust evidence that the WM impairments in the interhemispheric connections and frontal-subcortical neuronal circuits may play an important role in MDD pathogenesis. Copyright © 2017. Published by Elsevier Inc.

Parenting Stress in Families of Children with ADHD: A Meta-Analysis

ERIC Educational Resources Information Center

Theule, Jennifer; Wiener, Judith; Tannock, Rosemary; Jenkins, Jennifer M.

2013-01-01

Meta-analyses were conducted to examine findings on the association between parenting stress and ADHD. Predictors comprising child, parent, and contextual factors, and methodological and demographic moderators of the relationship between parenting stress and ADHD, were examined. Findings from 22 published and 22 unpublished studies were included.…

A systematic meta-review of evaluations of youth violence prevention programs: Common and divergent findings from 25 years of meta-analyses and systematic reviews☆

PubMed Central

Matjasko, Jennifer L.; Vivolo-Kantor, Alana M.; Massetti, Greta M.; Holland, Kristin M.; Holt, Melissa K.; Cruz, Jason Dela

2018-01-01

Violence among youth is a pervasive public health problem. In order to make progress in reducing the burden of injury and mortality that result from youth violence, it is imperative to identify evidence-based programs and strategies that have a significant impact on violence. There have been many rigorous evaluations of youth violence prevention programs. However, the literature is large, and it is difficult to draw conclusions about what works across evaluations from different disciplines, contexts, and types of programs. The current study reviews the meta-analyses and systematic reviews published prior to 2009 that synthesize evaluations of youth violence prevention programs. This meta-review reports the findings from 37 meta-analyses and 15 systematic reviews; the included reviews were coded on measures of the social ecology, prevention approach, program type, and study design. A majority of the meta-analyses and systematic reviews were found to demonstrate moderate program effects. Meta-analyses yielded marginally smaller effect sizes compared to systematic reviews, and those that included programs targeting family factors showed marginally larger effects than those that did not. In addition, there are a wide range of individual/family, program, and study moderators of program effect sizes. Implications of these findings and suggestions for future research are discussed. PMID:29503594

Obesity and gynaecological and obstetric conditions: umbrella review of the literature.

PubMed

Kalliala, Ilkka; Markozannes, Georgios; Gunter, Marc J; Paraskevaidis, Evangelos; Gabra, Hani; Mitra, Anita; Terzidou, Vasso; Bennett, Phillip; Martin-Hirsch, Pierre; Tsilidis, Konstantinos K; Kyrgiou, Maria

2017-10-26

Objective  To study the strength and validity of associations between adiposity and risk of any type of obstetric or gynaecological conditions. Design  An umbrella review of meta-analyses. Data sources  PubMed, Cochrane database of systematic reviews, manual screening of references for systematic reviews or meta-analyses of observational and interventional studies evaluating the association between adiposity and risk of any obstetrical or gynaecological outcome. Main outcomes  Meta-analyses of cohort studies on associations between indices of adiposity and obstetric and gynaecological outcomes. Data synthesis  Evidence from observational studies was graded into strong, highly suggestive, suggestive, or weak based on the significance of the random effects summary estimate and the largest study in the included meta-analysis, the number of cases, heterogeneity between studies, 95% prediction intervals, small study effects, excess significance bias, and sensitivity analysis with credibility ceilings. Interventional meta-analyses were assessed separately. Results  156 meta-analyses of observational studies were included, investigating associations between adiposity and risk of 84 obstetric or gynaecological outcomes. Of the 144 meta-analyses that included cohort studies, only 11 (8%) had strong evidence for eight outcomes: adiposity was associated with a higher risk of endometrial cancer, ovarian cancer, antenatal depression, total and emergency caesarean section, pre-eclampsia, fetal macrosomia, and low Apgar score. The summary effect estimates ranged from 1.21 (95% confidence interval 1.13 to 1.29) for an association between a 0.1 unit increase in waist to hip ratio and risk endometrial cancer up to 4.14 (3.61 to 4.75) for risk of pre-eclampsia for BMI >35 compared with <25. Only three out of these eight outcomes were also assessed in meta-analyses of trials evaluating weight loss interventions. These interventions significantly reduced the risk of caesarean section and pre-eclampsia, whereas there was no evidence of association with fetal macrosomia. Conclusions  Although the associations between adiposity and obstetric and gynaecological outcomes have been extensively studied, only a minority were considered strong and without hints of bias. 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.

Coordinate based random effect size meta-analysis of neuroimaging studies.

PubMed

Tench, C R; Tanasescu, Radu; Constantinescu, C S; Auer, D P; Cottam, W J

2017-06-01

Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely. Copyright © 2017 Elsevier Inc. All rights reserved.

Are we hammering square pegs into round holes? An investigation of the meta-analyses of reading research with students who are d/Deaf or hard of hearing and students who are hearing.

PubMed

Wang, Ye; Williams, Cheri

2014-01-01

In a qualitative meta-analysis, the researchers systematically reviewed qualitative and quantitative meta-analyses on reading research with PK-12 students published after the 2000 National Reading Panel (NRP) report. Eleven qualitative and 39 quantitative meta-analyses were reviewed examining reading research with typically developing hearing students, special education hearing students (including English Language Learners), and d/Deaf or hard of hearing (d/Dhh) students. Generally, the meta-analysis yielded findings similar to and corroborative of the NRP's. Contradictory results (e.g., regarding the role of rhyme awareness in reading outcomes) most often resulted from differing definitions of interventions and their measurements. The analysis provided evidence of several instructional approaches that support reading development. On the basis of the qualitative similarity hypothesis (Paul, 2010, 2012; Paul & Lee, 2010; Paul & Wang, 2012; Paul, Wang, & Williams, 2013), the researchers argue that these instructional strategies also should effectively support d/Dhh children's reading development.

A hands-on practical tutorial on performing meta-analysis with Stata.

PubMed

Chaimani, Anna; Mavridis, Dimitris; Salanti, Georgia

2014-11-01

Statistical synthesis of research findings via meta-analysis is widely used to assess the relative effectiveness of competing interventions. A series of three papers aimed at familiarising mental health scientists with the key statistical concepts and problems in meta-analysis was recently published in this journal. One paper focused on the selection and interpretation of the appropriate model to synthesise results (fixed effect or random effects model) whereas the other two papers focused on two major threats that compromise the validity of meta-analysis results, namely publication bias and missing outcome data. In this paper we provide guidance on how to undertake meta-analysis using Stata, one of the most commonly used software packages for meta-analysis. We address the three topics covered in the previous issues of the journal, focusing on their implementation in Stata using a working example from mental health research. 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.

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

PubMed Central

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

2015-01-01

Background Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. Objective The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. Methods A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Results Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. Conclusion In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association. PMID:26422698

Reaffirmed limitations of meta-analytic methods in the study of mild traumatic brain injury: a response to Rohling et al.

PubMed

Bigler, Erin D; Farrer, Thomas J; Pertab, Jon L; James, Kelly; Petrie, Jo Ann; Hedges, Dawson W

2013-01-01

In 2009 Pertab, James, and Bigler published a critique of two prior meta-analyses by Binder, Rohling, and Larrabee (1997) and Frencham, Fox, and Maybery (2005) that showed small effect size difference at least 3 months post-injury in individuals who had sustained a mild traumatic brain injury (mTBI). The Binder et al. and Frencham et al. meta-analyses have been widely cited as showing no lasting effect of mTBI. In their critique Pertab et al. (2009) point out many limitations of these two prior meta-analyses, demonstrating that depending on how inclusion/exclusion criteria were defined different meta-analytic findings occur, some supporting the persistence of neuropsychological impairments beyond 3 months. Rohling et al. (2011) have now critiqued Pertab et al. (2009). Herein we respond to the Rolling et al. (2011) critique reaffirming the original findings of Pertab et al. (2009), providing additional details concerning the flaws in prior meta-analytic mTBI studies and the effects on neuropsychological performance.

Predictive distributions for between-study heterogeneity and simple methods for their application in Bayesian meta-analysis

PubMed Central

Turner, Rebecca M; Jackson, Dan; Wei, Yinghui; Thompson, Simon G; Higgins, Julian P T

2015-01-01

Numerous meta-analyses in healthcare research combine results from only a small number of studies, for which the variance representing between-study heterogeneity is estimated imprecisely. A Bayesian approach to estimation allows external evidence on the expected magnitude of heterogeneity to be incorporated. The aim of this paper is to provide tools that improve the accessibility of Bayesian meta-analysis. We present two methods for implementing Bayesian meta-analysis, using numerical integration and importance sampling techniques. Based on 14 886 binary outcome meta-analyses in the Cochrane Database of Systematic Reviews, we derive a novel set of predictive distributions for the degree of heterogeneity expected in 80 settings depending on the outcomes assessed and comparisons made. These can be used as prior distributions for heterogeneity in future meta-analyses. The two methods are implemented in R, for which code is provided. Both methods produce equivalent results to standard but more complex Markov chain Monte Carlo approaches. The priors are derived as log-normal distributions for the between-study variance, applicable to meta-analyses of binary outcomes on the log odds-ratio scale. The methods are applied to two example meta-analyses, incorporating the relevant predictive distributions as prior distributions for between-study heterogeneity. We have provided resources to facilitate Bayesian meta-analysis, in a form accessible to applied researchers, which allow relevant prior information on the degree of heterogeneity to be incorporated. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:25475839

Meta-connectomics: human brain network and connectivity meta-analyses.

PubMed

Crossley, N A; Fox, P T; Bullmore, E T

2016-04-01

Abnormal brain connectivity or network dysfunction has been suggested as a paradigm to understand several psychiatric disorders. We here review the use of novel meta-analytic approaches in neuroscience that go beyond a summary description of existing results by applying network analysis methods to previously published studies and/or publicly accessible databases. We define this strategy of combining connectivity with other brain characteristics as 'meta-connectomics'. For example, we show how network analysis of task-based neuroimaging studies has been used to infer functional co-activation from primary data on regional activations. This approach has been able to relate cognition to functional network topology, demonstrating that the brain is composed of cognitively specialized functional subnetworks or modules, linked by a rich club of cognitively generalized regions that mediate many inter-modular connections. Another major application of meta-connectomics has been efforts to link meta-analytic maps of disorder-related abnormalities or MRI 'lesions' to the complex topology of the normative connectome. This work has highlighted the general importance of network hubs as hotspots for concentration of cortical grey-matter deficits in schizophrenia, Alzheimer's disease and other disorders. Finally, we show how by incorporating cellular and transcriptional data on individual nodes with network models of the connectome, studies have begun to elucidate the microscopic mechanisms underpinning the macroscopic organization of whole-brain networks. We argue that meta-connectomics is an exciting field, providing robust and integrative insights into brain organization that will likely play an important future role in consolidating network models of psychiatric disorders.

Development and validation of MIX: comprehensive free software for meta-analysis of causal research data

PubMed Central

Bax, Leon; Yu, Ly-Mee; Ikeda, Noriaki; Tsuruta, Harukazu; Moons, Karel GM

2006-01-01

Background Meta-analysis has become a well-known method for synthesis of quantitative data from previously conducted research in applied health sciences. So far, meta-analysis has been particularly useful in evaluating and comparing therapies and in assessing causes of disease. Consequently, the number of software packages that can perform meta-analysis has increased over the years. Unfortunately, it can take a substantial amount of time to get acquainted with some of these programs and most contain little or no interactive educational material. We set out to create and validate an easy-to-use and comprehensive meta-analysis package that would be simple enough programming-wise to remain available as a free download. We specifically aimed at students and researchers who are new to meta-analysis, with important parts of the development oriented towards creating internal interactive tutoring tools and designing features that would facilitate usage of the software as a companion to existing books on meta-analysis. Results We took an unconventional approach and created a program that uses Excel as a calculation and programming platform. The main programming language was Visual Basic, as implemented in Visual Basic 6 and Visual Basic for Applications in Excel 2000 and higher. The development took approximately two years and resulted in the 'MIX' program, which can be downloaded from the program's website free of charge. Next, we set out to validate the MIX output with two major software packages as reference standards, namely STATA (metan, metabias, and metatrim) and Comprehensive Meta-Analysis Version 2. Eight meta-analyses that had been published in major journals were used as data sources. All numerical and graphical results from analyses with MIX were identical to their counterparts in STATA and CMA. The MIX program distinguishes itself from most other programs by the extensive graphical output, the click-and-go (Excel) interface, and the educational features. Conclusion The MIX program is a valid tool for performing meta-analysis and may be particularly useful in educational environments. It can be downloaded free of charge via or . PMID:17038197

Meta-analytical prognostic accuracy of the Comprehensive Assessment of at Risk Mental States (CAARMS): The need for refined prediction.

PubMed

Oliver, D; Kotlicka-Antczak, M; Minichino, A; Spada, G; McGuire, P; Fusar-Poli, P

2018-03-01

Primary indicated prevention is reliant on accurate tools to predict the onset of psychosis. The gold standard assessment for detecting individuals at clinical high risk (CHR-P) for psychosis in the UK and many other countries is the Comprehensive Assessment for At Risk Mental States (CAARMS). While the prognostic accuracy of CHR-P instruments has been assessed in general, this is the first study to specifically analyse that of the CAARMS. As such, the CAARMS was used as the index test, with the reference index being psychosis onset within 2 years. Six independent studies were analysed using MIDAS (STATA 14), with a total of 1876 help-seeking subjects referred to high risk services (CHR-P+: n=892; CHR-P-: n=984). Area under the curve (AUC), summary receiver operating characteristic curves (SROC), quality assessment, likelihood ratios, and probability modified plots were computed, along with sensitivity analyses and meta-regressions. The current meta-analysis confirmed that the 2-year prognostic accuracy of the CAARMS is only acceptable (AUC=0.79 95% CI: 0.75-0.83) and not outstanding as previously reported. In particular, specificity was poor. Sensitivity of the CAARMS is inferior compared to the SIPS, while specificity is comparably low. However, due to the difficulties in performing these types of studies, power in this meta-analysis was low. These results indicate that refining and improving the prognostic accuracy of the CAARMS should be the mainstream area of research for the next era. Avenues of prediction improvement are critically discussed and presented to better benefit patients and improve outcomes of first episode psychosis. Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Genome-wide meta-analyses identify novel loci associated with n-3 and n-6 polyunsaturated fatty acid levels in Chinese and European-ancestry populations.

PubMed

Hu, Yao; Li, Huaixing; Lu, Ling; Manichaikul, Ani; Zhu, Jingwen; Chen, Yii-Der I; Sun, Liang; Liang, Shuang; Siscovick, David S; Steffen, Lyn M; Tsai, Michael Y; Rich, Stephen S; Lemaitre, Rozenn N; Lin, Xu

2016-03-15

Epidemiological studies suggest that levels of n-3 and n-6 long-chain polyunsaturated fatty acids are associated with risk of cardio-metabolic outcomes across different ethnic groups. Recent genome-wide association studies in populations of European ancestry have identified several loci associated with plasma and/or erythrocyte polyunsaturated fatty acids. To identify additional novel loci, we carried out a genome-wide association study in two population-based cohorts consisting of 3521 Chinese participants, followed by a trans-ethnic meta-analysis with meta-analysis results from 8962 participants of European ancestry. Four novel loci (MYB, AGPAT4, DGAT2 and PPT2) reached genome-wide significance in the trans-ethnic meta-analysis (log10(Bayes Factor) ≥ 6). Of them, associations of MYB and AGPAT4 with docosatetraenoic acid (log10(Bayes Factor) = 11.5 and 8.69, respectively) also reached genome-wide significance in the Chinese-specific genome-wide association analyses (P = 4.15 × 10(-14) and 4.30 × 10(-12), respectively), while associations of DGAT2 with gamma-linolenic acid (log10(Bayes Factor) = 6.16) and of PPT2 with docosapentaenoic acid (log10(Bayes Factor) = 6.24) were nominally significant in both Chinese- and European-specific genome-wide association analyses (P ≤ 0.003). We also confirmed previously reported loci including FADS1, NTAN1, NRBF2, ELOVL2 and GCKR. Different effect sizes in FADS1 and independent association signals in ELOVL2 were observed. These results provide novel insight into the genetic background of polyunsaturated fatty acids and their differences between Chinese and European populations. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interventions: checklist and explanations.

PubMed

Hutton, Brian; Salanti, Georgia; Caldwell, Deborah M; Chaimani, Anna; Schmid, Christopher H; Cameron, Chris; Ioannidis, John P A; Straus, Sharon; Thorlund, Kristian; Jansen, Jeroen P; Mulrow, Cynthia; Catalá-López, Ferrán; Gøtzsche, Peter C; Dickersin, Kay; Boutron, Isabelle; Altman, Douglas G; Moher, David

2015-06-02

The PRISMA statement is a reporting guideline designed to improve the completeness of reporting of systematic reviews and meta-analyses. Authors have used this guideline worldwide to prepare their reviews for publication. In the past, these reports typically compared 2 treatment alternatives. With the evolution of systematic reviews that compare multiple treatments, some of them only indirectly, authors face novel challenges for conducting and reporting their reviews. This extension of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement was developed specifically to improve the reporting of systematic reviews incorporating network meta-analyses. A group of experts participated in a systematic review, Delphi survey, and face-to-face discussion and consensus meeting to establish new checklist items for this extension statement. Current PRISMA items were also clarified. A modified, 32-item PRISMA extension checklist was developed to address what the group considered to be immediately relevant to the reporting of network meta-analyses. This document presents the extension and provides examples of good reporting, as well as elaborations regarding the rationale for new checklist items and the modification of previously existing items from the PRISMA statement. It also highlights educational information related to key considerations in the practice of network meta-analysis. The target audience includes authors and readers of network meta-analyses, as well as journal editors and peer reviewers.

Systematic reviews: guidance relevant for studies of older people.

PubMed

Shenkin, Susan D; Harrison, Jennifer K; Wilkinson, Tim; Dodds, Richard M; Ioannidis, John P A

2017-09-01

Systematic reviews and meta-analyses are increasingly common. This article aims to provide guidance for people conducting systematic reviews relevant to the healthcare of older people. An awareness of these issues will also help people reading systematic reviews to determine whether the results will influence their clinical practice. It is essential that systematic reviews are performed by a team which includes the required technical and clinical expertise. Those performing reviews for the first time should ensure they have appropriate training and support. They must be planned and performed in a transparent and methodologically robust way: guidelines are available. The protocol should be written-and if possible published-before starting the review. Geriatricians will be interested in a table of baseline characteristics, which will help to determine if the studied samples or populations are similar to their patients. Reviews of studies of older people should consider how they will manage issues such as different age cut-offs; non-specific presentations; multiple predictors and outcomes; potential biases and confounders. Systematic reviews and meta-analyses may provide evidence to improve older people's care, or determine where new evidence is required. Newer methodologies, such as meta-analyses of individual level data, network meta-analyses and umbrella reviews, and realist synthesis, may improve the reliability and clinical utility of systematic reviews. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.

Ethics and Community Involvement in Syntheses Concerning American Indian, Alaska Native, or Native Hawaiian Health: A Systematic Review

PubMed Central

Around Him, Deana M.

2014-01-01

Background The objective of the research was to review reporting of ethical concerns and community involvement in peer-reviewed systematic reviews or meta-analyses concerning American Indian, Alaska Native, or Native Hawaiian (AI/AN/NH) health. Methods Text words and indexed vocabulary terms were used to query PubMed, Embase, Cochrane Library, and the Native Health Database for systematic reviews or meta-analyses concerning AI/AN/NH health published in peer-reviewed journals, followed by a search through reference lists. Each article was abstracted by two independent reviewers; results were discussed until consensus was reached. Results We identified 107 papers published from 1986–2012 that were primarily about AI/AN/NH health or presented findings separately for AI/AN/NH communities. Two reported seeking indigenous reviewer feedback; none reported seeking input from tribes and communities. Approximately 7% reported on institutional review board (IRB) approval of included studies, 5% reported on tribal approval, and 4% referenced the sovereignty of AI/AN tribes. Approximately 63% used evidence from more than one AI/AN/NH population study, and 28% discussed potential benefits to communities from the synthesis research. Conclusions Reporting of ethics and community involvement are not prominent. Systematic reviews and meta-analyses making community-level inferences may pose risks to communities. Future systematic reviews and meta-analyses should consider ethical and participatory dimensions of research. PMID:25089283

Addressing Pediatric Obesity in Ambulatory Care: Where Are We and Where Are We Going?

PubMed

Lenders, Carine M; Manders, Aaron J; Perdomo, Joanna E; Ireland, Kathy A; Barlow, Sarah E

2016-06-01

Since the "2007 summary report of child and adolescent overweight and obesity treatment" published by Barlow, many obesity intervention studies have been conducted in pediatric ambulatory care. Although several meta-analyses have been published in the interim, many studies were excluded because of the focus and criteria of these meta-analyses. Therefore, the primary goal of this article was to identify randomized case-control trials conducted in the primary care setting and to report on treatment approaches, challenges, and successes. We have developed four themes for our discussion and provide a brief summary of our findings. Finally, we identified major gaps and potential solutions and describe several urgent key action items.

Effects of exercise on depressive symptoms in adults with arthritis and other rheumatic disease: a systematic review of meta-analyses

PubMed Central

2014-01-01

Background Depression is a major public health problem among adults with arthritis and other rheumatic disease. The purpose of this study was to conduct a systematic review of previous meta-analyses addressing the effects of exercise (aerobic, strength or both) on depressive symptoms in adults with osteoarthritis, rheumatoid arthritis, fibromyalgia and systemic lupus erythematous. Methods Previous meta-analyses of randomized controlled trials were included by searching nine electronic databases and cross-referencing. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. Random-effects models that included the standardized mean difference (SMD) and 95% confidence intervals (CIs) were reported. The alpha value for statistical significance was set at p ≤ 0.05. The U3 index, number needed to treat (NNT) and number of US people who could benefit were also calculated. Results Of the 95 citations initially identified, two aggregate data meta-analyses representing 6 and 19 effect sizes in as many as 870 fibromyalgia participants were included. Methodological quality was 91% and 82%, respectively. Exercise minus control group reductions in depressive symptoms were found for both meta-analyses (SMD, -0.61, 95% CI, -0.99 to -0.23, p = 0.002; SMD, -0.32, 95% CI, -0.53 to -0.12, p = 0.002). Percentile improvements (U3) were equivalent to 22.9 and 12.6. The number needed to treat was 6 and 9 with an estimated 0.83 and 0.56 million US people with fibromyalgia potentially benefitting. Conclusions Exercise improves depressive symptoms in adults with fibromyalgia. However, a need exists for additional meta-analytic work on this topic. PMID:24708605

Are K-12 Learners Motivated in Physical Education? A Meta-Analysis

ERIC Educational Resources Information Center

Chen, Senlin; Chen, Ang; Zhu, Xihe

2012-01-01

Previous studies devoted to K-12 learner motivation in physical education share a general assumption that students may lack motivation. This meta-analytic study examined published original studies (n = 79) to determine students' motivation level and the association between motivation and outcomes. Original means of motivation measures were…

Proper joint analysis of summary association statistics requires the adjustment of heterogeneity in SNP coverage pattern.

PubMed

Zhang, Han; Wheeler, William; Song, Lei; Yu, Kai

2017-07-07

As meta-analysis results published by consortia of genome-wide association studies (GWASs) become increasingly available, many association summary statistics-based multi-locus tests have been developed to jointly evaluate multiple single-nucleotide polymorphisms (SNPs) to reveal novel genetic architectures of various complex traits. The validity of these approaches relies on the accurate estimate of z-score correlations at considered SNPs, which in turn requires knowledge on the set of SNPs assessed by each study participating in the meta-analysis. However, this exact SNP coverage information is usually unavailable from the meta-analysis results published by GWAS consortia. In the absence of the coverage information, researchers typically estimate the z-score correlations by making oversimplified coverage assumptions. We show through real studies that such a practice can generate highly inflated type I errors, and we demonstrate the proper way to incorporate correct coverage information into multi-locus analyses. We advocate that consortia should make SNP coverage information available when posting their meta-analysis results, and that investigators who develop analytic tools for joint analyses based on summary data should pay attention to the variation in SNP coverage and adjust for it appropriately. Published by Oxford University Press 2017. This work is written by US Government employees and is in the public domain in the US.

Estimating the Difference between Published and Unpublished Effect Sizes: A Meta-Review

ERIC Educational Resources Information Center

Polanin, Joshua R.; Tanner-Smith, Emily E.; Hennessy, Emily A.

2016-01-01

Practitioners and policymakers rely on meta-analyses to inform decision making around the allocation of resources to individuals and organizations. It is therefore paramount to consider the validity of these results. A well-documented threat to the validity of research synthesis results is the presence of publication bias, a phenomenon where…

Estimating the Difference between Published and Unpublished Effect Sizes: A Meta-Review

ERIC Educational Resources Information Center

Polanin, Joshua R.; Tanner-Smith, Emily E.; Hennessy, Emily A.

2016-01-01

Practitioners and policymakers rely on meta-analyses to inform decision-making around the allocation of resources to individuals and organizations. It is therefore paramount to consider the validity of these results. A well-documented threat to the validity of research synthesis results is the presence of publication bias, a phenomenon where…

Meta-Analysis of Behavioral Self-Management Interventions in Single-Case Research

ERIC Educational Resources Information Center

Briesch, Amy M.; Briesch, Jacquelyn M.

2016-01-01

The current study meta-analyzed 47 single-subject studies of behavioral self-management interventions that were published between 1971 and 2011. In addition to obtaining an overall measure of effect across all self-management studies (f = 0.93), analyses were conducted to assess whether treatment effectiveness was moderated by factors such as…

The National Early Literacy Panel: A Summary of the Process and the Report

ERIC Educational Resources Information Center

Shanahan, Timothy; Lonigan, Christopher J.

2010-01-01

This article summarizes "Developing Early Literacy: Report of the National Early Literacy Panel," which was published in 2008.That report provides an extensive meta-analysis of approximately 300 studies showing which early literacy measures correlate with later literacy achievement. It also provides a series of meta-analyses of a comprehensive…

An Umbrella Review of Nuts Intake and Risk of Cardiovascular Disease.

PubMed

Schwingshackl, Lukas; Hoffmann, Georg; Missbach, Benjamin; Stelmach-Mardas, Marta; Boeing, Heiner

2017-01-01

Nuts have been an indispensable component of the human diet for hundreds because of their unique nutrient composition and are thought to play a beneficial part in the prevention of cardiovascular diseases. To evaluate the extent, validity and presence of evidence for studies investigating the impact of nuts intake on biomarkers of cardiovascular disease and cardiovascular events, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. PubMed (between 1966 and April 2016) was searched for systematic reviews and meta-analyses. Methodological quality was assessed by applying the AMSTAR score (0-11 points), and the meta-evidence by applying NutriGrade, our recently developed scoring system (0-10 points). In total, 14 meta-analyses were included in the umbrella review. Only 4 out of 14 reported an AMSTAR score ≥8 (high methodological quality), whereas NutriGrade meta-evidence score varied between 2 (very low meta-evidence) and 7.9 (moderate meta-evidence). There is consistent evidence from intervention trials, reporting significant reductions for total cholesterol, and from observational studies that higher intakes of nuts were associated with reduced risk of cardiovascular disease and hypertension. On the other side no effect could be observed for stroke, HDL-cholesterol, and blood pressure in the normal range. In summary, the present umbrella review showed that nuts intake was associated with reduced risk of cardiovascular disease and hypertension, and lower levels of total cholesterol. The observed evidence is limited by the moderate methodological quality and very low to moderate quality of evidence. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Meta-regression analysis of the effect of trans fatty acids on low-density lipoprotein cholesterol.

PubMed

Allen, Bruce C; Vincent, Melissa J; Liska, DeAnn; Haber, Lynne T

2016-12-01

We conducted a meta-regression of controlled clinical trial data to investigate quantitatively the relationship between dietary intake of industrial trans fatty acids (iTFA) and increased low-density lipoprotein cholesterol (LDL-C). Previous regression analyses included insufficient data to determine the nature of the dose response in the low-dose region and have nonetheless assumed a linear relationship between iTFA intake and LDL-C levels. This work contributes to the previous work by 1) including additional studies examining low-dose intake (identified using an evidence mapping procedure); 2) investigating a range of curve shapes, including both linear and nonlinear models; and 3) using Bayesian meta-regression to combine results across trials. We found that, contrary to previous assumptions, the linear model does not acceptably fit the data, while the nonlinear, S-shaped Hill model fits the data well. Based on a conservative estimate of the degree of intra-individual variability in LDL-C (0.1 mmoL/L), as an estimate of a change in LDL-C that is not adverse, a change in iTFA intake of 2.2% of energy intake (%en) (corresponding to a total iTFA intake of 2.2-2.9%en) does not cause adverse effects on LDL-C. The iTFA intake associated with this change in LDL-C is substantially higher than the average iTFA intake (0.5%en). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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.

Stress reduction programs in patients with elevated blood pressure: a systematic review and meta-analysis.

PubMed

Rainforth, Maxwell V; Schneider, Robert H; Nidich, Sanford I; Gaylord-King, Carolyn; Salerno, John W; Anderson, James W

2007-12-01

Substantial evidence indicates that psychosocial stress contributes to hypertension and cardiovascular disease (CVD). Previous meta-analyses of stress reduction and high blood pressure (BP) were outdated and/or methodologically limited. Therefore, we conducted an updated systematic review of the published literature and identified 107 studies on stress reduction and BP. Seventeen trials with 23 treatment comparisons and 960 participants with elevated BP met criteria for well-designed randomized controlled trials and were replicated within intervention categories. Meta-analysis was used to calculate BP changes for biofeedback, -0.8/-2.0 mm Hg (P = NS); relaxation-assisted biofeedback, +4.3/+2.4 mm Hg (P = NS); progressive muscle relaxation, -1.9/-1.4 mm Hg (P = NS); stress management training, -2.3/-1.3 mm (P = NS); and the Transcendental Meditation program, -5.0/-2.8 mm Hg (P = 0.002/0.02). Available evidence indicates that among stress reduction approaches, the Transcendental Meditation program is associated with significant reductions in BP. Related data suggest improvements in other CVD risk factors and clinical outcomes.

Stress Reduction Programs in Patients with Elevated Blood Pressure: A Systematic Review and Meta-analysis

PubMed Central

Rainforth, Maxwell V.; Schneider, Robert H.; Nidich, Sanford I.; Gaylord-King, Carolyn; Salerno, John W.; Anderson, James W.

2007-01-01

Substantial evidence indicates that psychosocial stress contributes to hypertension and cardiovascular disease (CVD). Previous meta-analyses of stress reduction and high blood pressure (BP) were outdated and/or methodologically limited. Therefore, we conducted an updated systematic review of the published literature and identified 107 studies on stress reduction and BP. Seventeen trials with 23 treatment comparisons and 960 participants with elevated BP met criteria for well-designed randomized controlled trials and were replicated within intervention categories. Meta-analysis was used to calculate BP changes for biofeedback, −0.8/−2.0 mm Hg (P = NS); relaxation-assisted biofeedback, +4.3/+2.4 mm Hg (P = NS); progressive muscle relaxation, −1.9/−1.4 mm Hg (P = NS); stress management training, −2.3/−1.3 mm (P = NS); and the Transcendental Meditation program, −5.0/−2.8 mm Hg (P = 0.002/0.02). Available evidence indicates that among stress reduction approaches, the Transcendental Meditation program is associated with significant reductions in BP. Related data suggest improvements in other CVD risk factors and clinical outcomes. PMID:18350109

How Efficacious is Danshen (Salvia miltiorrhiza) Dripping Pill in Treating Angina Pectoris? Evidence Assessment for Meta-Analysis of Randomized Controlled Trials.

PubMed

Jia, Yongliang; Leung, Siu-Wai

2017-09-01

More than 230 randomized controlled trials (RCTs) of danshen dripping pill (DSP) and isosorbide dinitrate (ISDN) in treating angina pectoris after the first preferred reporting items for systematic reviews and meta-analyses-compliant comprehensive meta-analysis were published in 2010. Other meta-analyses had flaws in study selection, statistical meta-analysis, and evidence assessment. This study completed the meta-analysis with an extensive assessment of the evidence. RCTs published from 1994 to 2016 on DSP and ISDN in treating angina pectoris for at least 4 weeks were included. The risk of bias (RoB) of included RCTs was assessed with the Cochrane's tool for assessing RoB. Meta-analyses based on a random-effects model were performed on two outcome measures: symptomatic (SYM) and electrocardiography (ECG) improvements. Subgroup analysis, sensitivity analysis, metaregression, and publication bias analysis were also conducted. The evidence strength was evaluated with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) method. Among the included 109 RCTs with 11,973 participants, 49 RCTs and 5042 participants were new (after 2010). The RoB of included RCTs was high in randomization and blinding. Overall effect sizes in odds ratios for DSP over ISDN were 2.94 (95% confidence interval [CI]: 2.53-3.41) on SYM (n = 108) and 2.37 (95% CI: 2.08-2.69) by ECG (n = 81) with significant heterogeneities (I 2  = 41%, p < 0.0001 on SYM and I 2  = 44%, p < 0.0001 on ECG). Subgroup, sensitivity, and metaregression analyses showed consistent results without publication bias. However, the evidence strength was low in GRADE. The efficacy of DSP was still better than ISDN in treating angina pectoris, but the confidence decreased due to high RoB and heterogeneities.

Meta-analysis of six genes (BDNF, DRD1, DRD3, DRD4, GRIN2B and MAOA) involved in neuroplasticity and the risk for alcohol dependence.

PubMed

Forero, Diego A; López-León, Sandra; Shin, Hyoung Doo; Park, Byung Lae; Kim, Dai-Jin

2015-04-01

Alcohol-related problems have a large impact on human health, accounting for around 4% of deaths and 4.5% of disability-adjusted life-years around the world. Genetic factors could explain a significant fraction of the risk for alcohol dependence (AD). Recent meta-analyses have found significant pooled odds ratios (ORs) for variants in the ADH1B, ADH1C, DRD2 and HTR2A genes. In the present study, we carried out a meta-analysis of common variants in 6 candidate genes involved in neurotransmission and neuroplasticity: BDNF, DRD1, DRD3, DRD4, GRIN2B and MAOA. We carried out a systematic search for published association studies that analyzed the genes of interest. Relevant articles were retrieved and demographic and genetic data were extracted. Pooled ORs were calculated using a random-effects model using the Meta-Analyst program. Dominant, recessive and allelic models were tested and analyses were also stratified by ethnicity. Forty two published studies were included in the current meta-analysis: BDNF-rs6265 (nine studies), DRD1-rs4532 (four studies), DRD3-rs6280 (eleven studies), DRD4-VNTR (seven studies), GRIN2B-rs1806201 (three studies) and MAOA-uVNTR (eight studies). We did not find significant pooled ORs for any of the six genes, under different models and stratifying for ethnicity. In terms of the number of candidate genes included, this is one of the most comprehensive meta-analyses for genetics of AD. Pooled ORs did not support consistent associations with any of the six candidate genes tested. Future studies of novel genes of functional relevance and meta-analyses of quantitative endophenotypes could identify further susceptibility molecular factors for AD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

What Can Meta-Analyses Tell Us About the Reliability of Life Cycle Assessment for Decision Support?

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

Brandao, M.; Heath, G.; Cooper, J.

2012-04-01

The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristicsmore » of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statistical sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue. (See the editorial from this special supplemental issue [Lifset 2012], which introduces this supplemental issue and discusses the origins, funding, peer review, and other aspects.) The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less

Long-Term Outcomes of Attention-Deficit/Hyperactivity Disorder and Conduct Disorder: A Systematic Review and Meta-Analysis.

PubMed

Erskine, Holly E; Norman, Rosana E; Ferrari, Alize J; Chan, Gary C K; Copeland, William E; Whiteford, Harvey A; Scott, James G

2016-10-01

Attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) are common externalizing disorders. Despite previous research demonstrating that both are longitudinally associated with adverse outcomes, there have been no systematic reviews examining all of the available evidence linking ADHD and CD with a range of health and psychosocial outcomes. Electronic databases (EMBASE, Medline, and PsycINFO) were searched for studies published from 1980 up to March 2015. Published cohort and case-control studies were included if they reported a longitudinal association between ADHD or CD and adverse outcomes with a minimum follow-up of 2 years. Outcomes with sufficient data were pooled in a random effects meta-analysis to give overall odds ratios (ORs) with corresponding 95% CIs. Of the 278 studies assessed, 114 met inclusion criteria and 98 were used in subsequent meta-analyses. ADHD was associated with adverse outcomes including academic achievement (e.g. failure to complete high school; odds ratio [OR] = 3.7, 95% CIs 2.0-7.0), other mental and substance use disorders (e.g. depression; OR = 2.3, 1.5-3.7), criminality (e.g. arrest; OR = 2.4, 1.5-3.8), and employment (e.g., unemployment; OR = 2.0, 1.0-3.9). CD was associated with outcomes relating to academic achievement (e.g. failure to complete high school; OR = 2.7, 1.5-4.7), other mental and substance use disorders (e.g., illicit drug use; OR = 2.1, 1.7-2.6), and criminality (e.g. violence; OR = 3.5, 2.3-5.3). This study demonstrated that ADHD and CD are associated with disability beyond immediate health loss. Although the analyses could not determine the mechanisms behind these longitudinal associations, they demonstrate the importance of addressing ADHD and CD early in life so as to potentially avert a wide range of future adverse outcomes. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Multi-ethnic fine-mapping of 14 central adiposity loci.

PubMed

Liu, Ching-Ti; Buchkovich, Martin L; Winkler, Thomas W; Heid, Iris M; Borecki, Ingrid B; Fox, Caroline S; Mohlke, Karen L; North, Kari E; Adrienne Cupples, L

2014-09-01

The Genetic Investigation of Anthropometric Traits (GIANT) consortium identified 14 loci in European Ancestry (EA) individuals associated with waist-to-hip ratio (WHR) adjusted for body mass index. These loci are wide and narrowing the signals remains necessary. Twelve of 14 loci identified in GIANT EA samples retained strong associations with WHR in our joint EA/individuals of African Ancestry (AA) analysis (log-Bayes factor >6.1). Trans-ethnic analyses at five loci (TBX15-WARS2, LYPLAL1, ADAMTS9, LY86 and ITPR2-SSPN) substantially narrowed the signals to smaller sets of variants, some of which are in regions that have evidence of regulatory activity. By leveraging varying linkage disequilibrium structures across different populations, single-nucleotide polymorphisms (SNPs) with strong signals and narrower credible sets from trans-ethnic meta-analysis of central obesity provide more precise localizations of potential functional variants and suggest a possible regulatory role. Meta-analysis results for WHR were obtained from 77 167 EA participants from GIANT and 23 564 AA participants from the African Ancestry Anthropometry Genetics Consortium. For fine mapping we interrogated SNPs within ± 250 kb flanking regions of 14 previously reported index SNPs from loci discovered in EA populations by performing trans-ethnic meta-analysis of results from the EA and AA meta-analyses. We applied a Bayesian approach that leverages allelic heterogeneity across populations to combine meta-analysis results and aids in fine-mapping shared variants at these locations. We annotated variants using information from the ENCODE Consortium and Roadmap Epigenomics Project to prioritize variants for possible functionality. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Genetic variations and risk of placental abruption: A genome-wide association study and meta-analysis of genome-wide association studies.

PubMed

Workalemahu, Tsegaselassie; Enquobahrie, Daniel A; Gelaye, Bizu; Sanchez, Sixto E; Garcia, Pedro J; Tekola-Ayele, Fasil; Hajat, Anjum; Thornton, Timothy A; Ananth, Cande V; Williams, Michelle A

2018-06-01

Accumulating epidemiological evidence points to strong genetic susceptibility to placental abruption (PA). However, characterization of genes associated with PA remains incomplete. We conducted a genome-wide association study (GWAS) of PA and a meta-analysis of GWAS. Participants of the Placental Abruption Genetic Epidemiology (PAGE) study, a population based case-control study of PA conducted in Lima, Peru, were genotyped using the Illumina HumanCore-24 BeadChip platform. Genotypes were imputed using the 1000 genomes reference panel, and >4.9 million SNPs that passed quality control were analyzed. We performed a GWAS in PAGE participants (507 PA cases and 1090 controls) and a GWAS meta-analysis in 2512 participants (959 PA cases and 1553 controls) that included PAGE and the previously reported Peruvian Abruptio Placentae Epidemiology (PAPE) study. We fitted population stratification-adjusted logistic regression models and fixed-effects meta-analyses using inverse-variance weighting. Independent loci (linkage-disequilibrium<0.80) suggestively associated with PA (P-value<5e-5) included rs4148646 and rs2074311 in ABCC8, rs7249210, rs7250184, rs7249100 and rs10401828 in ZNF28, rs11133659 in CTNND2, and rs2074314 and rs35271178 near KCNJ11 in the PAGE GWAS. Similarly, independent loci suggestively associated with PA in the GWAS meta-analysis included rs76258369 near IRX1, and rs7094759 and rs12264492 in ADAM12. Functional analyses of these genes showed trophoblast-like cell interaction, as well as networks involved in endocrine system disorders, cardiovascular diseases, and cellular function. We identified several genetic loci and related functions that may play a role in PA risk. Understanding genetic factors underlying pathophysiological mechanisms of PA may facilitate prevention and early diagnostic efforts. Published by Elsevier Ltd.

Genome-Wide Association Studies Identify CHRNA5/3 and HTR4 in the Development of Airflow Obstruction

PubMed Central

Shrine, Nick R. G.; Loehr, Laura R.; Zhao, Jing Hua; Manichaikul, Ani; Lopez, Lorna M.; Smith, Albert Vernon; Heckbert, Susan R.; Smolonska, Joanna; Tang, Wenbo; Loth, Daan W.; Curjuric, Ivan; Hui, Jennie; Latourelle, Jeanne C.; Henry, Amanda P.; Aldrich, Melinda; Bakke, Per; Beaty, Terri H.; Bentley, Amy R.; Borecki, Ingrid B.; Brusselle, Guy G.; Burkart, Kristin M.; Chen, Ting-hsu; Couper, David; Crapo, James D.; Davies, Gail; Dupuis, Josée; Franceschini, Nora; Gulsvik, Amund; Hancock, Dana B.; Harris, Tamara B.; Hofman, Albert; Imboden, Medea; James, Alan L.; Khaw, Kay-Tee; Lahousse, Lies; Launer, Lenore J.; Litonjua, Augusto; Liu, Yongmei; Lohman, Kurt K.; Lomas, David A.; Lumley, Thomas; Marciante, Kristin D.; McArdle, Wendy L.; Meibohm, Bernd; Morrison, Alanna C.; Musk, Arthur W.; Myers, Richard H.; North, Kari E.; Postma, Dirkje S.; Psaty, Bruce M.; Rich, Stephen S.; Rivadeneira, Fernando; Rochat, Thierry; Rotter, Jerome I.; Artigas, María Soler; Starr, John M.; Uitterlinden, André G.; Wareham, Nicholas J.; Wijmenga, Cisca; Zanen, Pieter; Province, Michael A.; Silverman, Edwin K.; Deary, Ian J.; Palmer, Lyle J.; Cassano, Patricia A.; Gudnason, Vilmundur; Barr, R. Graham; Loos, Ruth J. F.; Strachan, David P.; London, Stephanie J.; Boezen, H. Marike; Probst-Hensch, Nicole; Gharib, Sina A.; Hall, Ian P.; O’Connor, George T.; Tobin, Martin D.; Stricker, Bruno H.

2012-01-01

Rationale: Genome-wide association studies (GWAS) have identified loci influencing lung function, but fewer genes influencing chronic obstructive pulmonary disease (COPD) are known. Objectives: Perform meta-analyses of GWAS for airflow obstruction, a key pathophysiologic characteristic of COPD assessed by spirometry, in population-based cohorts examining all participants, ever smokers, never smokers, asthma-free participants, and more severe cases. Methods: Fifteen cohorts were studied for discovery (3,368 affected; 29,507 unaffected), and a population-based family study and a meta-analysis of case-control studies were used for replication and regional follow-up (3,837 cases; 4,479 control subjects). Airflow obstruction was defined as FEV1 and its ratio to FVC (FEV1/FVC) both less than their respective lower limits of normal as determined by published reference equations. Measurements and Main Results: The discovery meta-analyses identified one region on chromosome 15q25.1 meeting genome-wide significance in ever smokers that includes AGPHD1, IREB2, and CHRNA5/CHRNA3 genes. The region was also modestly associated among never smokers. Gene expression studies confirmed the presence of CHRNA5/3 in lung, airway smooth muscle, and bronchial epithelial cells. A single-nucleotide polymorphism in HTR4, a gene previously related to FEV1/FVC, achieved genome-wide statistical significance in combined meta-analysis. Top single-nucleotide polymorphisms in ADAM19, RARB, PPAP2B, and ADAMTS19 were nominally replicated in the COPD meta-analysis. Conclusions: These results suggest an important role for the CHRNA5/3 region as a genetic risk factor for airflow obstruction that may be independent of smoking and implicate the HTR4 gene in the etiology of airflow obstruction. PMID:22837378

Plantar pressure in diabetic peripheral neuropathy patients with active foot ulceration, previous ulceration and no history of ulceration: a meta-analysis of observational studies.

PubMed

Fernando, Malindu Eranga; Crowther, Robert George; Pappas, Elise; Lazzarini, Peter Anthony; Cunningham, Margaret; Sangla, Kunwarjit Singh; Buttner, Petra; Golledge, Jonathan

2014-01-01

Elevated dynamic plantar pressures are a consistent finding in diabetes patients with peripheral neuropathy with implications for plantar foot ulceration. This meta-analysis aimed to compare the plantar pressures of diabetes patients that had peripheral neuropathy and those with neuropathy with active or previous foot ulcers. Published articles were identified from Medline via OVID, CINAHL, SCOPUS, INFORMIT, Cochrane Central EMBASE via OVID and Web of Science via ISI Web of Knowledge bibliographic databases. Observational studies reporting barefoot dynamic plantar pressure in adults with diabetic peripheral neuropathy, where at least one group had a history of plantar foot ulcers were included. Interventional studies, shod plantar pressure studies and studies not published in English were excluded. Overall mean peak plantar pressure (MPP) and pressure time integral (PTI) were primary outcomes. The six secondary outcomes were MPP and PTI at the rear foot, mid foot and fore foot. The protocol of the meta-analysis was published with PROPSERO, (registration number CRD42013004310). Eight observational studies were included. Overall MPP and PTI were greater in diabetic peripheral neuropathy patients with foot ulceration compared to those without ulceration (standardised mean difference 0.551, 95% CI 0.290-0.811, p<0.001; and 0.762, 95% CI 0.303-1.221, p = 0.001, respectively). Sub-group analyses demonstrated no significant difference in MPP for those with neuropathy with active ulceration compared to those without ulcers. A significant difference in MPP was found for those with neuropathy with a past history of ulceration compared to those without ulcers; (0.467, 95% CI 0.181- 0.753, p = 0.001). Statistical heterogeneity between studies was moderate. Plantar pressures appear to be significantly higher in patients with diabetic peripheral neuropathy with a history of foot ulceration compared to those with diabetic neuropathy without a history of ulceration. More homogenous data is needed to confirm these findings.

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

PubMed

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

2016-10-01

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

Evidence for the Efficacy of Systemic Opioid-Sparing Analgesics in Pediatric Surgical Populations: A Systematic Review.

PubMed

Zhu, Alyssa; Benzon, Hubert A; Anderson, T Anthony

2017-11-01

While a large number of studies has examined the efficacy of opioid-sparing analgesics in adult surgical populations, fewer studies are available to guide postoperative pain treatment in pediatric patients. We systematically reviewed available publications on the use of systemic nonopioid agents for postoperative analgesia in pediatric surgical populations. A comprehensive literature search identified meta-analyses and randomized controlled trials (RCTs) assessing the effects of systemic, nonopioid agents on postoperative narcotic requirements or pain scores in pediatric surgical populations. If a meta-analysis was located, we summarized its results and any RCTs published after it. We located and reviewed 11 acetaminophen RCTs, 1 nonsteroidal anti-inflammatory drug (NSAID) meta-analysis, 2 NSAID RCTs, 1 dexamethasone meta-analysis, 3 dexamethasone RCTs, 2 ketamine meta-analyses, 5 ketamine RCTs, 2 gabapentin RCTs, 1 clonidine meta-analysis, 3 magnesium RCTs, 2 dexmedetomidine meta-analyses, and 1 dextromethorphan RCT. No meta-analyses or RCTs were found assessing the perioperative efficacy of intravenous lidocaine, amantadine, pregabalin, esmolol, or caffeine in pediatric surgical patients. The available evidence is limited, but suggests that perioperative acetaminophen, NSAIDs, dexamethasone, ketamine, clonidine, and dexmedetomidine may decrease postoperative pain and opioid consumption in some pediatric surgical populations. Not enough, or no, data exist from which to draw conclusions on the perioperative use of gabapentin, magnesium, dextromethorphan, lidocaine, amantadine, pregabalin, esmolol, and caffeine in pediatric surgical patients. Further pharmacokinetic and pharmacodynamics studies to establish both the clinical benefit and efficacy of nonopioid analgesia in pediatric populations are needed.

Investigation of 2-stage meta-analysis methods for joint longitudinal and time-to-event data through simulation and real data application.

PubMed

Sudell, Maria; Tudur Smith, Catrin; Gueyffier, François; Kolamunnage-Dona, Ruwanthi

2018-04-15

Joint modelling of longitudinal and time-to-event data is often preferred over separate longitudinal or time-to-event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time-to-event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta-analysis of joint model estimates from multiple studies. We propose a 2-stage method for meta-analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta-analyses of separate longitudinal or time-to-event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios. Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta-analytic setting where association exists between the longitudinal and time-to-event outcomes. Where evidence of association between longitudinal and time-to-event outcomes exists, results from joint models over standalone analyses should be pooled in 2-stage meta-analyses. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Antibiotic treatment of bacterial vaginosis in pregnancy: multiple meta-analyses and dilemmas in interpretation.

PubMed

Varma, Rajesh; Gupta, Janesh K

2006-01-01

There is considerable evidence to show an association between genital tract infections, such as bacterial vaginosis (BV), and preterm delivery (PTD). Meta-analyses to date have shown screening and treating BV in pregnancy does not prevent PTD. This casts doubt on a cause and effect relationship between BV and PTD. However, the meta-analyses reported significant clinical, methodological and statistical heterogeneity of the included studies. We therefore undertook a repeat meta-analysis, included recently published trials, and applied strict criteria on data extraction. We meta-analysed low and high-risk pregnancies separately. We found that screening and treating BV in low-risk pregnancies produced a statistically significant reduction in spontaneous PTD (RR 0.73; 95% CI 0.55-0.98). This beneficial effect was not observed in high-risk or combined risk groups. The differences in antibiotic sensitivity between high and low risk groups may suggest differing causal contributions of the infectious process to PTD. The evidence, along with prior knowledge of differing predisposing factors and prognosis between these risk groups, supports the hypothesis that PTD in high and low risk pregnant women are different entities and not linear extremes of the same syndrome.

Do Premarital Education Programs Really Work? A Meta-Analytic Study

ERIC Educational Resources Information Center

Fawcett, Elizabeth B.; Hawkins, Alan J.; Blanchard, Victoria L.; Carroll, Jason S.

2010-01-01

Previous studies (J. S. Carroll & W. J. Doherty, 2003) have asserted that premarital education programs have a positive effect on program participants. Using meta-analytic methods of current best practices to look across the entire body of published and unpublished evaluation research on premarital education, we found a more complex pattern of…

Intrinsic Motivation and Creativity Related to Product: A Meta-Analysis of the Studies Published between 1990-2010

ERIC Educational Resources Information Center

de Jesus, Saul Neves; Rus, Claudia Lenuta; Lens, Willy; Imaginário, Susana

2013-01-01

Although the relationship between motivation (especially intrinsic motivation) and creativity (especially as a product), no meta-analyses have been conducted on the relationship between these 2 concepts. This study aimed to analyze the relationship between intrinsic motivation and creativity related to product (i.e., creative outcomes) through…

A Meta-Analytic Review of Obesity Prevention in the Schools: 1997-2008

ERIC Educational Resources Information Center

Cook-Cottone, Catherine; Casey, Carolyn M.; Feeley, Thomas Hugh; Baran, Jennifer

2009-01-01

A meta-analysis was conducted on school-based interventions to reduce obesity in children. Sixty-six (k = 66, N = 31,059) comparisons from 40 published studies from 1997 through 2008 were included in analyses. Results indicated a significant effect for school-based interventions with an overall weighted effect size of r = 0.05. Several moderating…

Things I Have Learned about Meta-­Analysis since 1990: Reducing Bias in Search of "The Big Picture"

ERIC Educational Resources Information Center

Bernard, Robert M.

2014-01-01

This paper examines sources of potential bias in systematic reviews and meta-analyses which can distort their findings, leading to problems with interpretation and application by practitioners and policymakers. It follows from an article that was published in the "Canadian Journal of Communication" in 1990, "Integrating Research…

Meta-analysis of randomized controlled trials comparing 17α-hydroxyprogesterone caproate and vaginal progesterone for the prevention of recurrent spontaneous preterm delivery.

PubMed

Oler, Elizabeth; Eke, Ahizechukwu C; Hesson, Ashley

2017-07-01

Vaginal progesterone and 17α-hydroxyprogesterone (17α-OHP) are both used to prevent preterm delivery in women who have experienced spontaneous preterm delivery (SPTD) previously. Randomized trial data of the comparative effectiveness of these interventions have been mixed. To compare the efficacy of intramuscular 17α-OHP and vaginal progesterone in the prevention of recurrent SPTD. Cochrane Central Register of Controlled Trials, African Journals Online, Embase, Google Scholar, ISI Web of Science, LILACS, CINAHL, PubMed, and registers of ongoing trials were searched using keywords related to 17α-OHP, vaginal progesterone, and preterm delivery. Randomized controlled trials published between January 1, 1966, and November 30, 2016, comparing 17α-OHP and vaginal progesterone for the prevention of recurrent SPTD during singleton pregnancies were included. Study data were extracted and meta-analyses were performed when outcomes were comparable. The meta-analyses included data from three randomized trials. Lower rates of SPTD before 34 weeks (relative risk 0.71, 95% confidence interval 0.53-0.95) and before 32 weeks (relative risk 0.62, 95% confidence interval 0.40-0.94) of pregnancy were observed among patients treated with vaginal progesterone. Vaginal progesterone and 17α-OHP were comparable for the prevention of recurrent SPTD in singleton pregnancies; vaginal progesterone could be superior. © 2017 International Federation of Gynecology and Obstetrics.

Addressing pediatric obesity in ambulatory care: where are we and where are we going?

PubMed Central

Manders, Aaron J.; Perdomo, Joanna E.; Ireland, Kathy A.; Barlow, Sarah E.

2017-01-01

Since the “2007 summary report of child and adolescent overweight and obesity treatment” published by Barlow, many obesity intervention studies have been conducted in pediatric ambulatory care. Although several meta-analyses have been published in the interim, many studies were excluded because of the focus and criteria of these meta-analyses. Therefore, the primary goal of this article was to identify randomized case-control trials conducted in the primary care setting and to report on treatment approaches, challenges, and successes. We have developed four themes for our discussion and provide a brief summary of our findings. Finally, we identified major gaps and potential solutions, and describe several urgent key action items. PMID:27048522

Assessing sex-differences and the effect of timing of vaccination on immunogenicity, reactogenicity and efficacy of vaccines in young children: study protocol for an individual participant data meta-analysis of randomised controlled trials.

PubMed

Voysey, Merryn; Pollard, Andrew J; Perera, Rafael; Fanshawe, Thomas R

2016-07-29

Disease incidence differs between males and females for some infectious or inflammatory diseases. Sex-differences in immune responses to some vaccines have also been observed, mostly to viral vaccines in adults. Little evidence is available on whether sex-differences occur in response to immunisation in infancy even though this is the age group in which most vaccines are administered. Factors other than sex, such as timing or coadministration of other vaccines, can also influence the immune response to vaccination. Individual participant data meta-analysis of randomised controlled trials of vaccines in healthy infants and young children will be conducted. Fully anonymised data from ∼170 randomised controlled trials of vaccines for diphtheria, tetanus, Bordetella pertussis, polio, Haemophilus influenzae type B, hepatitis B, Streptococcus pneumoniae, Neisseria meningitidis, measles, mumps, rubella, varicella and rotavirus will be combined for analysis. Outcomes include measures of immunogenicity (immunoglobulins), reactogenicity, safety and disease-specific clinical efficacy. Data from trials of vaccines containing similar components will be combined in hierarchical models and the effect of sex and timing of vaccinations estimated for each outcome separately. Systematic reviews of published estimates of sex-differences cannot adequately answer questions in this field since such comparisons are never the main purpose of a clinical trial, thus a large degree of reporting bias exists in the published literature. Recent improvements in the widespread availability of individual participant data from randomised controlled trials makes it feasible to conduct extensive individual participant data meta-analyses which were previously impossible, thereby reducing the effect of publication or reporting bias on the understanding of the infant immune response.Preliminary results will be available in 2016 with final results available in 2019. No ethics review is required for secondary analyses of anonymised data. 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/

Sequence variation in SORL1 and Dementia risk in Swedes

PubMed Central

Reynolds, Chandra A.; Hong, Mun-Gwan; Eriksson, Ulrika K.; Blennow, Kaj; Johansson, Boo; Malmberg, Bo; Berg, Stig; Gatz, Margaret; Pedersen, Nancy L.; Bennet, Anna M.; Prince, Jonathan A.

2010-01-01

The gene encoding the neuronal sortilin-related receptor SORL1 has been claimed to be associated with Alzheimer Disease by independent groups and across various human populations. We evaluated six genetic markers in SORL1 in a sample of 1558 Swedish dementia cases (including 1270 Alzheimer disease cases) and 2179 controls. For both single marker and haplotype-based analyses we found no strong support for SORL1 as a dementia- or AD-risk modifying gene in our sample in isolation, nor did we observe association with AD/dementia-related traits, including CSF β-amyloid1–42, tau levels, or age-at-onset. However, meta-analyses of markers in this study together with previously published studies on SORL1 encompassing in excess of 13,000 individuals does suggest significant association with AD (best OR 1.097; 95% CI 1.038–1.158, p = 0.001). All six markers were significant in meta-analyses and it is notable that they occur in two distinct LD blocks. These data are consistent with either allelic heterogeneity or the existence of as yet untested functional variants and these will be important considerations in further attempts to evaluate the importance of sequence variation in SORL1 with AD risk. PMID:19653016

Vaccinations and childhood type 1 diabetes mellitus: a meta-analysis of observational studies.

PubMed

Morgan, Eileen; Halliday, Sophia R; Campbell, Gemma R; Cardwell, Chris R; Patterson, Chris C

2016-02-01

The aim of this study was to investigate the association between routine vaccinations and the risk of childhood type 1 diabetes mellitus by systematically reviewing the published literature and performing meta-analyses where possible. A comprehensive literature search was performed of MEDLINE and EMBASE to identify all studies that compared vaccination rates in children who subsequently developed type 1 diabetes mellitus and in control children. ORs and 95% CIs were obtained from published reports or derived from individual patient data and then combined using a random effects meta-analysis. In total, 23 studies investigating 16 vaccinations met the inclusion criteria. Eleven of these contributed to meta-analyses which included data from between 359 and 11,828 childhood diabetes cases. Overall, there was no evidence to suggest an association between any of the childhood vaccinations investigated and type 1 diabetes mellitus. The pooled ORs ranged from 0.58 (95% CI 0.24, 1.40) for the measles, mumps and rubella (MMR) vaccination in five studies up to 1.04 (95% CI 0.94, 1.14) for the haemophilus influenza B (HiB) vaccination in 11 studies. Significant heterogeneity was present in most of the pooled analyses, but was markedly reduced when analyses were restricted to study reports with high methodology quality scores. Neither this restriction by quality nor the original authors' adjustments for potential confounding made a substantial difference to the pooled ORs. This study provides no evidence of an association between routine vaccinations and childhood type 1 diabetes.

On Conducting Construct Validity Meta-Analyses for the Rorschach: A Reply to Tibon Czopp and Zeligman (2016).

PubMed

Mihura, Joni L; Meyer, Gregory J; Dumitrascu, Nicolae; Bombel, George

2016-01-01

We respond to Tibon Czopp and Zeligman's (2016) critique of our systematic reviews and meta-analyses of 65 Rorschach Comprehensive System (CS) variables published in Psychological Bulletin (2013). The authors endorsed our supportive findings but critiqued the same methodology when used for the 13 unsupported variables. Unfortunately, their commentary was based on significant misunderstandings of our meta-analytic method and results, such as thinking we used introspectively assessed criteria in classifying levels of support and reporting only a subset of our externally assessed criteria. We systematically address their arguments that our construct label and criterion variable choices were inaccurate and, therefore, meta-analytic validity for these 13 CS variables was artificially low. For example, the authors created new construct labels for these variables that they called "the customary CS interpretation," but did not describe their methodology nor provide evidence that their labels would result in better validity than ours. They cite studies they believe we should have included; we explain how these studies did not fit our inclusion criteria and that including them would have actually reduced the relevant CS variables' meta-analytic validity. Ultimately, criticisms alone cannot change meta-analytic support from negative to positive; Tibon Czopp and Zeligman would need to conduct their own construct validity meta-analyses.

Prevalence of scoliosis among primary and middle school students in Mainland China: a systematic review and meta-analysis.

PubMed

Zhang, Hongqi; Guo, Chaofeng; Tang, Mingxing; Liu, Shaohua; Li, Jinsong; Guo, Qiang; Chen, Lizhang; Zhu, Yong; Zhao, Shushan

2015-01-01

Systematic review and meta-analysis of published prevalence of scoliosis among primary and middle school students in Mainland China. To evaluate the prevalence of scoliosis among primary and middle school students in Mainland China. There is substantial uncertainty regarding the prevalence of scoliosis in Mainland China among the primary and middle school students. We conducted a systematic review aiming to describe the prevalence of scoliosis in Mainland China. We systematically reviewed the published epidemiological studies or reports on the prevalence of scoliosis in Chinese cities. Scopus, PubMed, WanFang Database, CNKI, China National Science and Technology Digital Library, and WeiPu Database were searched for studies reporting a prevalence estimate for scoliosis in primary and middle school students. Meta-analyses were performed to estimate the pooled prevalence of scoliosis by STATA 12.0. Subgroup analyses were conducted according to the sex, age, and geographical area. A total of 38 articles, including 697,043 patients, were eligible for inclusion in this review. Meta-analyses revealed the prevalence of scoliosis to be 1.02% (95% [confidence interval] CI, 0.85-1.18) among the primary and middle school students in Mainland China. The female to male ratio was 1.54 (95% CI, 1.35-1.74; P < 0.001). According to the subgroup analysis by different ages, the prevalence of scoliosis increased from 0.73% (95% CI, 0.55-0.90) to 1.14% (95% CI, 0.86-1.42). Meta-analyses showed that the prevalence of scoliosis in Mainland China was 1.02% among the primary and middle school students. The prevalence of scoliosis in females was higher than in males and the ratio was 1.54. As they grew older, the prevalence of scoliosis increased in the students.

Review of Research Reporting Guidelines for Radiology Researchers.

PubMed

Cronin, Paul; Rawson, James V

2016-05-01

Prior articles have reviewed reporting guidelines and study evaluation tools for clinical research. However, only some of the many available accepted reporting guidelines at the Enhancing the QUAlity and Transparency Of health Research Network have been discussed in previous reports. In this paper, we review the key Enhancing the QUAlity and Transparency Of health Research reporting guidelines that have not been previously discussed. The study types include diagnostic and prognostic studies, reliability and agreement studies, observational studies, analytical and descriptive, experimental studies, quality improvement studies, qualitative research, health informatics, systematic reviews and meta-analyses, economic evaluations, and mixed methods studies. There are also sections on study protocols, and statistical analyses and methods. In each section, there is a brief overview of the study type, and then the reporting guideline(s) that are most applicable to radiology researchers including radiologists involved in health services research are discussed. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Association of IL-10-1082A/G Polymorphism with Ischemic Stroke: Evidence from a Case-Control Study to an Updated Meta-Analysis.

PubMed

Liu, Xu; Li, Qu; Zhu, Ruixia; He, Zhiyi

2017-06-01

Interleukin-10 (IL-10) plays a vital part in the pathophysiology of vascular inflammation. Several studies have investigated the potential association between the IL-10-1082A/G polymorphism and the risk of ischemic stroke where the inflammatory process is involved, but the conclusions have been inconsistent. Three hundred eighty-six ischemic stroke patients and 386 healthy controls were recruited in the study. Genotyping was conducted by using the polymerase chain reaction-ligation detection reaction method. A meta-analysis was then performed by pooling our data with previous published studies. In our case-control study, a lack of association was revealed between IL-10-1082A/G and ischemic stroke (p > 0.05). When combined with previous studies, however, a significant relationship between IL-10-1082A/G and ischemic stroke risk was found (G vs. A: OR = 0.73, 95% CI = 0.60-0.88, p < 0.01; GG vs. AA: OR = 0.61, 95% CI = 0.49-0.76, p < 0.01; GG+AG vs. AA: OR = 0.70, 95% CI = 0.54-0.91, p < 0.01; GG vs. AG+AA: OR = 0.68, 95% CI = 0.52-0.89, p < 0.01), as well as in subgroup analyses. Sensitivity analysis and publication bias assessment supported the reliability of the results from the meta-analysis. Evidence from a case-control study to an updated meta-analysis suggests that the IL-10-1082A/G polymorphism is associated with ischemic stroke susceptibility.

Adding results to a meta-analysis: Theory and example

NASA Astrophysics Data System (ADS)

Willson, Victor L.

Meta-analysis has been used as a research method to describe bodies of research data. It promotes hypothesis formation and the development of science education laws. A function overlooked, however, is the role it plays in updating research. Methods to integrate new research with meta-analysis results need explication. A procedure is presented using Bayesian analysis. Research in science education attitude correlation with achievement has been published after a recent meta-analysis of the topic. The results show how new findings complement the previous meta-analysis and extend its conclusions. Additional methodological questions adddressed are how studies are to be weighted, which variables are to be examined, and how often meta-analysis are to be updated.

Meta-analysis of alcohol price and income elasticities – with corrections for publication bias

PubMed Central

2013-01-01

Background This paper contributes to the evidence-base on prices and alcohol use by presenting meta-analytic summaries of price and income elasticities for alcohol beverages. The analysis improves on previous meta-analyses by correcting for outliers and publication bias. Methods Adjusting for outliers is important to avoid assigning too much weight to studies with very small standard errors or large effect sizes. Trimmed samples are used for this purpose. Correcting for publication bias is important to avoid giving too much weight to studies that reflect selection by investigators or others involved with publication processes. Cumulative meta-analysis is proposed as a method to avoid or reduce publication bias, resulting in more robust estimates. The literature search obtained 182 primary studies for aggregate alcohol consumption, which exceeds the database used in previous reviews and meta-analyses. Results For individual beverages, corrected price elasticities are smaller (less elastic) by 28-29 percent compared with consensus averages frequently used for alcohol beverages. The average price and income elasticities are: beer, -0.30 and 0.50; wine, -0.45 and 1.00; and spirits, -0.55 and 1.00. For total alcohol, the price elasticity is -0.50 and the income elasticity is 0.60. Conclusions These new results imply that attempts to reduce alcohol consumption through price or tax increases will be less effective or more costly than previously claimed. PMID:23883547

Role of Acupuncture in the Treatment or Prevention of Migraine, Tension-Type Headache, or Chronic Headache Disorders.

PubMed

Coeytaux, Remy R; Befus, Deanna

2016-07-01

To summarize the current evidence that evaluates the effectiveness of acupuncture for the treatment or prevention of migraine, tension-type headache, and chronic headache disorders. Findings from selected systematic reviews and meta-analyses are summarized. Recently published systematic reviews and meta-analyses demonstrate that acupuncture is associated with improved clinical outcomes compared to routine care only, medical management, and sham acupuncture 2 months after randomization. The evidence in support of acupuncture's comparative effectiveness at longer follow-up periods is mixed. Cost effectiveness analyses conducted in the United Kingdom and Germany suggest that acupuncture is a cost-effective treatment option in those countries. There are few or no cost-effectiveness studies of acupuncture in the United States. This brief review of the current, published evidence does not include a discussion of potential risks or adverse events associated with acupuncture. There is also the question of the extent to which placebo effects might contribute to acupuncture's clinical effectiveness. From a purely comparative effectiveness perspective, however, the evidence from clinical trials and meta-analyses makes a compelling case in support of a potentially important role for acupuncture as part of a treatment plan for patients with migraine, tension-type headache, and several different types of chronic headache disorders. © 2016 American Headache Society.

Effectiveness of Light Sources on In-Office Dental Bleaching: A Systematic Review and Meta-Analyses.

PubMed

SoutoMaior, J R; de Moraes, Sld; Lemos, Caa; Vasconcelos, Bc do E; Montes, Majr; Pellizzer, E P

2018-06-12

A systematic review and meta-analyses were performed to evaluate the efficacy of tooth color change and sensitivity of teeth following in-office bleaching with and without light gel activation in adult patients. This review was registered at PROSPERO (CRD 42017060574) and is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Electronic systematic searches of PubMed/MEDLINE, Web of Science, and the Cochrane Library were conducted for published articles. Only randomized clinical trials among adults that compared in-office bleaching with and without light activation with the same bleaching gel concentrations were selected. The outcomes were tooth color change and tooth sensitivity prevalence and intensity. Twenty-three articles from 1054 data sources met the eligibility criteria. After title and abstract screening, 39 studies remained. Sixteen studies were further excluded. Twenty-three studies remained for qualitative analyses and 20 for meta-analyses of primary and secondary outcomes. No significant differences in tooth color change or tooth sensitivity incidence were found between the compared groups; however, tooth sensitivity intensity decreased when light sources were applied. The use of light sources for in-office bleaching is not imperative to achieve esthetic clinical results.

Is the concomitant use of clopidogrel and Proton Pump Inhibitors still associated with increased adverse cardiovascular outcomes following coronary angioplasty?: a systematic review and meta-analysis of recently published studies (2012 - 2016).

PubMed

Bundhun, Pravesh Kumar; Teeluck, Abhishek Rishikesh; Bhurtu, Akash; Huang, Wei-Qiang

2017-01-05

Controversies were previously observed with the concomitant use of clopidogrel and Proton Pump Inhibitors (PPIs), especially omeprazole, following coronary angioplasty. Even though several studies showed no interaction between clopidogrel and PPIs, questions have been raised about the decrease in antiplatelet effects of clopidogrel with PPIs. A previously published meta-analysis showed concomitant use of clopidogrel and PPIs to be associated with higher adverse cardiovascular outcomes. However, data which were used were extracted from studies published before the year 2012. Whether these controversies still exist in this new era is not clear. Therefore, we aim to show if the concomitant use of clopidogrel and PPIs is still associated with higher adverse outcomes following Percutaneous Coronary Intervention (PCI) using data obtained from recently published studies (2012 to 2016). Electronic databases were searched for recent publications (2012-2016) comparing (clopidogrel plus PPIs) versus clopidogrel alone following PCI. Adverse cardiovascular outcomes were considered as the clinical endpoints. Odds Ratios (OR) with 95% Confidence Intervals (CI) were used as the statistical parameters and the pooled analyses were performed with RevMan 5.3 software. Eleven studies with a total number of 84,729 patients (29,235 patients from the PPIs group versus 55,494 patients from the non-PPIs group) were included. Results of this analysis showed that short term mortality and Target Vessel Revascularization (TVR) significantly favored the non-PPIs group with OR: 1.55; 95% CI: 1.43-1.68, P < 0.00001 and OR: 1.26; 95% CI: 1.06-1.49, P = 0.009 respectively. Long-term Major Adverse Cardiac Events (MACEs), Myocardial Infarction (MI), Stent Thrombosis (ST) and TVR significantly favored patients who did not use PPIs with OR: 1.37; 95% CI: 1.23-1.53, P < 0.00001, OR: 1.41; 95% CI: 1.26-1.57, P < 0.00001 and OR: 1.38; 95% CI: 1.13-1.70, P = 0.002 and OR: 1.28; 95% CI: 1.01-1.61, P = 0.04 respectively. However, the result for long term mortality was not statistically significant. The combined use of clopidogrel with PPIs is still associated with significantly higher adverse cardiovascular events such as MACEs, ST and MI following PCI supporting results of the previously published meta-analysis. However, long-term mortality is not statistically significant warranting further analysis with randomized patients.

Effect Size for Token Economy Use in Contemporary Classroom Settings: A Meta-Analysis of Single-Case Research

ERIC Educational Resources Information Center

Soares, Denise A.; Harrison, Judith R.; Vannest, Kimberly J.; McClelland, Susan S.

2016-01-01

Recent meta-analyses of the effectiveness of token economies (TEs) report insufficient quality in the research or mixed effects in the results. This study examines the contemporary (post-Public Law 94-142) peer-reviewed published single-case research evaluating the effectiveness of TEs. The results are stratified across quality of demonstrated…

What's All the Noise? Differentiating Dimensions of Acoustic Stress and the Limits to Meta-Analysis: Reply to Smith (2012)

ERIC Educational Resources Information Center

Szalma, J. L.; Hancock, P. A.

2012-01-01

Smith (2012) has provided pertinent observations on our recently published meta-analytic review (Szalma & Hancock, 2011) of the effects of acoustic noise on performance. His main points are as follows: (a) our review excluded some areas of research; (b) there were conceptual problems with our moderator analyses; and (c) limitations to…

Association of HLA-DQA1 and -DQB1 alleles with type I diabetes in Arabs: a meta-analyses.

PubMed

Hamzeh, A R; Nair, P; Al-Khaja, N; Al Ali, M T

2015-07-01

This study aimed at assessing the nature and significance of associations between various alleles of HLA-DQA1, HLA-DQB1, and type I diabetes (T1D) in Arab populations. Evidence from literature (published before 20 April 2015) was amassed and analysed through multiple meta-analyses, which yielded effect summary odds ratios and 95% confidence intervals for 24 alleles and 4 haplotypes. A total of 1273 cases and 1747 controls from 16 studies were analysed. High levels of significance were obtained to support higher T1D risk when harbouring DQA1*03:01. The alleles DQB1*02:01 and *03:02 and the haplotypes DR3 and DR4 were significant risk factors, albeit with high publication heterogeneity. The protective effects of DQA1*01:01, DQB1*05:03, *06:02, *06:03, and *06:04 were robustly suggested by all indicators of meta-analyses. The haplotypes DR7 and DR11 were strongly suggested to be protective in Arabs. A relatively small number of studies have emerged from Arab countries, mostly with inadequate power on an individual basis. This study fills the gap by providing significant size effect of human leukocyte antigen (HLA) alleles and completes the continuum of global ethnic differences in this context. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Personality and job performance: the Big Five revisited.

PubMed

Hurtz, G M; Donovan, J J

2000-12-01

Prior meta-analyses investigating the relation between the Big 5 personality dimensions and job performance have all contained a threat to construct validity, in that much of the data included within these analyses was not derived from actual Big 5 measures. In addition, these reviews did not address the relations between the Big 5 and contextual performance. Therefore, the present study sought to provide a meta-analytic estimate of the criterion-related validity of explicit Big 5 measures for predicting job performance and contextual performance. The results for job performance closely paralleled 2 of the previous meta-analyses, whereas analyses with contextual performance showed more complex relations among the Big 5 and performance. A more critical interpretation of the Big 5-performance relationship is presented, and suggestions for future research aimed at enhancing the validity of personality predictors are provided.

A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation.

PubMed

Deci, E L; Koestner, R; Ryan, R M

1999-11-01

A meta-analysis of 128 studies examined the effects of extrinsic rewards on intrinsic motivation. As predicted, engagement-contingent, completion-contingent, and performance-contingent rewards significantly undermined free-choice intrinsic motivation (d = -0.40, -0.36, and -0.28, respectively), as did all rewards, all tangible rewards, and all expected rewards. Engagement-contingent and completion-contingent rewards also significantly undermined self-reported interest (d = -0.15, and -0.17), as did all tangible rewards and all expected rewards. Positive feedback enhanced both free-choice behavior (d = 0.33) and self-reported interest (d = 0.31). Tangible rewards tended to be more detrimental for children than college students, and verbal rewards tended to be less enhancing for children than college students. The authors review 4 previous meta-analyses of this literature and detail how this study's methods, analyses, and results differed from the previous ones.

Effects of Exercise in the Treatment of Overweight and Obese Children and Adolescents: A Systematic Review of Meta-Analyses

PubMed Central

Kelley, George A.; Kelley, Kristi S.

2013-01-01

Purpose. Conduct a systematic review of previous meta-analyses addressing the effects of exercise in the treatment of overweight and obese children and adolescents. Methods. Previous meta-analyses of randomized controlled exercise trials that assessed adiposity in overweight and obese children and adolescents were included by searching nine electronic databases and cross-referencing from retrieved studies. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. The alpha level for statistical significance was set at P ≤ 0.05. Results. Of the 308 studies reviewed, two aggregate data meta-analyses representing 14 and 17 studies and 481 and 701 boys and girls met all eligibility criteria. Methodological quality was 64% and 73%. For both studies, statistically significant reductions in percent body fat were observed (P = 0.006 and P < 0.00001). The number-needed-to treat (NNT) was 4 and 3 with an estimated 24.5 and 31.5 million overweight and obese children in the world potentially benefitting, 2.8 and 3.6 million in the US. No other measures of adiposity (BMI-related measures, body weight, and central obesity) were statistically significant. Conclusions. Exercise is efficacious for reducing percent body fat in overweight and obese children and adolescents. Insufficient evidence exists to suggest that exercise reduces other measures of adiposity. PMID:24455215

Identification of susceptibility loci for colorectal cancer in a genome-wide meta-analysis

PubMed Central

Whiffin, Nicola; Hosking, Fay J.; Farrington, Susan M.; Palles, Claire; Dobbins, Sara E.; Zgaga, Lina; Lloyd, Amy; Kinnersley, Ben; Gorman, Maggie; Tenesa, Albert; Broderick, Peter; Wang, Yufei; Barclay, Ella; Hayward, Caroline; Martin, Lynn; Buchanan, Daniel D.; Win, Aung Ko; Hopper, John; Jenkins, Mark; Lindor, Noralane M.; Newcomb, Polly A.; Gallinger, Steve; Conti, David; Schumacher, Fred; Casey, Graham; Liu, Tao; Campbell, Harry; Lindblom, Annika; Houlston, Richard S.; Tomlinson, Ian P.; Dunlop, Malcolm G.

2014-01-01

To identify common variants influencing colorectal cancer (CRC) risk, we performed a meta-analysis of five genome-wide association studies, comprising 5626 cases and 7817 controls of European descent. We conducted replication of top ranked single nucleotide polymorphisms (SNPs) in additional series totalling 14 037 cases and 15 937 controls, identifying a new CRC risk locus at 10q24.2 [rs1035209; odds ratio (OR) = 1.13, P = 4.54 × 10−11]. We also performed meta-analysis of our studies, with previously published data, of several recently purported CRC risk loci. We failed to find convincing evidence for a previously reported genome-wide association at rs11903757 (2q32.3). Of the three additional loci for which evidence of an association in Europeans has been previously described we failed to show an association between rs59336 (12q24.21) and CRC risk. However, for the other two SNPs, our analyses demonstrated new, formally significant associations with CRC. These are rs3217810 intronic in CCND2 (12p13.32; OR = 1.19, P = 2.16 × 10−10) and rs10911251 near LAMC1 (1q25.3; OR = 1.09, P = 1.75 × 10−8). Additionally, we found some evidence to support a relationship between, rs647161, rs2423297 and rs10774214 and CRC risk originally identified in East Asians in our European datasets. Our findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to CRC. PMID:24737748

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.

Comparison of pharmacological and non-pharmacological interventions to prevent delirium in critically ill patients: a protocol for a systematic review incorporating network meta-analyses.

PubMed

Burry, L D; Hutton, B; Guenette, M; Williamson, D; Mehta, S; Egerod, I; Kanji, S; Adhikari, N K; Moher, D; Martin, C M; Rose, L

2016-09-08

Delirium is characterized by acute changes in mental status including inattention, disorganized thinking, and altered level of consciousness, and is highly prevalent in critically ill adults. Delirium has adverse consequences for both patients and the healthcare system; however, at this time, no effective treatment exists. The identification of effective prevention strategies is therefore a clinical and research imperative. An important limitation of previous reviews of delirium prevention is that interventions were considered in isolation and only direct evidence was used. Our systematic review will synthesize all existing data using network meta-analysis, a powerful statistical approach that enables synthesis of both direct and indirect evidence. We will search Ovid MEDLINE, CINAHL, Embase, PsycINFO, and Web of Science from 1980 to March 2016. We will search the PROSPERO registry for protocols and the Cochrane Library for published systematic reviews. We will examine reference lists of pertinent reviews and search grey literature and the International Clinical Trials Registry Platform for unpublished studies and ongoing trials. We will include randomized and quasi-randomized trials of critically ill adults evaluating any pharmacological, non-pharmacological, or multi-component intervention for delirium prevention, administered in or prior to (i.e., peri-operatively) transfer to the ICU. Two authors will independently screen search results and extract data from eligible studies. Risk of bias assessments will be completed on all included studies. To inform our network meta-analysis, we will first conduct conventional pair-wise meta-analyses for primary and secondary outcomes using random-effects models. We will generate our network meta-analysis using a Bayesian framework, assuming a common heterogeneity parameter across all comparisons, and accounting for correlations in multi-arm studies. We will perform analyses using WinBUGS software. This systematic review will address the existing knowledge gap regarding best practices for delirium prevention in critically ill adults by synthesizing evidence from trials of pharmacological, non-pharmacological, and multi-component interventions administered in or prior to transfer to the ICU. Use of network meta-analysis will clarify which delirium prevention strategies are most effective in improving clinical outcomes while causing least harm. The network meta-analysis is a novel approach and will provide knowledge users and decision makers with comparisons of multiple interventions of delirium prevention strategies. PROSPERO CRD42016036313.

Joint models for longitudinal and time-to-event data: a review of reporting quality with a view to meta-analysis.

PubMed

Sudell, Maria; Kolamunnage-Dona, Ruwanthi; Tudur-Smith, Catrin

2016-12-05

Joint models for longitudinal and time-to-event data are commonly used to simultaneously analyse correlated data in single study cases. Synthesis of evidence from multiple studies using meta-analysis is a natural next step but its feasibility depends heavily on the standard of reporting of joint models in the medical literature. During this review we aim to assess the current standard of reporting of joint models applied in the literature, and to determine whether current reporting standards would allow or hinder future aggregate data meta-analyses of model results. We undertook a literature review of non-methodological studies that involved joint modelling of longitudinal and time-to-event medical data. Study characteristics were extracted and an assessment of whether separate meta-analyses for longitudinal, time-to-event and association parameters were possible was made. The 65 studies identified used a wide range of joint modelling methods in a selection of software. Identified studies concerned a variety of disease areas. The majority of studies reported adequate information to conduct a meta-analysis (67.7% for longitudinal parameter aggregate data meta-analysis, 69.2% for time-to-event parameter aggregate data meta-analysis, 76.9% for association parameter aggregate data meta-analysis). In some cases model structure was difficult to ascertain from the published reports. Whilst extraction of sufficient information to permit meta-analyses was possible in a majority of cases, the standard of reporting of joint models should be maintained and improved. Recommendations for future practice include clear statement of model structure, of values of estimated parameters, of software used and of statistical methods applied.

Citrus fruits intake and oral cancer risk: a systematic review and meta-analysis.

PubMed

Cirmi, Santa; Navarra, Michele; Woodside, Jayne V; Cantwell, Marie M

2018-05-10

To quantify the relationship between Citrus intake and risk of cancer of the oral cavity and pharynx. Systematic review and meta-analysis. Ovid MEDLINE, EMBASE, and Web of Science were searched until September 2017. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, Citrus oil, fruits, oral cancer, mouth cancer, mouth neoplasm. The selection of studies and the systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A pre-defined inclusion checklist resulted in the inclusion of articles which were (i) published in peer-reviewed scientific journals; (ii) English language; (iii) and included a measure of Citrus fruit intake and risk of oral and pharyngeal cancer. Studies were excluded if (i) preparations derived from other fruits were used, (ii) Citrus intake was combined with intake of other fruits; (iii) in vitro or animal models were used. We also excluded reviews, systematic reviews, meta-analyses, letters, personal opinions, conference abstracts and book chapters. Three reviewers independently performed the extraction of data from studies included. Seventeen studies met our inclusion criteria and were included in the final review. Pooled analyses showed that those with the highest Citrus fruit intake compared to the lowest intake had a 50% reduction in risk of oral cavity and pharyngeal cancer (OR 0.50; 95% CI 0.43-0.59). The studies included in this review and meta-analysis showed an inverse association between Citrus fruit intake and oral cancer. Copyright © 2018. Published by Elsevier Ltd.

Meta-Analyses of Diagnostic Accuracy in Imaging Journals: Analysis of Pooling Techniques and Their Effect on Summary Estimates of Diagnostic Accuracy.

PubMed

McGrath, Trevor A; McInnes, Matthew D F; Korevaar, Daniël A; Bossuyt, Patrick M M

2016-10-01

Purpose To determine whether authors of systematic reviews of diagnostic accuracy studies published in imaging journals used recommended methods for meta-analysis, and to evaluate the effect of traditional methods on summary estimates of sensitivity and specificity. Materials and Methods Medline was searched for published systematic reviews that included meta-analysis of test accuracy data limited to imaging journals published from January 2005 to May 2015. Two reviewers independently extracted study data and classified methods for meta-analysis as traditional (univariate fixed- or random-effects pooling or summary receiver operating characteristic curve) or recommended (bivariate model or hierarchic summary receiver operating characteristic curve). Use of methods was analyzed for variation with time, geographical location, subspecialty, and journal. Results from reviews in which study authors used traditional univariate pooling methods were recalculated with a bivariate model. Results Three hundred reviews met the inclusion criteria, and in 118 (39%) of those, authors used recommended meta-analysis methods. No change in the method used was observed with time (r = 0.54, P = .09); however, there was geographic (χ(2) = 15.7, P = .001), subspecialty (χ(2) = 46.7, P < .001), and journal (χ(2) = 27.6, P < .001) heterogeneity. Fifty-one univariate random-effects meta-analyses were reanalyzed with the bivariate model; the average change in the summary estimate was -1.4% (P < .001) for sensitivity and -2.5% (P < .001) for specificity. The average change in width of the confidence interval was 7.7% (P < .001) for sensitivity and 9.9% (P ≤ .001) for specificity. Conclusion Recommended methods for meta-analysis of diagnostic accuracy in imaging journals are used in a minority of reviews; this has not changed significantly with time. Traditional (univariate) methods allow overestimation of diagnostic accuracy and provide narrower confidence intervals than do recommended (bivariate) methods. (©) RSNA, 2016 Online supplemental material is available for this article.

Prevention of infections associated with combat-related thoracic and abdominal cavity injuries.

PubMed

Martin, Gregory J; Dunne, James R; Cho, John M; Solomkin, Joseph S

2011-08-01

Trauma-associated injuries of the thorax and abdomen account for the majority of combat trauma-associated deaths, and infectious complications are common in those who survive the initial injury. This review focuses on the initial surgical and medical management of torso injuries intended to diminish the occurrence of infection. The evidence for recommendations is drawn from published military and civilian data in case reports, clinical trials, meta-analyses, and previously published guidelines, in the interval since publication of the 2008 guidelines. The emphasis of these recommendations is on actions that can be taken in the forward-deployed setting within hours to days of injury. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Individual patient data meta-analysis of combined treatments versus psychotherapy (with or without pill placebo), pharmacotherapy or pill placebo for adult depression: a protocol.

PubMed

Weitz, Erica; Kleiboer, Annet; van Straten, Annemieke; Hollon, Steven D; Cuijpers, Pim

2017-02-13

There are many proven treatments (psychotherapy, pharmacotherapy or their combination) for the treatment of depression. Although there is growing evidence for the effectiveness of combination treatment (psychotherapy + pharmacotherapy) over pharmacotherapy alone, psychotherapy alone or psychotherapy plus pill placebo, for depression, little is known about which specific groups of patients may respond best to combined treatment versus monotherapy. Conventional meta-analyses techniques have limitations when tasked with examining whether specific individual characteristics moderate the effect of treatment on depression. Therefore, this protocol outlines an individual patient data (IPD) meta-analysis to explore which patients, with which clinical characteristics, have better outcomes in combined treatment compared with psychotherapy (alone or with pill placebo), pharmacotherapy and pill placebo. Study searches are completed using an established database of randomised controlled trials (RCTs) on the psychological treatment of adult depression that has previously been reported. Searches were conducted in PubMed, PsycInfo, Embase and the Cochrane Central Register of Controlled Trials. RCTs comparing combination treatment (psychotherapy + pharmacotherapy) with psychotherapy (with or without pill placebo), pharmacotherapy or pill placebo for the treatment of adult depression will be included. Study authors of eligible trials will be contacted and asked to contribute IPD. Conventional meta-analysis techniques will be used to examine differences between studies that have contributed data and those that did not. Then, IPD will be harmonised and analysis using multilevel regression will be conducted to examine effect moderators of treatment outcomes. Study results outlined above will be published in peer-reviewed journals. Study results will contribute to better understanding whether certain patients respond best to combined treatment or other depression treatments and provide new information on moderators of treatment outcome that can be used by patients, clinicians and researchers. CRD42016039028. 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/.

Homocysteine and Coronary Heart Disease: Meta-analysis of MTHFR Case-Control Studies, Avoiding Publication Bias

PubMed Central

Verhoef, Petra; Dötsch-Klerk, Mariska; Lathrop, Mark; Xu, Peng; Nordestgaard, Børge G.; Holm, Hilma; Hopewell, Jemma C.; Saleheen, Danish; Tanaka, Toshihiro; Anand, Sonia S.; Chambers, John C.; Kleber, Marcus E.; Ouwehand, Willem H.; Yamada, Yoshiji; Elbers, Clara; Peters, Bas; Stewart, Alexandre F. R.; Reilly, Muredach M.; Thorand, Barbara; Yusuf, Salim; Engert, James C.; Assimes, Themistocles L.; Kooner, Jaspal; Danesh, John; Watkins, Hugh; Samani, Nilesh J.

2012-01-01

Background Moderately elevated blood levels of homocysteine are weakly correlated with coronary heart disease (CHD) risk, but causality remains uncertain. When folate levels are low, the TT genotype of the common C677T polymorphism (rs1801133) of the methylene tetrahydrofolate reductase gene (MTHFR) appreciably increases homocysteine levels, so “Mendelian randomization” studies using this variant as an instrumental variable could help test causality. Methods and Findings Nineteen unpublished datasets were obtained (total 48,175 CHD cases and 67,961 controls) in which multiple genetic variants had been measured, including MTHFR C677T. These datasets did not include measurements of blood homocysteine, but homocysteine levels would be expected to be about 20% higher with TT than with CC genotype in the populations studied. In meta-analyses of these unpublished datasets, the case-control CHD odds ratio (OR) and 95% CI comparing TT versus CC homozygotes was 1.02 (0.98–1.07; p = 0.28) overall, and 1.01 (0.95–1.07) in unsupplemented low-folate populations. By contrast, in a slightly updated meta-analysis of the 86 published studies (28,617 CHD cases and 41,857 controls), the OR was 1.15 (1.09–1.21), significantly discrepant (p = 0.001) with the OR in the unpublished datasets. Within the meta-analysis of published studies, the OR was 1.12 (1.04–1.21) in the 14 larger studies (those with variance of log OR<0.05; total 13,119 cases) and 1.18 (1.09–1.28) in the 72 smaller ones (total 15,498 cases). Conclusions The CI for the overall result from large unpublished datasets shows lifelong moderate homocysteine elevation has little or no effect on CHD. The discrepant overall result from previously published studies reflects publication bias or methodological problems. Please see later in the article for the Editors' Summary PMID:22363213

Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials

PubMed Central

Tzoulaki, Ioanna; Zgaga, Lina; Ioannidis, John P A

2014-01-01

Objective To evaluate the breadth, validity, and presence of biases of the associations of vitamin D with diverse outcomes. Design Umbrella review of the evidence across systematic reviews and meta-analyses of observational studies of plasma 25-hydroxyvitamin D or 1,25-dihydroxyvitamin D concentrations and randomised controlled trials of vitamin D supplementation. Data sources Medline, Embase, and screening of citations and references. Eligibility criteria Three types of studies were eligible for the umbrella review: systematic reviews and meta-analyses that examined observational associations between circulating vitamin D concentrations and any clinical outcome; and meta-analyses of randomised controlled trials assessing supplementation with vitamin D or active compounds (both established and newer compounds of vitamin D). Results 107 systematic literature reviews and 74 meta-analyses of observational studies of plasma vitamin D concentrations and 87 meta-analyses of randomised controlled trials of vitamin D supplementation were identified. The relation between vitamin D and 137 outcomes has been explored, covering a wide range of skeletal, malignant, cardiovascular, autoimmune, infectious, metabolic, and other diseases. Ten outcomes were examined by both meta-analyses of observational studies and meta-analyses of randomised controlled trials, but the direction of the effect and level of statistical significance was concordant only for birth weight (maternal vitamin D status or supplementation). On the basis of the available evidence, an association between vitamin D concentrations and birth weight, dental caries in children, maternal vitamin D concentrations at term, and parathyroid hormone concentrations in patients with chronic kidney disease requiring dialysis is probable, but further studies and better designed trials are needed to draw firmer conclusions. In contrast to previous reports, evidence does not support the argument that vitamin D only supplementation increases bone mineral density or reduces the risk of fractures or falls in older people. Conclusions Despite a few hundred systematic reviews and meta-analyses, highly convincing evidence of a clear role of vitamin D does not exist for any outcome, but associations with a selection of outcomes are probable. PMID:24690624

The Relation between Self-Regulated Learning and Academic Achievement across Childhood and Adolescence: A Meta-Analysis

ERIC Educational Resources Information Center

Dent, Amy L.; Koenka, Alison C.

2016-01-01

This research synthesis explores how academic achievement relates to two main components of self-regulated learning for students in elementary and secondary school. Two meta-analyses integrated previous findings on (1) the defining metacognitive processes of self-regulated learning and (2) students' use of cognitive strategies. Overall…

Breaking the Discrepancy Code: A Meta-Analysis of the Specific Learning Disability Literature

ERIC Educational Resources Information Center

Bachmeier, Randy J.

2009-01-01

Previous "selective" meta-analyses of the literature relating to the IQ-achievement discrepancy model of specific learning disability identification have concluded that "underachieving" and "low-achieving" poor readers do not differ in any educationally meaningful way. Underachievers are those poor readers who qualify as learning disabled using an…

Introduction, comparison, and validation of Meta-Essentials: A free and simple tool for meta-analysis.

PubMed

Suurmond, Robert; van Rhee, Henk; Hak, Tony

2017-12-01

We present a new tool for meta-analysis, Meta-Essentials, which is free of charge and easy to use. In this paper, we introduce the tool and compare its features to other tools for meta-analysis. We also provide detailed information on the validation of the tool. Although free of charge and simple, Meta-Essentials automatically calculates effect sizes from a wide range of statistics and can be used for a wide range of meta-analysis applications, including subgroup analysis, moderator analysis, and publication bias analyses. The confidence interval of the overall effect is automatically based on the Knapp-Hartung adjustment of the DerSimonian-Laird estimator. However, more advanced meta-analysis methods such as meta-analytical structural equation modelling and meta-regression with multiple covariates are not available. In summary, Meta-Essentials may prove a valuable resource for meta-analysts, including researchers, teachers, and students. © 2017 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd.

Citation Discovery Tools for Conducting Adaptive Meta-analyses to Update Systematic Reviews.

PubMed

Bae, Jong-Myon; Kim, Eun Hee

2016-03-01

The systematic review (SR) is a research methodology that aims to synthesize related evidence. Updating previously conducted SRs is necessary when new evidence has been produced, but no consensus has yet emerged on the appropriate update methodology. The authors have developed a new SR update method called 'adaptive meta-analysis' (AMA) using the 'cited by', 'similar articles', and 'related articles' citation discovery tools in the PubMed and Scopus databases. This study evaluates the usefulness of these citation discovery tools for updating SRs. Lists were constructed by applying the citation discovery tools in the two databases to the articles analyzed by a published SR. The degree of overlap between the lists and distribution of excluded results were evaluated. The articles ultimately selected for the SR update meta-analysis were found in the lists obtained from the 'cited by' and 'similar' tools in PubMed. Most of the selected articles appeared in both the 'cited by' lists in Scopus and PubMed. The Scopus 'related' tool did not identify the appropriate articles. The AMA, which involves using both citation discovery tools in PubMed, and optionally, the 'related' tool in Scopus, was found to be useful for updating an SR.

Efficacy of fibrin glue versus sutures for attaching conjunctival autografts in pterygium surgery: a systematic review with meta-analysis and trial sequential analysis of evidence.

PubMed

Lan, Aihua; Xiao, Feifan; Wang, Yun; Luo, Zhen; Cao, Qixin

2017-06-20

Previous meta-analyses have been conducted to compare the efficacy of fibrin glue (FG) versus sutures in pterygium surgery; however, additional clinical trials have since been published. Therefore, we conducted an updated meta-analysis to further explore the association between FG application in pterygium surgery, and the recurrence rate, complication rate, and surgical duration. An electronic literature search for eligible studies published before July 29, 2016 was conducted across multiple databases. Odds ratios (ORs), standardized mean difference (SMD), and 95% confidence intervals (CI) were calculated. Publication bias of the included articles was evaluated by funnel plots. Differences in recurrence rate and complication rate between the FG and suture groups were evaluated in terms of OR with 95% CI, and SMD with 95% CI were used to estimate the difference in surgical duration. Trial sequential analysis (TSA) was used to determine whether the currently available evidence was sufficient and conclusive. Twenty-four studies were included in this study. The pooled ORs for recurrence rate and complication rate were 0.35 and 1.121, respectively. The pooled SMD for surgical duration was -4.142. The TSA results indicated that evidence of the effect was sufficient in the recurrence group and surgical duration group. Although there was no difference in complication rate between FG and sutures, the apparent advantages of FG over sutures are shorter surgical duration and greater reduction in the recurrence rate of pterygium.

Efficacy of fibrin glue versus sutures for attaching conjunctival autografts in pterygium surgery: a systematic review with meta-analysis and trial sequential analysis of evidence

PubMed Central

Luo, Zhen; Cao, Qixin

2017-01-01

Previous meta-analyses have been conducted to compare the efficacy of fibrin glue (FG) versus sutures in pterygium surgery; however, additional clinical trials have since been published. Therefore, we conducted an updated meta-analysis to further explore the association between FG application in pterygium surgery, and the recurrence rate, complication rate, and surgical duration. An electronic literature search for eligible studies published before July 29, 2016 was conducted across multiple databases. Odds ratios (ORs), standardized mean difference (SMD), and 95% confidence intervals (CI) were calculated. Publication bias of the included articles was evaluated by funnel plots. Differences in recurrence rate and complication rate between the FG and suture groups were evaluated in terms of OR with 95% CI, and SMD with 95% CI were used to estimate the difference in surgical duration. Trial sequential analysis (TSA) was used to determine whether the currently available evidence was sufficient and conclusive. Twenty-four studies were included in this study. The pooled ORs for recurrence rate and complication rate were 0.35 and 1.121, respectively. The pooled SMD for surgical duration was −4.142. The TSA results indicated that evidence of the effect was sufficient in the recurrence group and surgical duration group. Although there was no difference in complication rate between FG and sutures, the apparent advantages of FG over sutures are shorter surgical duration and greater reduction in the recurrence rate of pterygium. PMID:28489563

Examining Ecological Constraints on the Intergenerational Transmission of Attachment Via Individual Participant Data Meta-analysis.

PubMed

Verhage, Marije L; Fearon, R M Pasco; Schuengel, Carlo; van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J; Madigan, Sheri; Roisman, Glenn I; Oosterman, Mirjam; Behrens, Kazuko Y; Wong, Maria S; Mangelsdorf, Sarah; Priddis, Lynn E; Brisch, Karl-Heinz

2018-05-09

Parents' attachment representations and child-parent attachment have been shown to be associated, but these associations vary across populations (Verhage et al., 2016). The current study examined whether ecological factors may explain variability in the strength of intergenerational transmission of attachment, using individual participant data (IPD) meta-analysis. Analyses on 4,396 parent-child dyads (58 studies, child age 11-96 months) revealed a combined effect size of r = .29. IPD meta-analyses revealed that effect sizes for the transmission of autonomous-secure representations to secure attachments were weaker under risk conditions and weaker in adolescent parent-child dyads, whereas transmission was stronger for older children. Findings support the ecological constraints hypothesis on attachment transmission. Implications for attachment theory and the use of IPD meta-analysis are discussed. © 2018 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.

Publication Bias Currently Makes an Accurate Estimate of the Benefits of Enrichment Programs Difficult: A Postmortem of Two Meta-Analyses Using Statistical Power Analysis

ERIC Educational Resources Information Center

Warne, Russell T.

2016-01-01

Recently Kim (2016) published a meta-analysis on the effects of enrichment programs for gifted students. She found that these programs produced substantial effects for academic achievement (g = 0.96) and socioemotional outcomes (g = 0.55). However, given current theory and empirical research these estimates of the benefits of enrichment programs…

A Systematic Review and Quantitative Meta-Analysis of Oxytocin's Effects on Feeding.

PubMed

Leslie, Monica; Silva, Paulo; Paloyelis, Yannis; Blevins, James; Treasure, Janet

2018-02-26

Oxytocin's anorexigenic effects have been widely documented and accepted; however, no paper has yet used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to compile previous findings in a single systematic review and quantitative meta-analysis. The current paper aimed to identify published and unpublished studies examining the effects of oxytocin on energy intake in animals and humans, and the factors that moderate this effect. Web of Science, Pub Med, and Ovid were searched for published and unpublished studies reporting the effects of oxytocin on energy intake in wild-type animals and in humans, when administered in the absence of other active drugs or surgery. 2049 articles were identified through the original systematic literature search, from which 54 articles were identified as relevant for inclusion in this review. An additional 3 relevant articles were identified in a later update of the literature search. Overall, a single-dose of oxytocin was found to reduce feeding in animals. Despite several individual studies which found that this effect persists to the end of the third week of chronic administration in rodent models, overall, this anorexigenic effect did not hold in the meta-analyses testing the effects of chronic administration. There was no overall effect of oxytocin on energy intake in humans, although a trend was identified for oxytocin to reduce consumption of solid foods. Oxytocin reduces energy intake when administered as a single dose. Oxytocin can inhibit feeding over two- to three-week periods in rodent models. These effects typically do not persist beyond the third week of treatment. The anorexigenic effect of oxytocin is moderated by pregnant status, dose, method of administration, and diet composition. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Major publications in the critical care pharmacotherapy literature: January-December 2017.

PubMed

Hammond, Drayton A; Baumgartner, Laura; Cooper, Craig; Donahey, Elisabeth; Harris, Serena A; Mercer, Jessica M; Morris, Mandy; Patel, Mona K; Plewa-Rusiecki, Angela M; Poore, Alia A; Szaniawski, Ryan; Horner, Deanna

2018-06-01

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2017. The Critical Care Pharmacotherapy Literature Update (CCPLU) Group screened 32 journals monthly for impactful articles and reviewed 115 during 2017. Two meta-analyses and eight original research trials were reviewed here from those included in the monthly CCPLU. Meta-analyses on early, goal-directed therapy for septic shock and statin therapy for acute respiratory distress syndrome were summarized. Original research trials that were included evaluate thrombolytic therapy in severe stroke, hyperoxia and hypertonic saline in septic shock, intraoperative ketamine for prevention of post-operative delirium, intravenous ketorolac dosing regimens for acute pain, angiotensin II for vasodilatory shock, dabigatran reversal with idarucizumab, bivalirudin versus heparin monotherapy for myocardial infarction, and balanced crystalloids versus saline fluid resuscitation. This clinical review provides perspectives on impactful critical care pharmacotherapy publications in 2017. Copyright © 2018 Elsevier Inc. All rights reserved.

Economic evaluation of algae biodiesel based on meta-analyses

NASA Astrophysics Data System (ADS)

Zhang, Yongli; Liu, Xiaowei; White, Mark A.; Colosi, Lisa M.

2017-08-01

The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be 5.00-10.31/gal, higher than the selected benchmarks: 3.77/gal for petroleum diesel, and 4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel (2.76-4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.

The effects of resistance training interventions on vertical jump performance in basketball players: a meta-analysis.

PubMed

Sperlich, Paula F; Behringer, Michael; Mester, Joachim

2016-01-01

Vertical jump performance is one of the key factors in basketball. In order to determine the effectiveness of previously published interventions and their influencing factors we performed a meta-analysis. A computerized search was conducted using the databases PubMed (1966), Web of Science (1900), SPORTDiscus™ (1975),Medline (1966) and SportPilot (2008). Studies involving healthy male or female basketball players at any age and performance level were included. All trials had to investigate the benefits of resistance training programs on jumping performance in basketball players and provide a control group. The effect size (ES) was computed and the relationship between ESs and continuous variables was examined by meta-regressions, whereas subgroup meta-analyses and z-tests were used to assess the impact of categorical moderator variables. The meta-analysis included 14 studies with 20 subgroups and a total of 37 outcomes. A total of 399 participants were examined, N.=157 served as control and N.=242 took part in particular training interventions. The overall weighted ES of 0.78 (95% CI 0.41, 1.15) was significantly greater than zero (P<0.001). None of the categorical moderator variables affected the training effect. However, positive correlations were found for training duration (r=0.68; P=0.02). The present meta-analysis demonstrates that resistance training throughout the year, using bodyweight or external weight, significantly improves vertical jump performance in healthy basketball players. Since vertical jump improvements were independent of intervention period but dependent on the duration of each individual training session the total training amount should be based on longer training sessions.

Association between the interleukin-1β C-511T polymorphism and periodontitis: a meta-analysis in the Chinese population.

PubMed

Wang, H F; He, F Q; Xu, C J; Li, D M; Sun, X J; Chi, Y T; Guo, W

2017-02-23

The association between the interleukin-1 beta (IL-1β) C-511T (or rs16944) polymorphism and periodontitis remains inconclusive, even though there have been previous studies on this association. To assess the effects of IL-1β C-511T variants on the risk of development of periodontitis, a meta-analysis was performed in a single ethnic population. Studies, published up to December 2015, were selected for the meta-analysis from PubMed and Chinese databases. The associations were assessed with pooled OR and 95%CI. This meta-analysis identified 8 studies, including 1276 periodontitis cases and 1558 controls. Overall, a significant association between the IL-1β C-511T polymorphism and periodontitis was found in the Chinese population (TT vs CC: OR = 1.48, 95%CI = 1.19-1.85; TT + CT vs CC: OR = 1.50, 95%CI = 1.25-1.81; T vs C: OR = 1.33, 95%CI = 1.06-1.68). In the subgroup analyses based on geographical area(s), source of controls, and type of periodontitis, significant results were obtained for the association between IL-1β C-511T variants and periodontitis. Our meta-analysis indicated that the IL-1β C-511T polymorphism may be a genetic susceptibility factor for periodontitis in the Chinese population. This marker could be used to identify Chinese individuals at a high risk for periodontitis.

Meta-analyses and Forest plots using a microsoft excel spreadsheet: step-by-step guide focusing on descriptive data analysis.

PubMed

Neyeloff, Jeruza L; Fuchs, Sandra C; Moreira, Leila B

2012-01-20

Meta-analyses are necessary to synthesize data obtained from primary research, and in many situations reviews of observational studies are the only available alternative. General purpose statistical packages can meta-analyze data, but usually require external macros or coding. Commercial specialist software is available, but may be expensive and focused in a particular type of primary data. Most available softwares have limitations in dealing with descriptive data, and the graphical display of summary statistics such as incidence and prevalence is unsatisfactory. Analyses can be conducted using Microsoft Excel, but there was no previous guide available. We constructed a step-by-step guide to perform a meta-analysis in a Microsoft Excel spreadsheet, using either fixed-effect or random-effects models. We have also developed a second spreadsheet capable of producing customized forest plots. It is possible to conduct a meta-analysis using only Microsoft Excel. More important, to our knowledge this is the first description of a method for producing a statistically adequate but graphically appealing forest plot summarizing descriptive data, using widely available software.

Meta-analyses and Forest plots using a microsoft excel spreadsheet: step-by-step guide focusing on descriptive data analysis

PubMed Central

2012-01-01

Background Meta-analyses are necessary to synthesize data obtained from primary research, and in many situations reviews of observational studies are the only available alternative. General purpose statistical packages can meta-analyze data, but usually require external macros or coding. Commercial specialist software is available, but may be expensive and focused in a particular type of primary data. Most available softwares have limitations in dealing with descriptive data, and the graphical display of summary statistics such as incidence and prevalence is unsatisfactory. Analyses can be conducted using Microsoft Excel, but there was no previous guide available. Findings We constructed a step-by-step guide to perform a meta-analysis in a Microsoft Excel spreadsheet, using either fixed-effect or random-effects models. We have also developed a second spreadsheet capable of producing customized forest plots. Conclusions It is possible to conduct a meta-analysis using only Microsoft Excel. More important, to our knowledge this is the first description of a method for producing a statistically adequate but graphically appealing forest plot summarizing descriptive data, using widely available software. PMID:22264277

Non-invasive brain stimulation to investigate language production in healthy speakers: A meta-analysis.

PubMed

Klaus, Jana; Schutter, Dennis J L G

2018-06-01

Non-invasive brain stimulation (NIBS) has become a common method to study the interrelations between the brain and language functioning. This meta-analysis examined the efficacy of transcranial magnetic stimulation (TMS) and direct current stimulation (tDCS) in the study of language production in healthy volunteers. Forty-five effect sizes from 30 studies which investigated the effects of NIBS on picture naming or verbal fluency in healthy participants were meta-analysed. Further sub-analyses investigated potential influences of stimulation type, control, target site, task, online vs. offline application, and current density of the target electrode. Random effects modelling showed a small, but reliable effect of NIBS on language production. Subsequent analyses indicated larger weighted mean effect sizes for TMS as compared to tDCS studies. No statistical differences for the other sub-analyses were observed. We conclude that NIBS is a useful method for neuroscientific studies on language production in healthy volunteers. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

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

PubMed Central

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

2016-01-01

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

Effect of periodontal treatment on preterm birth rate: a systematic review of meta-analyses.

PubMed

López, Néstor J; Uribe, Sergio; Martinez, Benjamín

2015-02-01

Preterm birth is a major cause of neonatal morbidity and mortality in both developed and developing countries. Preterm birth is a highly complex syndrome that includes distinct clinical subtypes in which many different causes may be involved. The results of epidemiological, molecular, microbiological and animal-model studies support a positive association between maternal periodontal disease and preterm birth. However, the results of intervention studies carried out to determine the effect of periodontal treatment on reducing the risk of preterm birth are controversial. This systematic review critically analyzes the methodological issues of meta-analyses of the studies to determine the effect of periodontal treatment to reduce preterm birth. The quality of the individual randomized clinical trials selected is of highest relevance for a systematic review. This article describes the methodological features that should be identified a priori and assessed individually to determine the quality of a randomized controlled trial performed to evaluate the effect of periodontal treatment on pregnancy outcomes. The AMSTAR and the PRISMA checklist tools were used to assess the quality of the six meta-analyses selected, and the bias domain of the Cochrane Collaboration's Tool was applied to evaluate each of the trials included in the meta-analyses. In addition, the methodological characteristics of each clinical trial were assessed. The majority of the trials included in the meta-analyses have significant methodological flaws that threaten their internal validity. The lack of effect of periodontal treatment on preterm birth rate concluded by four meta-analyses, and the positive effect of treatment for reducing preterm birth risk concluded by the remaining two meta-analyses are not based on consistent scientific evidence. Well-conducted randomized controlled trials using rigorous methodology, including appropriate definition of the exposure, adequate control of confounders for preterm birth and application of effective periodontal interventions to eliminate periodontal infection, are needed to confirm the positive association between periodontal disease and preterm birth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Barrett’s oesophagus: Evidence from the current meta-analyses

PubMed Central

Gatenby, Piers; Soon, Yuen

2014-01-01

Guidelines have been published regarding the management of Barrett’s oesophagus (columnar-lined oesophagus). These have examined the role of surveillance in an effort to detect dysplasia and early cancer. The guidelines have provided criteria for enrolment into surveillance and some risk stratification with regard to surveillance interval. The research basis for the decisions reached with regard to cancer risk is weak and this manuscript has examined the available data published from meta-analyses up to 25th April 2013 (much of which has been published since the guidelines and their most recent updates have been written). There were 9 meta-analyses comparing patients with Barrett’s oesophagus to control populations. These have demonstrated that Barrett’s oesophagus is more common in males than females, in subjects who have ever smoked, in subjects with obesity, in subjects with prolonged symptoms of gastro-oesophageal reflux disease, in subjects who do not have infection with Helicobacter pylori and in subjects with hiatus hernia. These findings should inform public health measures in reducing the risk of Barrett’s oesophagus and subsequent surveillance burden and cancer risk. There were 8 meta-analyses comparing different groups of patients with Barrett’s oesophagus with regard to cancer risk. These have demonstrated that there was no statistically significant benefit of antireflux surgery over medical therapy, that endoscopic ablative therapy was effective in reducing cancer risk that there was similar cancer risk in patients with Barrett’s oesophagus independent of geographic origin, that the adenocarcinoma incidence in males is twice the rate in females, that the cancer risk in long segment disease showed a trend to be higher than in short segment disease, that there was a trend for higher cancer risk in low-grade dysplasia over non-dysplastic Barrett’s oesophagus, that there is a lower risk in patients with Helicobacter pylori infection and that there is a significant protective effect of aspirin and statins. There were no meta-analyses examining the role of intestinal metaplasia. These results demonstrate that guidance regarding surveillance based on the presence of intestinal metaplasia, segment length and the presence of low-grade dysplasia has a weak basis, and further consideration should be given to gender and helicobacter status, ablation of the metaplastic segment as well as the chemoprotective role of aspirin and statins. PMID:25133020

Barrett's oesophagus: Evidence from the current meta-analyses.

PubMed

Gatenby, Piers; Soon, Yuen

2014-08-15

Guidelines have been published regarding the management of Barrett's oesophagus (columnar-lined oesophagus). These have examined the role of surveillance in an effort to detect dysplasia and early cancer. The guidelines have provided criteria for enrolment into surveillance and some risk stratification with regard to surveillance interval. The research basis for the decisions reached with regard to cancer risk is weak and this manuscript has examined the available data published from meta-analyses up to 25(th) April 2013 (much of which has been published since the guidelines and their most recent updates have been written). There were 9 meta-analyses comparing patients with Barrett's oesophagus to control populations. These have demonstrated that Barrett's oesophagus is more common in males than females, in subjects who have ever smoked, in subjects with obesity, in subjects with prolonged symptoms of gastro-oesophageal reflux disease, in subjects who do not have infection with Helicobacter pylori and in subjects with hiatus hernia. These findings should inform public health measures in reducing the risk of Barrett's oesophagus and subsequent surveillance burden and cancer risk. There were 8 meta-analyses comparing different groups of patients with Barrett's oesophagus with regard to cancer risk. These have demonstrated that there was no statistically significant benefit of antireflux surgery over medical therapy, that endoscopic ablative therapy was effective in reducing cancer risk that there was similar cancer risk in patients with Barrett's oesophagus independent of geographic origin, that the adenocarcinoma incidence in males is twice the rate in females, that the cancer risk in long segment disease showed a trend to be higher than in short segment disease, that there was a trend for higher cancer risk in low-grade dysplasia over non-dysplastic Barrett's oesophagus, that there is a lower risk in patients with Helicobacter pylori infection and that there is a significant protective effect of aspirin and statins. There were no meta-analyses examining the role of intestinal metaplasia. These results demonstrate that guidance regarding surveillance based on the presence of intestinal metaplasia, segment length and the presence of low-grade dysplasia has a weak basis, and further consideration should be given to gender and helicobacter status, ablation of the metaplastic segment as well as the chemoprotective role of aspirin and statins.

A meta-analysis of neuropsychological outcome after mild traumatic brain injury: re-analyses and reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009).

PubMed

Rohling, Martin L; Binder, Laurence M; Demakis, George J; Larrabee, Glenn J; Ploetz, Danielle M; Langhinrichsen-Rohling, Jennifer

2011-05-01

The meta-analytic findings of Binder et al. (1997) and Frencham et al. (2005) showed that the neuropsychological effect of mild traumatic brain injury (mTBI) was negligible in adults by 3 months post injury. Pertab et al. (2009) reported that verbal paired associates, coding tasks, and digit span yielded significant differences between mTBI and control groups. We re-analyzed data from the 25 studies used in the prior meta-analyses, correcting statistical and methodological limitations of previous efforts, and analyzed the chronicity data by discrete epochs. Three months post injury the effect size of -0.07 was not statistically different from zero and similar to that which has been found in several other meta-analyses (Belanger et al., 2005; Schretlen & Shapiro, 2003). The effect size 7 days post injury was -0.39. The effect of mTBI immediately post injury was largest on Verbal and Visual Memory domains. However, 3 months post injury all domains improved to show non-significant effect sizes. These findings indicate that mTBI has an initial small effect on neuropsychological functioning that dissipates quickly. The evidence of recovery in the present meta-analysis is consistent with previous conclusions of both Binder et al. and Frencham et al. Our findings may not apply to people with a history of multiple concussions or complicated mTBIs.

The albatross plot: A novel graphical tool for presenting results of diversely reported studies in a systematic review.

PubMed

Harrison, Sean; Jones, Hayley E; Martin, Richard M; Lewis, Sarah J; Higgins, Julian P T

2017-09-01

Meta-analyses combine the results of multiple studies of a common question. Approaches based on effect size estimates from each study are generally regarded as the most informative. However, these methods can only be used if comparable effect sizes can be computed from each study, and this may not be the case due to variation in how the studies were done or limitations in how their results were reported. Other methods, such as vote counting, are then used to summarize the results of these studies, but most of these methods are limited in that they do not provide any indication of the magnitude of effect. We propose a novel plot, the albatross plot, which requires only a 1-sided P value and a total sample size from each study (or equivalently a 2-sided P value, direction of effect and total sample size). The plot allows an approximate examination of underlying effect sizes and the potential to identify sources of heterogeneity across studies. This is achieved by drawing contours showing the range of effect sizes that might lead to each P value for given sample sizes, under simple study designs. We provide examples of albatross plots using data from previous meta-analyses, allowing for comparison of results, and an example from when a meta-analysis was not possible. Copyright © 2017 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd.

Association between acute mountain sickness (AMS) and age: a meta-analysis.

PubMed

Wu, Yu; Zhang, Chi; Chen, Yu; Luo, Yong-Jun

2018-05-11

Acute mountain sickness (AMS) is a potentially lethal condition caused by acute hypoxia after ascending to altitudes higher than 2500 m in a short time. The main symptom of AMS is headache. Numerous risk factors of AMS have been examined, including gender, obesity, ascent rate, age and individual susceptibility. In previous studies, age was considered a predisposing factor for AMS. However, different opinions have been raised in recent years. To clarify the association between AMS and age, we conducted this meta-analysis. We obtained observational studies that explored risk factors for AMS by searching PubMed, Embase, China National Knowledge Internet (CNKI), the Wanfang database and CQVIP for articles published before March 2017. The studies included were required to provide the mean age and its standard deviation for subjects with and without AMS, the maximum altitude attained and the mode of ascent. The Lake Louse Score (LLS) or the Chinese AMS score (CAS) was used to judge the severity of AMS symptoms and incidence. Studies were pooled for the analysis by using a random effects model in RevMan 5.0. Meta-regression and subgroup analyses were conducted to identify sources of heterogeneity using Stata 14.2 and RevMan 5.0. In total, 17 studies were included, and the overall number of subjects with and without AMS was 1810 and 3014, respectively. The age ranged from 10 to 76 years. Analysis of the 17 included studies showed that age was not associated with AMS (mean difference (MD) = 0.10; 95% CI: -0.38-0.58; P = 0.69). This meta-analysis suggests that there is no association between age and the risk of AMS. Race, age, and ascent mode are common sources of heterogeneity, which may provide an analytical orientation for future heterogeneity analyses.

CARING (CAncer Risk and INsulin analoGues): The Association of Diabetes Mellitus and Cancer Risk with Focus on Possible Determinants - A Systematic Review and a Meta-Analysis

PubMed Central

Starup-Linde, Jakob; Karlstad, Øystein; Eriksen, Stine Aistrup; Vestergaard, Peter; Bronsveld, Heleen K.; de Vries, Frank; Andersen, Morten; Auvinen, Anssi; Haukka, Jari; Hjellvik, Vidar; Bazelier, Marloes T.; de Boer, Anthonius; Furu, Kari; De Bruin, Marie L.

2013-01-01

Background: Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se. Objective: To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines. Data Sources: The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: “Diabetes mellitus”, “Neoplasms”, and “Risk of cancer”. Study Eligibility Criteria: The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included. Results: Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment). Limitations: Publication bias seemed to be present. Only published data were used in the analyses. Conclusions: The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer. PMID:24215312

Analysis and meta-analysis of single-case designs with a standardized mean difference statistic: a primer and applications.

PubMed

Shadish, William R; Hedges, Larry V; Pustejovsky, James E

2014-04-01

This article presents a d-statistic for single-case designs that is in the same metric as the d-statistic used in between-subjects designs such as randomized experiments and offers some reasons why such a statistic would be useful in SCD research. The d has a formal statistical development, is accompanied by appropriate power analyses, and can be estimated using user-friendly SPSS macros. We discuss both advantages and disadvantages of d compared to other approaches such as previous d-statistics, overlap statistics, and multilevel modeling. It requires at least three cases for computation and assumes normally distributed outcomes and stationarity, assumptions that are discussed in some detail. We also show how to test these assumptions. The core of the article then demonstrates in depth how to compute d for one study, including estimation of the autocorrelation and the ratio of between case variance to total variance (between case plus within case variance), how to compute power using a macro, and how to use the d to conduct a meta-analysis of studies using single-case designs in the free program R, including syntax in an appendix. This syntax includes how to read data, compute fixed and random effect average effect sizes, prepare a forest plot and a cumulative meta-analysis, estimate various influence statistics to identify studies contributing to heterogeneity and effect size, and do various kinds of publication bias analyses. This d may prove useful for both the analysis and meta-analysis of data from SCDs. Copyright © 2013 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis.

PubMed

Starup-Linde, Jakob; Karlstad, Oystein; Eriksen, Stine Aistrup; Vestergaard, Peter; Bronsveld, Heleen K; de Vries, Frank; Andersen, Morten; Auvinen, Anssi; Haukka, Jari; Hjellvik, Vidar; Bazelier, Marloes T; Boer, Anthonius de; Furu, Kari; De Bruin, Marie L

2013-11-01

Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se. To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines. The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: "Diabetes mellitus", "Neoplasms", and "Risk of cancer". The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included. Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment). Publication bias seemed to be present. Only published data were used in the analyses. The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer.

Mismatch Negativity in Han Chinese Patients with Schizophrenia: A Meta-Analysis.

PubMed

Xiong, Yanbing; Ll, Xianbin; Zhao, Lei; Wang, Chuanyue

2017-10-25

Previous meta-analysis revealed that mismatch negativity(MMN) amplitude decreased in patients with schizophrenia compared with healthy controls (Cohen's d, d about 1), leading to the possibility of mismatch negativity being used as a biomarker for schizophrenia. However, it is unknown whether MMN is reliably changed in Chinese patients. It is necessary to carry out a meta-analysis on MMN of Han Chinese patients with schizophrenia. To investigate whether MMN could be used as a biomarker for Han Chinese patients with schizophrenia. A literature search was conducted to identify clinical trials on MMN in Han Chinese schizophrenia patients published before May 8, 2017, by searching the Chinese language databases CNKI, WanFang Data, VIP Data and PubMed. The effects of MMN deficits were evaluated for MMN amplitude by calculating standard mean difference (SMDs) between schizophrenia patient groups and healthy control groups. A total of 11 studies were included in the analysis. The total quality of all the studies were more than 6 as evaluated by Newcastle-Ottawa Scale (NOS). Meta-analysis of data from these studies had a pooled sample of 432 patients with schizophrenia and 392 healthy controls. There exists significant MMN deficit in schizophrenia patients compared to healthy controls (Cohen's d =1.004). When studies were excluded due to heterogeneity, the pooled effect size of the MMN differences between the patient group and healthy controls dropped to 0.79 (Cohen's d =0.79). Subgroup analysis showed that MMN amplitude deficits of schizophrenia over three years had the pooled effect size of 0.95, and less than three years had the pooled effect size of 0.77. Publication bias conducted via Egger regression test ( t = 1.83; p = 0.101), suggested that there was no publication bias. The effect size of MMN amplitude between Chinese patients with schizophrenia and healthy controls is consistent with other meta-analyses published on this topic, suggesting that Han Chinese patients with schizophrenia also exhibited MMN deficits.

Intervention Effects on Spoken-Language Outcomes for Children with Autism: A Systematic Review and Meta-Analysis

ERIC Educational Resources Information Center

Hampton, L. H.; Kaiser, A. P.

2016-01-01

Background: Although spoken-language deficits are not core to an autism spectrum disorder (ASD) diagnosis, many children with ASD do present with delays in this area. Previous meta-analyses have assessed the effects of intervention on reducing autism symptomatology, but have not determined if intervention improves spoken language. This analysis…

The Efficacy of Violence Prediction: A Meta-Analytic Comparison of Nine Risk Assessment Tools

ERIC Educational Resources Information Center

Yang, Min; Wong, Stephen C. P.; Coid, Jeremy

2010-01-01

Actuarial risk assessment tools are used extensively to predict future violence, but previous studies comparing their predictive accuracies have produced inconsistent findings as a result of various methodological issues. We conducted meta-analyses of the effect sizes of 9 commonly used risk assessment tools and their subscales to compare their…

Interaction between the serotonin transporter gene (5-HTTLPR), stressful life events, and risk of depression: a meta-analysis.

PubMed

Risch, Neil; Herrell, Richard; Lehner, Thomas; Liang, Kung-Yee; Eaves, Lindon; Hoh, Josephine; Griem, Andrea; Kovacs, Maria; Ott, Jurg; Merikangas, Kathleen Ries

2009-06-17

Substantial resources are being devoted to identify candidate genes for complex mental and behavioral disorders through inclusion of environmental exposures following the report of an interaction between the serotonin transporter linked polymorphic region (5-HTTLPR) and stressful life events on an increased risk of major depression. To conduct a meta-analysis of the interaction between the serotonin transporter gene and stressful life events on depression using both published data and individual-level original data. Search of PubMed, EMBASE, and PsycINFO databases through March 2009 yielded 26 studies of which 14 met criteria for the meta-analysis. Criteria for studies for the meta-analyses included published data on the association between 5-HTTLPR genotype (SS, SL, or LL), number of stressful life events (0, 1, 2, > or = 3) or equivalent, and a categorical measure of depression defined by the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) or the International Statistical Classification of Diseases, 10th Revision (ICD-10) or use of a cut point to define depression from standardized rating scales. To maximize our ability to use a common framework for variable definition, we also requested original data from all studies published prior to 2008 that met inclusion criteria. Of the 14 studies included in the meta-analysis, 10 were also included in a second sex-specific meta-analysis of original individual-level data. Logistic regression was used to estimate the effects of the number of short alleles at 5-HTTLPR, the number of stressful life events, and their interaction on depression. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated separately for each study and then weighted averages of the individual estimates were obtained using random-effects meta-analysis. Both sex-combined and sex-specific meta-analyses were conducted. Of a total of 14,250 participants, 1769 were classified as having depression; 12,481 as not having depression. In the meta-analysis of published data, the number of stressful life events was significantly associated with depression (OR, 1.41; 95% CI,1.25-1.57). No association was found between 5-HTTLPR genotype and depression in any of the individual studies nor in the weighted average (OR, 1.05; 95% CI, 0.98-1.13) and no interaction effect between genotype and stressful life events on depression was observed (OR, 1.01; 95% CI, 0.94-1.10). Comparable results were found in the sex-specific meta-analysis of individual-level data. This meta-analysis yielded no evidence that the serotonin transporter genotype alone or in interaction with stressful life events is associated with an elevated risk of depression in men alone, women alone, or in both sexes combined.

Parental experiences of providing skin-to-skin care to their newborn infant—Part 2: A qualitative meta-synthesis

PubMed Central

Anderzén-Carlsson, Agneta; Lamy, Zeni C.; Tingvall, Maria; Eriksson, Mats

2014-01-01

Aim To synthesize and interpret qualitative research findings focusing on parental experiences of skin-to-skin care (SSC) for newborn infants. Background SSC induces many benefits for newborn infants and their parents. Three meta-analyses have been conducted on physiological outcomes, but no previous qualitative meta-synthesis on parental experiences of SSC has been identified. Design The present meta-synthesis was guided by the methodology described by Paterson and co-workers. Data sources Four databases were searched, without year or language limitations, up until December 2013. Manual searches were also performed. The searches and subsequent quality appraisal resulted in the inclusion of 29 original qualitative papers from 9 countries, reporting experiences from 401 mothers and 94 fathers. Review methods The meta-synthesis entails a meta-data analysis, analysis of meta-method, and meta-theory in the included primary studies. Based on the three analyses, the meta-synthesis represents a new interpretation of a phenomenon. The results of the meta-data analysis have been presented as a qualitative systematic review in a separate paper. Results When synthesizing and interpreting the findings from the included analyses, a theoretical model of Becoming a parent under unfamiliar circumstances emerged. Providing SSC seems to be a restorative as well as an energy-draining experience. A supportive environment has been described as facilitating the restorative experience, whereas obstacles in the environment seem to make the provision of SSC energy-draining for parents. When the process is experienced as positive, it facilitates the growth of parental self-esteem and makes the parents ready to assume full responsibility for their child. Conclusion The results show that SSC can be interpreted not only as a family-including and important health care intervention but also in terms of actually becoming a parent. The process of becoming a parent in this specific situation is influenced by external factors in three different levels; family and friends, community, and society at large. The descriptions of providing SSC are similar to what has previously been described as the natural process of becoming a mother or a father. PMID:25319747

Parental experiences of providing skin-to-skin care to their newborn infant--part 2: a qualitative meta-synthesis.

PubMed

Anderzén-Carlsson, Agneta; Lamy, Zeni C; Tingvall, Maria; Eriksson, Mats

2014-01-01

To synthesize and interpret qualitative research findings focusing on parental experiences of skin-to-skin care (SSC) for newborn infants. SSC induces many benefits for newborn infants and their parents. Three meta-analyses have been conducted on physiological outcomes, but no previous qualitative meta-synthesis on parental experiences of SSC has been identified. The present meta-synthesis was guided by the methodology described by Paterson and co-workers. Four databases were searched, without year or language limitations, up until December 2013. Manual searches were also performed. The searches and subsequent quality appraisal resulted in the inclusion of 29 original qualitative papers from 9 countries, reporting experiences from 401 mothers and 94 fathers. The meta-synthesis entails a meta-data analysis, analysis of meta-method, and meta-theory in the included primary studies. Based on the three analyses, the meta-synthesis represents a new interpretation of a phenomenon. The results of the meta-data analysis have been presented as a qualitative systematic review in a separate paper. When synthesizing and interpreting the findings from the included analyses, a theoretical model of Becoming a parent under unfamiliar circumstances emerged. Providing SSC seems to be a restorative as well as an energy-draining experience. A supportive environment has been described as facilitating the restorative experience, whereas obstacles in the environment seem to make the provision of SSC energy-draining for parents. When the process is experienced as positive, it facilitates the growth of parental self-esteem and makes the parents ready to assume full responsibility for their child. The results show that SSC can be interpreted not only as a family-including and important health care intervention but also in terms of actually becoming a parent. The process of becoming a parent in this specific situation is influenced by external factors in three different levels; family and friends, community, and society at large. The descriptions of providing SSC are similar to what has previously been described as the natural process of becoming a mother or a father.

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.

Gender differences in depression in representative national samples: Meta-analyses of diagnoses and symptoms.

PubMed

Salk, Rachel H; Hyde, Janet S; Abramson, Lyn Y

2017-08-01

In 2 meta-analyses on gender differences in depression in nationally representative samples, we advance previous work by including studies of depression diagnoses and symptoms to (a) estimate the magnitude of the gender difference in depression across a wide array of nations and ages; (b) use a developmental perspective to elucidate patterns of gender differences across the life span; and (c) incorporate additional theory-driven moderators (e.g., gender equity). For major depression diagnoses and depression symptoms, respectively, we meta-analyzed data from 65 and 95 articles and their corresponding national data sets, representing data from 1,716,195 and 1,922,064 people in over 90 different nations. Overall, odds ratio (OR) = 1.95, 95% confidence interval (CI) [1.88, 2.03], and d = 0.27 [0.26, 0.29]. Age was the strongest predictor of effect size. The gender difference for diagnoses emerged earlier than previously thought, with OR = 2.37 at age 12. For both meta-analyses, the gender difference peaked in adolescence (OR = 3.02 for ages 13-15, and d = 0.47 for age 16) but then declined and remained stable in adulthood. Cross-national analyses indicated that larger gender differences were found in nations with greater gender equity, for major depression, but not depression symptoms. The gender difference in depression represents a health disparity, especially in adolescence, yet the magnitude of the difference indicates that depression in men should not be overlooked. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Bullied children and psychosomatic problems: a meta-analysis.

PubMed

Gini, Gianluca; Pozzoli, Tiziana

2013-10-01

A previous meta-analysis showed that being bullied during childhood is related to psychosomatic problems, but many other studies have been published since then, including some longitudinal studies. We performed a new meta-analysis to quantify the association between peer victimization and psychosomatic complaints in the school-aged population. We searched online databases up to April 2012, and bibliographies of retrieved studies and of narrative reviews, for studies that examined the association between being bullied and psychosomatic complaints in children and adolescents. The original search identified 119 nonduplicated studies, of which 30 satisfied the prestated inclusion criteria. Two separate random effects meta-analyses were performed on 6 longitudinal studies (odds ratio = 2.39, 95% confidence interval, 1.76 to 3.24) and 24 cross-sectional studies (odds ratio = 2.17, 95% confidence interval, 1.91 to 2.46), respectively. Results showed that bullied children and adolescents have a significantly higher risk for psychosomatic problems than non-bullied agemates. In the cross-sectional studies, the magnitude of effect size significantly decreased with the increase of the proportion of female participants in the study sample. No other moderators were statistically significant. The association between being bullied and psychosomatic problems was confirmed. Given that school bullying is a widespread phenomenon in many countries around the world, the present results indicate that bullying should be considered a significant international public health problem.

Allowing for uncertainty due to missing continuous outcome data in pairwise and network meta-analysis.

PubMed

Mavridis, Dimitris; White, Ian R; Higgins, Julian P T; Cipriani, Andrea; Salanti, Georgia

2015-02-28

Missing outcome data are commonly encountered in randomized controlled trials and hence may need to be addressed in a meta-analysis of multiple trials. A common and simple approach to deal with missing data is to restrict analysis to individuals for whom the outcome was obtained (complete case analysis). However, estimated treatment effects from complete case analyses are potentially biased if informative missing data are ignored. We develop methods for estimating meta-analytic summary treatment effects for continuous outcomes in the presence of missing data for some of the individuals within the trials. We build on a method previously developed for binary outcomes, which quantifies the degree of departure from a missing at random assumption via the informative missingness odds ratio. Our new model quantifies the degree of departure from missing at random using either an informative missingness difference of means or an informative missingness ratio of means, both of which relate the mean value of the missing outcome data to that of the observed data. We propose estimating the treatment effects, adjusted for informative missingness, and their standard errors by a Taylor series approximation and by a Monte Carlo method. We apply the methodology to examples of both pairwise and network meta-analysis with multi-arm trials. © 2014 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Ataxia Telangiectasia–Mutated Gene Polymorphisms and Acute Normal Tissue Injuries in Cancer Patients After Radiation Therapy: A Systematic Review and Meta-analysis

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

Dong, Lihua; Cui, Jingkun; Tang, Fengjiao

Purpose: Studies of the association between ataxia telangiectasia–mutated (ATM) gene polymorphisms and acute radiation injuries are often small in sample size, and the results are inconsistent. We conducted the first meta-analysis to provide a systematic review of published findings. Methods and Materials: Publications were identified by searching PubMed up to April 25, 2014. Primary meta-analysis was performed for all acute radiation injuries, and subgroup meta-analyses were based on clinical endpoint. The influence of sample size and radiation injury incidence on genetic effects was estimated in sensitivity analyses. Power calculations were also conducted. Results: The meta-analysis was conducted on the ATMmore » polymorphism rs1801516, including 5 studies with 1588 participants. For all studies, the cut-off for differentiating cases from controls was grade 2 acute radiation injuries. The primary meta-analysis showed a significant association with overall acute radiation injuries (allelic model: odds ratio = 1.33, 95% confidence interval: 1.04-1.71). Subgroup analyses detected an association between the rs1801516 polymorphism and a significant increase in urinary and lower gastrointestinal injuries and an increase in skin injury that was not statistically significant. There was no between-study heterogeneity in any meta-analyses. In the sensitivity analyses, small studies did not show larger effects than large studies. In addition, studies with high incidence of acute radiation injuries showed larger effects than studies with low incidence. Power calculations revealed that the statistical power of the primary meta-analysis was borderline, whereas there was adequate power for the subgroup analysis of studies with high incidence of acute radiation injuries. Conclusions: Our meta-analysis showed a consistency of the results from the overall and subgroup analyses. We also showed that the genetic effect of the rs1801516 polymorphism on acute radiation injuries was dependent on the incidence of the injury. These support the evidence of an association between the rs1801516 polymorphism and acute radiation injuries, encouraging further research of this topic.« less

Development of the Veritas plot and its application in cardiac surgery: an evidence-synthesis graphic tool for the clinician to assess multiple meta-analyses reporting on a common outcome.

PubMed

Panesar, Sukhmeet S; Rao, Christopher; Vecht, Joshua A; Mirza, Saqeb B; Netuveli, Gopalakrishnan; Morris, Richard; Rosenthal, Joe; Darzi, Ara; Athanasiou, Thanos

2009-10-01

Meta-analyses may be prone to generating misleading results because of a paucity of experimental studies (especially in surgery); publication bias; and heterogeneity in study design, intervention and the patient population of included studies. When investigating a specific clinical or scientific question on which several relevant meta-analyses may have been published, value judgments must be applied to determine which analysis represents the most robust evidence. These value judgments should be specifically acknowledged. We designed the Veritas plot to explicitly explore important elements of quality and to facilitate decision-making by highlighting specific areas in which meta-analyses are found to be deficient. Furthermore, as a graphic tool, it may be more intuitive than when similar data are presented in a tabular or text format. The Veritas plot is an adaption of the radar plot, a graphic tool for the description of multiattribute data. Key elements of meta-analytical quality such as heterogeneity, publication bias and study design are assessed. Existing qualitative methods such as the Assessment of Multiple Systematic Reviews (AMSTAR) tool have been incorporated in addition to important considerations when interpreting surgical meta-analyses such as the year of publication and population characteristics. To demonstrate the potential of the Veritas plot to inform clinical practice, we apply the Veritas plot to the meta-analytical literature comparing the incidence of 30-day stroke in off-pump coronary artery bypass surgery and conventional coronary artery bypass surgery. We demonstrate that a visually-stimulating and practical evidence-synthesis tool can direct the clinician and scientist to a particular meta-analytical study to inform clinical practice. The Veritas plot is also cumulative and allowed us to assess the quality of evidence over time. We have presented a practical graphic application for scientists and clinicians to identify and interpret variability in meta-analyses. Although further validation of the Veritas plot is required, it may have the potential to contribute to the implementation of evidence-based practice.

A genome-wide association study of corneal astigmatism: The CREAM Consortium.

PubMed

Shah, Rupal L; Li, Qing; Zhao, Wanting; Tedja, Milly S; Tideman, J Willem L; Khawaja, Anthony P; Fan, Qiao; Yazar, Seyhan; Williams, Katie M; Verhoeven, Virginie J M; Xie, Jing; Wang, Ya Xing; Hess, Moritz; Nickels, Stefan; Lackner, Karl J; Pärssinen, Olavi; Wedenoja, Juho; Biino, Ginevra; Concas, Maria Pina; Uitterlinden, André; Rivadeneira, Fernando; Jaddoe, Vincent W V; Hysi, Pirro G; Sim, Xueling; Tan, Nicholas; Tham, Yih-Chung; Sensaki, Sonoko; Hofman, Albert; Vingerling, Johannes R; Jonas, Jost B; Mitchell, Paul; Hammond, Christopher J; Höhn, René; Baird, Paul N; Wong, Tien-Yin; Cheng, Chinfsg-Yu; Teo, Yik Ying; Mackey, David A; Williams, Cathy; Saw, Seang-Mei; Klaver, Caroline C W; Guggenheim, Jeremy A; Bailey-Wilson, Joan E

2018-01-01

To identify genes and genetic markers associated with corneal astigmatism. A meta-analysis of genome-wide association studies (GWASs) of corneal astigmatism undertaken for 14 European ancestry (n=22,250) and 8 Asian ancestry (n=9,120) cohorts was performed by the Consortium for Refractive Error and Myopia. Cases were defined as having >0.75 diopters of corneal astigmatism. Subsequent gene-based and gene-set analyses of the meta-analyzed results of European ancestry cohorts were performed using VEGAS2 and MAGMA software. Additionally, estimates of single nucleotide polymorphism (SNP)-based heritability for corneal and refractive astigmatism and the spherical equivalent were calculated for Europeans using LD score regression. The meta-analysis of all cohorts identified a genome-wide significant locus near the platelet-derived growth factor receptor alpha ( PDGFRA ) gene: top SNP: rs7673984, odds ratio=1.12 (95% CI:1.08-1.16), p=5.55×10 -9 . No other genome-wide significant loci were identified in the combined analysis or European/Asian ancestry-specific analyses. Gene-based analysis identified three novel candidate genes for corneal astigmatism in Europeans-claudin-7 ( CLDN7 ), acid phosphatase 2, lysosomal ( ACP2 ), and TNF alpha-induced protein 8 like 3 ( TNFAIP8L3 ). In addition to replicating a previously identified genome-wide significant locus for corneal astigmatism near the PDGFRA gene, gene-based analysis identified three novel candidate genes, CLDN7 , ACP2 , and TNFAIP8L3 , that warrant further investigation to understand their role in the pathogenesis of corneal astigmatism. The much lower number of genetic variants and genes demonstrating an association with corneal astigmatism compared to published spherical equivalent GWAS analyses suggest a greater influence of rare genetic variants, non-additive genetic effects, or environmental factors in the development of astigmatism.

Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia.

PubMed

Dickson, H; Laurens, K R; Cullen, A E; Hodgins, S

2012-04-01

Previous reviews have reported cognitive and motor deficits in childhood and adolescence among individuals who later develop schizophrenia. However, these reviews focused exclusively on studies of individuals with affected relatives or on population/birth cohorts, incorporated studies with estimated measures of pre-morbid intelligence, or included investigations that examined symptomatic at-risk participants or participants 18 years or older. Thus, it remains unclear whether cognitive and motor deficits constitute robust antecedents of schizophrenia. Meta-analyses were conducted on published studies that examined cognitive or motor function in youth aged 16 years or younger who later developed schizophrenia or a schizophrenia spectrum disorder (SSD) and those who did not. Twenty-three studies fulfilled the following inclusion criteria: (1) written in English; (2) prospective investigations of birth or genetic high-risk cohorts, or follow-back investigations of population samples; (3) objective measures of cognitive or motor performance at age 16 or younger; (4) results provided for individuals who did and who did not develop schizophrenia/SSD later in life; and (5) sufficient data to calculate effect sizes. Four domains of function were examined: IQ; Motor Function; General Academic Achievement; and Mathematics Achievement. Meta-analyses showed that, by age 16, individuals who subsequently developed schizophrenia/SSD displayed significant deficits in IQ (d=0.51) and motor function (d=0.56), but not in general academic achievement (d=0.25) or mathematics achievement (d=0.21). Subsidiary analysis indicated that the IQ deficit was present by age 13. These results demonstrate that deficits in IQ and motor performance precede the prodrome and the onset of illness.

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

PubMed

Gao, L; Zhang, L; Jin, Q

2009-09-01

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

A narrative meta-review of a series of systematic and meta-analytic reviews on the intervention outcome for children with developmental co-ordination disorder.

PubMed

Miyahara, M; Lagisz, M; Nakagawa, S; Henderson, S E

2017-09-01

Systematic reviews and meta-analyses are considered to be the 'gold standards' for synthesizing research evidence in particular areas of enquiry. However, such reviews are only useful if they themselves are conducted to a sufficiently high standard. The aim of this study was to conduct a narrative meta-review of existing analyses of the effectiveness of interventions designed for children with developmental co-ordination disorder (DCD). A narrative meta-review of systematic and meta-analytic reviews aimed at evaluating the effectiveness of intervention for children with DCD was conducted on studies published between 1950 and 2014. We identified suitable reviews, using a modification of the Population, Intervention, Comparison, Outcome (PICO) system and evaluated their methodological quality using the Assessment of Multiple Systematic Reviews (AMSTAR). In addition, the consistency of the quality of evidence and classification of intervention approaches was assessed independently by two assessors. The literature search yielded a total of four appropriate reviews published in the selected time span. The Assessment of Multiple Systematic Reviews percentage quality scores assigned to each review ranged from 0% (low quality) to 55% (medium quality). Evaluation of the quality of evidence and classification of intervention approaches yielded a discrepancy rate of 25%. All reviews concluded that some kind of intervention was better than none at all. Although the quality of the reviews progressively improved over the years, the shortcomings identified need to be addressed before concrete evidence regarding the best approach to intervention for children with DCD can be specified. © 2016 John Wiley & Sons Ltd.

Nonsyndromic cleft palate: An association study at GWAS candidate loci in a multiethnic sample.

PubMed

Ishorst, Nina; Francheschelli, Paola; Böhmer, Anne C; Khan, Mohammad Faisal J; Heilmann-Heimbach, Stefanie; Fricker, Nadine; Little, Julian; Steegers-Theunissen, Regine P M; Peterlin, Borut; Nowak, Stefanie; Martini, Markus; Kruse, Teresa; Dunsche, Anton; Kreusch, Thomas; Gölz, Lina; Aldhorae, Khalid; Halboub, Esam; Reutter, Heiko; Mossey, Peter; Nöthen, Markus M; Rubini, Michele; Ludwig, Kerstin U; Knapp, Michael; Mangold, Elisabeth

2018-06-01

Nonsyndromic cleft palate only (nsCPO) is a common and multifactorial form of orofacial clefting. In contrast to successes achieved for the other common form of orofacial clefting, that is, nonsyndromic cleft lip with/without cleft palate (nsCL/P), genome wide association studies (GWAS) of nsCPO have identified only one genome wide significant locus. Aim of the present study was to investigate whether common variants contribute to nsCPO and, if so, to identify novel risk loci. We genotyped 33 SNPs at 27 candidate loci from 2 previously published nsCPO GWAS in an independent multiethnic sample. It included: (i) a family-based sample of European ancestry (n = 212); and (ii) two case/control samples of Central European (n = 94/339) and Arabian ancestry (n = 38/231), respectively. A separate association analysis was performed for each genotyped dataset, and meta-analyses were performed. After association analysis and meta-analyses, none of the 33 SNPs showed genome-wide significance. Two variants showed nominally significant association in the imputed GWAS dataset and exhibited a further decrease in p-value in a European and an overall meta-analysis including imputed GWAS data, respectively (rs395572: P MetaEU  = 3.16 × 10 -4 ; rs6809420: P MetaAll  = 2.80 × 10 -4 ). Our findings suggest that there is a limited contribution of common variants to nsCPO. However, the individual effect sizes might be too small for detection of further associations in the present sample sizes. Rare variants may play a more substantial role in nsCPO than in nsCL/P, for which GWAS of smaller sample sizes have identified genome-wide significant loci. Whole-exome/genome sequencing studies of nsCPO are now warranted. © 2018 Wiley Periodicals, Inc.

International Society for the Study of Fatty Acids and Lipids 2016 Debate: For Science-Based Dietary Guidelines on Fats, Meta-Analysis and Systematic Reviews Are Decisive.

PubMed

Nettleton, Joyce A; von Schacky, Clemens; Brouwer, Ingeborg A; Koletzko, Berthold

2017-01-01

This paper summarizes a debate on whether meta-analyses and systematic reviews are decisive in formulating guidelines for dietary fat. Held during the 12th congress of the International Society for the Study of Fatty Acids and Lipids in Stellenbosch, South Africa, September 7, 2016, the debate was hosted by the International Union of Nutritional Sciences and the International Expert Movement to Improve Dietary Fat Quality (IEM, www.theiem.org). Clemens von Schacky, Ludwig Maximilians-University, Munich, Germany, supported the statement, describing the types of weaknesses in individual studies and clinical trials. With examples of how to overcome such limitations, he concluded that nutritional guidelines on fat need a proper scientific basis in which randomized controlled trials (RCTs) with clinical endpoints and their meta-analyses are essential and decisive. In contention, Ingeborg Brouwer, Vrije Universiteit, Amsterdam, declared that recommendations on dietary fat intake should always be based on the totality of the evidence, including physiologic and biochemical knowledge and associations from observational epidemiology. RCTs and meta-analyses have their shortcomings, but well-conducted systematic reviews and meta-analyses support a transparent process for developing dietary fat guidelines. Participants agreed that evidence-based decision-making for dietary guidance should consider all the best available evidence using a transparent, systematic review. © 2017 The Author(s) Published by S. Karger AG, Basel.

Gene-centric meta-analysis in 87,736 individuals of European ancestry identifies multiple blood-pressure-related loci.

PubMed

Tragante, Vinicius; Barnes, Michael R; Ganesh, Santhi K; Lanktree, Matthew B; Guo, Wei; Franceschini, Nora; Smith, Erin N; Johnson, Toby; Holmes, Michael V; Padmanabhan, Sandosh; Karczewski, Konrad J; Almoguera, Berta; Barnard, John; Baumert, Jens; Chang, Yen-Pei Christy; Elbers, Clara C; Farrall, Martin; Fischer, Mary E; Gaunt, Tom R; Gho, Johannes M I H; Gieger, Christian; Goel, Anuj; Gong, Yan; Isaacs, Aaron; Kleber, Marcus E; Mateo Leach, Irene; McDonough, Caitrin W; Meijs, Matthijs F L; Melander, Olle; Nelson, Christopher P; Nolte, Ilja M; Pankratz, Nathan; Price, Tom S; Shaffer, Jonathan; Shah, Sonia; Tomaszewski, Maciej; van der Most, Peter J; Van Iperen, Erik P A; Vonk, Judith M; Witkowska, Kate; Wong, Caroline O L; Zhang, Li; Beitelshees, Amber L; Berenson, Gerald S; Bhatt, Deepak L; Brown, Morris; Burt, Amber; Cooper-DeHoff, Rhonda M; Connell, John M; Cruickshanks, Karen J; Curtis, Sean P; Davey-Smith, George; Delles, Christian; Gansevoort, Ron T; Guo, Xiuqing; Haiqing, Shen; Hastie, Claire E; Hofker, Marten H; Hovingh, G Kees; Kim, Daniel S; Kirkland, Susan A; Klein, Barbara E; Klein, Ronald; Li, Yun R; Maiwald, Steffi; Newton-Cheh, Christopher; O'Brien, Eoin T; Onland-Moret, N Charlotte; Palmas, Walter; Parsa, Afshin; Penninx, Brenda W; Pettinger, Mary; Vasan, Ramachandran S; Ranchalis, Jane E; M Ridker, Paul; Rose, Lynda M; Sever, Peter; Shimbo, Daichi; Steele, Laura; Stolk, Ronald P; Thorand, Barbara; Trip, Mieke D; van Duijn, Cornelia M; Verschuren, W Monique; Wijmenga, Cisca; Wyatt, Sharon; Young, J Hunter; Zwinderman, Aeilko H; Bezzina, Connie R; Boerwinkle, Eric; Casas, Juan P; Caulfield, Mark J; Chakravarti, Aravinda; Chasman, Daniel I; Davidson, Karina W; Doevendans, Pieter A; Dominiczak, Anna F; FitzGerald, Garret A; Gums, John G; Fornage, Myriam; Hakonarson, Hakon; Halder, Indrani; Hillege, Hans L; Illig, Thomas; Jarvik, Gail P; Johnson, Julie A; Kastelein, John J P; Koenig, Wolfgang; Kumari, Meena; März, Winfried; Murray, Sarah S; O'Connell, Jeffery R; Oldehinkel, Albertine J; Pankow, James S; Rader, Daniel J; Redline, Susan; Reilly, Muredach P; Schadt, Eric E; Kottke-Marchant, Kandice; Snieder, Harold; Snyder, Michael; Stanton, Alice V; Tobin, Martin D; Uitterlinden, André G; van der Harst, Pim; van der Schouw, Yvonne T; Samani, Nilesh J; Watkins, Hugh; Johnson, Andrew D; Reiner, Alex P; Zhu, Xiaofeng; de Bakker, Paul I W; Levy, Daniel; Asselbergs, Folkert W; Munroe, Patricia B; Keating, Brendan J

2014-03-06

Blood pressure (BP) is a heritable risk factor for cardiovascular disease. To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP), we genotyped ~50,000 SNPs in up to 87,736 individuals of European ancestry and combined these in a meta-analysis. We replicated findings in an independent set of 68,368 individuals of European ancestry. Our analyses identified 11 previously undescribed associations in independent loci containing 31 genes including PDE1A, HLA-DQB1, CDK6, PRKAG2, VCL, H19, NUCB2, RELA, HOXC@ complex, FBN1, and NFAT5 at the Bonferroni-corrected array-wide significance threshold (p < 6 × 10(-7)) and confirmed 27 previously reported associations. Bioinformatic analysis of the 11 loci provided support for a putative role in hypertension of several genes, such as CDK6 and NUCB2. Analysis of potential pharmacological targets in databases of small molecules showed that ten of the genes are predicted to be a target for small molecules. In summary, we identified previously unknown loci associated with BP. Our findings extend our understanding of genes involved in BP regulation, which may provide new targets for therapeutic intervention or drug response stratification. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Risk factors for Clostridium difficile infections - an overview of the evidence base and challenges in data synthesis.

PubMed

Eze, Paul; Balsells, Evelyn; Kyaw, Moe H; Nair, Harish

2017-06-01

Recognition of a broad spectrum of disease and development of Clostridium difficile infection (CDI) and recurrent CDI (rCDI) in populations previously considered to be at low risk has renewed attention on differences in the risk profile of patients. In the absence of primary prevention for CDI and limited treatment options, it is important to achieve a deep understanding of the multiple factors that influence the risk of developing CDI and rCDI. We conducted a review of systematic reviews and meta-analyses on risk factors for CDI and rCDI published between 1990 and October 2016. 22 systematic reviews assessing risk factors for CDI (n = 19) and rCDI (n = 6) were included. Meta-analyses were conducted in 17 of the systematic reviews. Over 40 risk factors have been associated with CDI and rCDI and can be classified into three categories: pharmacological risk factors, host-related risk factors, and clinical characteristics or interventions. Most systematic reviews and meta-analyses have focused on antibiotic use (n = 8 for CDI, 3 for rCDI), proton pump inhibitors (n = 8 for CDI, 4 for rCDI), and histamine 2 receptor antagonists (n = 4 for CDI) and chronic kidney disease (n = 4 for rCDI). However, other risk factors have been assessed. We discuss the state of the evidence, methods, and challenges for data synthesis. Several studies, synthesized in different systematic review, provide valuable insights into the role of different risk factors for CDI. Meta-analytic evidence of association has been reported for factors such as antibiotics, gastric acid suppressants, non-selective NSAID, and some co-morbidities. However, despite statistical significance, issues of high heterogeneity, bias and confounding remain to be addressed effectively to improve overall risk estimates. Large, prospective primary studies on risk factors for CDI with standardised case definitions and stratified analyses are required to develop more accurate and robust estimates of risk effects that can inform targeted-CDI clinical management procedures, prevention, and research.

Cancer and central nervous system disorders: protocol for an umbrella review of systematic reviews and updated meta-analyses of observational studies.

PubMed

Catalá-López, Ferrán; Hutton, Brian; Driver, Jane A; Page, Matthew J; Ridao, Manuel; Valderas, José M; Alonso-Arroyo, Adolfo; Forés-Martos, Jaume; Martínez, Salvador; Gènova-Maleras, Ricard; Macías-Saint-Gerons, Diego; Crespo-Facorro, Benedicto; Vieta, Eduard; Valencia, Alfonso; Tabarés-Seisdedos, Rafael

2017-04-04

The objective of this study will be to synthesize the epidemiological evidence and evaluate the validity of the associations between central nervous system disorders and the risk of developing or dying from cancer. We will perform an umbrella review of systematic reviews and conduct updated meta-analyses of observational studies (cohort and case-control) investigating the association between central nervous system disorders and the risk of developing or dying from any cancer or specific types of cancer. Searches involving PubMed/MEDLINE, EMBASE, SCOPUS and Web of Science will be used to identify systematic reviews and meta-analyses of observational studies. In addition, online databases will be checked for observational studies published outside the time frames of previous reviews. Eligible central nervous system disorders will be Alzheimer's disease, anorexia nervosa, amyotrophic lateral sclerosis, autism spectrum disorders, bipolar disorder, depression, Down's syndrome, epilepsy, Huntington's disease, multiple sclerosis, Parkinson's disease and schizophrenia. The primary outcomes will be cancer incidence and cancer mortality in association with a central nervous system disorder. Secondary outcome measures will be site-specific cancer incidence and mortality, respectively. Two reviewers will independently screen references identified by the literature search, as well as potentially relevant full-text articles. Data will be abstracted, and study quality/risk of bias will be appraised by two reviewers independently. Conflicts at all levels of screening and abstraction will be resolved through discussion. Random-effects meta-analyses of primary observational studies will be conducted where appropriate. Parameters for exploring statistical heterogeneity are pre-specified. The World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) criteria and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach will be used for determining the quality of evidence for cancer outcomes. Our study will establish the extent of the epidemiological evidence underlying the associations between central nervous system disorders and cancer and will provide a rigorous and updated synthesis of a range of important site-specific cancer outcomes. PROSPERO CRD42016052762.

The role of social support on physical activity behaviour in adolescent girls: a systematic review and meta-analysis.

PubMed

Laird, Yvonne; Fawkner, Samantha; Kelly, Paul; McNamee, Lily; Niven, Ailsa

2016-07-07

Adolescent girls have been targeted as a priority group for promoting physical activity levels however it is unclear how this can be achieved. There is some evidence to suggest that social support could impact the physical activity levels of adolescent girls, although the relationship is complex and not well understood. We aimed to systematically review and meta-analyse the relationship between social support and physical activity in adolescent girls, exploring how different types and providers of social support might influence the relationship. Articles were identified through a systematic search of the literature using 14 electronic databases, personal resources, grey literature, and reference lists of included studies and previous reviews. Search terms representing social support, physical activity and adolescent girls were identified and used in various combinations to form a search strategy which was adapted for different databases. Cross-sectional or longitudinal articles published in English that reported an association between social support and physical activity in adolescent girls between the ages of 10 to 19 years were included. Studies that focused only on clinical or overweight populations were excluded. Data extraction was carried out by one reviewer using an electronic extraction form. A random 25 % of included articles were selected for data extraction by a second reviewer to check fidelity. Risk of bias was assessed using a custom tool informed by the Critical Appraisal Skills Programme Cohort Study Checklist in conjunction with data extraction. Cross-sectional results were meta-analysed and longitudinal results were presented narratively. Small but significant associations between all available providers of total social support (except teachers) and physical activity were found (r = .14-.24). Small but significant associations were also identified for emotional, instrumental and modelling support for some providers of support (r = .10-.21). Longitudinal research supported the cross-sectional analyses. Many of the meta-analysis results suggested high heterogeneity and there was some evidence of publication bias, therefore, the meta-analysis results should be interpreted with caution. In conclusion, the meta-analysis results suggest that social support is not a strong predictor of physical activity in adolescent girls though parents and friends may have a role in enhancing PA. PROSPERO 2014: CRD42014006738.

An umbrella review of garlic intake and risk of cardiovascular disease.

PubMed

Schwingshackl, Lukas; Missbach, Benjamin; Hoffmann, Georg

2016-10-15

To gain further insight into the strength of evidence and extent of possible biases in the scope of studies investigating the impact of garlic and garlic supplement intake on biomarkers of cardiovascular disease, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. Electronic database PubMed (between 1966 and June 2015) was searched for systematic reviews and meta-analyses using following search terms: ("garlic" OR "allium sativum" OR "allicin" OR "organosulfur") AND ("cardiovascular" OR "coronary" OR "cholesterol" OR "triglyceride" OR "atherosclerosis" OR "blood pressure" OR "hypertension" OR "blood glucose") AND ("systematic review" OR "meta-analysis"), with no restriction to calendar data and language. Hand-search of reference lists and relevant clinical guidelines was performed as well. Nine systematic reviews investigated the effects of garlic on lipid parameters and eight systematic reviews analyzed the effects on blood pressure parameters were identified. Eight of nine meta-analyses synthesizing the effect of garlic on blood lipids reported significantly decreased total cholesterol levels. Inconsistent results could be detected for HDL-cholestrol, LDL-cholesterol, and triacylglycerols. The effect of garlic on systolic blood pressure showed consistent results across publications with 7 out of 8 meta-analyses demonstrating a substantial decrease in systolic blood pressure. Similar results could be reported regarding the effect of garlic on diastolic blood pressure, i.e. 6 out of 8 meta-analyses detected significant reductions in diastolic blood pressure levels following interventions with garlic. According to the data summarized in the present umbrella review, garlic preparations as well as garlic exerted some positive effects on indicators and biomarkers of cardiovascular disease, typically without causing any serious side effects. However, with regard to the substantial heterogeneities between the different trials enrolled in the various meta-analyses of this review, a conservative interpretation of the outcome seems to be appropriate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are interventions for low-income groups effective in changing healthy eating, physical activity and smoking behaviours? A systematic review and meta-analysis.

PubMed

Bull, Eleanor R; Dombrowski, Stephan U; McCleary, Nicola; Johnston, Marie

2014-11-28

To conduct a systematic review and meta-analysis examining the effectiveness of behavioural interventions targeting diet, physical activity or smoking in low-income adults. Systematic review with random effects meta-analyses. Studies before 2006 were identified from a previously published systematic review (searching 1995-2006) with similar but broader inclusion criteria (including non-randomised controlled trials (RCTs)). Studies from 2006 to 2014 were identified from eight electronic databases using a similar search strategy. MEDLINE, EMBASE, PsycINFO, ASSIA, CINAHL, Cochrane Controlled Trials, Cochrane Systematic Review and DARE. RCTs and cluster RCTs published from 1995 to 2014; interventions targeting dietary, physical activity and smoking; low-income adults; reporting of behavioural outcomes. Dietary, physical activity and smoking cessation behaviours. 35 studies containing 45 interventions with 17,000 participants met inclusion criteria. At postintervention, effects were positive but small for diet (standardised mean difference (SMD) 0.22, 95% CI 0.14 to 0.29), physical activity (SMD 0.21, 95% CI 0.06 to 0.36) and smoking (relative risk (RR) of 1.59, 95% CI 1.34 to 1.89). Studies reporting follow-up results suggested that effects were maintained over time for diet (SMD 0.16, 95% CI 0.08 to 0.25) but not physical activity (SMD 0.17, 95% CI -0.02 to 0.37) or smoking (RR 1.11, 95% CI 0.93 to 1.34). Behaviour change interventions for low-income groups had small positive effects on healthy eating, physical activity and smoking. Further work is needed to improve the effectiveness of behaviour change interventions for deprived populations. 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.

Using beta coefficients to impute missing correlations in meta-analysis research: Reasons for caution.

PubMed

Roth, Philip L; Le, Huy; Oh, In-Sue; Van Iddekinge, Chad H; Bobko, Philip

2018-06-01

Meta-analysis has become a well-accepted method for synthesizing empirical research about a given phenomenon. Many meta-analyses focus on synthesizing correlations across primary studies, but some primary studies do not report correlations. Peterson and Brown (2005) suggested that researchers could use standardized regression weights (i.e., beta coefficients) to impute missing correlations. Indeed, their beta estimation procedures (BEPs) have been used in meta-analyses in a wide variety of fields. In this study, the authors evaluated the accuracy of BEPs in meta-analysis. We first examined how use of BEPs might affect results from a published meta-analysis. We then developed a series of Monte Carlo simulations that systematically compared the use of existing correlations (that were not missing) to data sets that incorporated BEPs (that impute missing correlations from corresponding beta coefficients). These simulations estimated ρ̄ (mean population correlation) and SDρ (true standard deviation) across a variety of meta-analytic conditions. Results from both the existing meta-analysis and the Monte Carlo simulations revealed that BEPs were associated with potentially large biases when estimating ρ̄ and even larger biases when estimating SDρ. Using only existing correlations often substantially outperformed use of BEPs and virtually never performed worse than BEPs. Overall, the authors urge a return to the standard practice of using only existing correlations in meta-analysis. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Reliability of Computerized Neurocognitive Tests for Concussion Assessment: A Meta-Analysis.

PubMed

Farnsworth, James L; Dargo, Lucas; Ragan, Brian G; Kang, Minsoo

2017-09-01

  Although widely used, computerized neurocognitive tests (CNTs) have been criticized because of low reliability and poor sensitivity. A systematic review was published summarizing the reliability of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores; however, this was limited to a single CNT. Expansion of the previous review to include additional CNTs and a meta-analysis is needed. Therefore, our purpose was to analyze reliability data for CNTs using meta-analysis and examine moderating factors that may influence reliability.   A systematic literature search (key terms: reliability, computerized neurocognitive test, concussion) of electronic databases (MEDLINE, PubMed, Google Scholar, and SPORTDiscus) was conducted to identify relevant studies.   Studies were included if they met all of the following criteria: used a test-retest design, involved at least 1 CNT, provided sufficient statistical data to allow for effect-size calculation, and were published in English.   Two independent reviewers investigated each article to assess inclusion criteria. Eighteen studies involving 2674 participants were retained. Intraclass correlation coefficients were extracted to calculate effect sizes and determine overall reliability. The Fisher Z transformation adjusted for sampling error associated with averaging correlations. Moderator analyses were conducted to evaluate the effects of the length of the test-retest interval, intraclass correlation coefficient model selection, participant demographics, and study design on reliability. Heterogeneity was evaluated using the Cochran Q statistic.   The proportion of acceptable outcomes was greatest for the Axon Sports CogState Test (75%) and lowest for the ImPACT (25%). Moderator analyses indicated that the type of intraclass correlation coefficient model used significantly influenced effect-size estimates, accounting for 17% of the variation in reliability.   The Axon Sports CogState Test, which has a higher proportion of acceptable outcomes and shorter test duration relative to other CNTs, may be a reliable option; however, future studies are needed to compare the diagnostic accuracy of these instruments.

Sequential change detection and monitoring of temporal trends in random-effects meta-analysis.

PubMed

Dogo, Samson Henry; Clark, Allan; Kulinskaya, Elena

2017-06-01

Temporal changes in magnitude of effect sizes reported in many areas of research are a threat to the credibility of the results and conclusions of meta-analysis. Numerous sequential methods for meta-analysis have been proposed to detect changes and monitor trends in effect sizes so that meta-analysis can be updated when necessary and interpreted based on the time it was conducted. The difficulties of sequential meta-analysis under the random-effects model are caused by dependencies in increments introduced by the estimation of the heterogeneity parameter τ 2 . In this paper, we propose the use of a retrospective cumulative sum (CUSUM)-type test with bootstrap critical values. This method allows retrospective analysis of the past trajectory of cumulative effects in random-effects meta-analysis and its visualization on a chart similar to CUSUM chart. Simulation results show that the new method demonstrates good control of Type I error regardless of the number or size of the studies and the amount of heterogeneity. Application of the new method is illustrated on two examples of medical meta-analyses. © 2016 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. © 2016 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd.

Workplace health promotion: a meta-analysis of effectiveness.

PubMed

Rongen, Anne; Robroek, Suzan J W; van Lenthe, Frank J; Burdorf, Alex

2013-04-01

An unhealthy lifestyle may contribute to ill health, absence due to sickness, productivity loss at work, and reduced ability to work. Workplace health promotion programs (WHPPs) aim to improve lifestyle and consequently improve health, work ability, and work productivity. However, systematic reviews on intervention studies have reported small effects, and the overall evaluation of effectiveness of WHPPs is hampered by a large heterogeneity in interventions and study populations. This systematic review aims to investigate the influence of population, study and intervention characteristics, and study quality on the effectiveness of workplace health promotion programs. A systematic literature search was conducted identifying RCTs, published before June 2012, evaluating the effect of a WHPP aimed at smoking cessation, physical activity, healthy nutrition, and/or obesity on self-perceived health, work absence due to sickness, work productivity, or work ability. Studies were included in the meta-analyses if quantitative information was present to calculate an effect size (ES). A meta-analysis, stratified meta-analyses, and meta-regression analyses were performed in Spring 2012 using Comprehensive Meta-analysis software 2.0 and PAWS 17.0.2. In 18 studies describing 21 interventions, the overall effect of a WHPP was small (ES=0.24, 95% CI=0.14, 0.34). The effectiveness of a WHPP was larger in younger populations, in interventions with weekly contacts, and in studies in which the control group received no health promotion. A 2.6-fold lower effectiveness was observed for studies performing an intention-to-treat analysis and a 1.7-fold lower effectiveness for studies controlling for confounders. Studies of poor methodologic quality reported a 2.9-fold higher effect size of the WHPP. The effectiveness of a WHPP is partly determined by intervention characteristics and statistical analysis. High-quality RCTs reported lower effect sizes. It is important to determine the effectiveness of WHPPs in RCTs of high quality. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Long-term influences of parental divorce on offspring affective disorders: A systematic review and meta-analysis.

PubMed

Sands, Amy; Thompson, Ellen J; Gaysina, Darya

2017-08-15

The prevalence of divorce in Western countries has increased in recent decades. However, there is no recent systematic review and/or meta-analysis of studies testing for long-term effects of parental divorce on offspring affective disorders. The present study conducted a systematic review and meta-analysis of studies published since 1980 testing for the association between parental divorce and offspring depression and anxiety in adulthood. PUBMED, Science Direct, Medline, PsychInfo, and PsychArticles databases were searched for eligible studies. Random-effect meta-analyses were used to synthesize effect sizes and to test whether associations of parental divorce with offspring affective disorders differed among three publication periods (i.e., before 1996, 1996-2005, 2006-2015). In total, 29 studies were eligible for the systematic review, and 18 studies were included in the meta-analyses (depression: n=21,581; anxiety: n=2472). There was significant association between parental divorce and offspring depression (OR=1.56; 95%CI [1.31, 1.86]), but not anxiety (OR=1.16; 95%CI [0.98, 1.38]). The effect of parental divorce on offspring depression was not weaker in the reports published in more recent decades. There is limited research in relation to offspring anxiety in adulthood. Parental divorce is associated with an increased risk of adult offspring depression, with no indication of the effect being weaker in recent publications. Copyright © 2017 Elsevier B.V. All rights reserved.

Maternal Active Smoking During Pregnancy and Low Birth Weight in the Americas: A Systematic Review and Meta-analysis.

PubMed

Pereira, Priscilla Perez da Silva; Da Mata, Fabiana A F; Figueiredo, Ana Claudia Godoy; de Andrade, Keitty Regina Cordeiro; Pereira, Maurício Gomes

2017-05-01

Smoking during pregnancy may negatively impact newborn birth weight. This study investigates the relationship between maternal active smoking during pregnancy and low birth weight in the Americas through systematic review and meta-analysis. A literature search was conducted through indexed databases and the grey literature. Case-control and cohort studies published between 1984 and 2016 conducted within the Americas were included without restriction regarding publication language. The article selection process and data extraction were performed by two independent investigators. A meta-analysis of random effects was conducted, and possible causes of between-study heterogeneity were evaluated by meta-regressions and subgroup analyses. Publication bias was assessed by visual inspection of Begg's funnel plot and by Egger's regression test. The literature search yielded 848 articles from which 34 studies were selected for systematic review and 30 for meta-analysis. Active maternal smoking was associated with low birth weight, OR = 2.00 (95% CI: 1.77-2.26; I2 = 66.3%). The funnel plot and Egger's test (p = .14) indicated no publication bias. Meta-regression revealed that sample size, study quality, and the number of confounders in the original studies did not account for the between-study heterogeneity. Subgroup analysis indicated no significant differences when studies were compared by design, sample size, and regions of the Americas. Low birth weight is associated with maternal active smoking during pregnancy regardless of the region in the Americas or the studies' methodological aspects. A previous search of the major electronic databases revealed that no studies appear to have been conducted to summarize the association between maternal active smoking during pregnancy and low birth weight within the Americas. Therefore, this systematic review may help to fill the information gap. The region of the Americas contains some of the most populous countries in the world; therefore, this study may provide useful data from this massive segment of the world's population. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Vitamin D and depression: a systematic review and meta-analysis comparing studies with and without biological flaws.

PubMed

Spedding, Simon

2014-04-11

Efficacy of Vitamin D supplements in depression is controversial, awaiting further literature analysis. Biological flaws in primary studies is a possible reason meta-analyses of Vitamin D have failed to demonstrate efficacy. This systematic review and meta-analysis of Vitamin D and depression compared studies with and without biological flaws. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was undertaken through four databases for randomized controlled trials (RCTs). Studies were critically appraised for methodological quality and biological flaws, in relation to the hypothesis and study design. Meta-analyses were performed for studies according to the presence of biological flaws. The 15 RCTs identified provide a more comprehensive evidence-base than previous systematic reviews; methodological quality of studies was generally good and methodology was diverse. A meta-analysis of all studies without flaws demonstrated a statistically significant improvement in depression with Vitamin D supplements (+0.78 CI +0.24, +1.27). Studies with biological flaws were mainly inconclusive, with the meta-analysis demonstrating a statistically significant worsening in depression by taking Vitamin D supplements (-1.1 CI -0.7, -1.5). Vitamin D supplementation (≥800 I.U. daily) was somewhat favorable in the management of depression in studies that demonstrate a change in vitamin levels, and the effect size was comparable to that of anti-depressant medication.

Meta-analytic estimates predict the effectiveness of emotion regulation strategies in the "real world": reply to Augustine and Hemenover (2013).

PubMed

Miles, Eleanor; Sheeran, Paschal; Webb, Thomas L

2013-05-01

Augustine and Hemenover (2013) were right to state that meta-analyses should be accurate and generalizable. However, we disagree that our meta-analysis of emotion regulation strategies (Webb, Miles, & Sheeran, 2012) fell short in these respects. Augustine and Hemenover's concerns appear to have accrued from misunderstandings of our inclusion criteria or from disagreements with methodological decisions that are crucial to the validity of meta-analysis. This response clarifies the bases of these decisions and discusses implications for the accuracy and validity of meta-analyses. Furthermore, we show that our findings are consistent with theoretical predictions and previous reviews, and we present new evidence that the effect sizes that we obtained are generalizable. In particular, we demonstrate that our estimates of the effectiveness of emotion regulation strategies reveal how well these strategies predict important emotional outcomes over 1 year. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Bias from historical control groups used in orthodontic research: a meta-epidemiological study.

PubMed

Papageorgiou, Spyridon N; Koretsi, Vasiliki; Jäger, Andreas

2017-02-01

The validity of meta-analysis is dependent upon the quality of included studies. Here, we investigated whether the design of untreated control groups (i.e. source and timing of data collection) influences the results of clinical trials in orthodontic research. This meta-epidemiological study used unrestricted literature searching for meta-analyses in orthodontics including clinical trials with untreated control groups. Differences in standardized mean differences (ΔSMD) and their 95% confidence intervals (CIs) were calculated according to the untreated control group through multivariable random-effects meta-regression controlling for nature of the interventional group and study sample size. Effects were pooled with random-effects synthesis, followed by mixed-effect subgroup and sensitivity analyses. Studies with historical control groups reported deflated treatment effects compared to studies with concurrent control groups (13 meta-analyses; ΔSMD = -0.31; 95% CI = -0.53, -0.10; P = 0.004). Significant differences were found according to the type of historical control group (based either on growth study or clinical archive; 11 meta-analyses; ΔSMD = 0.40; 95% CI = 0.21, 0.59; P < 0.001). The use of historical control groups in orthodontic clinical research was associated with deflation of treatment effects, which was independent from whether the interventional group was prospective or retrospective and from the study's sample size. Caution is warranted when interpreting clinical studies with historical untreated control groups or when interpreting systematic reviews that include such studies. PROSPERO (CRD42015024179). None. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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

PubMed

Petrou, Stavros; Kwon, Joseph; Madan, Jason

2018-05-10

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

Drivers of wetland conversion: a global meta-analysis.

PubMed

van Asselen, Sanneke; Verburg, Peter H; Vermaat, Jan E; Janse, Jan H

2013-01-01

Meta-analysis of case studies has become an important tool for synthesizing case study findings in land change. Meta-analyses of deforestation, urbanization, desertification and change in shifting cultivation systems have been published. This present study adds to this literature, with an analysis of the proximate causes and underlying forces of wetland conversion at a global scale using two complementary approaches of systematic review. Firstly, a meta-analysis of 105 case-study papers describing wetland conversion was performed, showing that different combinations of multiple-factor proximate causes, and underlying forces, drive wetland conversion. Agricultural development has been the main proximate cause of wetland conversion, and economic growth and population density are the most frequently identified underlying forces. Secondly, to add a more quantitative component to the study, a logistic meta-regression analysis was performed to estimate the likelihood of wetland conversion worldwide, using globally-consistent biophysical and socioeconomic location factor maps. Significant factors explaining wetland conversion, in order of importance, are market influence, total wetland area (lower conversion probability), mean annual temperature and cropland or built-up area. The regression analyses results support the outcomes of the meta-analysis of the processes of conversion mentioned in the individual case studies. In other meta-analyses of land change, similar factors (e.g., agricultural development, population growth, market/economic factors) are also identified as important causes of various types of land change (e.g., deforestation, desertification). Meta-analysis helps to identify commonalities across the various local case studies and identify which variables may lead to individual cases to behave differently. The meta-regression provides maps indicating the likelihood of wetland conversion worldwide based on the location factors that have determined historic conversions.

Drivers of Wetland Conversion: a Global Meta-Analysis

PubMed Central

van Asselen, Sanneke; Verburg, Peter H.; Vermaat, Jan E.; Janse, Jan H.

2013-01-01

Meta-analysis of case studies has become an important tool for synthesizing case study findings in land change. Meta-analyses of deforestation, urbanization, desertification and change in shifting cultivation systems have been published. This present study adds to this literature, with an analysis of the proximate causes and underlying forces of wetland conversion at a global scale using two complementary approaches of systematic review. Firstly, a meta-analysis of 105 case-study papers describing wetland conversion was performed, showing that different combinations of multiple-factor proximate causes, and underlying forces, drive wetland conversion. Agricultural development has been the main proximate cause of wetland conversion, and economic growth and population density are the most frequently identified underlying forces. Secondly, to add a more quantitative component to the study, a logistic meta-regression analysis was performed to estimate the likelihood of wetland conversion worldwide, using globally-consistent biophysical and socioeconomic location factor maps. Significant factors explaining wetland conversion, in order of importance, are market influence, total wetland area (lower conversion probability), mean annual temperature and cropland or built-up area. The regression analyses results support the outcomes of the meta-analysis of the processes of conversion mentioned in the individual case studies. In other meta-analyses of land change, similar factors (e.g., agricultural development, population growth, market/economic factors) are also identified as important causes of various types of land change (e.g., deforestation, desertification). Meta-analysis helps to identify commonalities across the various local case studies and identify which variables may lead to individual cases to behave differently. The meta-regression provides maps indicating the likelihood of wetland conversion worldwide based on the location factors that have determined historic conversions. PMID:24282580

The Influence of Study-Level Inference Models and Study Set Size on Coordinate-Based fMRI Meta-Analyses

PubMed Central

Bossier, Han; Seurinck, Ruth; Kühn, Simone; Banaschewski, Tobias; Barker, Gareth J.; Bokde, Arun L. W.; Martinot, Jean-Luc; Lemaitre, Herve; Paus, Tomáš; Millenet, Sabina; Moerkerke, Beatrijs

2018-01-01

Given the increasing amount of neuroimaging studies, there is a growing need to summarize published results. Coordinate-based meta-analyses use the locations of statistically significant local maxima with possibly the associated effect sizes to aggregate studies. In this paper, we investigate the influence of key characteristics of a coordinate-based meta-analysis on (1) the balance between false and true positives and (2) the activation reliability of the outcome from a coordinate-based meta-analysis. More particularly, we consider the influence of the chosen group level model at the study level [fixed effects, ordinary least squares (OLS), or mixed effects models], the type of coordinate-based meta-analysis [Activation Likelihood Estimation (ALE) that only uses peak locations, fixed effects, and random effects meta-analysis that take into account both peak location and height] and the amount of studies included in the analysis (from 10 to 35). To do this, we apply a resampling scheme on a large dataset (N = 1,400) to create a test condition and compare this with an independent evaluation condition. The test condition corresponds to subsampling participants into studies and combine these using meta-analyses. The evaluation condition corresponds to a high-powered group analysis. We observe the best performance when using mixed effects models in individual studies combined with a random effects meta-analysis. Moreover the performance increases with the number of studies included in the meta-analysis. When peak height is not taken into consideration, we show that the popular ALE procedure is a good alternative in terms of the balance between type I and II errors. However, it requires more studies compared to other procedures in terms of activation reliability. Finally, we discuss the differences, interpretations, and limitations of our results. PMID:29403344

Toward systems neuroscience in mild cognitive impairment and Alzheimer's disease: a meta-analysis of 75 fMRI studies.

PubMed

Li, Hui-Jie; Hou, Xiao-Hui; Liu, Han-Hui; Yue, Chun-Lin; He, Yong; Zuo, Xi-Nian

2015-03-01

Most of the previous task functional magnetic resonance imaging (fMRI) studies found abnormalities in distributed brain regions in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and few studies investigated the brain network dysfunction from the system level. In this meta-analysis, we aimed to examine brain network dysfunction in MCI and AD. We systematically searched task-based fMRI studies in MCI and AD published between January 1990 and January 2014. Activation likelihood estimation meta-analyses were conducted to compare the significant group differences in brain activation, the significant voxels were overlaid onto seven referenced neuronal cortical networks derived from the resting-state fMRI data of 1,000 healthy participants. Thirty-nine task-based fMRI studies (697 MCI patients and 628 healthy controls) were included in MCI-related meta-analysis while 36 task-based fMRI studies (421 AD patients and 512 healthy controls) were included in AD-related meta-analysis. The meta-analytic results revealed that MCI and AD showed abnormal regional brain activation as well as large-scale brain networks. MCI patients showed hypoactivation in default, frontoparietal, and visual networks relative to healthy controls, whereas AD-related hypoactivation mainly located in visual, default, and ventral attention networks relative to healthy controls. Both MCI-related and AD-related hyperactivation fell in frontoparietal, ventral attention, default, and somatomotor networks relative to healthy controls. MCI and AD presented different pathological while shared similar compensatory large-scale networks in fulfilling the cognitive tasks. These system-level findings are helpful to link the fundamental declines of cognitive tasks to brain networks in MCI and AD. © 2014 Wiley Periodicals, Inc.

The Effects of Music on Pain: A Meta-Analysis.

PubMed

Lee, Jin Hyung

2016-01-01

Numerous meta-analyses have been conducted on the topic of music and pain, with the latest comprehensive study published in 2006. Since that time, more than 70 randomized controlled trials (RCTs) have been published, necessitating a new and comprehensive review. The aim of this meta-analysis was to examine published RCT studies investigating the effect of music on pain. The present study included RCTs published between 1995 and 2014. Studies were obtained by searching 12 databases and hand-searching related journals and reference lists. Main outcomes were pain intensity, emotional distress from pain, vital signs, and amount of analgesic intake. Study quality was evaluated according to the Cochrane Collaboration guidelines. Analysis of the 97 included studies revealed that music interventions had statistically significant effects in decreasing pain on 0-10 pain scales (MD = -1.13), other pain scales (SMD = -0.39), emotional distress from pain (MD = -10.83), anesthetic use (SMD = -0.56), opioid intake (SMD = -0.24), non-opioid intake (SMD = -0.54), heart rate (MD = -4.25), systolic blood pressure (MD = -3.34), diastolic blood pressure (MD = -1.18), and respiration rate (MD = -1.46). Subgroup and moderator analyses yielded additional clinically informative outcomes. Considering all the possible benefits, music interventions may provide an effective complementary approach for the relief of acute, procedural, and cancer/chronic pain in the medical setting. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Epidemiology, quality and reporting characteristics of meta-analyses of observational studies published in Chinese journals.

PubMed

Zhang, Zhe-wen; Cheng, Juan; Liu, Zhuan; Ma, Ji-chun; Li, Jin-long; Wang, Jing; Yang, Ke-hu

2015-12-07

The aim of this study was to examine the epidemiological and reporting characteristics as well as the methodological quality of meta-analyses (MAs) of observational studies published in Chinese journals. 5 Chinese databases were searched for MAs of observational studies published from January 1978 to May 2014. Data were extracted into Excel spreadsheets, and Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Assessment of Multiple Systematic Reviews (AMSTAR) checklists were used to assess reporting characteristics and methodological quality, respectively. A total of 607 MAs were included. Only 52.2% of the MAs assessed the quality of the included primary studies, and the retrieval information was not comprehensive in more than half (85.8%) of the MAs. In addition, 50 (8.2%) MAs did not search any Chinese databases, while 126 (20.8%) studies did not search any English databases. Approximately 41.2% of the MAs did not describe the statistical methods in sufficient details, and most (95.5%) MAs did not report on conflicts of interest. However, compared with the before publication of the MOOSE Checklist, the quality of reporting improved significantly for 20 subitems after publication of the MOOSE Checklist, and 7 items of the included MAs demonstrated significant improvement after publication of the AMSTAR Checklist (p<0.05). Although many MAs of observational studies have been published in Chinese journals, the reporting quality is questionable. Thus, there is an urgent need to increase the use of reporting guidelines and methodological tools in China; we recommend that Chinese journals adopt the MOOSE and AMSTAR criteria. 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/

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

PubMed Central

Gudlaugsdottir, Katrin; Andrews, James

2017-01-01

Objective Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality. Background Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated. Methods Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality. Results 112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression. Conclusions There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians. PMID:28384296

Meta-Analyses of Predictors of Hope in Adolescents.

PubMed

Yarcheski, Adela; Mahon, Noreen E

2016-03-01

The purposes of this study were to identify predictors of hope in the literature reviewed, to use meta-analysis to determine the mean effect size (ES) across studies between each predictor and hope, and to examine four moderators on each predictor-hope relationship. Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for the literature reviewed, 77 published studies or doctoral dissertations completed between 1990 and 2012 met the inclusion criteria. Eleven predictors of hope were identified and each predictor in relation to hope was subjected to meta-analysis. Five predictors (positive affect, life satisfaction, optimism, self-esteem, and social support) of hope had large mean ESs, 1 predictor (depression) had a medium ES, 4 predictors (negative affect, stress, academic achievement, and violence) had small ESs, and 1 predictor (gender) had a trivial ES. Findings are interpreted for the 11 predictors in relation to hope. Limitations and conclusions are addressed; future studies are recommended. © The Author(s) 2014.

Self-esteem of children and adolescents with chronic illness: a meta-analysis.

PubMed

Pinquart, M

2013-03-01

Chronic illness may be a risk factor for low self-esteem; however, previous meta-analyses are inconclusive whether children with a chronic illness have lower self-esteem than their healthy peers. The goal of the present study was to summarize available research in order to compare the self-esteem of children and adolescents with a chronic illness with that of healthy children. Random-effects meta-analysis was used to integrate the results of 621 empirical studies that compare levels of self-esteem of children with a chronic physical illness with healthy peers or general test norms. Studies were identified via the electronic databases Adolesc, Embase, Google Scholar, MEDLINE, PSNYDEX, PSYCINFO, and cross-referencing. Children with chronic illnesses have lower self-esteem than healthy peers or test norms (g = -0.18 standard deviation units). The lowest levels of self-esteem were observed in children with chronic fatigue syndrome and chronic headaches. Lower levels of self-esteem in children with a chronic illness were found in girls than in boys, in adolescents than in children, in children from developing or threshold countries, when results were collected from observer ratings rather than child reports, in studies published in the 1990s, and when children with chronic illnesses were directly compared with healthy children instead of test norms. Paediatricians, parents, and teachers should promote experiences of success and positive peer-relations, which are important sources of self-esteem. In addition, psychosocial interventions for children with chronic illnesses should be offered for children with reduced self-esteem. © 2012 Blackwell Publishing Ltd.

Is there any association between Sarcoidosis and infectious agents?: a systematic review and meta-analysis.

PubMed

Esteves, Tiago; Aparicio, Gloria; Garcia-Patos, Vicente

2016-11-28

During the last few years, investigators have debated the role that infectious agents may have in sarcoidosis pathogenesis. With the emergence of new molecular biology techniques, several studies have been conducted; therefore, we performed a meta-analysis in order to better explain this possible association. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from the Cochrane collaboration guidelines. Four different databases (Medline, Scopus, Web of Science, and Cochrane Collaboration) were searched for all original articles published from 1980 to 2015. The present meta-analysis included case-control studies that reported the presence of microorganisms in samples of patients with sarcoidosis using culture methods or molecular biology techniques. We used a random effects or a fixed-effect model to calculate the odds ratio (OR) and 95% confidence intervals (CI). Sensitivity and subgroup analyses were performed in order to explore the heterogeneity among studies. Fifty-eight studies qualified for the purpose of this analysis. The present meta-analysis, the first, to our knowledge, in evaluation of all infectious agents proposed to be associated with sarcoidosis and involving more than 6000 patients in several countries, suggests an etiological link between Propionibacterium acnes and sarcoidosis, with an OR of 18.80 (95% CI 12.62, 28.01). We also found a significant association between sarcoidosis and mycobacteria, with an OR of 6.8 (95% CI 3.73, 12.39). Borrelia (OR 4.82; 95% CI 0.98, 23.81), HHV-8 (OR 1.47; 95% CI 0.02, 110.06) as well as Rickettsia helvetica, Chlamydia pneumoniae, Epstein-barr virus and Retrovirus, although suggested by previous investigations, were not associated with sarcoidosis. This meta-analysis suggests that some infectious agents can be associated with sarcoidosis. What seems clear is that more than one infectious agent might be implicated in the pathogenesis of sarcoidosis; probably the patient's geographical location might dictate which microorganisms are more involved. Future investigations and more clinical trials are need to bring these evidences to a more global level.

Missing binary data extraction challenges from Cochrane reviews in mental health and Campbell reviews with implications for empirical research.

PubMed

Spineli, Loukia M

2017-12-01

Tο report challenges encountered during the extraction process from Cochrane reviews in mental health and Campbell reviews and to indicate their implications on the empirical performance of different methods to handle missingness. We used a collection of meta-analyses on binary outcomes collated from a previous work on missing outcome data. To evaluate the accuracy of their extraction, we developed specific criteria pertaining to the reporting of missing outcome data in systematic reviews. Using the most popular methods to handle missing binary outcome data, we investigated the implications of the accuracy of the extracted meta-analysis on the random-effects meta-analysis results. Of 113 meta-analyses from Cochrane reviews, 60 (53%) were judged as "unclearly" extracted (ie, no information on the outcome of completers but available information on how missing participants were handled) and 42 (37%) as "unacceptably" extracted (ie, no information on the outcome of completers as well as no information on how missing participants were handled). For the remaining meta-analyses, it was judged that data were "acceptably" extracted (ie, information on the completers' outcome was provided for all trials). Overall, "unclear" extraction overestimated the magnitude of the summary odds ratio and the between-study variance and additionally inflated the uncertainty of both meta-analytical parameters. The only eligible Campbell review was judged as "unclear." Depending on the extent of missingness, the reporting quality of the systematic reviews can greatly affect the accuracy of the extracted meta-analyses and by extent, the empirical performance of different methods to handle missingness. Copyright © 2017 John Wiley & Sons, Ltd.

What We Have Learned from the Recent Meta-analyses on Diagnostic Methods for Atherosclerotic Plaque Regression.

PubMed

Biondi-Zoccai, Giuseppe; Mastrangeli, Simona; Romagnoli, Enrico; Peruzzi, Mariangela; Frati, Giacomo; Roever, Leonardo; Giordano, Arturo

2018-01-17

Atherosclerosis has major morbidity and mortality implications globally. While it has often been considered an irreversible degenerative process, recent evidence provides compelling proof that atherosclerosis can be reversed. Plaque regression is however difficult to appraise and quantify, with competing diagnostic methods available. Given the potential of evidence synthesis to provide clinical guidance, we aimed to review recent meta-analyses on diagnostic methods for atherosclerotic plaque regression. We identified 8 meta-analyses published between 2015 and 2017, including 79 studies and 14,442 patients, followed for a median of 12 months. They reported on atherosclerotic plaque regression appraised with carotid duplex ultrasound, coronary computed tomography, carotid magnetic resonance, coronary intravascular ultrasound, and coronary optical coherence tomography. Overall, all meta-analyses showed significant atherosclerotic plaque regression with lipid-lowering therapy, with the most notable effects on echogenicity, lipid-rich necrotic core volume, wall/plaque volume, dense calcium volume, and fibrous cap thickness. Significant interactions were found with concomitant changes in low density lipoprotein cholesterol, high density lipoprotein cholesterol, and C-reactive protein levels, and with ethnicity. Atherosclerotic plaque regression and conversion to a stable phenotype is possible with intensive medical therapy and can be demonstrated in patients using a variety of non-invasive and invasive imaging modalities.

Genome-wide association study for longevity with whole-genome sequencing in 3 cattle breeds.

PubMed

Zhang, Qianqian; Guldbrandtsen, Bernt; Thomasen, Jørn Rind; Lund, Mogens Sandø; Sahana, Goutam

2016-09-01

Longevity is an important economic trait in dairy production. Improvements in longevity could increase the average number of lactations per cow, thereby affecting the profitability of the dairy cattle industry. Improved longevity for cows reduces the replacement cost of stock and enables animals to achieve the highest production period. Moreover, longevity is an indirect indicator of animal welfare. Using whole-genome sequencing variants in 3 dairy cattle breeds, we carried out an association study and identified 7 genomic regions in Holstein and 5 regions in Red Dairy Cattle that were associated with longevity. Meta-analyses of 3 breeds revealed 2 significant genomic regions, located on chromosomes 6 (META-CHR6-88MB) and 18 (META-CHR18-58MB). META-CHR6-88MB overlaps with 2 known genes: neuropeptide G-protein coupled receptor (NPFFR2; 89,052,210-89,059,348 bp) and vitamin D-binding protein precursor (GC; 88,695,940-88,739,180 bp). The NPFFR2 gene was previously identified as a candidate gene for mastitis resistance. META-CHR18-58MB overlaps with zinc finger protein 717 (ZNF717; 58,130,465-58,141,877 bp) and zinc finger protein 613 (ZNF613; 58,115,782-58,117,110 bp), which have been associated with calving difficulties. Information on longevity-associated genomic regions could be used to find causal genes/variants influencing longevity and exploited to improve the reliability of genomic prediction. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Meat consumption and cancer risk: a critical review of published meta-analyses.

PubMed

Lippi, Giuseppe; Mattiuzzi, Camilla; Cervellin, Gianfranco

2016-01-01

Dietary habits play a substantial role for increasing or reducing cancer risk. We performed a critical review of scientific literature, to describe the findings of meta-analyses that explored the association between meat consumption and cancer risk. Overall, 42 eligible meta-analyses were included in this review, in which meat consumption was assumed from sheer statistics. Convincing association was found between larger intake of red meat and cancer, especially with colorectal, lung, esophageal and gastric malignancies. Increased consumption of processed meat was also found to be associated with colorectal, esophageal, gastric and bladder cancers. Enhanced intake of white meat or poultry was found to be negatively associated with some types of cancers. Larger beef consumption was significantly associated with cancer, whereas the risk was not increased consuming high amounts of pork. Our analysis suggest increased risk of cancer in subjects consuming large amounts of red and processed meat, but not in those with high intake of white meat or poultry. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Age differences in the effect of framing on risky choice: A meta-analysis

PubMed Central

Best, Ryan; Charness, Neil

2015-01-01

The framing of decision scenarios in terms of potential gains versus losses has been shown to influence choice preferences between sure and risky options. Normative cognitive changes associated with aging have been known to affect decision-making, which has led to a number of studies investigating the influence of aging on the effect of framing. Mata, Josef, Samanez-Larkin, and Hertwig (2011) systematically reviewed the available literature using a meta-analytic approach, but did not include tests of homogeneity nor subsequent moderator variable analyses. The current review serves to extend the previous analysis to include such tests as well as update the pool of studies available for analysis. Results for both positively and negatively framed conditions were reviewed using two meta-analyses encompassing data collected from 3,232 subjects across 18 studies. Deviating from the previous results, the current analysis finds a tendency for younger adults to choose the risky option more often than older adults for positively framed items. Moderator variable analyses find this effect to likely be driven by the specific decision scenario, showing a significant effect with younger adults choosing the risky option more often in small-amount financial and large-amount mortality-based scenarios. For negatively framed items, the current review found no overall age difference in risky decision making, confirming the results from the prior meta-analysis. Moderator variable analyses conducted to address heterogeneity found younger adults to be more likely than older adults to choose the risky option for negatively framed high-amount mortality-based decision scenarios. Practical implications for older adults are discussed. PMID:26098168

Age differences in the effect of framing on risky choice: A meta-analysis.

PubMed

Best, Ryan; Charness, Neil

2015-09-01

The framing of decision scenarios in terms of potential gains versus losses has been shown to influence choice preferences between sure and risky options. Normative cognitive changes associated with aging have been known to affect decision making, which has led to a number of studies investigating the influence of aging on the effect of framing. Mata, Josef, Samanez-Larkin, and Hertwig (2011) systematically reviewed the available literature using a meta-analytic approach, but did not include tests of homogeneity or subsequent moderator variable analyses. The current review serves to extend the previous analysis to include such tests as well as update the pool of studies available for analysis. Results for both positively and negatively framed conditions were reviewed using 2 meta-analyses encompassing data collected from 3,232 subjects across 18 studies. Deviating from the previous results, the current analysis found a tendency for younger adults to choose the risky option more often than older adults for positively framed items. Moderator variable analyses found this effect likely to be driven by the specific decision scenario, showing a significant effect, with younger adults choosing the risky option more often in small-amount financial and large-amount mortality-based scenarios. For negatively framed items, the current review found no overall age difference in risky decision making, confirming the results from the prior meta-analysis. Moderator variable analyses conducted to address heterogeneity found younger adults to be more likely than older adults to choose the risky option for negatively framed high-amount mortality-based decision scenarios. Practical implications for older adults are discussed. (c) 2015 APA, all rights reserved).

Soy Consumption and the Risk of Prostate Cancer: An Updated Systematic Review and Meta-Analysis

PubMed Central

Ranard, Katherine M.; Jeon, Sookyoung; Erdman, John W.

2018-01-01

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men, accounting for 15% of all cancers in men worldwide. Asian populations consume soy foods as part of a regular diet, which may contribute to the lower PCa incidence observed in these countries. This meta-analysis provides a comprehensive updated analysis that builds on previously published meta-analyses, demonstrating that soy foods and their isoflavones (genistein and daidzein) are associated with a lower risk of prostate carcinogenesis. Thirty articles were included for analysis of the potential impacts of soy food intake, isoflavone intake, and circulating isoflavone levels, on both primary and advanced PCa. Total soy food (p < 0.001), genistein (p = 0.008), daidzein (p = 0.018), and unfermented soy food (p < 0.001) intakes were significantly associated with a reduced risk of PCa. Fermented soy food intake, total isoflavone intake, and circulating isoflavones were not associated with PCa risk. Neither soy food intake nor circulating isoflavones were associated with advanced PCa risk, although very few studies currently exist to examine potential associations. Combined, this evidence from observational studies shows a statistically significant association between soy consumption and decreased PCa risk. Further studies are required to support soy consumption as a prophylactic dietary approach to reduce PCa carcinogenesis. PMID:29300347

Follow up of a robust meta-signature to identify Zika virus infection in Aedes aegypti: another brick in the wall.

PubMed

Fukutani, Eduardo; Rodrigues, Moreno; Kasprzykowski, José Irahe; Araujo, Cintia Figueiredo de; Paschoal, Alexandre Rossi; Ramos, Pablo Ivan Pereira; Fukutani, Kiyoshi Ferreira; Queiroz, Artur Trancoso Lopo de

2018-01-01

The mosquito Aedes aegypti is the main vector of several arthropod-borne diseases that have global impacts. In a previous meta-analysis, our group identified a vector gene set containing 110 genes strongly associated with infections of dengue, West Nile and yellow fever viruses. Of these 110 genes, four genes allowed a highly accurate classification of infected status. More recently, a new study of Ae. aegypti infected with Zika virus (ZIKV) was published, providing new data to investigate whether this "infection" gene set is also altered during a ZIKV infection. Our hypothesis is that the infection-associated signature may also serve as a proxy to classify the ZIKV infection in the vector. Raw data associated with the NCBI/BioProject were downloaded and re-analysed. A total of 18 paired-end replicates corresponding to three ZIKV-infected samples and three controls were included in this study. The nMDS technique with a logistic regression was used to obtain the probabilities of belonging to a given class. Thus, to compare both gene sets, we used the area under the curve and performed a comparison using the bootstrap method. Our meta-signature was able to separate the infected mosquitoes from the controls with good predictive power to classify the Zika-infected mosquitoes.

2,4-Dichlorophenoxyacetic acid and non-Hodgkin's lymphoma, gastric cancer, and prostate cancer: meta-analyses of the published literature.

PubMed

Goodman, Julie E; Loftus, Christine T; Zu, Ke

2015-08-01

Despite evidence from experimental studies indicating that the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), is not carcinogenic, several epidemiology studies have evaluated links between 2,4-D and cancer. Some suggest that 2,4-D is associated with non-Hodgkin's lymphoma (NHL), gastric cancer, and prostate cancer, but results have been inconsistent. We conducted meta-analyses to evaluate the weight of epidemiology evidence for these cancers. We identified articles from PubMed, Scopus, and TOXLINE databases and reference lists of review articles. We evaluated study quality and calculated summary risk estimates using random effects models. We conducted subgroup and sensitivity analyses when possible. We identified nine NHL, three gastric cancer, and two prostate cancer studies for inclusion in our meta-analyses. We found that 2,4-D was not associated with NHL (relative risk [RR] = 0.97, 95% confidence interval [CI] = 0.77-1.22, I(2) = 28.8%, Pheterogeneity = .19), and this result was generally robust to subgroup and sensitivity analyses. 2,4-D was not associated with gastric (RR = 1.14, 95% CI = 0.62-2.10, I(2) = 54.9%, Pheterogeneity = .11) or prostate cancer (RR = 1.32, 95% CI = 0.37-4.69, I(2) 87.0%, Pheterogeneity = .01). The epidemiology evidence does not support an association between 2,4-D and NHL, gastric cancer, or prostate cancer risk. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

An investigation of the impact of using different methods for network meta-analysis: a protocol for an empirical evaluation.

PubMed

Karahalios, Amalia Emily; Salanti, Georgia; Turner, Simon L; Herbison, G Peter; White, Ian R; Veroniki, Areti Angeliki; Nikolakopoulou, Adriani; Mckenzie, Joanne E

2017-06-24

Network meta-analysis, a method to synthesise evidence from multiple treatments, has increased in popularity in the past decade. Two broad approaches are available to synthesise data across networks, namely, arm- and contrast-synthesis models, with a range of models that can be fitted within each. There has been recent debate about the validity of the arm-synthesis models, but to date, there has been limited empirical evaluation comparing results using the methods applied to a large number of networks. We aim to address this gap through the re-analysis of a large cohort of published networks of interventions using a range of network meta-analysis methods. We will include a subset of networks from a database of network meta-analyses of randomised trials that have been identified and curated from the published literature. The subset of networks will include those where the primary outcome is binary, the number of events and participants are reported for each direct comparison, and there is no evidence of inconsistency in the network. We will re-analyse the networks using three contrast-synthesis methods and two arm-synthesis methods. We will compare the estimated treatment effects, their standard errors, treatment hierarchy based on the surface under the cumulative ranking (SUCRA) curve, the SUCRA value, and the between-trial heterogeneity variance across the network meta-analysis methods. We will investigate whether differences in the results are affected by network characteristics and baseline risk. The results of this study will inform whether, in practice, the choice of network meta-analysis method matters, and if it does, in what situations differences in the results between methods might arise. The results from this research might also inform future simulation studies.

Cognitive remediation in schizophrenia: A methodological appraisal of systematic reviews and meta-analyses.

PubMed

Bryce, Shayden; Sloan, Elise; Lee, Stuart; Ponsford, Jennie; Rossell, Susan

2016-04-01

Systematic reviews and meta-analyses are a primary source of evidence when evaluating the benefit(s) of cognitive remediation (CR) in schizophrenia. These studies are designed to rigorously synthesize scientific literature; however, cannot be assumed to be of high methodological quality. The aims of this report were to: 1) review the use of systematic reviews and meta-analyses regarding CR in schizophrenia; 2) conduct a systematic methodological appraisal of published reports examining the benefits of this intervention on core outcome domains; and 3) compare the correspondence between methodological and reporting quality. Electronic databases were searched for relevant articles. Twenty-one reviews met inclusion criteria and were scored according to the AMSTAR checklist-a validated scale of methodological quality. Five meta-analyses were also scored according to PRISMA statement to compare 'quality of conduct' with 'quality of reporting'. Most systematic reviews and meta-analyses shared strengths and fell within a 'medium' level of methodological quality. Nevertheless, there were consistent areas of potential weakness that were not addressed by most reviews. These included the lack of protocol registration, uncertainty regarding independent data extraction and consensus procedures, and the minimal assessment of publication bias. Moreover, quality of conduct may not necessarily parallel quality of reporting, suggesting that consideration of these methods independently may be important. Reviews concerning CR for schizophrenia are a valuable source of evidence. However, the methodological quality of these reports may require additional consideration. Enhancing quality of conduct is essential for enabling research literature to be interpreted with confidence. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions.

PubMed

Page, Matthew J; McKenzie, Joanne E; Kirkham, Jamie; Dwan, Kerry; Kramer, Sharon; Green, Sally; Forbes, Andrew

2014-10-01

Systematic reviews may be compromised by selective inclusion and reporting of outcomes and analyses. Selective inclusion occurs when there are multiple effect estimates in a trial report that could be included in a particular meta-analysis (e.g. from multiple measurement scales and time points) and the choice of effect estimate to include in the meta-analysis is based on the results (e.g. statistical significance, magnitude or direction of effect). Selective reporting occurs when the reporting of a subset of outcomes and analyses in the systematic review is based on the results (e.g. a protocol-defined outcome is omitted from the published systematic review). To summarise the characteristics and synthesise the results of empirical studies that have investigated the prevalence of selective inclusion or reporting in systematic reviews of randomised controlled trials (RCTs), investigated the factors (e.g. statistical significance or direction of effect) associated with the prevalence and quantified the bias. We searched the Cochrane Methodology Register (to July 2012), Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO and ISI Web of Science (each up to May 2013), and the US Agency for Healthcare Research and Quality (AHRQ) Effective Healthcare Program's Scientific Resource Center (SRC) Methods Library (to June 2013). We also searched the abstract books of the 2011 and 2012 Cochrane Colloquia and the article alerts for methodological work in research synthesis published from 2009 to 2011 and compiled in Research Synthesis Methods. We included both published and unpublished empirical studies that investigated the prevalence and factors associated with selective inclusion or reporting, or both, in systematic reviews of RCTs of healthcare interventions. We included empirical studies assessing any type of selective inclusion or reporting, such as investigations of how frequently RCT outcome data is selectively included in systematic reviews based on the results, outcomes and analyses are discrepant between protocol and published review or non-significant outcomes are partially reported in the full text or summary within systematic reviews. Two review authors independently selected empirical studies for inclusion, extracted the data and performed a risk of bias assessment. A third review author resolved any disagreements about inclusion or exclusion of empirical studies, data extraction and risk of bias. We contacted authors of included studies for additional unpublished data. Primary outcomes included overall prevalence of selective inclusion or reporting, association between selective inclusion or reporting and the statistical significance of the effect estimate, and association between selective inclusion or reporting and the direction of the effect estimate. We combined prevalence estimates and risk ratios (RRs) using a random-effects meta-analysis model. Seven studies met the inclusion criteria. No studies had investigated selective inclusion of results in systematic reviews, or discrepancies in outcomes and analyses between systematic review registry entries and published systematic reviews. Based on a meta-analysis of four studies (including 485 Cochrane Reviews), 38% (95% confidence interval (CI) 23% to 54%) of systematic reviews added, omitted, upgraded or downgraded at least one outcome between the protocol and published systematic review. The association between statistical significance and discrepant outcome reporting between protocol and published systematic review was uncertain. The meta-analytic estimate suggested an increased risk of adding or upgrading (i.e. changing a secondary outcome to primary) when the outcome was statistically significant, although the 95% CI included no association and a decreased risk as plausible estimates (RR 1.43, 95% CI 0.71 to 2.85; two studies, n = 552 meta-analyses). Also, the meta-analytic estimate suggested an increased risk of downgrading (i.e. changing a primary outcome to secondary) when the outcome was statistically significant, although the 95% CI included no association and a decreased risk as plausible estimates (RR 1.26, 95% CI 0.60 to 2.62; two studies, n = 484 meta-analyses). None of the included studies had investigated whether the association between statistical significance and adding, upgrading or downgrading of outcomes was modified by the type of comparison, direction of effect or type of outcome; or whether there is an association between direction of the effect estimate and discrepant outcome reporting.Several secondary outcomes were reported in the included studies. Two studies found that reasons for discrepant outcome reporting were infrequently reported in published systematic reviews (6% in one study and 22% in the other). One study (including 62 Cochrane Reviews) found that 32% (95% CI 21% to 45%) of systematic reviews did not report all primary outcomes in the abstract. Another study (including 64 Cochrane and 118 non-Cochrane reviews) found that statistically significant primary outcomes were more likely to be completely reported in the systematic review abstract than non-significant primary outcomes (RR 2.66, 95% CI 1.81 to 3.90). None of the studies included systematic reviews published after 2009 when reporting standards for systematic reviews (Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Statement, and Methodological Expectations of Cochrane Intervention Reviews (MECIR)) were disseminated, so the results might not be generalisable to more recent systematic reviews. Discrepant outcome reporting between the protocol and published systematic review is fairly common, although the association between statistical significance and discrepant outcome reporting is uncertain. Complete reporting of outcomes in systematic review abstracts is associated with statistical significance of the results for those outcomes. Systematic review outcomes and analysis plans should be specified prior to seeing the results of included studies to minimise post-hoc decisions that may be based on the observed results. Modifications that occur once the review has commenced, along with their justification, should be clearly reported. Effect estimates and CIs should be reported for all systematic review outcomes regardless of the results. The lack of research on selective inclusion of results in systematic reviews needs to be addressed and studies that avoid the methodological weaknesses of existing research are also needed.

Conflict of interest reporting in dentistry meta-analyses: A systematic review

PubMed Central

Beyari, Mohammed M.; Strain, Dan; Lamfon, Hanadi A.

2014-01-01

Objectives: The issue of reporting conflicts of interest (COI) in medical research has come under scrutiny over the past decade. Absolute transparency is important when dealing with conflicts of interest to provide readers with all essential information required to make an informative decision of the results. The key objective of this study was to examine the prevalence of reporting conflicts of interest in therapeutic dental meta-analyses of Randomized Control Trials (RCTs), and to investigate possible associations with other categorical variables. Study Design: We conducted an extensive literature search across multiple databases to search for relevant review articles for this study. We utilized pre-determined key words, and relied on three reviewers to test and review the use of a data extraction form that was used for the meta-analyses. Data regarding study characteristics, direction of results, and the significance of the results from each meta-analysis were extracted. Results: There were 129 meta-analyses used in this review, and the reporting on conflict of interest was low with only 50 (38.8%) of the articles possessing a conflict of interest statement (either confirming of denying COI). Of these 50 articles, there were only 4 (8%) studies that reported an actual conflict of interest. A statement of conflicts of interest was found in 29 (35.3%) of the papers that reported significant findings, whereas 35% of the papers that reported positive results reported on conflict of interest. Prior to 2009, only 17 (25%) papers reported conflicts of interest, but since 2009, 54.1% of papers collected had a conflict of interest statement. Conclusions: Meta-analyses published in the field of dentistry do not routinely report author conflicts of interest. Although few conflicts appear to exist, the field of dentistry should continue to ensure that best evidence reports provide clear and transparent reporting of potential conflicts of interest in academic journals. Key words:Dentistry, dentition, meta-analysis, quantitative review. PMID:25136431

Chronic care management for patients with COPD: a critical review of available evidence.

PubMed

Lemmens, Karin M M; Lemmens, Lidwien C; Boom, José H C; Drewes, Hanneke W; Meeuwissen, Jolanda A C; Steuten, Lotte M G; Vrijhoef, Hubertus J M; Baan, Caroline A

2013-10-01

Clinical diversity and methodological heterogeneity exists between studies on chronic care management. This study aimed to examine the effectiveness of chronic care management in chronic obstructive pulmonary disease (COPD) while taking heterogeneity into account, enabling the understanding of and the decision making about such programmes. Three investigated sources of heterogeneity were study quality, length of follow-up, and number of intervention components. We performed a review of previously published reviews and meta-analyses on COPD chronic care management. Their primary studies that were analyzed as statistical, clinical and methodological heterogeneity were present. Meta-regression analyses were performed to explain the variances among the primary studies. Generally, the included reviews showed positive results on quality of life and hospitalizations. Inconclusive effects were found on emergency department visits and no effects on mortality. Pooled effects on hospitalizations, emergency department visits and quality of life of primary studies did not reach significant improvement. No effects were found on mortality. Meta-regression showed that the number of components of chronic care management programmes explained present heterogeneity for hospitalizations and emergency department visits. Four components showed significant effects on hospitalizations, whereas two components had significant effects on emergency department visits. Methodological study quality and length of follow-up did not significantly explain heterogeneity. This study demonstrated that COPD chronic care management has the potential to improve outcomes of care; heterogeneity in outcomes was explained. Further research is needed to elucidate the diversity between COPD chronic care management studies in terms of the effects measured and strengthen the support for chronic care management. © 2011 John Wiley & Sons Ltd.

Collaborative meta-analysis finds no evidence of a strong interaction between stress and 5-HTTLPR genotype contributing to the development of depression

PubMed Central

Culverhouse, Robert C.; Saccone, Nancy L.; Horton, Amy C.; Ma, Yinjiao; Anstey, Kaarin J.; Banaschewski, Tobias; Burmeister, Margit; Cohen-Woods, Sarah; Etain, Bruno; Fisher, Helen L.; Goldman, Noreen; Guillaume, Sébastien; Horwood, John; Juhasz, Gabriella; Lester, Kathryn J.; Mandelli, Laura; Middeldorp, Christel M.; Olié, Emilie; Villafuerte, Sandra; Air, Tracy M.; Araya, Ricardo; Bowes, Lucy; Burns, Richard; Byrne, Enda M.; Coffey, Carolyn; Coventry, William L.; Gawronski, Katerina; Glei, Dana; Hatzimanolis, Alex; Hottenga, Jouke-Jan; Jaussent, Isabelle; Jawahar, Catharine; Jennen-Steinmetz, Christine; Kramer, John R.; Lajnef, Mohamed; Little, Keriann; Meyer zu Schwabedissen, Henriette; Nauck, Matthias; Nederhof, Esther; Petschner, Peter; Peyrot, Wouter J.; Schwahn, Christian; Sinnamon, Grant; Stacey, David; Tian, Yan; Toben, Catherine; Van der Auwera, Sandra; Wainwright, Nick; Wang, Jen-Chyong; Willemsen, Gonneke; Anderson, Ian M.; Arolt, Volker; Åslund, Cecilia; Bagdy, Gyorgy; Baune, Bernhard T.; Bellivier, Frank; Boomsma, Dorret I.; Courtet, Philippe; Dannlowski, Udo; de Geus, Eco J.C.; Deakin, John F. W.; Easteal, Simon; Eley, Thalia; Fergusson, David M.; Goate, Alison M.; Gonda, Xenia; Grabe, Hans J.; Holzman, Claudia; Johnson, Eric O.; Kennedy, Martin; Laucht, Manfred; Martin, Nicholas G.; Munafò, Marcus; Nilsson, Kent W.; Oldehinkel, Albertine J.; Olsson, Craig; Ormel, Johan; Otte, Christian; Patton, George C.; Penninx, Brenda W.J.H.; Ritchie, Karen; Sarchiapone, Marco; Scheid, JM; Serretti, Alessandro; Smit, Johannes H.; Stefanis, Nicholas C.; Surtees, Paul G.; Völzke, Henry; Weinstein, Maxine; Whooley, Mary; Nurnberger, John I.; Breslau, Naomi; Bierut, Laura J.

2017-01-01

The hypothesis that the S allele of the 5-HTTLPR serotonin transporter promoter region is associated with increased risk of depression, but only in individuals exposed to stressful situations, has generated much interest, research, and controversy since first proposed in 2003. Multiple meta-analyses combining results from heterogeneous analyses have not settled the issue. To determine the magnitude of the interaction and the conditions under which it might be observed, we performed new analyses on 31 datasets containing 38 802 European-ancestry subjects genotyped for 5-HTTLPR and assessed for depression and childhood maltreatment or other stressful life events, and meta-analyzed the results. Analyses targeted two stressors (narrow, broad) and two depression outcomes (current, lifetime). All groups that published on this topic prior to the initiation of our study and met the assessment and sample size criteria were invited to participate. Additional groups, identified by consortium members or self-identified in response to our protocol (published prior to the start of analysis1) with qualifying unpublished data were also invited to participate. A uniform data analysis script implementing the protocol was executed by each of the consortium members. Our findings do not support the interaction hypothesis. We found no subgroups or variable definitions for which an interaction between stress and 5-HTTLPR genotype was statistically significant. In contrast, our findings for the main effects of life stressors (strong risk factor) and 5-HTTLPR genotype (no impact on risk) are strikingly consistent across our contributing studies, the original study reporting the interaction, and subsequent meta-analyses. Our conclusion is that if an interaction exists in which the S allele of 5-HTTLPR increases risk of depression only in stressed individuals, then it is not broadly generalizable, but must be of modest effect size and only observable in limited situations. PMID:28373689

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers.

PubMed

Lenters, Virissa; Basinas, Ioannis; Beane-Freeman, Laura; Boffetta, Paolo; Checkoway, Harvey; Coggon, David; Portengen, Lützen; Sim, Malcolm; Wouters, Inge M; Heederik, Dick; Vermeulen, Roel

2010-04-01

To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins. Risk estimates were extracted from studies published before 2009 that met predefined quality criteria, including 8 cohort, 1 case-cohort, and 2 case-control studies of cotton textile industry workers, and 15 cohort and 2 case-control studies of agricultural workers. Summary risk estimates were calculated using random effects meta-analyses. Potential sources of heterogeneity were explored through subgroup analyses. The summary risk of lung cancer was 0.72 (95% CI, 0.57-0.90) for textile workers and 0.62 (0.52-0.75) for agricultural workers. The relative risk of lung cancer was below 1.0 for most subgroups defined according to sex, study design, outcome, smoking adjustment, and geographic area. Two studies provided quantitative estimates of endotoxin exposure and both studies tended to support a dose-dependent protective effect of endotoxins on lung cancer risk. Despite several limitations, this meta-analysis based on high-quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer.

Serum S100B Is Related to Illness Duration and Clinical Symptoms in Schizophrenia—A Meta-Regression Analysis

PubMed Central

Schümberg, Katharina; Polyakova, Maryna; Steiner, Johann; Schroeter, Matthias L.

2016-01-01

S100B has been linked to glial pathology in several psychiatric disorders. Previous studies found higher S100B serum levels in patients with schizophrenia compared to healthy controls, and a number of covariates influencing the size of this effect have been proposed in the literature. Here, we conducted a meta-analysis and meta-regression analysis on alterations of serum S100B in schizophrenia in comparison with healthy control subjects. The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to guarantee a high quality and reproducibility. With strict inclusion criteria 19 original studies could be included in the quantitative meta-analysis, comprising a total of 766 patients and 607 healthy control subjects. The meta-analysis confirmed higher values of the glial serum marker S100B in schizophrenia if compared with control subjects. Meta-regression analyses revealed significant effects of illness duration and clinical symptomatology, in particular the total score of the Positive and Negative Syndrome Scale (PANSS), on serum S100B levels in schizophrenia. In sum, results confirm glial pathology in schizophrenia that is modulated by illness duration and related to clinical symptomatology. Further studies are needed to investigate mechanisms and mediating factors related to these findings. PMID:26941608

Post-partum depressive symptoms and medically assisted conception: a systematic review and meta-analysis.

PubMed

Gressier, F; Letranchant, A; Cazas, O; Sutter-Dallay, A L; Falissard, B; Hardy, P

2015-11-01

Does medically assisted conception increase the risk of post-partum depressive symptoms? Our literature review and meta-analysis showed no increased risk of post-partum depressive symptoms in women after medically assisted conception. Women who conceive with medically assisted conception, which can be considered as a stressful life event, could face an increased risk of depressive symptoms. However, no previous meta-analysis has been performed on the association between medically assisted conception and post-partum depressive symptoms. A systematic review with electronic searches of PubMed, ISI Web of Knowledge and PsycINFO databases up to December 2014 was conducted to identify articles evaluating post-partum depressive symptoms in women who had benefited from medically assisted conception compared with those with a spontaneous pregnancy. Meta-analyses were also performed on clinically significant post-partum depressive symptoms according to PRISMA guidelines. From 569 references, 492 were excluded on title, 42 on abstract and 17 others on full-text. Therefore, 18 studies were included in the review and 8 in the meta-analysis (2451 women) on clinically significant post-partum depressive symptoms after medically assisted conception compared with a spontaneous pregnancy. A sensitivity meta-analysis on assisted reproductive technologies and spontaneous pregnancy (6 studies, 1773 women) was also performed. The quality of the studies included in the meta-analyses was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology Statement for observational research. The data were pooled using RevMan software by the Cochrane Collaboration. Heterogeneity between studies was assessed from the results of the χ(2) and I(2) statistics. Biases were assessed with funnel plots and Egger's test. A fixed effects model was used for the meta-analyses because of the low level of heterogeneity between the studies. The systematic review of studies examining post-partum depressive symptoms after medically assisted conception compared with spontaneous pregnancy is not in favor of an association. Our meta-analysis on clinically significant post-partum depressive symptoms showed no significant difference between women who used medically assisted conception and those with spontaneous pregnancy: odds ratio (OR) = 0.93 (0.67-1.31), Z = 0.40, P = 0.69. The sensitivity meta-analysis reported no significant difference either: OR = 1.04 (0.71-1.52), Z = 0.18, P = 0.86. The literature on post-partum depressive symptoms and medically assisted conception is sparse. Only eight studies were available for our meta-analysis taking into account the rates of clinically significant post-partum depressive symptoms after medically assisted conception. However, the quality of the studies was high and the heterogeneity between trials was not significant. Whilst post-partum anxiety is more prevalent than depressive states and they can co-occur, it was not considered in these review and meta-analyses. In addition, other risk factors, such as maternal age, socio-demographic data or obstetric factors, are important for the assessment of post-partum depressive symptoms. Our review reported that several of these confounding risk factors were, however, analyzed and controlled for in the studies. Our literature review and meta-analyses showed no increased risk of post-partum depressive symptoms in women after medically assisted conception. Even if the rates of depressive symptoms are the same in the medically assisted conception population as among controls, the risk factors could be different. Though medically assisted conception can be considered as a stressful life event, these women have also lower prevalence of the usual risks. Professionals should also be careful to screen for prenatal and post-partum depressive symptoms, as with all pregnant women. Further studies are needed to clarify the specific features of post-partum depressive symptoms in this population. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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.

Health Benefits of Dietary Whole Grains: An Umbrella Review of Meta-analyses.

PubMed

McRae, Marc P

2017-03-01

The purpose of this study is to review the effectiveness of the role of whole grain as a therapeutic agent in type 2 diabetes, cardiovascular disease, cancer, and obesity. An umbrella review of all published meta-analyses was performed. A PubMed search from January 1, 1980, to May 31, 2016, was conducted using the following search strategy: (whole grain OR whole grains) AND (meta-analysis OR systematic review). Only English language publications that provided quantitative statistical analysis on type 2 diabetes, cardiovascular disease, cancer, and weight loss were retrieved. Twenty-one meta-analyses were retrieved for inclusion in this umbrella review, and all the meta-analyses reported statistically significant positive benefits for reducing the incidence of type 2 diabetes (relative risk [RR] = 0.68-0.80), cardiovascular disease (RR = 0.63-0.79), and colorectal, pancreatic, and gastric cancers (RR = 0.57-0.94) and a modest effect on body weight, waist circumference, and body fat mass. Significant reductions in cardiovascular and cancer mortality were also observed (RR = 0.82 and 0.89, respectively). Some problems of heterogeneity, publication bias, and quality assessment were found among the studies. This review suggests that there is some evidence for dietary whole grain intake to be beneficial in the prevention of type 2 diabetes, cardiovascular disease, and colorectal, pancreatic, and gastric cancers. The potential benefits of these findings suggest that the consumption of 2 to 3 servings per day (~45 g) of whole grains may be a justifiable public health goal.

Does the Use of Platelet-Rich Plasma at the Time of Surgery Improve Clinical Outcomes in Arthroscopic Rotator Cuff Repair When Compared With Control Cohorts? A Systematic Review of Meta-analyses.

PubMed

Saltzman, Bryan M; Jain, Akshay; Campbell, Kirk A; Mascarenhas, Randy; Romeo, Anthony A; Verma, Nikhil N; Cole, Brian J

2016-05-01

The aims of the study were as follows: (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) use at the time of arthroscopic rotator cuff repair surgery and to determine its effect on retear rates and clinical outcomes; (2) to provide a framework for the analysis and interpretation of the best currently available evidence; and (3) to identify gaps within the literature where suggestions for continued investigational efforts would be valid. Literature searches were performed to identify meta-analyses examining arthroscopic rotator cuff repairs augmented with PRP versus control (no PRP). Clinical data were extracted and meta-analysis quality was assessed using the Quality of Reporting of Meta-analyses and Oxman-Guyatt scales. Seven meta-analyses met inclusion and exclusion criteria. All were considered as being of similar quality with Quality of Reporting of Meta-analyses scores >15 and Oxman scores of 7. A total of 3,193 overlapping patients treated were included with mean follow-up from 12 to 31 months. When compared with control patients, use of PRP at the time of rotator cuff repair did not result in significantly lower overall retear rates or improved clinical outcome scores. The following postoperative functional scores comparing PRP versus control were reported: Constant (no significant difference demonstrated with PRP use in 5 of 6 reporting meta-analyses), University of California - Los Angeles (no difference, 6 of 6), American Shoulder and Elbow Society (no difference, 4 of 4), and Simple Shoulder Test (no difference, 3 of 5). Subgroup analysis performed by 3 meta-analyses showed evidence of improved outcomes with solid PRP matrix versus liquid, small- and/or medium-sized versus large and/or massive tears, PRP application at the tendon-bone interface versus over tendon, and in the setting of double-row versus single-row rotator cuff. The current highest level of evidence suggests that PRP use at the time of arthroscopic rotator cuff repair does not universally improve retear rates or affect clinical outcome scores. However, the effects of PRP use on retear rates trend toward beneficial outcomes if evaluated in the context of the following specific variables: use of a solid PRP matrix; application of PRP at the tendon-bone interface; in double-row repairs; and with small- and/or medium-sized rotator cuff tears. Level III, systematic review of Level II and III studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Is Local Viscosupplementation Injection Clinically Superior to Other Therapies in the Treatment of Osteoarthritis of the Knee: A Systematic Review of Overlapping Meta-analyses.

PubMed

Campbell, Kirk A; Erickson, Brandon J; Saltzman, Bryan M; Mascarenhas, Randy; Bach, Bernard R; Cole, Brian J; Verma, Nikhil N

2015-10-01

To conduct a systematic review of overlapping meta-analyses comparing treatment of knee osteoarthritis (OA) with intra-articular viscosupplementation (intra-articular hyaluronic acid [IA-HA]) versus oral nonsteroidal anti-inflammatory drugs (NSAIDs), intra-articular corticosteroids (IA-corticosteroids), intra-articular platelet-rich plasma (IA-PRP), or intra-articular placebo (IA-placebo) to determine which meta-analyses provide the best current evidence and identify potential causes of discordance. Literature searches were performed for meta-analyses examining use of IA-HA versus NSAIDs, IA-corticosteroids, IA-PRP, or IA-placebo. Clinical data were extracted, and meta-analysis quality was assessed. The Jadad algorithm was applied to determine which meta-analyses provided the highest level of evidence. Fourteen meta-analyses met the eligibility criteria and ranged in quality from Level I to IV evidence. In studies reporting patient numbers, there were a total of 20,049 patients: 13,698 receiving IA-HA, 355 receiving NSAIDs, 294 receiving IA-corticosteroids, and 5,702 receiving IA-placebo. Ten studies examined the effects of IA-HA versus IA-placebo; of these, 5 found that IA-HA improved pain and 4 found that IA-HA improved function. No clinically relevant differences in the efficacy of IA-HA versus NSAIDs regarding pain and function were found. Regarding IA-HA versus IA-PRP, IA-HA improved knee function at 2 and 6 months after injection but the effects were less robust than those of IA-PRP. Regarding IA-HA versus IA-corticosteroids, the positive effects of IA-HA were greater at 5 to 13 weeks and persisted for up to 26 weeks. After application of the Jadad algorithm, 2 concordant high-quality meta-analyses were selected and both showed that IA-HA provided clinically relevant improvements in pain and function compared with IA-placebo. This systematic review of overlapping meta-analyses comparing IA-HA with other nonoperative treatment modalities for knee OA shows that the current highest level of evidence suggests that IA-HA is a viable option for knee OA. Its use results in improvements in knee pain and function that can persist for up to 26 weeks. IA-HA has a good safety profile, and its use should be considered in patients with early knee OA. Level IV, systematic review of Level I to IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Neurological Soft Signs in Schizophrenia: A Meta-analysis

PubMed Central

Chan, Raymond C. K.; Xu, Ting; Heinrichs, R. Walter; Yu, Yue; Wang, Ya

2010-01-01

Background: Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups. Method: A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms. Results: A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%–10% of their variance with NSS. Conclusions: NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness. PMID:19377058

Are Study and Journal Characteristics Reliable Indicators of "Truth" in Imaging Research?

PubMed

Frank, Robert A; McInnes, Matthew D F; Levine, Deborah; Kressel, Herbert Y; Jesurum, Julia S; Petrcich, William; McGrath, Trevor A; Bossuyt, Patrick M

2018-04-01

Purpose To evaluate whether journal-level variables (impact factor, cited half-life, and Standards for Reporting of Diagnostic Accuracy Studies [STARD] endorsement) and study-level variables (citation rate, timing of publication, and order of publication) are associated with the distance between primary study results and summary estimates from meta-analyses. Materials and Methods MEDLINE was searched for meta-analyses of imaging diagnostic accuracy studies, published from January 2005 to April 2016. Data on journal-level and primary-study variables were extracted for each meta-analysis. Primary studies were dichotomized by variable as first versus subsequent publication, publication before versus after STARD introduction, STARD endorsement, or by median split. The mean absolute deviation of primary study estimates from the corresponding summary estimates for sensitivity and specificity was compared between groups. Means and confidence intervals were obtained by using bootstrap resampling; P values were calculated by using a t test. Results Ninety-eight meta-analyses summarizing 1458 primary studies met the inclusion criteria. There was substantial variability, but no significant differences, in deviations from the summary estimate between paired groups (P > .0041 in all comparisons). The largest difference found was in mean deviation for sensitivity, which was observed for publication timing, where studies published first on a topic demonstrated a mean deviation that was 2.5 percentage points smaller than subsequently published studies (P = .005). For journal-level factors, the greatest difference found (1.8 percentage points; P = .088) was in mean deviation for sensitivity in journals with impact factors above the median compared with those below the median. Conclusion Journal- and study-level variables considered important when evaluating diagnostic accuracy information to guide clinical decisions are not systematically associated with distance from the truth; critical appraisal of individual articles is recommended. © RSNA, 2017 Online supplemental material is available for this article.

21 CFR 814.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... agency, which may include (but are not limited to) data derived from new clinical studies, reports of adverse events, or new analyses of previously submitted data (e.g., meta-analyses) if the studies, events... criteria in § 1271.10(a) and that is also regulated as a device. (q) Unique device identifier (UDI) means...

Metaprop: a Stata command to perform meta-analysis of binomial data.

PubMed

Nyaga, Victoria N; Arbyn, Marc; Aerts, Marc

2014-01-01

Meta-analyses have become an essential tool in synthesizing evidence on clinical and epidemiological questions derived from a multitude of similar studies assessing the particular issue. Appropriate and accessible statistical software is needed to produce the summary statistic of interest. Metaprop is a statistical program implemented to perform meta-analyses of proportions in Stata. It builds further on the existing Stata procedure metan which is typically used to pool effects (risk ratios, odds ratios, differences of risks or means) but which is also used to pool proportions. Metaprop implements procedures which are specific to binomial data and allows computation of exact binomial and score test-based confidence intervals. It provides appropriate methods for dealing with proportions close to or at the margins where the normal approximation procedures often break down, by use of the binomial distribution to model the within-study variability or by allowing Freeman-Tukey double arcsine transformation to stabilize the variances. Metaprop was applied on two published meta-analyses: 1) prevalence of HPV-infection in women with a Pap smear showing ASC-US; 2) cure rate after treatment for cervical precancer using cold coagulation. The first meta-analysis showed a pooled HPV-prevalence of 43% (95% CI: 38%-48%). In the second meta-analysis, the pooled percentage of cured women was 94% (95% CI: 86%-97%). By using metaprop, no studies with 0% or 100% proportions were excluded from the meta-analysis. Furthermore, study specific and pooled confidence intervals always were within admissible values, contrary to the original publication, where metan was used.

Examining the associations between HIV-related stigma and health outcomes in people living with HIV/AIDS: a series of meta-analyses.

PubMed

Rueda, Sergio; Mitra, Sanjana; Chen, Shiyi; Gogolishvili, David; Globerman, Jason; Chambers, Lori; Wilson, Mike; Logie, Carmen H; Shi, Qiyun; Morassaei, Sara; Rourke, Sean B

2016-07-13

To conduct a systematic review and series of meta-analyses on the association between HIV-related stigma and health among people living with HIV. A structured search was conducted on 6 electronic databases for journal articles reporting associations between HIV-related stigma and health-related outcomes published between 1996 and 2013. Controlled studies, cohort studies, case-control studies and cross-sectional studies in people living with HIV were considered for inclusion. Mental health (depressive symptoms, emotional and mental distress, anxiety), quality of life, physical health, social support, adherence to antiretroviral therapy, access to and usage of health/social services and risk behaviours. 64 studies were included in our meta-analyses. We found significant associations between HIV-related stigma and higher rates of depression, lower social support and lower levels of adherence to antiretroviral medications and access to and usage of health and social services. Weaker relationships were observed between HIV-related stigma and anxiety, quality of life, physical health, emotional and mental distress and sexual risk practices. While risk of bias assessments revealed overall good quality related to how HIV stigma and health outcomes were measured on the included studies, high risk of bias among individual studies was observed in terms of appropriate control for potential confounders. Additional research should focus on elucidating the mechanisms behind the negative relationship between stigma and health to better inform interventions to reduce the impact of stigma on the health and well-being of people with HIV. This systematic review and series of meta-analyses support the notion that HIV-related stigma has a detrimental impact on a variety of health-related outcomes in people with HIV. This review can inform the development of multifaceted, intersectoral interventions to reduce the impact of HIV-related stigma on the health and well-being of people living with HIV. 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/

The Reporting Quality of Systematic Reviews and Meta-Analyses in Industrial and Organizational Psychology: A Systematic Review

PubMed Central

Schalken, Naomi; Rietbergen, Charlotte

2017-01-01

Objective: The goal of this systematic review was to examine the reporting quality of the method section of quantitative systematic reviews and meta-analyses from 2009 to 2016 in the field of industrial and organizational psychology with the help of the Meta-Analysis Reporting Standards (MARS), and to update previous research, such as the study of Aytug et al. (2012) and Dieckmann et al. (2009). Methods: A systematic search for quantitative systematic reviews and meta-analyses was conducted in the top 10 journals in the field of industrial and organizational psychology between January 2009 and April 2016. Data were extracted on study characteristics and items of the method section of MARS. A cross-classified multilevel model was analyzed, to test whether publication year and journal impact factor (JIF) were associated with the reporting quality scores of articles. Results: Compliance with MARS in the method section was generally inadequate in the random sample of 120 articles. Variation existed in the reporting of items. There were no significant effects of publication year and journal impact factor (JIF) on the reporting quality scores of articles. Conclusions: The reporting quality in the method section of systematic reviews and meta-analyses was still insufficient, therefore we recommend researchers to improve the reporting in their articles by using reporting standards like MARS. PMID:28878704

A Critical Meta-Analysis of Lens Model Studies in Human Judgment and Decision-Making

PubMed Central

Kaufmann, Esther; Reips, Ulf-Dietrich; Wittmann, Werner W.

2013-01-01

Achieving accurate judgment (‘judgmental achievement’) is of utmost importance in daily life across multiple domains. The lens model and the lens model equation provide useful frameworks for modeling components of judgmental achievement and for creating tools to help decision makers (e.g., physicians, teachers) reach better judgments (e.g., a correct diagnosis, an accurate estimation of intelligence). Previous meta-analyses of judgment and decision-making studies have attempted to evaluate overall judgmental achievement and have provided the basis for evaluating the success of bootstrapping (i.e., replacing judges by linear models that guide decision making). However, previous meta-analyses have failed to appropriately correct for a number of study design artifacts (e.g., measurement error, dichotomization), which may have potentially biased estimations (e.g., of the variability between studies) and led to erroneous interpretations (e.g., with regards to moderator variables). In the current study we therefore conduct the first psychometric meta-analysis of judgmental achievement studies that corrects for a number of study design artifacts. We identified 31 lens model studies (N = 1,151, k = 49) that met our inclusion criteria. We evaluated overall judgmental achievement as well as whether judgmental achievement depended on decision domain (e.g., medicine, education) and/or the level of expertise (expert vs. novice). We also evaluated whether using corrected estimates affected conclusions with regards to the success of bootstrapping with psychometrically-corrected models. Further, we introduce a new psychometric trim-and-fill method to estimate the effect sizes of potentially missing studies correct psychometric meta-analyses for effects of publication bias. Comparison of the results of the psychometric meta-analysis with the results of a traditional meta-analysis (which only corrected for sampling error) indicated that artifact correction leads to a) an increase in values of the lens model components, b) reduced heterogeneity between studies, and c) increases the success of bootstrapping. We argue that psychometric meta-analysis is useful for accurately evaluating human judgment and show the success of bootstrapping. PMID:24391781

A critical meta-analysis of lens model studies in human judgment and decision-making.

PubMed

Kaufmann, Esther; Reips, Ulf-Dietrich; Wittmann, Werner W

2013-01-01

Achieving accurate judgment ('judgmental achievement') is of utmost importance in daily life across multiple domains. The lens model and the lens model equation provide useful frameworks for modeling components of judgmental achievement and for creating tools to help decision makers (e.g., physicians, teachers) reach better judgments (e.g., a correct diagnosis, an accurate estimation of intelligence). Previous meta-analyses of judgment and decision-making studies have attempted to evaluate overall judgmental achievement and have provided the basis for evaluating the success of bootstrapping (i.e., replacing judges by linear models that guide decision making). However, previous meta-analyses have failed to appropriately correct for a number of study design artifacts (e.g., measurement error, dichotomization), which may have potentially biased estimations (e.g., of the variability between studies) and led to erroneous interpretations (e.g., with regards to moderator variables). In the current study we therefore conduct the first psychometric meta-analysis of judgmental achievement studies that corrects for a number of study design artifacts. We identified 31 lens model studies (N = 1,151, k = 49) that met our inclusion criteria. We evaluated overall judgmental achievement as well as whether judgmental achievement depended on decision domain (e.g., medicine, education) and/or the level of expertise (expert vs. novice). We also evaluated whether using corrected estimates affected conclusions with regards to the success of bootstrapping with psychometrically-corrected models. Further, we introduce a new psychometric trim-and-fill method to estimate the effect sizes of potentially missing studies correct psychometric meta-analyses for effects of publication bias. Comparison of the results of the psychometric meta-analysis with the results of a traditional meta-analysis (which only corrected for sampling error) indicated that artifact correction leads to a) an increase in values of the lens model components, b) reduced heterogeneity between studies, and c) increases the success of bootstrapping. We argue that psychometric meta-analysis is useful for accurately evaluating human judgment and show the success of bootstrapping.

Is the evaluation of risk of bias in periodontology and implant dentistry comprehensive? A systematic review.

PubMed

Faggion, Clovis Mariano; Listl, Stefan; Alarcón, Marco Antonio

2015-05-01

The objective of this study was to assess how authors of systematic reviews (SRs) with meta-analyses published in periodontology and implant dentistry evaluate risk of bias (ROB) in primary studies included in these reviews. A literature search for SRs with meta-analyses was performed in PubMed and Cochrane library databases up to July 20th 2014. The reference lists of included articles were screened for further reviews. The standards of evaluating ROB in primary studies were evaluated by using a 14-item checklist based on the Cochrane approach for evaluating ROB. Standards in ROB evaluations in Cochrane and paper-based SRs were compared using the Fisher's exact test. All searches, data extraction and evaluations were performed independently and in duplicate. Seventy SRs were included (45 paper-based and 25 Cochrane SRs, respectively). The median percentage of items addressed was 58% (interquartile range 4-100%). Cochrane SRs more frequently included ROB assessments than paper-based reviews in terms of examiner blinding (p = 0.0026), selective outcome reporting (p = 0.0207) and other bias (p = 0.0241). The ROB evaluation in primary studies currently included in SRs with meta-analyses in periodontology and implant dentistry is not sufficiently comprehensive. Cochrane SRs have more comprehensive ROB evaluation than paper-based reviews. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Gender-specific Differences in Recurrence of Non-muscle-invasive Bladder Cancer: A Systematic Review and Meta-analysis.

PubMed

Uhlig, Annemarie; Strauss, Arne; Seif Amir Hosseini, Ali; Lotz, Joachim; Trojan, Lutz; Schmid, Marianne; Uhlig, Johannes

2017-09-06

The incidence of urothelial carcinoma of the bladder (UCB) is lower in women; however, women tend to present with more advanced disease. To date, there is no quantitative synthesis of studies reporting gender-specific outcomes in non-muscle-invasive UCB. To conduct a meta-analysis evaluating gender-specific differences in recurrence of non-muscle-invasive urinary bladder cancer (NMIBC). An unrestricted systematic literature search of the MEDLINE, EMBASE, and Cochrane libraries was conducted. Studies evaluating the impact of gender on disease recurrence after local treatment of NMIBC using multivariable Cox proportional hazard models were included. Random effect meta-analysis, subgroup analyses, meta-influence, and cumulative meta-analyses were conducted. Publication bias was assessed via a funnel plot and Eggeŕs test. Of 609 studies screened, 27 comprising 23 754 patients were included. Random effect meta-analyses indicated women at increased risk for UCB recurrence compared with men (hazard ratio [HR]=1.11, 95% confidence interval [CI]: 1.01-1.23, p=0.03). Subgroup analyses yielded estimates between HR=0.99 and HR=1.68. Gender-specific differences in UCB recurrence were most pronounced in studies administering exclusively bacillus Calmette-Guerin (BCG; HR=1.64, 95% CI: 1.13-2.39, p=0.01), especially in a long-term treatment regimen (HR=1.68, 95% CI: 1.32-2.15, p<0.001). Sensitivity analyses confirmed female patients at increased risk for UCB recurrence. Women are at increased risk for disease recurrence after local treatment of NMIBC compared with male patients. Reduced effectiveness of BCG treatment might underlie this observation. Gender-specific differences were evident across various subgroups and proved robust upon sensitivity analyses. In this report, we combined several studies on gender-specific differences in relapse of superficial bladder cancer. Women were more likely to experience cancer relapse than men. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Meta-analysis of workplace physical activity interventions.

PubMed

Conn, Vicki S; Hafdahl, Adam R; Cooper, Pamela S; Brown, Lori M; Lusk, Sally L

2009-10-01

Most adults do not achieve adequate physical activity levels. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from such programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21); fitness (0.57); lipids (0.13); anthropometric measures (0.08); work attendance (0.19); and job stress (0.33). The significant effect size for diabetes risk (0.98) is less robust given small sample sizes. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on VO2max of 3.5 mL/kg/min; for lipids, -0.2 on the ratio of total cholesterol to high-density lipoprotein; and for diabetes risk, -12.6 mg/dL on fasting glucose. These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity.

Fruit and vegetable intake and prostate cancer risk: a meta-analysis.

PubMed

Meng, Hongzhou; Hu, Wenyi; Chen, Zhaodian; Shen, Yuehong

2014-06-01

Recent reports have examined the effect of fruit and vegetable intake on the risk of prostate cancer, but the results are inconsistent. A meta-analysis of prospective studies was conducted to arrive at quantitative conclusions about the contribution of vegetable and fruit intake to the incidence of prostate cancer. A comprehensive, systematic search of medical literature published up to June 2012 was performed to identify relevant studies. Separate meta-analyses were conducted for fruit and vegetable consumption. The presence of publication bias was assessed using Egger and Begg tests. In total, 16 cohort studies met the inclusion criteria and were included in the meta-analysis. The combined adjusted relative risk comparing highest with lowest categories showed that there was no association between vegetable and fruit consumption and prostate cancer incidence. The pooled relative risk was 0.97 (95%CI 0.93, 1.01) for vegetables and 1.02 (95%CI 0.98, 1.07) for fruit. There is no heterogeneity between the studies. No publication bias was detected. This meta-analysis suggests that total fruit or vegetable consumption may not exert a protective role in the risk of prostate cancer. © 2013 Wiley Publishing Asia Pty Ltd.

The effectiveness of interventions to increase physical activity among young girls: a meta-analysis.

PubMed

Biddle, Stuart J H; Braithwaite, Rock; Pearson, Natalie

2014-05-01

Pre-adolescent girls are an important target population for physical activity behaviour change as it may enhance tracking into the crucial period of adolescence. The quantification of intervention effectiveness for this age group of girls has not been previously reported. Studies published in English up to and including August 2013 were located from computerised (MedLine, PsychInfo, Science Direct, Web of Science, EPPI centre databases, and Cochrane Library database) and manual searches. Intervention studies aimed at promoting physical activity, which included pre-adolescent girls aged 5-11 years, and a non-physical activity control/comparison group were included. A random effects meta-analysis was conducted. The average treatment effect for pre-adolescent girls involved in physical activity interventions was significant but small (g=0.314, p<.001). Moderator analyses showed larger effects for interventions that catered for girls only and used educational and multicomponent strategies. Interventions to increase physical activity in pre-adolescent girls show small but significant effects, suggesting that behaviour change may be challenging, but results suggest some strategies that could be successful. Copyright © 2014 Elsevier Inc. All rights reserved.

Vitamin D and Depression: A Systematic Review and Meta-Analysis Comparing Studies with and without Biological Flaws

PubMed Central

Spedding, Simon

2014-01-01

Efficacy of Vitamin D supplements in depression is controversial, awaiting further literature analysis. Biological flaws in primary studies is a possible reason meta-analyses of Vitamin D have failed to demonstrate efficacy. This systematic review and meta-analysis of Vitamin D and depression compared studies with and without biological flaws. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was undertaken through four databases for randomized controlled trials (RCTs). Studies were critically appraised for methodological quality and biological flaws, in relation to the hypothesis and study design. Meta-analyses were performed for studies according to the presence of biological flaws. The 15 RCTs identified provide a more comprehensive evidence-base than previous systematic reviews; methodological quality of studies was generally good and methodology was diverse. A meta-analysis of all studies without flaws demonstrated a statistically significant improvement in depression with Vitamin D supplements (+0.78 CI +0.24, +1.27). Studies with biological flaws were mainly inconclusive, with the meta-analysis demonstrating a statistically significant worsening in depression by taking Vitamin D supplements (−1.1 CI −0.7, −1.5). Vitamin D supplementation (≥800 I.U. daily) was somewhat favorable in the management of depression in studies that demonstrate a change in vitamin levels, and the effect size was comparable to that of anti-depressant medication. PMID:24732019

Perspective: NutriGrade: A Scoring System to Assess and Judge the Meta-Evidence of Randomized Controlled Trials and Cohort Studies in Nutrition Research.

PubMed

Schwingshackl, Lukas; Knüppel, Sven; Schwedhelm, Carolina; Hoffmann, Georg; Missbach, Benjamin; Stelmach-Mardas, Marta; Dietrich, Stefan; Eichelmann, Fabian; Kontopantelis, Evangelos; Iqbal, Khalid; Aleksandrova, Krasimira; Lorkowski, Stefan; Leitzmann, Michael F; Kroke, Anja; Boeing, Heiner

2016-11-01

The objective of this study was to develop a scoring system (NutriGrade) to evaluate the quality of evidence of randomized controlled trial (RCT) and cohort study meta-analyses in nutrition research, building upon previous tools and expert recommendations. NutriGrade aims to assess the meta-evidence of an association or effect between different nutrition factors and outcomes, taking into account nutrition research-specific requirements not considered by other tools. In a pretest study, 6 randomly selected meta-analyses investigating diet-disease relations were evaluated with NutriGrade by 5 independent raters. After revision, NutriGrade was applied by the same raters to 30 randomly selected meta-analyses in the same thematic area. The reliability of ratings of NutriGrade items was calculated with the use of a multirater κ, and reliability of the total (summed scores) was calculated with the use of intraclass correlation coefficients (ICCs). The following categories for meta-evidence evaluation were established: high (8-10), moderate (6-7.99), low (4-5.99), and very low (0-3.99). The NutriGrade scoring system (maximum of 10 points) comprises the following items: 1) risk of bias, study quality, and study limitations, 2) precision, 3) heterogeneity, 4) directness, 5) publication bias, 6) funding bias, 7) study design, 8) effect size, and 9) dose-response. The NutriGrade score varied between 2.9 (very low meta-evidence) and 8.8 (high meta-evidence) for meta-analyses of RCTs, and it ranged between 3.1 and 8.8 for meta-analyses of cohort studies. The κ value of the ratings for each scoring item varied from 0.32 (95% CI: 0.22, 0.42) for risk of bias for cohort studies and 0.95 (95% CI: 0.91, 0.99) for study design, with a mean κ of 0.66 (95% CI: 0.53, 0.79). The ICC of the total score was 0.81 (95% CI: 0.69, 0.90). The NutriGrade scoring system showed good agreement and reliability. The initial findings regarding the performance of this newly established scoring system need further evaluation in independent analyses. © 2016 American Society for Nutrition.

Perspective: NutriGrade: A Scoring System to Assess and Judge the Meta-Evidence of Randomized Controlled Trials and Cohort Studies in Nutrition Research123

PubMed Central

Knüppel, Sven; Schwedhelm, Carolina; Hoffmann, Georg; Missbach, Benjamin; Stelmach-Mardas, Marta; Dietrich, Stefan; Eichelmann, Fabian; Kontopanteils, Evangelos; Iqbal, Khalid; Aleksandrova, Krasimira; Lorkowski, Stefan; Leitzmann, Michael F; Kroke, Anja; Boeing, Heiner

2016-01-01

The objective of this study was to develop a scoring system (NutriGrade) to evaluate the quality of evidence of randomized controlled trial (RCT) and cohort study meta-analyses in nutrition research, building upon previous tools and expert recommendations. NutriGrade aims to assess the meta-evidence of an association or effect between different nutrition factors and outcomes, taking into account nutrition research–specific requirements not considered by other tools. In a pretest study, 6 randomly selected meta-analyses investigating diet–disease relations were evaluated with NutriGrade by 5 independent raters. After revision, NutriGrade was applied by the same raters to 30 randomly selected meta-analyses in the same thematic area. The reliability of ratings of NutriGrade items was calculated with the use of a multirater κ, and reliability of the total (summed scores) was calculated with the use of intraclass correlation coefficients (ICCs). The following categories for meta-evidence evaluation were established: high (8–10), moderate (6–7.99), low (4–5.99), and very low (0–3.99). The NutriGrade scoring system (maximum of 10 points) comprises the following items: 1) risk of bias, study quality, and study limitations, 2) precision, 3) heterogeneity, 4) directness, 5) publication bias, 6) funding bias, 7) study design, 8) effect size, and 9) dose-response. The NutriGrade score varied between 2.9 (very low meta-evidence) and 8.8 (high meta-evidence) for meta-analyses of RCTs, and it ranged between 3.1 and 8.8 for meta-analyses of cohort studies. The κ value of the ratings for each scoring item varied from 0.32 (95% CI: 0.22, 0.42) for risk of bias for cohort studies and 0.95 (95% CI: 0.91, 0.99) for study design, with a mean κ of 0.66 (95% CI: 0.53, 0.79). The ICC of the total score was 0.81 (95% CI: 0.69, 0.90). The NutriGrade scoring system showed good agreement and reliability. The initial findings regarding the performance of this newly established scoring system need further evaluation in independent analyses. PMID:28140319

Comparative Analyses of Zebrafish Anxiety-Like Behavior Using Conflict-Based Novelty Tests.

PubMed

Kysil, Elana V; Meshalkina, Darya A; Frick, Erin E; Echevarria, David J; Rosemberg, Denis B; Maximino, Caio; Lima, Monica Gomes; Abreu, Murilo S; Giacomini, Ana C; Barcellos, Leonardo J G; Song, Cai; Kalueff, Allan V

2017-06-01

Modeling of stress and anxiety in adult zebrafish (Danio rerio) is increasingly utilized in neuroscience research and central nervous system (CNS) drug discovery. Representing the most commonly used zebrafish anxiety models, the novel tank test (NTT) focuses on zebrafish diving in response to potentially threatening stimuli, whereas the light-dark test (LDT) is based on fish scototaxis (innate preference for dark vs. bright areas). Here, we systematically evaluate the utility of these two tests, combining meta-analyses of published literature with comparative in vivo behavioral and whole-body endocrine (cortisol) testing. Overall, the NTT and LDT behaviors demonstrate a generally good cross-test correlation in vivo, whereas meta-analyses of published literature show that both tests have similar sensitivity to zebrafish anxiety-like states. Finally, NTT evokes higher levels of cortisol, likely representing a more stressful procedure than LDT. Collectively, our study reappraises NTT and LDT for studying anxiety-like states in zebrafish, and emphasizes their developing utility for neurobehavioral research. These findings can help optimize drug screening procedures by choosing more appropriate models for testing anxiolytic or anxiogenic drugs.

Nutritional support in chronic obstructive pulmonary disease: a systematic review and meta-analysis.

PubMed

Collins, Peter F; Stratton, Rebecca J; Elia, Marinos

2012-06-01

The efficacy of nutritional support in the management of malnutrition in chronic obstructive pulmonary disease (COPD) is controversial. Previous meta-analyses, based on only cross-sectional analysis at the end of intervention trials, found no evidence of improved outcomes. The objective was to conduct a meta-analysis of randomized controlled trials (RCTs) to clarify the efficacy of nutritional support in improving intake, anthropometric measures, and grip strength in stable COPD. Literature databases were searched to identify RCTs comparing nutritional support with controls in stable COPD. Thirteen RCTs (n = 439) of nutritional support [dietary advice (1 RCT), oral nutritional supplements (ONS; 11 RCTs), and enteral tube feeding (1 RCT)] with a control comparison were identified. An analysis of the changes induced by nutritional support and those obtained only at the end of the intervention showed significantly greater increases in mean total protein and energy intakes with nutritional support of 14.8 g and 236 kcal daily. Meta-analyses also showed greater mean (±SE) improvements in favor of nutritional support for body weight (1.94 ± 0.26 kg, P < 0.001; 11 studies, n = 308) and grip strength (5.3%, P < 0.050; 4 studies, n = 156), which was not shown by ANOVA at the end of the intervention, largely because of bias associated with baseline imbalance between groups. This systematic review and meta-analysis showed that nutritional support, mainly in the form of ONS, improves total intake, anthropometric measures, and grip strength in COPD. These results contrast with the results of previous analyses that were based on only cross-sectional measures at the end of intervention trials.

Parent and Friend Social Support and Adolescent Hope.

PubMed

Mahon, Noreen E; Yarcheski, Adela

2017-04-01

The purpose of this study was to conduct two meta-analyses. The first examined social support from parents in relation to adolescent hope, and the second examined social support from friends in relation to adolescent hope. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the literature reviewed, nine published studies or doctoral dissertations completed between 1990 and 2014 met the inclusion criteria. Using meta-analytic techniques and the mean weighted r statistic, the results indicated that social support from friends had a stronger mean effect size (ES = .31) than social support from parents (ES = .21); there was a statistically significant difference between the two ESs. Two of the four moderators for the parent social support-adolescent hope relationship were statistically significant. They were quality score and health status. Implications for school nurses and nurses in all settings are addressed, and conclusions are drawn based on the findings.

Effects of electroconvulsive therapy on cognitive functioning in patients with depression: protocol for a systematic review and meta-analysis.

PubMed

Oremus, Carolina; Oremus, Mark; McNeely, Heather; Losier, Bruno; Parlar, Melissa; King, Matthew; Hasey, Gary; Fervaha, Gagan; Graham, Allyson C; Gregory, Caitlin; Hanford, Lindsay; Nazarov, Anthony; Restivo, Maria; Tatham, Erica; Truong, Wanda; Hall, Geoffrey B C; Lanius, Ruth; McKinnon, Margaret

2015-03-11

Depression is the leading cause of disability worldwide, affecting approximately 350 million people. Evidence indicates that only 60-70% of persons with major depressive disorder who tolerate antidepressants respond to first-line drug treatment; the remainder become treatment resistant. Electroconvulsive therapy (ECT) is considered an effective therapy in persons with treatment-resistant depression. The use of ECT is controversial due to concerns about temporary cognitive impairment in the acute post-treatment period. We will conduct a meta-analysis to examine the effects of ECT on cognition in persons with depression. This systematic review and meta-analysis has been registered with PROSPERO (registration number: CRD42014009100). We developed our methods following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. We are searching MEDLINE, PsychINFO, EMBASE, CINAHL and Cochrane from the date of database inception to the end of October 2014. We are also searching the reference lists of published reviews and evidence reports for additional citations. Comparative studies (randomised controlled trials, cohort and case-control) published in English will be included in the meta-analysis. Three clinical neuropsychologists will group the cognitive tests in each included article into a set of mutually exclusive cognitive subdomains. The risk of bias of randomised controlled trials will be assessed using the Jadad scale. We will supplement the Jadad scale with additional questions based on the Cochrane risk of bias tool. The risk of bias of cohort and case-control studies will be assessed using the Newcastle-Ottawa Scale. We will employ the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to assess the strength of evidence. Separate meta-analyses will be conducted for each ECT treatment modality and cognitive subdomain using Comprehensive Meta-Analysis V.2.0. 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.

Bleeding and pneumonia in intensive care patients given ranitidine and sucralfate for prevention of stress ulcer: meta-analysis of randomised controlled trials

PubMed Central

Messori, A; Trippoli, S; Vaiani, M; Gorini, M; Corrado, A

2000-01-01

Objectives To determine the effectiveness of ranitidine and sucralfate in the prevention of stress ulcer in critical patients and to assess if these treatments affect the risk of nosocomial pneumonia. Design Published studies retrieved through Medline and other databases. Five meta-analyses evaluated effectiveness in terms of bleeding rates (A: ranitidine v placebo; B: sucralfate v placebo) and infectious complications in terms of incidence of nosocomial pneumonia (C: ranitidine v placebo; D: sucralfate v placebo; E: ranitidine v sucralfate). Trial quality was determined with an empirical ad hoc procedure. Main outcome measures Rates of clinically important gastrointestinal bleeding and nosocomial pneumonia (compared between the two study arms and expressed with odds ratios specific for individual studies and meta-analytic summary odds ratios). Results Meta-analysis A (five studies) comprised 398 patients; meta-analysis C (three studies) comprised 311 patients; meta-analysis D (two studies) comprised 226 patients: and meta-analysis E (eight studies) comprised 1825 patients. Meta-analysis B was not carried out as the literature search selected only one clinical trial. In meta-analysis A ranitidine was found to have the same effectiveness as placebo (odds ratio of bleeding 0.72, 95% confidence interval 0.30 to 1.70, P=0.46). In placebo controlled studies (meta-analyses C and D) ranitidine and sucralfate had no influence on the incidence of nosocomial pneumonia. In comparison with sucralfate, ranitidine significantly increased the incidence of nosocomial pneumonia (meta-analysis E: 1.35, 1.07 to 1.70, P=0.012). The mean quality score in the four analyses (on a 0 to 10 scale) ranged from 5.6 in meta-analysis E to 6.6 in meta-analysis A. Conclusions Ranitidine is ineffective in the prevention of gastrointestinal bleeding in patients in intensive care and might increase the risk of pneumonia. Studies on sucralfate do not provide conclusive results. These findings are based on small numbers of patients, and firm conclusions cannot presently be proposed. PMID:11061729

Association between response rates and survival outcomes in patients with newly diagnosed multiple myeloma. A systematic review and meta-regression analysis.

PubMed

Mainou, Maria; Madenidou, Anastasia-Vasiliki; Liakos, Aris; Paschos, Paschalis; Karagiannis, Thomas; Bekiari, Eleni; Vlachaki, Efthymia; Wang, Zhen; Murad, Mohammad Hassan; Kumar, Shaji; Tsapas, Apostolos

2017-06-01

We performed a systematic review and meta-regression analysis of randomized control trials to investigate the association between response to initial treatment and survival outcomes in patients with newly diagnosed multiple myeloma (MM). Response outcomes included complete response (CR) and the combined outcome of CR or very good partial response (VGPR), while survival outcomes were overall survival (OS) and progression-free survival (PFS). We used random-effect meta-regression models and conducted sensitivity analyses based on definition of CR and study quality. Seventy-two trials were included in the systematic review, 63 of which contributed data in meta-regression analyses. There was no association between OS and CR in patients without autologous stem cell transplant (ASCT) (regression coefficient: .02, 95% confidence interval [CI] -0.06, 0.10), in patients undergoing ASCT (-.11, 95% CI -0.44, 0.22) and in trials comparing ASCT with non-ASCT patients (.04, 95% CI -0.29, 0.38). Similarly, OS did not correlate with the combined metric of CR or VGPR, and no association was evident between response outcomes and PFS. Sensitivity analyses yielded similar results. This meta-regression analysis suggests that there is no association between conventional response outcomes and survival in patients with newly diagnosed MM. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Do health technology assessments comply with QUOROM diagram guidance? An empirical study.

PubMed

Hind, Daniel; Booth, Andrew

2007-11-20

The Quality of Reporting of Meta-analyses (QUOROM) statement provides guidance for improving the quality of reporting of systematic reviews and meta-analyses. To make the process of study selection transparent it recommends "a flow diagram providing information about the number of RCTs identified, included, and excluded and the reasons for excluding them". We undertook an empirical study to identify the extent of compliance in the UK Health Technology Assessment (HTA) programme. We searched Medline to retrieve all systematic reviews of therapeutic interventions in the HTA monograph series published from 2001 to 2005. Two researchers recorded whether each study contained a meta-analysis of controlled trials, whether a QUOROM flow diagram was presented and, if so, whether it expressed the relationship between the number of citations and the number of studies. We used Cohen's kappa to test inter-rater reliability. 87 systematic reviews were retrieved. There was good and excellent inter-rater reliability for, respectively, whether a review contained a meta-analysis and whether each diagram contained a citation-to-study relationship. 49% of systematic reviews used a study selection flow diagram. When only systematic reviews containing a meta-analysis were analysed, compliance was only 32%. Only 20 studies (23% of all systematic reviews; 43% of those having a study selection diagram) had a diagram which expressed the relationship between citations and studies. Compliance with the recommendations of the QUOROM statement is not universal in systematic reviews or meta-analyses. Flow diagrams make the conduct of study selection transparent only if the relationship between citations and studies is clearly expressed. Reviewers should understand what they are counting: citations, papers, studies and trials are fundamentally different concepts which should not be confused in a diagram.

Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer: Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses.

PubMed

Khankari, Nikhil K; Shu, Xiao-Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I; Easton, Douglas; Eeles, Rosalind A; Gruber, Stephen B; Haiman, Christopher A; Hunter, David J; Chanock, Stephen J; Pierce, Brandon L; Zheng, Wei

2016-09-01

Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using height-associated genetic variants identified in a genome-wide association study (GWAS), to evaluate the association of adult height with these cancers. A systematic review of prospective studies was conducted using the PubMed, Embase, and Web of Science databases. Using meta-analyses, results obtained from 62 studies were summarized for the association of a 10-cm increase in height with cancer risk. Mendelian randomization analyses were conducted using summary statistics obtained for 423 genetic variants identified from a recent GWAS of adult height and from a cancer genetics consortium study of multiple cancers that included 47,800 cases and 81,353 controls. For a 10-cm increase in height, the summary relative risks derived from the meta-analyses of prospective studies were 1.12 (95% CI 1.10, 1.15), 1.07 (95% CI 1.05, 1.10), and 1.06 (95% CI 1.02, 1.11) for colorectal, prostate, and lung cancers, respectively. Mendelian randomization analyses showed increased risks of colorectal (odds ratio [OR] = 1.58, 95% CI 1.14, 2.18) and lung cancer (OR = 1.10, 95% CI 1.00, 1.22) associated with each 10-cm increase in genetically predicted height. No association was observed for prostate cancer (OR = 1.03, 95% CI 0.92, 1.15). Our meta-analysis was limited to published studies. The sample size for the Mendelian randomization analysis of colorectal cancer was relatively small, thus affecting the precision of the point estimate. Our study provides evidence for a potential causal association of adult height with the risk of colorectal and lung cancers and suggests that certain genetic factors and biological pathways affecting adult height may also affect the risk of these cancers.

Pharmacologic Treatment of Repetitive Behaviors in Autism Spectrum Disorders: Evidence of Publication Bias

PubMed Central

Volkmar, Fred R.; Bloch, Michael H.

2012-01-01

OBJECTIVE: The goal of this study was to examine the efficacy of serotonin receptor inhibitors (SRIs) for the treatment of repetitive behaviors in autism spectrum disorders (ASD). METHODS: Two reviewers searched PubMed and Clinicaltrials.gov for randomized, double-blind, placebo-controlled trials evaluating the efficacy of SRIs for repetitive behaviors in ASD. Our primary outcome was mean improvement in ratings scales of repetitive behavior. Publication bias was assessed by using a funnel plot, the Egger’s test, and a meta-regression of sample size and effect size. RESULTS: Our search identified 5 published and 5 unpublished but completed trials eligible for meta-analysis. Meta-analysis of 5 published and 1 unpublished trial (which provided data) demonstrated a small but significant effect of SRI for the treatment of repetitive behaviors in ASD (standardized mean difference: 0.22 [95% confidence interval: 0.07–0.37], z score = 2.87, P < .005). There was significant evidence of publication bias in all analyses. When Duval and Tweedie's trim and fill method was used to adjust for the effect of publication bias, there was no longer a significant benefit of SRI for the treatment of repetitive behaviors in ASD (standardized mean difference: 0.12 [95% confidence interval: –0.02 to 0.27]). Secondary analyses demonstrated no significant effect of type of medication, patient age, method of analysis, trial design, or trial duration on reported SRI efficacy. CONCLUSIONS: Meta-analysis of the published literature suggests a small but significant effect of SRI in the treatment of repetitive behaviors in ASD. This effect may be attributable to selective publication of trial results. Without timely, transparent, and complete disclosure of trial results, it remains difficult to determine the efficacy of available medications. PMID:22529279

An international systematic review and meta-analysis of multisession psychosocial interventions compared with educational or minimal interventions on the HIV sex risk behaviors of people who use drugs.

PubMed

Meader, Nicholas; Semaan, Salaam; Halton, Marie; Bhatti, Henna; Chan, Melissa; Llewellyn, Alexis; Des Jarlais, Don C

2013-07-01

This systematic review and meta-analysis examines the effectiveness of multisession psychosocial interventions compared with educational interventions and minimal interventions in reducing sexual risk in people who use drugs (51 studies; 19,209 participants). We conducted comprehensive searches (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials and PsychINFO 1998-2012). Outcomes (unprotected sex, condom use, or a composite outcome) were extracted by two authors and synthesised using meta-analysis. Subgroup analyses and meta-regression were conducted to explore heterogeneity. Multisession psychosocial interventions had modest additional benefits compared to educational interventions (K = 46; OR 0.86; 95% CI 0.77, 0.96), and large positive effects compared to minimal interventions (K = 7; OR 0.60; 95% CI 0.46, 0.78). Comparison with previous meta-analyses suggested limited progress in recent years in developing more effective interventions. Multisession psychosocial and educational interventions provided similar modest sexual risk reduction justifying offering educational interventions in settings with limited exposure to sexual risk reduction interventions, messages, and resources.

Patent foramen ovale closure vs medical therapy for stroke prevention: meta-analysis of randomized trials and review of heterogeneity in meta-analyses.

PubMed

Udell, Jacob A; Opotowsky, Alexander R; Khairy, Paul; Silversides, Candice K; Gladstone, David J; O'Gara, Patrick T; Landzberg, Michael J

2014-10-01

Patent foramen ovale (PFO) might be a risk factor for unexplained ("cryptogenic") stroke or transient ischemic attack (TIA). We sought to determine the efficacy and safety of transcatheter PFO closure compared with antithrombotic therapy for secondary prevention of cerebrovascular events among patients with cryptogenic stroke. We performed a systematic review and meta-analysis of MedLine and Embase (from inception to March 2013) for randomized controlled trials (RCTs) that compared transcatheter PFO closure with medical therapy in subjects with cryptogenic stroke. Data were independently extracted on trial conduct quality, baseline characteristics, efficacy, and safety events from published articles and appendices. Risk ratios (RRs) and 95% confidence intervals (CIs) for the composite of stroke or TIA, and adverse cardiovascular events including atrial fibrillation/flutter were constructed. Three RCTs of 2303 subjects with previous stroke, TIA, or systemic arterial embolism (mean age, 45.7 years; 47.3% women; mean follow-up, 2.6 years) were included. PFO closure did not significantly reduce the risk of recurrent stroke/TIA (3.7% vs 5.2%; RR, 0.73; 95% CI, 0.50-1.07; P = 0.10); however, an increased risk of incident atrial fibrillation/flutter was detected (3.8% vs 1.0%; RR, 3.67; 95% CI, 1.95-6.89; P < 0.0001). No significant heterogeneity was detected for any end point among subgroups of patients stratified according to age, sex, index cardiovascular event, device type, interatrial shunt size, and presence of an atrial septal aneurysm (all P interactions ≥ 0.09). Meta-analysis of RCTs that assessed transcatheter PFO closure for secondary prevention of cerebrovascular events in subjects with cryptogenic stroke does not demonstrate benefit compared with antithrombotic therapy, and suggests potential risks. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Meta-analysis of the effect of road work zones on crash occurrence.

PubMed

Theofilatos, Athanasios; Ziakopoulos, Apostolos; Papadimitriou, Eleonora; Yannis, George; Diamandouros, Konstantinos

2017-11-01

There is strong evidence that work zones pose increased risk of crashes and injuries. The two most common risk factors associated with increased crash frequencies are work zone duration and length. However, relevant research on the topic is relatively limited. For that reason, this paper presents formal meta-analyses of studies that have estimated the relationship between the number of crashes and work zone duration and length, in order to provide overall estimates of those effects on crash frequencies. All studies presented in this paper are crash prediction models with similar specifications. According to the meta-analyses and after correcting for publication bias when it was considered appropriate, the summary estimates of regression coefficients were found to be 0.1703 for duration and 0.862 for length. These effects were significant for length but not for duration. However, the overall estimate of duration was significant before correcting for publication bias. Separate meta-analyses on the studies examining both duration and length was also carried out in order to have rough estimates of the combined effects. The estimate of duration was found to be 0.953, while for length was 0.847. Similar to previous meta-analyses the effect of duration after correcting for publication bias is not significant, while the effect of length was significant at a 95% level. Meta-regression findings indicate that the main factors influencing the overall estimates of the beta coefficients are study year and region for duration and study year and model specification for length. Copyright © 2017 Elsevier Ltd. All rights reserved.

Screening Mammography & Breast Cancer Mortality: Meta-Analysis of Quasi-Experimental Studies

PubMed Central

Irvin, Veronica L.; Kaplan, Robert M.

2014-01-01

Background The magnitude of the benefit associated with screening has been debated. We present a meta-analysis of quasi-experimental studies on the effects of mammography screening. Methods We searched MEDLINE/PubMed and Embase for articles published through January 31, 2013. Studies were included if they reported: 1) a population-wide breast cancer screening program using mammography with 5+ years of data post-implementation; 2) a comparison group with equal access to therapies; and 3) breast cancer mortality. Studies excluded were: RCTs, case-control, or simulation studies. We defined quasi-experimental as studies that compared either geographical, historical or birth cohorts with a screening program to an equivalent cohort without a screening program. Meta-analyses were conducted in Stata using the metan command, random effects. Meta-analyses were conducted separately for ages screened: under 50, 50 to 69 and over 70 and weighted by population and person-years. Results Among 4,903 published papers that were retrieved, 19 studies matched eligibility criteria. Birth cohort studies reported a significant benefit for women screened

Long-chain omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid and blood pressure: a meta-analysis of randomized controlled trials.

PubMed

Miller, Paige E; Van Elswyk, Mary; Alexander, Dominik D

2014-07-01

Although a large body of literature has been devoted to examining the relationship between eicosapentaenoic and docosahexaenoic acids (EPA+DHA) and blood pressure, past systematic reviews have been hampered by narrow inclusion criteria and a limited scope of analytical subgroups. In addition, no meta-analysis to date has captured the substantial volume of randomized controlled trials (RCTs) published in the past 2 years. The objective of this meta-analysis was to examine the effect of EPA+DHA, without upper dose limits and including food sources, on blood pressure in RCTs. Random-effects meta-analyses were used to generate weighted group mean differences and 95% confidence intervals (CIs) between the EPA+DHA group and the placebo group. Analyses were conducted for subgroups defined by key subject or study characteristics. Seventy RCTs were included. Compared with placebo, EPA+DHA provision reduced systolic blood pressure (-1.52 mm Hg; 95% confidence interval (CI) = -2.25 to -0.79) and diastolic blood pressure (-0.99 mm Hg; 95% CI = -1.54 to -0.44) in the meta-analyses of all studies combined. The strongest effects of EPA+DHA were observed among untreated hypertensive subjects (systolic blood pressure = -4.51 mm Hg, 95% CI = -6.12 to -2.83; diastolic blood pressure = -3.05 mm Hg, 95% CI = -4.35 to - 1.74), although blood pressure also was lowered among normotensive subjects (systolic blood pressure = -1.25 mm Hg, 95% CI = -2.05 to -0.46; diastolic blood pressure = -0.62 mm Hg, 95% CI = -1.22 to -0.02). Overall, available evidence from RCTs indicates that provision of EPA+DHA reduces systolic blood pressure, while provision of ≥2 grams reduces diastolic blood pressure. © The Author 2014. Published by Oxford University Press on behalf of the American Journal of Hypertension.

RAMESES publication standards: meta-narrative reviews

PubMed Central

2013-01-01

Background Meta-narrative review is one of an emerging menu of new approaches to qualitative and mixed-method systematic review. A meta-narrative review seeks to illuminate a heterogeneous topic area by highlighting the contrasting and complementary ways in which researchers have studied the same or a similar topic. No previous publication standards exist for the reporting of meta-narrative reviews. This publication standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards) project. The project's aim is to produce preliminary publication standards for meta-narrative reviews. Methods We (a) collated and summarized existing literature on the principles of good practice in meta-narrative reviews; (b) considered the extent to which these principles had been followed by published reviews, thereby identifying how rigor may be lost and how existing methods could be improved; (c) used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, meta-narrative reviews, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d) provided real-time support to ongoing meta-narrative reviews and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e) synthesized expert input, evidence review and real-time problem analysis into a definitive set of standards. Results We identified nine published meta-narrative reviews, provided real-time support to four ongoing reviews and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature, and common questions and challenges into briefing materials for the Delphi panel, comprising 33 members. Within three rounds this panel had reached consensus on 20 key publication standards, with an overall response rate of 90%. Conclusion This project used multiple sources to draw together evidence and expertise in meta-narrative reviews. For each item we have included an explanation for why it is important and guidance on how it might be reported. Meta-narrative review is a relatively new method for evidence synthesis and as experience and methodological developments occur, we anticipate that these standards will evolve to reflect further theoretical and methodological developments. We hope that these standards will act as a resource that will contribute to improving the reporting of meta-narrative reviews. To encourage dissemination of the RAMESES publication standards, this article is co-published in the Journal of Advanced Nursing and is freely accessible on Wiley Online Library (http://www.wileyonlinelibrary.com/journal/jan). Please see related articles http://www.biomedcentral.com/1741-7015/11/21 and http://www.biomedcentral.com/1741-7015/11/22 PMID:23360661

Impact of 68Ga-PSMA PET on the Management of Patients with Prostate Cancer: A Systematic Review and Meta-analysis.

PubMed

Han, Sangwon; Woo, Sungmin; Kim, Yeon Joo; Suh, Chong Hyun

2018-04-18

68 Gallium prostate-specific membrane antigen positron emission tomography ( 68 Ga-PSMA PET) is an emerging imaging modality for assessment of prostate cancer. Recent studies show promising results regarding its ability to detect recurrent or metastatic prostate cancer superior to that of conventional imaging modalities. However, the impact of 68 Ga-PSMA PET on management of patients with prostate cancer has not been well established. To perform a systematic review and meta-analysis to evaluate the impact of 68 Ga-PSMA PET on management of patients with prostate cancer. Pubmed and EMBASE databases were searched up to January 20, 2018. We included studies that reported proportion of management change after 68 Ga-PSMA PET in patients with prostate cancer. The quality of the studies was evaluated using the GRADE system. The proportion of management changes were pooled using random-effects model. Subgroup analyses and meta-regression analyses were performed to explore heterogeneity. Fifteen studies (1163 patients) were included. The pooled proportion of management changes was 54% (95% confidence interval 47-60%). At meta-regression analyses, PET positivity (%) was a significant factor of heterogeneity (p=0.0486). For patients with biochemical failure, the proportion of radiotherapy (from 56% to 61%), surgery (from 1% to 7%), focal therapy (from 1% to 2%), and multimodal treatment (from 2% to 6%) increased, whereas that of systemic treatment (from 26% to 12%) and no treatment (from 14% to 11%) decreased with 68 Ga-PSMA PET. 68 Ga-PSMA PET had a large impact on the management of patients with prostate cancer. Greater PET positivity was associated with higher proportion of management changes. We reviewed all previous studies assessing the impact of 68 Gallium prostate-specific membrane antigen positron emission tomography ( 68 Ga-PSMA PET) in patients with prostate cancer. We found that 68 Ga-PSMA PET altered the management in approximately half of the patients. Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Parent-Based Adolescent Sexual Health Interventions And Effect on Communication Outcomes: A Systematic Review and Meta-Analyses

PubMed Central

Maria, Diane Santa; Markham, Christine; Mullen, Patricia Dolan; Bluethmann, Shirley

2016-01-01

Context Parent-based adolescent sexual health interventions aim to reduce sexual risk behaviors by bolstering parental protective behaviors. Few studies of theory use, methods, applications, delivery and outcomes of parent-based interventions have been conducted. Methods A systematic search of databases for the period 1998–2013 identified 28 published trials of U.S. parent-based interventions to examine theory use, setting, reach, delivery mode, dose and effects on parent-child communication. Established coding schemes were used to assess use of theory and describe methods employed to achieve behavioral change; intervention effects were explored in meta-analyses. Results Most interventions were conducted with minority parents in group sessions or via self-paced activities; interventions averaged seven hours, and most used theory extensively. Meta-analyses found improvements in sexual health communication: Analysis of 11 controlled trials indicated a medium effect on increasing communication (Cohen's d, 0.5), and analysis of nine trials found a large effect on increasing parental comfort with communication (0.7); effects were positive regardless of delivery mode or intervention dose. Intervention participants were 68% more likely than controls to report increased communication and 75% more likely to report increased comfort. Conclusions These findings point to gaps in the range of programs examined in published trials—for example, interventions for parents of sexual minority youth, programs for custodial grandparents and faith-based services. Yet they provide support for the effectiveness of parent-based interventions in improving communication. Innovative delivery approaches could extend programs' reach, and further research on sexual health outcomes would facilitate the meta-analysis of intervention effectiveness in improving adolescent sexual health behaviors. PMID:25639664

Parent-based adolescent sexual health interventions and effect on communication outcomes: a systematic review and meta-analyses.

PubMed

Santa Maria, Diane; Markham, Christine; Bluethmann, Shirley; Mullen, Patricia Dolan

2015-03-01

Parent-based adolescent sexual health interventions aim to reduce sexual risk behaviors by bolstering parental protective behaviors. Few studies of theory use, methods, applications, delivery and outcomes of parent-based interventions have been conducted. A systematic search of databases for the period 1998-2013 identified 28 published trials of U.S. parent-based interventions to examine theory use, setting, reach, delivery mode, dose and effects on parent-child communication. Established coding schemes were used to assess use of theory and describe methods employed to achieve behavioral change; intervention effects were explored in meta-analyses. Most interventions were conducted with minority parents in group sessions or via self-paced activities; interventions averaged seven hours, and most used theory extensively. Meta-analyses found improvements in sexual health communication: Analysis of 11 controlled trials indicated a medium effect on increasing communication (Cohen's d, 0.5), and analysis of nine trials found a large effect on increasing parental comfort with communication (0.7); effects were positive regardless of delivery mode or intervention dose. Intervention participants were 68% more likely than controls to report increased communication and 75% more likely to report increased comfort. These findings point to gaps in the range of programs examined in published trials-for example, interventions for parents of sexual minority youth, programs for custodial grandparents and faith-based services. Yet they provide support for the effectiveness of parent-based interventions in improving communication. Innovative delivery approaches could extend programs' reach, and further research on sexual health outcomes would facilitate the meta-analysis of intervention effectiveness in improving adolescent sexual health behaviors. Copyright © 2015 by the Guttmacher Institute.

Frequency of progression from acute to chronic pancreatitis and risk factors: a meta-analysis.

PubMed

Sankaran, Sharanya J; Xiao, Amy Y; Wu, Landy M; Windsor, John A; Forsmark, Christopher E; Petrov, Maxim S

2015-11-01

Acute pancreatitis (AP) and chronic pancreatitis (CP) traditionally have been thought to be distinct diseases, but there is evidence that AP can progress to CP. Little is known about the mechanisms of pancreatitis progression. We performed a meta-analysis to quantify the frequency of transition of AP to CP and identify risk factors for progression. We searched PubMed, Scopus, and Embase for studies of patients with AP who developed CP, published from 1966 through November 2014. Pooled prevalence and 95% confidence intervals (CIs) were calculated for these outcomes, and sensitivity, subgroup, and meta-regression analyses were conducted. We analyzed 14 studies, which included a total of 8492 patients. The pooled prevalence of recurrent AP was 22% (95% CI, 18%-26%), and the pooled prevalence of CP was 10% (95% CI, 6%-15%). Sensitivity analyses yielded a pooled prevalence of CP of 10% (95% CI, 4%-19%) and 36% (95% CI, 20%-53%) in patients after the first occurrence and recurrent AP, respectively. Subgroup analyses found alcohol use and smoking to be the largest risk factors for the development of CP, with pooled prevalence values of 65% (95% CI, 48%-56%) and 61% (95% CI, 47%-73%), respectively. Meta-regression analysis found that men were more likely than women to transition from AP to CP. Ten percent of patients with a first episode of AP and 36% of patients with recurrent AP develop CP; the risk is higher among smokers, alcoholics, and men. Prospective clinical studies are needed to study pancreatitis progression. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Reporting and handling missing outcome data in mental health: a systematic review of Cochrane systematic reviews and meta-analyses.

PubMed

Spineli, Loukia M; Pandis, Nikolaos; Salanti, Georgia

2015-06-01

The purpose of the study was to provide empirical evidence about the reporting of methodology to address missing outcome data and the acknowledgement of their impact in Cochrane systematic reviews in the mental health field. Systematic reviews published in the Cochrane Database of Systematic Reviews after January 1, 2009 by three Cochrane Review Groups relating to mental health were included. One hundred ninety systematic reviews were considered. Missing outcome data were present in at least one included study in 175 systematic reviews. Of these 175 systematic reviews, 147 (84%) accounted for missing outcome data by considering a relevant primary or secondary outcome (e.g., dropout). Missing outcome data implications were reported only in 61 (35%) systematic reviews and primarily in the discussion section by commenting on the amount of the missing outcome data. One hundred forty eligible meta-analyses with missing data were scrutinized. Seventy-nine (56%) of them had studies with total dropout rate between 10 and 30%. One hundred nine (78%) meta-analyses reported to have performed intention-to-treat analysis by including trials with imputed outcome data. Sensitivity analysis for incomplete outcome data was implemented in less than 20% of the meta-analyses. Reporting of the techniques for handling missing outcome data and their implications in the findings of the systematic reviews are suboptimal. Copyright © 2014 John Wiley & Sons, Ltd.

Generating the evidence for risk reduction: a contribution to the future of food-based dietary guidelines.

PubMed

Schwingshackl, Lukas; Schlesinger, Sabrina; Devleesschauwer, Brecht; Hoffmann, Georg; Bechthold, Angela; Schwedhelm, Carolina; Iqbal, Khalid; Knüppel, Sven; Boeing, Heiner

2018-04-30

A major advantage of analyses on the food group level is that the results are better interpretable compared with nutrients or complex dietary patterns. Such results are also easier to transfer into recommendations on primary prevention of non-communicable diseases. As a consequence, food-based dietary guidelines (FBDG) are now the preferred approach to guide the population regarding their dietary habits. However, such guidelines should be based on a high grade of evidence as requested in many other areas of public health practice. The most straightforward approach to generate evidence is meta-analysing published data based on a careful definition of the research question. Explicit definitions of study questions should include participants, interventions/exposure, comparisons, outcomes and study design. Such type of meta-analyses should not only focus on categorical comparisons, but also on linear and non-linear dose-response associations. Risk of bias of the individual studies of the meta-analysis should be assessed, rated and the overall credibility of the results scored (e.g. using NutriGrade). Tools such as a measurement tool to assess systematic reviews or ROBIS are available to evaluate the methodological quality/risk of bias of meta-analyses. To further evaluate the complete picture of evidence, we propose conducting network meta-analyses (NMA) of intervention trials, mostly on intermediate disease markers. To rank food groups according to their impact, disability-adjusted life years can be used for the various clinical outcomes and the overall results can be compared across the food groups. For future FBDG, we recommend to implement evidence from pairwise and NMA and to quantify the health impact of diet-disease relationships.

Pharmacogenetics of clozapine response and induced weight gain: A comprehensive review and meta-analysis.

PubMed

Gressier, Florence; Porcelli, Stefano; Calati, Raffaella; Serretti, Alessandro

2016-02-01

Clozapine (CLZ) is the prototype atypical antipsychotic and it has many advantages over other antipsychotic drugs. Several data suggest that both CLZ response and induced weight gain are strongly determined by genetic variability. However, results remain mainly inconclusive. We aim to review the literature data about pharmacogenetics studies on CLZ efficacy, focusing on pharmacodynamic genes. Further, we performed meta-analyses on response when at least three studies for each polymorphism were available. Sensitivity analyses were conducted on Caucasian population when feasible. Electronic literature search was performed to identify pertinent studies published until May 2014 using PubMed, ISI Web of Knowledge and PsycINFO databases. For meta-analyses, data were entered and analyzed through RevMan version 5.2 using a random-effect model. Our literature search yielded 9266 articles on CLZ; among these, we identified 59 pertinent pharmacogenetic studies. Genotype data were retrieved for 14 polymorphisms in 9 genes. Among these, we had available data from at least three independent samples for 8 SNPs in 6 genes to perform meta-analyses: DRD2 rs1799732, DRD3 rs6280, HTR2A rs6313, rs6311, rs6314, HTR2C rs6318, HTR3A rs1062613, TNFa rs1800629. Although literature review provided conflicting results, in meta-analyses three genetic variants within serotonin genes resulted associated to CLZ response: rs6313 and rs6314 within HTR2A gene and rs1062613 within HT3A gene. On the other hand, no clear finding emerged for CLZ-induced weight gain. Our results suggest a possible serotonergic modulation of CLZ clinical response. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Relationship between miR-146a rs2910164 (G>C) Polymorphism and Digestive System Cancer Susceptibility: A Meta-Analysis.

PubMed

Xiong, Xin; Yan, Junfeng; Li, Linghua; Li, Yun; Cao, Yi; Tu, Yi; Mei, Jinhong

2017-08-01

MicroRNAs (miRNAs) are identified negatively regulating gene expression and acting as oncogenes or tumor suppressors in tumorigenesis. The association between miR-146a rs2910164 (G>C) polymorphism and susceptibility to digestive system cancers was contradictory and inconsistent in previously published studies. Presently, we performed a comprehensive literature retrieve on PubMed, Web of Science, Embase, Wanfang and CNKI databases to identify all relevant studies published before July 30, 2016. Odds ratio (OR) and 95% confidential interval (95%CI) were used to calculate the relationship between miR-146a rs2910164 (G>C) polymorphism and digestive system cancers susceptibility. Finally, a total of 45 publications comprising 47 separate case-control studies were enrolled in the present updated meta-analysis including 20,281 cases and 26,099 controls. However, no significant association was uncovered for miR-146a rs2910164 polymorphism and digestive system cancers susceptibility in all the genetic models. Moreover, in the stratification analyses by cancer type, the source of control, ethnicity and Hardy-Weinberg Equilibrium (HWE) status, we also revealed a negative result. To conclude, our work suggests that miR-146a rs2910164 (G>C) polymorphism is not a susceptibility factor for digestive system cancers. © 2017 by the Association of Clinical Scientists, Inc.

Breast implants and the risk of breast cancer: a meta-analysis of cohort studies.

PubMed

Noels, Eline C; Lapid, Oren; Lindeman, Jan H N; Bastiaannet, Esther

2015-01-01

The popularity of cosmetic breast augmentation and the incidence of breast cancer have been increasing worldwide. It has been hypothesized that the risk of breast cancer may be greater among patients who have undergone cosmetic breast implantation. The authors performed a meta-analysis of the available literature on the risk of breast cancer among women with cosmetic breast implants. The study was designed as a meta-analysis of observational studies. A systematic search of the English literature (published by August 28, 2013) was conducted in PubMed and EMBASE. Eligible reports were those that included relative risk (RR; the increased or decreased risk of breast cancer associated with breast implants) or the standardized incidence ratio (SIR) of the observed number of cases of breast cancer to the expected number of cases among patients that previously underwent cosmetic breast augmentation. Seventeen studies representing 7 cohorts were selected. Some of these were follow-up reports of previously published studies; in such cases, only the most recent reports were included in the meta-analysis. Summary SIR and RR rates and the corresponding 95% confidence intervals (CIs) were calculated with a random-effects (SIR) or fixed-effects (RR) model. The overall SIR estimate was 0.69 (95% CI, 0.56-0.85), and the overall RR, based on 4 studies, was 0.63 (95% CI, 0.56-0.71). Finding of this meta-analysis suggest that women who have undergone cosmetic breast implantation do not have an increased risk of breast cancer. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

The effect of Tai Chi on four chronic conditions-cancer, osteoarthritis, heart failure and chronic obstructive pulmonary disease: a systematic review and meta-analyses.

PubMed

Chen, Yi-Wen; Hunt, Michael A; Campbell, Kristin L; Peill, Kortni; Reid, W Darlene

2016-04-01

Many middle-aged and older persons have more than one chronic condition. Thus, it is important to synthesise the effectiveness of interventions across several comorbidities. The aim of this systematic review was to summarise current evidence regarding the effectiveness of Tai Chi in individuals with four common chronic conditions-cancer, osteoarthritis (OA), heart failure (HF) and chronic obstructive pulmonary disease (COPD). 4 databases (MEDLINE, EMBASE, CINAHL and SPORTDiscus) were searched for original articles. Two reviewers independently screened the titles and abstracts and then conducted full-text reviews, quality assessment and finally data abstraction. 33 studies met the inclusion criteria. Meta-analyses were performed on disease-specific symptoms, physiological outcomes and physical performance of each chronic condition. Subgroup analyses on disease-specific symptoms were conducted by categorising studies into subsets based on the type of comparison groups. Meta-analyses showed that Tai Chi improved or showed a tendency to improve physical performance outcomes, including 6-min walking distance (6MWD) and knee extensor strength, in most or all four chronic conditions. Tai Chi also improved disease-specific symptoms of pain and stiffness in OA. The results demonstrated a favourable effect or tendency of Tai Chi to improve physical performance and showed that this type of exercise could be performed by individuals with different chronic conditions, including COPD, HF and OA. 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/

Threatening communication: a critical re-analysis and a revised meta-analytic test of fear appeal theory.

PubMed

Peters, Gjalt-Jorn Ygram; Ruiter, Robert A C; Kok, Gerjo

2013-05-01

Despite decades of research, consensus regarding the dynamics of fear appeals remains elusive. A meta-analysis was conducted that was designed to resolve this controversy. Publications that were included in previous meta-analyses were re-analysed, and a number of additional publications were located. The inclusion criteria were full factorial orthogonal manipulations of threat and efficacy, and measurement of behaviour as an outcome. Fixed and random effects models were used to compute mean effect size estimates. Meta-analysis of the six studies that satisfied the inclusion criteria clearly showed a significant interaction between threat and efficacy, such that threat only had an effect under high efficacy (d = 0.31), and efficacy only had an effect under high threat (d = 0.71). Inconsistency in results regarding the effectiveness of threatening communication can likely be attributed to flawed methodology. Proper tests of fear appeal theory yielded the theoretically hypothesised interaction effect. Threatening communication should exclusively be used when pilot studies indicate that an intervention successfully enhances efficacy.

Threatening communication: a critical re-analysis and a revised meta-analytic test of fear appeal theory

PubMed Central

Peters, Gjalt-Jorn Ygram; Ruiter, Robert A.C.; Kok, Gerjo

2013-01-01

Despite decades of research, consensus regarding the dynamics of fear appeals remains elusive. A meta-analysis was conducted that was designed to resolve this controversy. Publications that were included in previous meta-analyses were re-analysed, and a number of additional publications were located. The inclusion criteria were full factorial orthogonal manipulations of threat and efficacy, and measurement of behaviour as an outcome. Fixed and random effects models were used to compute mean effect size estimates. Meta-analysis of the six studies that satisfied the inclusion criteria clearly showed a significant interaction between threat and efficacy, such that threat only had an effect under high efficacy (d = 0.31), and efficacy only had an effect under high threat (d = 0.71). Inconsistency in results regarding the effectiveness of threatening communication can likely be attributed to flawed methodology. Proper tests of fear appeal theory yielded the theoretically hypothesised interaction effect. Threatening communication should exclusively be used when pilot studies indicate that an intervention successfully enhances efficacy. PMID:23772231

Cardiovascular risk from water arsenic exposure in Vietnam: Application of systematic review and meta-regression analysis in chemical health risk assessment.

PubMed

Phung, Dung; Connell, Des; Rutherford, Shannon; Chu, Cordia

2017-06-01

A systematic review (SR) and meta-analysis cannot provide the endpoint answer for a chemical risk assessment (CRA). The objective of this study was to apply SR and meta-regression (MR) analysis to address this limitation using a case study in cardiovascular risk from arsenic exposure in Vietnam. Published studies were searched from PubMed using the keywords of arsenic exposure and cardiovascular diseases (CVD). Random-effects meta-regression was applied to model the linear relationship between arsenic concentration in water and risk of CVD, and then the no-observable-adverse-effect level (NOAEL) were identified from the regression function. The probabilistic risk assessment (PRA) technique was applied to characterize risk of CVD due to arsenic exposure by estimating the overlapping coefficient between dose-response and exposure distribution curves. The risks were evaluated for groundwater, treated and drinking water. A total of 8 high quality studies for dose-response and 12 studies for exposure data were included for final analyses. The results of MR suggested a NOAEL of 50 μg/L and a guideline of 5 μg/L for arsenic in water which valued as a half of NOAEL and guidelines recommended from previous studies and authorities. The results of PRA indicated that the observed exposure level with exceeding CVD risk was 52% for groundwater, 24% for treated water, and 10% for drinking water in Vietnam, respectively. The study found that systematic review and meta-regression can be considered as an ideal method to chemical risk assessment due to its advantages to bring the answer for the endpoint question of a CRA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compressive cryotherapy versus cryotherapy alone in patients undergoing knee surgery: a meta-analysis.

PubMed

Song, Mingzhi; Sun, Xiaohong; Tian, Xiliang; Zhang, Xianbin; Shi, Tieying; Sun, Ran; Dai, Wei

2016-01-01

This study aims to conduct a meta-analysis to identify and compare the effectiveness of compressive cryotherapy and cryotherapy alone for patients undergoing knee surgery. Postoperative management is an important guarantee for the success of surgery. Cryotherapy and compression are two common nursing techniques after knee surgery, and are considered to be effective for postoperative clinical symptoms such as local pain and swelling. However, no previous meta-analyses have compared the effectiveness of compressive cryotherapy and cryotherapy alone in patients undergoing knee surgery. A meta-analysis of randomized controlled trials (RCTs). We conducted a search in MEDLINE (via Pubmed, 1990-2014), EMBASE (via Elsevier, 1990-2014), Cochrane Central Register of Controlled Trials (The Cochrane Library, 1990-2014), CINAHL (1990-2014) and China National Knowledge Infrastructure (1990-2014) databases for RCTs published in English and Chinese. The primary outcome measure of interest was visual analog scale and girth measure. Finally, a meta-analysis was carried out using RevMan 5.3. Among the 593 RCTs, 10 RCTs were selected and included into this study. These studies included 522 patients who underwent knee surgery. Patients who underwent compressive cryotherapy tended to have less pain than patients who underwent cryotherapy alone at POD2 and POD3, while compressive cryotherapy had a strong tendency towards less swelling over cryotherapy alone at POD1 and POD2. However, there was no significant difference between compressive cryotherapy and cryotherapy alone at the intermediate stage of rehabilitation after knee surgery. All adverse reactions were recorded in all included RCTs. Current evidence suggests that compressive cryotherapy is beneficial to patients undergoing knee surgery at the early rehabilitation stage. At the last stage, the effectiveness of compressive cryotherapy and cryotherapy alone were found to be similar.

Occupational exposure and risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis.

PubMed

Alif, Sheikh M; Dharmage, Shyamali C; Bowatte, Gayan; Karahalios, Amalia; Benke, Geza; Dennekamp, Martine; Mehta, Amar J; Miedinger, David; Künzli, Nino; Probst-Hensch, Nicole; Matheson, Melanie C

2016-08-01

Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD). Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.

Environmental risk factors and Parkinson's disease: An umbrella review of meta-analyses.

PubMed

Bellou, Vanesa; Belbasis, Lazaros; Tzoulaki, Ioanna; Evangelou, Evangelos; Ioannidis, John P A

2016-02-01

Parkinson's disease is a neurological disorder with complex pathogenesis implicating both environmental and genetic factors. We aimed to summarise the environmental risk factors that have been studied for potential association with Parkinson's disease, assess the presence of diverse biases, and identify the risk factors with the strongest support. We searched PubMed from inception to September 18, 2015, to identify systematic reviews and meta-analyses of observational studies that examined associations between environmental factors and Parkinson's disease. For each meta-analysis we estimated the summary effect size by random-effects and fixed-effects models, the 95% confidence interval and the 95% prediction interval. We estimated the between-study heterogeneity expressed by I(2), evidence of small-study effects and evidence of excess significance bias. Overall, 75 unique meta-analyses on different risk factors for Parkinson's disease were examined, covering diverse biomarkers, dietary factors, drugs, medical history or comorbid diseases, exposure to toxic environmental agents and habits. 21 of 75 meta-analyses had results that were significant at p < 0.001 by random-effects. Evidence for an association was convincing (more than 1000 cases, p < 10(-6) by random-effects, not large heterogeneity, 95% prediction interval excluding the null value and absence of hints for small-study effects and excess significance bias) for constipation, and physical activity. Many environmental factors have substantial evidence of association with Parkinson's disease, but several, perhaps most, of them may reflect reverse causation, residual confounding, information bias, sponsor conflicts or other caveats. Copyright © 2016. Published by Elsevier Ltd.

Assessment of the quality of reporting in abstracts of systematic reviews with meta-analyses in periodontology and implant dentistry.

PubMed

Faggion, C M; Liu, J; Huda, F; Atieh, M

2014-04-01

Proper scientific reporting is necessary to ensure the correct interpretation of study results by readers. The main objective of this study was to assess the quality of reporting in abstracts of systematic reviews (SRs) with meta-analyses in periodontology and implant dentistry. Differences in reporting of abstracts in Cochrane and paper-based reviews were also assessed. The PubMed electronic database and the Cochrane database for SRs were searched on November 11, 2012, independently and in duplicate, for SRs with meta-analyses related to interventions in periodontology and implant dentistry. Assessment of the quality of reporting was performed independently and in duplicate, taking into account items related to the effect direction, numerical estimates of effect size, measures of precision, probability and consistency. We initially screened 433 papers and included 146 (127 paper-based and 19 Cochrane reviews, respectively). The direction of evidence was reported in two-thirds of the abstracts while strength of evidence and measure of precision (i.e., confidence interval) were reported in less than half the selected abstracts. Measures of consistency such as I(2) statistics were reported in only 5% of the selected sample of abstracts. Cochrane abstracts reported the limitations of evidence and precision better than paper-based ones. Two items ("meta-analysis" in title and abstract, respectively), were nevertheless better reported in paper-based abstracts. Abstracts of SRs with meta-analyses in periodontology and implant dentistry currently have no uniform standard of reporting, which may hinder readers' understanding of study outcomes. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The interrelation between hypothyroidism and glaucoma: a critical review and meta-analyses.

PubMed

Thvilum, Marianne; Brandt, Frans; Brix, Thomas Heiberg; Hegedüs, Laszlo

2017-12-01

Data on the association between hypothyroidism and glaucoma are conflicting. We sought to shed light on this by conducting a critical review and meta-analyses. The meta-analyses were conducted in adherence with the widely accepted MOOSE guidelines. Using the Medical Subject Heading (MeSH) terms: hypothyroidism, myxoedema and glaucoma or intraocular pressure, case-control studies, cohort studies and cross-sectional studies were identified (PubMed) and reviewed. Using meta-analysis, the relative risk (RR) of coexistence of glaucoma and hypothyroidism was calculated. Based on the literature search, thirteen studies fulfilled the inclusion criteria and could be categorized into two groups based on the exposure. The designs of the studies varied considerably, and there was heterogeneity related to lack of power, weak phenotype classifications and length of follow-up. Eight studies had glaucoma (5757 patients) as exposure and hypothyroidism as outcome. Among these, we found a non-significantly increased risk of hypothyroidism associated with glaucoma (RR 1.65; 95% confidence interval [CI]: 0.97-2.82). Based on five studies (168 006 patients) with hypothyroidism as exposure and glaucoma as outcome, we found the risk of glaucoma to be significantly increased (RR 1.33; 95% CI: 1.13-1.58). Based on these meta-analyses, there seems to be an association between hypothyroidism and glaucoma, which does not seem to be the case between glaucoma and hypothyroidism. However, larger scale studies with better phenotype classification, longer follow-up and taking comorbidity and other biases into consideration are needed to address a potential causal relationship. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels.

PubMed

Spracklen, Cassandra N; Chen, Peng; Kim, Young Jin; Wang, Xu; Cai, Hui; Li, Shengxu; Long, Jirong; Wu, Ying; Wang, Ya Xing; Takeuchi, Fumihiko; Wu, Jer-Yuarn; Jung, Keum-Ji; Hu, Cheng; Akiyama, Koichi; Zhang, Yonghong; Moon, Sanghoon; Johnson, Todd A; Li, Huaixing; Dorajoo, Rajkumar; He, Meian; Cannon, Maren E; Roman, Tamara S; Salfati, Elias; Lin, Keng-Hung; Guo, Xiuqing; Sheu, Wayne H H; Absher, Devin; Adair, Linda S; Assimes, Themistocles L; Aung, Tin; Cai, Qiuyin; Chang, Li-Ching; Chen, Chien-Hsiun; Chien, Li-Hsin; Chuang, Lee-Ming; Chuang, Shu-Chun; Du, Shufa; Fan, Qiao; Fann, Cathy S J; Feranil, Alan B; Friedlander, Yechiel; Gordon-Larsen, Penny; Gu, Dongfeng; Gui, Lixuan; Guo, Zhirong; Heng, Chew-Kiat; Hixson, James; Hou, Xuhong; Hsiung, Chao Agnes; Hu, Yao; Hwang, Mi Yeong; Hwu, Chii-Min; Isono, Masato; Juang, Jyh-Ming Jimmy; Khor, Chiea-Chuen; Kim, Yun Kyoung; Koh, Woon-Puay; Kubo, Michiaki; Lee, I-Te; Lee, Sun-Ju; Lee, Wen-Jane; Liang, Kae-Woei; Lim, Blanche; Lim, Sing-Hui; Liu, Jianjun; Nabika, Toru; Pan, Wen-Harn; Peng, Hao; Quertermous, Thomas; Sabanayagam, Charumathi; Sandow, Kevin; Shi, Jinxiu; Sun, Liang; Tan, Pok Chien; Tan, Shu-Pei; Taylor, Kent D; Teo, Yik-Ying; Toh, Sue-Anne; Tsunoda, Tatsuhiko; van Dam, Rob M; Wang, Aili; Wang, Feijie; Wang, Jie; Wei, Wen Bin; Xiang, Yong-Bing; Yao, Jie; Yuan, Jian-Min; Zhang, Rong; Zhao, Wanting; Chen, Yii-Der Ida; Rich, Stephen S; Rotter, Jerome I; Wang, Tzung-Dau; Wu, Tangchun; Lin, Xu; Han, Bok-Ghee; Tanaka, Toshihiro; Cho, Yoon Shin; Katsuya, Tomohiro; Jia, Weiping; Jee, Sun-Ha; Chen, Yuan-Tsong; Kato, Norihiro; Jonas, Jost B; Cheng, Ching-Yu; Shu, Xiao-Ou; He, Jiang; Zheng, Wei; Wong, Tien-Yin; Huang, Wei; Kim, Bong-Jo; Tai, E-Shyong; Mohlke, Karen L; Sim, Xueling

2017-05-01

Large-scale meta-analyses of genome-wide association studies (GWAS) have identified >175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 × 10-8) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 × 10-9), NCOA2 (P = 1.6 × 10-8), and NID2-PTGDR (P = 4.2 × 10-8), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 × 10-10). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log10Bayes Factor ≥6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 × 10-5) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Red and processed meat consumption and breast cancer: UK Biobank cohort study and meta-analysis.

PubMed

Anderson, Jana J; Darwis, Narisa D M; Mackay, Daniel F; Celis-Morales, Carlos A; Lyall, Donald M; Sattar, Naveed; Gill, Jason M R; Pell, Jill P

2018-02-01

Red and processed meat may be risk factors for breast cancer due to their iron content, administration of oestrogens to cattle or mutagens created during cooking. We studied the associations in UK Biobank and then included the results in a meta-analysis of published cohort studies. UK Biobank, a general population cohort study, recruited participants aged 40-69 years. Incident breast cancer was ascertained via linkage to routine hospital admission, cancer registry and death certificate data. Univariate and multivariable Cox proportional hazard models were used to explore the associations between red and processed meat consumption and breast cancer. Previously published cohort studies were identified from a systematic review using PubMed and Ovid and a meta-analysis conducted using a random effects model. Over a median of 7 years follow-up, 4819 of the 262,195 women developed breast cancer. The risk was increased in the highest tertile (>9 g/day) of processed meat consumption (adjusted hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.08-1.35, p = 0.001). Collation with 10 previous cohort studies provided data on 40,257 incident breast cancers in 1.65 million women. On meta-analysis, processed meat consumption was associated with overall (relative risk [RR] 1.06, 95% CI 1.01-1.11) and post-menopausal (RR 1.09, 95% CI 1.03-1.15), but not pre-menopausal (RR 0.99, 95% CI 0.88-1.10), breast cancer. In UK Biobank and the meta-analysis, red meat consumption was not associated with breast cancer (adjusted HR 0.99 95% CI 0.88-1.12 and RR 1.03, 95% CI 0.99-1.08, respectively). Consumption of processed meat, but not red meat, may increase the risk of breast cancer. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Epstein-Barr Virus and Gastric Cancer Risk: A Meta-analysis With Meta-regression of Case-control Studies.

PubMed

Bae, Jong-Myon; Kim, Eun Hee

2016-03-01

Research on how the risk of gastric cancer increases with Epstein-Barr virus (EBV) infection is lacking. In a systematic review that investigated studies published until September 2014, the authors did not calculate the summary odds ratio (SOR) due to heterogeneity across studies. Therefore, we include here additional studies published until October 2015 and conduct a meta-analysis with meta-regression that controls for the heterogeneity among studies. Using the studies selected in the previously published systematic review, we formulated lists of references, cited articles, and related articles provided by PubMed. From the lists, only case-control studies that detected EBV in tissue samples were selected. In order to control for the heterogeneity among studies, subgroup analysis and meta-regression were performed. In the 33 case-control results with adjacent non-cancer tissue, the total number of test samples in the case and control groups was 5280 and 4962, respectively. In the 14 case-control results with normal tissue, the total number of test samples in case and control groups was 1393 and 945, respectively. Upon meta-regression, the type of control tissue was found to be a statistically significant variable with regard to heterogeneity. When the control tissue was normal tissue of healthy individuals, the SOR was 3.41 (95% CI, 1.78 to 6.51; I-squared, 65.5%). The results of the present study support the argument that EBV infection increases the risk of gastric cancer. In the future, age-matched and sex-matched case-control studies should be conducted.

Introspective Minds: Using ALE Meta-Analyses to Study Commonalities in the Neural Correlates of Emotional Processing, Social & Unconstrained Cognition

PubMed Central

Schilbach, Leonhard; Bzdok, Danilo; Timmermans, Bert; Fox, Peter T.; Laird, Angela R.; Vogeley, Kai; Eickhoff, Simon B.

2012-01-01

Previous research suggests overlap between brain regions that show task-induced deactivations and those activated during the performance of social-cognitive tasks. Here, we present results of quantitative meta-analyses of neuroimaging studies, which confirm a statistical convergence in the neural correlates of social and resting state cognition. Based on the idea that both social and unconstrained cognition might be characterized by introspective processes, which are also thought to be highly relevant for emotional experiences, a third meta-analysis was performed investigating studies on emotional processing. By using conjunction analyses across all three sets of studies, we can demonstrate significant overlap of task-related signal change in dorso-medial prefrontal and medial parietal cortex, brain regions that have, indeed, recently been linked to introspective abilities. Our findings, therefore, provide evidence for the existence of a core neural network, which shows task-related signal change during socio-emotional tasks and during resting states. PMID:22319593

A Meta-Analysis of Randomized Controlled Trials and Prospective Cohort Studies of Eicosapentaenoic and Docosahexaenoic Long-Chain Omega-3 Fatty Acids and Coronary Heart Disease Risk.

PubMed

Alexander, Dominik D; Miller, Paige E; Van Elswyk, Mary E; Kuratko, Connye N; Bylsma, Lauren C

2017-01-01

To conduct meta-analyses of randomized controlled trials (RCTs) to estimate the effect of eicosapentaenoic and docosahexaenoic acid (EPA+DHA) on coronary heart disease (CHD), and to conduct meta-analyses of prospective cohort studies to estimate the association between EPA+DHA intake and CHD risk. A systematic literature search of Ovid/Medline, PubMed, Embase, and the Cochrane Library from January 1, 1947, to November 2, 2015, was conducted; 18 RCTs and 16 prospective cohort studies examining EPA+DHA from foods or supplements and CHD, including myocardial infarction, sudden cardiac death, coronary death, and angina, were identified. Random-effects meta-analysis models were used to generate summary relative risk estimates (SRREs) and 95% CIs. Heterogeneity was examined in subgroup and sensitivity analyses and by meta-regression. Dose-response was evaluated in stratified dose or intake analyses. Publication bias assessments were performed. Among RCTs, there was a nonstatistically significant reduction in CHD risk with EPA+DHA provision (SRRE=0.94; 95% CI, 0.85-1.05). Subgroup analyses of data from RCTs indicated a statistically significant CHD risk reduction with EPA+DHA provision among higher-risk populations, including participants with elevated triglyceride levels (SRRE=0.84; 95% CI, 0.72-0.98) and elevated low-density lipoprotein cholesterol (SRRE=0.86; 95% CI, 0.76-0.98). Meta-analysis of data from prospective cohort studies resulted in a statistically significant SRRE of 0.82 (95% CI, 0.74-0.92) for higher intakes of EPA+DHA and risk of any CHD event. Results indicate that EPA+DHA may be associated with reducing CHD risk, with a greater benefit observed among higher-risk populations in RCTs. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer’s disease

PubMed Central

Lambert, Jean-Charles; Ibrahim-Verbaas, Carla A; Harold, Denise; Naj, Adam C; Sims, Rebecca; Bellenguez, Céline; Jun, Gyungah; DeStefano, Anita L; Bis, Joshua C; Beecham, Gary W; Grenier-Boley, Benjamin; Russo, Giancarlo; Thornton-Wells, Tricia A; Jones, Nicola; Smith, Albert V; Chouraki, Vincent; Thomas, Charlene; Ikram, M Arfan; Zelenika, Diana; Vardarajan, Badri N; Kamatani, Yoichiro; Lin, Chiao-Feng; Gerrish, Amy; Schmidt, Helena; Kunkle, Brian; Dunstan, Melanie L; Ruiz, Agustin; Bihoreau, Marie-Thérèse; Choi, Seung-Hoan; Reitz, Christiane; Pasquier, Florence; Hollingworth, Paul; Ramirez, Alfredo; Hanon, Olivier; Fitzpatrick, Annette L; Buxbaum, Joseph D; Campion, Dominique; Crane, Paul K; Baldwin, Clinton; Becker, Tim; Gudnason, Vilmundur; Cruchaga, Carlos; Craig, David; Amin, Najaf; Berr, Claudine; Lopez, Oscar L; De Jager, Philip L; Deramecourt, Vincent; Johnston, Janet A; Evans, Denis; Lovestone, Simon; Letenneur, Luc; Morón, Francisco J; Rubinsztein, David C; Eiriksdottir, Gudny; Sleegers, Kristel; Goate, Alison M; Fiévet, Nathalie; Huentelman, Matthew J; Gill, Michael; Brown, Kristelle; Kamboh, M Ilyas; Keller, Lina; Barberger-Gateau, Pascale; McGuinness, Bernadette; Larson, Eric B; Green, Robert; Myers, Amanda J; Dufouil, Carole; Todd, Stephen; Wallon, David; Love, Seth; Rogaeva, Ekaterina; Gallacher, John; St George-Hyslop, Peter; Clarimon, Jordi; Lleo, Alberto; Bayer, Anthony; Tsuang, Debby W; Yu, Lei; Tsolaki, Magda; Bossù, Paola; Spalletta, Gianfranco; Proitsi, Petroula; Collinge, John; Sorbi, Sandro; Sanchez-Garcia, Florentino; Fox, Nick C; Hardy, John; Deniz Naranjo, Maria Candida; Bosco, Paolo; Clarke, Robert; Brayne, Carol; Galimberti, Daniela; Mancuso, Michelangelo; Matthews, Fiona; Moebus, Susanne; Mecocci, Patrizia; Zompo, Maria Del; Maier, Wolfgang; Hampel, Harald; Pilotto, Alberto; Bullido, Maria; Panza, Francesco; Caffarra, Paolo; Nacmias, Benedetta; Gilbert, John R; Mayhaus, Manuel; Lannfelt, Lars; Hakonarson, Hakon; Pichler, Sabrina; Carrasquillo, Minerva M; Ingelsson, Martin; Beekly, Duane; Alvarez, Victoria; Zou, Fanggeng; Valladares, Otto; Younkin, Steven G; Coto, Eliecer; Hamilton-Nelson, Kara L; Gu, Wei; Razquin, Cristina; Pastor, Pau; Mateo, Ignacio; Owen, Michael J; Faber, Kelley M; Jonsson, Palmi V; Combarros, Onofre; O’Donovan, Michael C; Cantwell, Laura B; Soininen, Hilkka; Blacker, Deborah; Mead, Simon; Mosley, Thomas H; Bennett, David A; Harris, Tamara B; Fratiglioni, Laura; Holmes, Clive; de Bruijn, Renee F A G; Passmore, Peter; Montine, Thomas J; Bettens, Karolien; Rotter, Jerome I; Brice, Alexis; Morgan, Kevin; Foroud, Tatiana M; Kukull, Walter A; Hannequin, Didier; Powell, John F; Nalls, Michael A; Ritchie, Karen; Lunetta, Kathryn L; Kauwe, John S K; Boerwinkle, Eric; Riemenschneider, Matthias; Boada, Mercè; Hiltunen, Mikko; Martin, Eden R; Schmidt, Reinhold; Rujescu, Dan; Wang, Li-san; Dartigues, Jean-François; Mayeux, Richard; Tzourio, Christophe; Hofman, Albert; Nöthen, Markus M; Graff, Caroline; Psaty, Bruce M; Jones, Lesley; Haines, Jonathan L; Holmans, Peter A; Lathrop, Mark; Pericak-Vance, Margaret A; Launer, Lenore J; Farrer, Lindsay A; van Duijn, Cornelia M; Van Broeckhoven, Christine; Moskvina, Valentina; Seshadri, Sudha; Williams, Julie; Schellenberg, Gerard D; Amouyel, Philippe

2013-01-01

Eleven susceptibility loci for late-onset Alzheimer’s disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer’s disease cases and 37,154 controls. In stage 2,11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer’s disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10−8) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer’s disease. PMID:24162737

Saitohin Q7R polymorphism is associated with late-onset Alzheimer's disease susceptibility among caucasian populations: a meta-analysis.

PubMed

Huang, Rong; Tian, Sai; Cai, Rongrong; Sun, Jie; Xia, Wenqing; Dong, Xue; Shen, Yanjue; Wang, Shaohua

2017-08-01

Saitohin (STH) Q7R polymorphism has been reported to influence the individual's susceptibility to Alzheimer's disease (AD); however, conclusions remain controversial. Therefore, we performed this meta-analysis to explore the association between STH Q7R polymorphism and AD risk. Systematic literature searches were performed in the PubMed, Embase, Cochrane Library and Web of Science for studies published before 31 August 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of the association using a fixed- or random-effects model. Subgroup analyses, Galbraith plot and sensitivity analyses were also performed. All statistical analyses were performed with STATA Version 12.0. A total of 19 case-control studies from 17 publications with 4387 cases and 3972 controls were included in our meta-analysis. The results showed that the Q7R polymorphism was significantly associated with an increased risk of AD in a recessive model (RR versus QQ+QR, OR = 1.27, 95% CI = 1.01-1.60, P = 0.040). After excluding the four studies not carried out in caucasians, the overall association was unchanged in all comparison models. Further subgroup analyses stratified by the time of AD onset, and the quality of included studies provided statistical evidence of significant increased risk of AD in RR versus QQ+QR model only in late-onset subjects (OR = 1.56, 95% CI = 1.07-2.26, P = 0.021) and in studies with high quality (OR = 1.37, 95% CI = 1.01-1.86, P = 0.043). This meta-analysis suggests that the RR genotype in saitohin Q7R polymorphism may be a human-specific risk factor for AD, especially among late-onset AD subjects and caucasian populations. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies.

PubMed

Hua, Yong-Fei; Wang, Gao-Qing; Jiang, Wei; Huang, Jing; Chen, Guo-Chong; Lu, Cai-De

2016-01-01

Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association. Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity. Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52-0.66), 0.93 (95% CI: 0.78-1.11) and 0.66 (95% CI: 0.58-0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies. There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed.

Transversal changes, space closure, and efficiency of conventional and self-ligating appliances : A quantitative systematic review.

PubMed

Yang, Xianrui; Xue, Chaoran; He, Yiruo; Zhao, Mengyuan; Luo, Mengqi; Wang, Peiqi; Bai, Ding

2018-01-01

Self-ligating brackets (SLBs) were compared to conventional brackets (CBs) regarding their effectiveness on transversal changes and space closure, as well as the efficiency of alignment and treatment time. All previously published randomized controlled clinical trials (RCTs) dealing with SLBs and CBs were searched via electronic databases, e.g., MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, World Health Organization International Clinical Trials Registry Platform, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. In addition, relevant journals were searched manually. Data extraction was performed independently by two reviewers and assessment of the risk of bias was executed using Cochrane Collaboration's tool. Discrepancies were resolved by discussion with a third reviewer. Meta-analyses were conducted using Review Manager (version 5.3). A total of 976 patients in 17 RCTs were included in the study, of which 11 could be produced quantitatively and 2 showed a low risk of bias. Meta-analyses were found to favor CB for mandibular intercanine width expansion, while passive SLBs were more effective in posterior expansion. Moreover, CBs had an apparent advantage during short treatment periods. However, SLBs and CBs did not differ in closing spaces. Based on current clinical evidence obtained from RCTs, SLBs do not show clinical superiority compared to CBs in expanding transversal dimensions, space closure, or orthodontic efficiency. Further high-level studies involving randomized, controlled, clinical trials are warranted to confirm these results.

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.

Heterogeneity in Unclassifiable Interstitial Lung Disease: A Systematic Review and Meta-Analysis.

PubMed

Guler, Sabina A; Ellison, Kina; Algamdi, Mohmmed; Collard, Harold R; Ryerson, Christopher J

2018-05-20

Accurate diagnosis of interstitial lung disease (ILD) is necessary to identify the most appropriate management strategy and to inform prognosis. Many patients cannot be provided a confident diagnosis despite an exhaustive search for potential etiologies and review in a multidisciplinary conference; and are consequently labelled with unclassifiable ILD. to systematically review and meta-analyse previous studies reporting on the diagnostic criteria, prevalence, clinical features, and outcome of unclassifiable ILD. Medline, Embase, and the Cochrane Central Register of Controlled Trials databases were systematically searched for all studies related to unclassifiable ILD published before September 1, 2017. Two authors independently screened each citation for eligibility criteria, serially reviewing the title, abstract, and full-text manuscript, and then abstracted data pertaining to the study objectives from eligible studies. Articles were stratified by risk of selection bias, whether the publication stated that patients were reviewed in a multidisciplinary discussion, and by the frequency of surgical lung biopsy. Meta-analyses and meta-regression were performed to calculate the pooled prevalence of unclassifiable ILD within an ILD population and within specific subgroups to identify reasons for across-study heterogeneity. The search identified 10130 unique citations, 313 articles underwent full-text review, and eligibility criteria were met in 88 articles. Twenty-two studies were deemed low risk of selection bias, including 1060 patients with unclassifiable ILD from a total of 10174 patients with ILD. The terminology and definition of unclassifiable ILD varied substantially across publications, with inconsistent diagnostic criteria and evaluation processes. The prevalence of unclassifiable ILD was 11.9% (95% confidence interval 8.5% to 15.6%), with lower prevalence in centers that reported use of a formal multidisciplinary discussion of cases (9.5% vs. 14.5%). Four articles reported survival of unclassifiable ILD, with 1-year, 2-year, and 5-year survival of 84-89%, 70-76%, and 46-70%, respectively. This systematic review and meta-analysis shows that unclassifiable ILD is common but has substantial heterogeneity and inconsistent definitions across ILD cohorts. These findings highlight important limitations in multicentre studies of fibrotic ILD and the need for a standardized approach to ILD diagnostic classification.

An umbrella review of meta-analyses of interventions to improve maternal outcomes for teen mothers.

PubMed

SmithBattle, Lee; Loman, Deborah G; Chantamit-O-Pas, Chutima; Schneider, Joanne Kraenzle

2017-08-01

The purpose of this study was to perform an umbrella review of meta-analyses of intervention studies designed to improve outcomes of pregnant or parenting teenagers. An extensive search retrieved nine reports which provided 21 meta-analyses analyses. Data were extracted by two reviewers. Methodological quality was assessed using the AMSTAR Instrument. Most effect sizes were small but high quality studies showed significant outcomes for reduced low birth weight (RR = 0.60), repeat pregnancies/births (OR = 0.47-0.62), maternal education (OR = 1.21-1.83), and maternal employment (OR = 1.26). Several parenting outcomes (parent-child teaching interaction post-intervention [SMD = -0.91] and at follow-up [SMD = -1.07], and parent-child relationship post-intervention [SMD = -0.71] and at follow-up [SMD = -0.90]) were significant, but sample sizes were very small. Many reports did not include moderator analyses. Behavioral interventions offer limited resources and occur too late to mitigate the educational and social disparities that precede teen pregnancy. Future intervention research and policies that redress the social determinants of early childbearing are recommended. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Why prudence is needed when interpreting articles reporting clinical trial results in mental health.

PubMed

Dal-Ré, Rafael; Bobes, Julio; Cuijpers, Pim

2017-03-28

Clinical trial results' reliability is impacted by reporting bias. This is primarily manifested as publication bias and outcome reporting bias. Mental health trials are prone to two methodological deficiencies: (1) using small numbers of participants that facilitates false positive findings and exaggerated size effects, and (2) the obligatory use of psychometric scales that require subjective assessments. These two deficiencies contribute to the publication of unreliable results. Considerable reporting bias has been found in safety and efficacy findings in psychotherapy and pharmacotherapy trials. Reporting bias can be carried forward to meta-analyses, a key source for clinical practice guidelines. The final result is the frequent overestimation of treatment effects that could impact patients and clinician-informed decisions. Prospective registration of trials and publication of results are the two major methods to reduce reporting bias. Prospective trial registration will allow checking whether they are published (so it will help to prevent publication bias) and, if published, whether those outcomes and analyses that were deemed as appropriate before trial commencement are actually published (hence helping to find out selective reporting of outcomes). Unfortunately, the rate of registered trials in mental health interventions is low and, frequently, of poor quality. Clinicians should be prudent when interpreting the results of published trials and some meta-analyses - such as those conducted by scientists working for the sponsor company or those that only include published trials. Prescribers, however, should be confident when prescribing drugs following the summary of product characteristics, since regulatory agencies have access to all clinical trial results.

Non-steroidal anti-inflammatory drug use and ovarian cancer risk: findings from the NIH-AARP Diet and Health Study and systematic review.

PubMed

Murphy, Megan A; Trabert, Britton; Yang, Hannah P; Park, Yikyung; Brinton, Louise A; Hartge, Patricia; Sherman, Mark E; Hollenbeck, Albert; Wentzensen, Nicolas

2012-11-01

Chronic inflammation has been proposed as a risk factor for ovarian cancer. Some data suggest that anti-inflammatory medications may be protective against ovarian cancer; however, results have been inconsistent. We evaluated the risk of epithelial ovarian cancer with regular use of NSAIDs prospectively in the NIH-AARP Diet and Health Study, using Cox proportional hazard models. We also examined the risk of common subtypes of epithelial ovarian cancer (serous, mucinous, endometrioid, clear cell, and other epithelial) with regular use of NSAIDs. In addition, we performed meta-analyses summarizing the risk of ovarian cancer with "regular use" of NSAIDs in previously published studies. We did not observe a significant association between regular use of NSAIDs with ovarian cancer risk in the AARP cohort (aspirin: RR 1.06, 95 % CI 0.87-1.29; non-aspirin NSAIDs: RR 0.93, 95 % CI 0.74-1.15); however, summary estimates from prospective cohort studies demonstrated that use of non-aspirin NSAIDs may reduce the risk of ovarian cancer (RR 0.88, 95 % CI 0.77-1.01). Although not significant, we found that mucinous tumors were inversely associated with non-aspirin NSAID use (RR 0.69, 95 % CI 0.23-2.10) in the AARP cohort, which was supported by the meta-analysis (RR 0.69, CI 0.50-0.94.) Although results from the NIH-AARP cohort study were not statistically significant, our meta-analysis suggests that non-aspirin NSAIDs may be protective against ovarian cancer. Additional analyses, focusing on dose, duration, and frequency of NSAID use and accounting for ovarian cancer heterogeneity are necessary to further elucidate the association between NSAID use and ovarian cancer risk.

A descriptive analysis of oral health systematic reviews published 1991-2012: cross sectional study.

PubMed

Saltaji, Humam; Cummings, Greta G; Armijo-Olivo, Susan; Major, Michael P; Amin, Maryam; Major, Paul W; Hartling, Lisa; Flores-Mir, Carlos

2013-01-01

To identify all systematic reviews (SRs) published in the domain of oral health research and describe them in terms of their epidemiological and descriptive characteristics. Cross sectional, descriptive study. An electronic search of seven databases was performed from inception through May 2012; bibliographies of relevant publications were also reviewed. Studies were considered for inclusion if they were oral health SRs defined as therapeutic or non-therapeutic investigations that studied a topic or an intervention related to dental, oral or craniofacial diseases/disorders. Data were extracted from all the SRs based on a number of epidemiological and descriptive characteristics. Data were analysed descriptively for all the SRs, within each of the nine dental specialities, and for Cochrane and non-Cochrane SRs separately. 1,188 oral health (126 Cochrane and 1062 non-Cochrane) SRs published from 1991 through May 2012 were identified, encompassing the nine dental specialties. Over half (n = 676; 56.9%) of the SRs were published in specialty oral health journals, with almost all (n = 1,178; 99.2%) of the SRs published in English and almost none of the non-Cochrane SRs (n = 11; 0.9%) consisting of updates of previously published SRs. 75.3% of the SRs were categorized as therapeutic, with 64.5% examining non-drug interventions, while approximately half (n = 150/294; 51%) of the non-therapeutic SRs were classified as epidemiological SRs. The SRs included a median of 15 studies, with a meta-analysis conducted in 43.6%, in which a median of 9 studies/1 randomized trial were included in the largest meta-analysis conducted. Funding was received for 25.1% of the SRs, including nearly three-quarters (n = 96; 76.2%) of the Cochrane SRs. Epidemiological and descriptive characteristics of the 1,188 oral health SRs varied across the nine dental specialties and by SR category (Cochrane vs. non-Cochrane). There is a clear need for more updates of SRs in all the dental specialties.

Therapist-Supported Internet-Based Cognitive Behavior Therapy for Stress, Anxiety, and Depressive Symptoms Among Postpartum Women: A Systematic Review and Meta-Analysis.

PubMed

Lau, Ying; Htun, Tha Pyai; Wong, Suei Nee; Tam, Wai San Wilson; Klainin-Yobas, Piyanee

2017-04-28

A growing number of meta-analyses have supported the application of therapist-supported Internet-based cognitive behavior therapy (iCBT) for psychological disorders across different populations, but relatively few meta-analyses have concentrated on postpartum women. This meta-analysis evaluated the efficacy of therapist-supported iCBT in improving stress, anxiety, and depressive symptoms among postpartum women. A total of 10 electronic databases were used to search for published and unpublished trials. Cochrane Collaboration tool for assessing risk of bias was utilized to measure methodological quality. Meta-analysis was performed using the RevMan software (Review Manager version 5.3 for Windows from the Nordic Cochrane Centre, the Cochrane Collaboration, 2014). Among the 789 studies identified, 8 randomized controlled trials were selected, involving 1523 participants across 6 countries. More than half (65%) of the eligible studies had a low risk of bias with no heterogeneity. Results revealed that therapist-supported iCBT significantly improved stress (d=0.84, n=5), anxiety (d=0.36, n=6), and depressive symptoms (d=0.63, n=8) of the intervention group compared with those of the control group at post-intervention. This review revealed that therapist-supported iCBT significantly improves stress, anxiety, and depressive symptoms among postpartum women with small to large effects. Future effectiveness studies should establish the essential components, format, and approach of iCBT with optimal levels of human support to maximize a long-term effect. ©Ying Lau, Tha Pyai Htun, Suei Nee Wong, Wai San Wilson Tam, Piyanee Klainin-Yobas. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 28.04.2017.

Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation.

PubMed

Shamseer, Larissa; Moher, David; Clarke, Mike; Ghersi, Davina; Liberati, Alessandro; Petticrew, Mark; Shekelle, Paul; Stewart, Lesley A

2015-01-02

Protocols of systematic reviews and meta-analyses allow for planning and documentation of review methods, act as a guard against arbitrary decision making during review conduct, enable readers to assess for the presence of selective reporting against completed reviews, and, when made publicly available, reduce duplication of efforts and potentially prompt collaboration. Evidence documenting the existence of selective reporting and excessive duplication of reviews on the same or similar topics is accumulating and many calls have been made in support of the documentation and public availability of review protocols. Several efforts have emerged in recent years to rectify these problems, including development of an international register for prospective reviews (PROSPERO) and launch of the first open access journal dedicated to the exclusive publication of systematic review products, including protocols (BioMed Central's Systematic Reviews). Furthering these efforts and building on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, an international group of experts has created a guideline to improve the transparency, accuracy, completeness, and frequency of documented systematic review and meta-analysis protocols--PRISMA-P (for protocols) 2015. The PRISMA-P checklist contains 17 items considered to be essential and minimum components of a systematic review or meta-analysis protocol.This PRISMA-P 2015 Explanation and Elaboration paper provides readers with a full understanding of and evidence about the necessity of each item as well as a model example from an existing published protocol. This paper should be read together with the PRISMA-P 2015 statement. Systematic review authors and assessors are strongly encouraged to make use of PRISMA-P when drafting and appraising review protocols. © BMJ Publishing Group Ltd 2014.

A genome-wide association study of corneal astigmatism: The CREAM Consortium

PubMed Central

Shah, Rupal L.; Li, Qing; Zhao, Wanting; Tedja, Milly S.; Tideman, J. Willem L.; Khawaja, Anthony P.; Fan, Qiao; Yazar, Seyhan; Williams, Katie M.; Verhoeven, Virginie J.M.; Xie, Jing; Wang, Ya Xing; Hess, Moritz; Nickels, Stefan; Lackner, Karl J.; Pärssinen, Olavi; Wedenoja, Juho; Biino, Ginevra; Concas, Maria Pina; Uitterlinden, André; Rivadeneira, Fernando; Jaddoe, Vincent W.V.; Hysi, Pirro G.; Sim, Xueling; Tan, Nicholas; Tham, Yih-Chung; Sensaki, Sonoko; Hofman, Albert; Vingerling, Johannes R.; Jonas, Jost B.; Mitchell, Paul; Hammond, Christopher J.; Höhn, René; Baird, Paul N.; Wong, Tien-Yin; Cheng, Chinfsg-Yu; Teo, Yik Ying; Mackey, David A.; Williams, Cathy; Saw, Seang-Mei; Klaver, Caroline C.W.; Bailey-Wilson, Joan E.

2018-01-01

Purpose To identify genes and genetic markers associated with corneal astigmatism. Methods A meta-analysis of genome-wide association studies (GWASs) of corneal astigmatism undertaken for 14 European ancestry (n=22,250) and 8 Asian ancestry (n=9,120) cohorts was performed by the Consortium for Refractive Error and Myopia. Cases were defined as having >0.75 diopters of corneal astigmatism. Subsequent gene-based and gene-set analyses of the meta-analyzed results of European ancestry cohorts were performed using VEGAS2 and MAGMA software. Additionally, estimates of single nucleotide polymorphism (SNP)-based heritability for corneal and refractive astigmatism and the spherical equivalent were calculated for Europeans using LD score regression. Results The meta-analysis of all cohorts identified a genome-wide significant locus near the platelet-derived growth factor receptor alpha (PDGFRA) gene: top SNP: rs7673984, odds ratio=1.12 (95% CI:1.08–1.16), p=5.55×10−9. No other genome-wide significant loci were identified in the combined analysis or European/Asian ancestry-specific analyses. Gene-based analysis identified three novel candidate genes for corneal astigmatism in Europeans—claudin-7 (CLDN7), acid phosphatase 2, lysosomal (ACP2), and TNF alpha-induced protein 8 like 3 (TNFAIP8L3). Conclusions In addition to replicating a previously identified genome-wide significant locus for corneal astigmatism near the PDGFRA gene, gene-based analysis identified three novel candidate genes, CLDN7, ACP2, and TNFAIP8L3, that warrant further investigation to understand their role in the pathogenesis of corneal astigmatism. The much lower number of genetic variants and genes demonstrating an association with corneal astigmatism compared to published spherical equivalent GWAS analyses suggest a greater influence of rare genetic variants, non-additive genetic effects, or environmental factors in the development of astigmatism. PMID:29422769

Association between coffee intake and gastroesophageal reflux disease: a meta-analysis.

PubMed

Kim, J; Oh, S-W; Myung, S-K; Kwon, H; Lee, C; Yun, J M; Lee, H K

2014-01-01

Gastroesophageal reflux disease (GERD) is one of the most common diseases affecting patients worldwide, but its risk factors and causes are not clearly known. The aim of this study was to investigate the effect of coffee intake on GERD by a meta-analysis. We searched online published research databases such as PubMed, EMBASE, and Cochrane Library for studies that were published up to December 2012. These publications were reviewed by two independent authors, and studies that fulfilled the criteria were selected. Whenever there was a disagreement between the authors, a consensus was reached by discussion. Fifteen case-control studies were included in the final analysis. A meta-analysis showed that there was no significant association between coffee intake and GERD. The odds ratio was 1.06 (95% confidence interval, 0.94-1.19). In subgroup analyses in which the groups were subdivided based on the definition of GERD (diagnosed by endoscopy or by symptoms alone), only the endoscopy group showed a significantly higher odds ratio. In subgroup analyses in which the groups were subdivided based on the amount of coffee intake, quality of study, and assessment of exposure, there was no significant association between coffee intake and GERD. © 2013 Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Methological quality of systematic reviews and meta-analyses on acupuncture for stroke: A review of review.

PubMed

Chen, Xin-Lin; Mo, Chuan-Wei; Lu, Li-Ya; Gao, Ri-Yang; Xu, Qian; Wu, Min-Feng; Zhou, Qian-Yi; Hu, Yue; Zhou, Xuan; Li, Xian-Tao

2017-11-01

To assess the methodological quality of systematic reviews and meta-analyses regarding acupuncture intervention for stroke and the primary studies within them. Two researchers searched PubMed, Cumulative index to Nursing and Allied Health Literature, Embase, ISI Web of Knowledge, Cochrane, Allied and Complementary Medicine, Ovid Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Traditional Chinese Medical Database to identify systematic reviews and meta-analyses about acupuncture for stroke published from the inception to December 2016. Review characteristics and the criteria for assessing the primary studies within reviews were extracted. The methodological quality of the reviews was assessed using adapted Oxman and Guyatt Scale. The methodological quality of primary studies was also assessed. Thirty-two eligible reviews were identified, 15 in English and 17 in Chinese. The English reviews were scored higher than the Chinese reviews (P=0.025), especially in criteria for avoiding bias and the scope of search. All reviews used the quality criteria to evaluate the methodological quality of primary studies, but some criteria were not comprehensive. The primary studies, in particular the Chinese reviews, had problems with randomization, allocation concealment, blinding, dropouts and withdrawals, intent-to-treat analysis and adverse events. Important methodological flaws were found in Chinese systematic reviews and primary studies. It was necessary to improve the methodological quality and reporting quality of both the systematic reviews published in China and primary studies on acupuncture for stroke.

[Memantine as add-on medication to acetylcholinesterase inhibitor therapy for Alzheimer dementia].

PubMed

Haussmann, R; Donix, M

2017-01-01

Currently available data indicate superior therapeutic effects of combination treatment for Alzheimer dementia with memantine and acetylcholine esterase inhibitors in certain clinical contexts. Out of five randomized, placebo-controlled, double-blind trials two showed superior therapeutic effects in comparison to monotherapy with acetylcholinesterase inhibitors regarding various domains. Recently published meta-analyses and cost-benefit analyses also showed positive results. Recently published German guidelines for dementia treatment also take these new data into account and recommend combination treatment in patients with severe dementia on stable donepezil medication. This article gives an overview of current evidence for combination therapy.

The Complications of Bariatric Surgery Patients with Type 2 Diabetes in the World: A systematic Review and Meta-Analysis.

PubMed

Kabir, Ali; Mousavi, Sara; Pazouki, Abdolreza

2018-04-03

In this Meta-analysis, we aimed to quantify the incidence of complications of different methods of bariatric surgery on diabetic patients. Type 2 Diabetes mellitus (T2DM) is increasing worldwide specifically in obese cases. Additionally, obesity worsens T2DM. Complications of each bariatric surgery method were assessed separately; but, meta-analysis of these complications and comparison between procedures in T2DM patients has not been investigated previously. The result of this study will help surgeons to choose the most appropriate surgical technique, considering individual conditions for a diabetic patient. We searched PubMed, Scopus, and ISI for original papers including bariatric surgical procedures for diabetic population and the reported consequences. Data analyses were done using Stata software. Mortality percentage between diabetic and non-diabetic patients was statistically non-significant (P = 0.987). Early and late complications were higher in diabetic group in comparison with non-diabetic (6.0% vs. 1.8%, P = 0.024 and 0.6% vs. 0.3%, P = 0.04, respectively). Most prevalent findings in malabsorptive (7.8%, P < 0.001) and restrictive procedures (80%, P < 0.001) were major complications and hypoglycemic episodes, respectively. As our study showed, most of the complications are not necessarily higher in diabetic population but dependent on the method of surgery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Nutritional Deficiencies and Clinical Correlates in First-Episode Psychosis: A Systematic Review and Meta-analysis.

PubMed

Firth, Joseph; Carney, Rebekah; Stubbs, Brendon; Teasdale, Scott B; Vancampfort, Davy; Ward, Philip B; Berk, Michael; Sarris, Jerome

2017-11-30

Diet is increasingly recognized as a potentially modifiable factor influencing the onset and outcomes of psychiatric disorders. Whereas, previous research has shown long-term schizophrenia is associated with various nutritional deficiencies, this meta-analysis aimed to determine the prevalence and extent of nutritional deficits in first-episode psychosis (FEP). A search of electronic databases conducted in July 2017 identified 28 eligible studies, examining blood levels of 6 vitamins and 10 minerals across 2612 individuals: 1221 individuals with FEP and 1391 control subjects. Meta-analyses compared nutrient levels in FEP to nonpsychiatric controls. Clinical correlates of nutritional status in patient samples were systematically reviewed. Significantly lower blood levels of folate (N = 6, n = 827, g = -0.624, 95% confidence interval [CI] = -1.176 to -0.072, P = .027) and vitamin D (N = 7, n = 906, g = -1.055, 95% CI = -1.99 to -0.119, P = .027) were found in FEP compared to healthy controls. Synthesis of clinical correlates found both folate and vitamin D held significant inverse relationships with psychiatric symptoms in FEP. There was also limited evidence for serum level reductions of vitamin C (N = 2, n = 96, g = -2.207, 95% CI = -3.71 to -0.71, P = .004). No differences were found for other vitamins or minerals. Deficits in vitamin D and folate previously observed in long-term schizophrenia appear to exist from illness onset, and are associated with worse symptomology. Further research must examine the direction and nature of these relationships (ie, mediator, moderator, or marker) with clinical status in FEP. Future trials assessing efficacy of nutrient supplementation in FEP samples should consider targeting and stratifying for baseline deficiency. © The Author(s) 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

Diverging Conclusions from the Same Meta-Analysis in Drug Safety: Source of Data (Primary Versus Secondary) Takes a Toll.

PubMed

Prada-Ramallal, Guillermo; Takkouche, Bahi; Figueiras, Adolfo

2017-04-01

Meta-analyses of observational studies represent an important tool for assessing efficacy and safety in the pharmacoepidemiologic field. The data from the individual studies are either primary (i.e., collected through interviews or self-administered questionnaires) or secondary (i.e., collected from databases that were established for other purposes). So far, the origin of the data (primary vs. secondary) has not been systematically assessed as a source of heterogeneity in pharmacoepidemiologic meta-analyses. The aim was to assess the impact of considering the source of exposure data as a criterion in sensitivity and subgroup analysis on the conclusions of drug safety meta-analyses. We selected meta-analyses published between 2013 and 2015 in which the intake of frequently used over-the-counter medicines was either the main exposure or a concomitant treatment and the outcome had short latency and induction periods. We stratified the results by origin of data (primary vs. secondary) and compared the new results to those presented originally in the meta-analyses. We used four meta-analyses that fulfilled our criteria of inclusion. The results were selective serotonin reuptake inhibitors and upper gastrointestinal bleeding: original estimate odds ratio (OR) = 1.71 [95% confidence interval (CI) 1.44-2.04], OR primary data = 1.19 (95% CI 0.90-1.58), OR secondary data = 1.81 (95% CI 1.50-2.17); proton pump inhibitors and cardiac events: original estimate hazard ratio (HR) = 1.35 (95% CI 1.18-1.54), HR primary data = 1.05 (95% CI 0.87-1.26), HR secondary data = 1.43 (95% CI 1.23-1.66); non-aspirin non-steroidal anti-inflammatory drugs and myocardial infarction: original estimate risk ratio (RR) = 1.08 (95% CI 0.95-1.22), RR primary data = 0.57 (95% CI 0.34-0.96), RR secondary data = 1.15 (95% CI 1.03-1.28); paracetamol during pregnancy and childhood asthma: original estimate OR = 1.32 (95% CI 1.14-1.52), OR primary data = 1.23 (95% CI 1.06-1.42), OR secondary data = 1.53 (95% CI 1.33-1.75). The results after stratification are considerably modified. It is crucial to explore the origin of the data, either primary or secondary, as a source of heterogeneity in pharmacoepidemiologic meta-analyses to avoid misleading conclusions.

An overview of meta-analysis for clinicians.

PubMed

Lee, Young Ho

2018-03-01

The number of medical studies being published is increasing exponentially, and clinicians must routinely process large amounts of new information. Moreover, the results of individual studies are often insufficient to provide confident answers, as their results are not consistently reproducible. A meta-analysis is a statistical method for combining the results of different studies on the same topic and it may resolve conflicts among studies. Meta-analysis is being used increasingly and plays an important role in medical research. This review introduces the basic concepts, steps, advantages, and caveats of meta-analysis, to help clinicians understand it in clinical practice and research. A major advantage of a meta-analysis is that it produces a precise estimate of the effect size, with considerably increased statistical power, which is important when the power of the primary study is limited because of a small sample size. A meta-analysis may yield conclusive results when individual studies are inconclusive. Furthermore, meta-analyses investigate the source of variation and different effects among subgroups. In summary, a meta-analysis is an objective, quantitative method that provides less biased estimates on a specific topic. Understanding how to conduct a meta-analysis aids clinicians in the process of making clinical decisions.

Interrater reliability of schizoaffective disorder compared with schizophrenia, bipolar disorder, and unipolar depression - A systematic review and meta-analysis.

PubMed

Santelmann, Hanno; Franklin, Jeremy; Bußhoff, Jana; Baethge, Christopher

2016-10-01

Schizoaffective disorder is a common diagnosis in clinical practice but its nosological status has been subject to debate ever since it was conceptualized. Although it is key that diagnostic reliability is sufficient, schizoaffective disorder has been reported to have low interrater reliability. Evidence based on systematic review and meta-analysis methods, however, is lacking. Using a highly sensitive literature search in Medline, Embase, and PsycInfo we identified studies measuring the interrater reliability of schizoaffective disorder in comparison to schizophrenia, bipolar disorder, and unipolar disorder. Out of 4126 records screened we included 25 studies reporting on 7912 patients diagnosed by different raters. The interrater reliability of schizoaffective disorder was moderate (meta-analytic estimate of Cohen's kappa 0.57 [95% CI: 0.41-0.73]), and substantially lower than that of its main differential diagnoses (difference in kappa between 0.22 and 0.19). Although there was considerable heterogeneity, analyses revealed that the interrater reliability of schizoaffective disorder was consistently lower in the overwhelming majority of studies. The results remained robust in subgroup and sensitivity analyses (e.g., diagnostic manual used) as well as in meta-regressions (e.g., publication year) and analyses of publication bias. Clinically, the results highlight the particular importance of diagnostic re-evaluation in patients diagnosed with schizoaffective disorder. They also quantify a widely held clinical impression of lower interrater reliability and agree with earlier meta-analysis reporting low test-retest reliability. Copyright © 2016. Published by Elsevier B.V.

Gender and telomere length: systematic review and meta-analysis.

PubMed

Gardner, Michael; Bann, David; Wiley, Laura; Cooper, Rachel; Hardy, Rebecca; Nitsch, Dorothea; Martin-Ruiz, Carmen; Shiels, Paul; Sayer, Avan Aihie; Barbieri, Michelangela; Bekaert, Sofie; Bischoff, Claus; Brooks-Wilson, Angela; Chen, Wei; Cooper, Cyrus; Christensen, Kaare; De Meyer, Tim; Deary, Ian; Der, Geoff; Diez Roux, Ana; Fitzpatrick, Annette; Hajat, Anjum; Halaschek-Wiener, Julius; Harris, Sarah; Hunt, Steven C; Jagger, Carol; Jeon, Hyo-Sung; Kaplan, Robert; Kimura, Masayuki; Lansdorp, Peter; Li, Changyong; Maeda, Toyoki; Mangino, Massimo; Nawrot, Tim S; Nilsson, Peter; Nordfjall, Katarina; Paolisso, Giuseppe; Ren, Fu; Riabowol, Karl; Robertson, Tony; Roos, Goran; Staessen, Jan A; Spector, Tim; Tang, Nelson; Unryn, Brad; van der Harst, Pim; Woo, Jean; Xing, Chao; Yadegarfar, Mohammad E; Park, Jae Yong; Young, Neal; Kuh, Diana; von Zglinicki, Thomas; Ben-Shlomo, Yoav

2014-03-01

It is widely believed that females have longer telomeres than males, although results from studies have been contradictory. We carried out a systematic review and meta-analyses to test the hypothesis that in humans, females have longer telomeres than males and that this association becomes stronger with increasing age. Searches were conducted in EMBASE and MEDLINE (by November 2009) and additional datasets were obtained from study investigators. Eligible observational studies measured telomeres for both females and males of any age, had a minimum sample size of 100 and included participants not part of a diseased group. We calculated summary estimates using random-effects meta-analyses. Heterogeneity between studies was investigated using sub-group analysis and meta-regression. Meta-analyses from 36 cohorts (36,230 participants) showed that on average females had longer telomeres than males (standardised difference in telomere length between females and males 0.090, 95% CI 0.015, 0.166; age-adjusted). There was little evidence that these associations varied by age group (p=1.00) or cell type (p=0.29). However, the size of this difference did vary by measurement methods, with only Southern blot but neither real-time PCR nor Flow-FISH showing a significant difference. This difference was not associated with random measurement error. Telomere length is longer in females than males, although this difference was not universally found in studies that did not use Southern blot methods. Further research on explanations for the methodological differences is required. Copyright © 2013. Published by Elsevier Inc.

Grey Matter Alterations Co-Localize with Functional Abnormalities in Developmental Dyslexia: An ALE Meta-Analysis

PubMed Central

Linkersdörfer, Janosch; Lonnemann, Jan; Lindberg, Sven; Hasselhorn, Marcus; Fiebach, Christian J.

2012-01-01

The neural correlates of developmental dyslexia have been investigated intensively over the last two decades and reliable evidence for a dysfunction of left-hemispheric reading systems in dyslexic readers has been found in functional neuroimaging studies. In addition, structural imaging studies using voxel-based morphometry (VBM) demonstrated grey matter reductions in dyslexics in several brain regions. To objectively assess the consistency of these findings, we performed activation likelihood estimation (ALE) meta-analysis on nine published VBM studies reporting 62 foci of grey matter reduction in dyslexic readers. We found six significant clusters of convergence in bilateral temporo-parietal and left occipito-temporal cortical regions and in the cerebellum bilaterally. To identify possible overlaps between structural and functional deviations in dyslexic readers, we conducted additional ALE meta-analyses of imaging studies reporting functional underactivations (125 foci from 24 studies) or overactivations (95 foci from 11 studies ) in dyslexics. Subsequent conjunction analyses revealed overlaps between the results of the VBM meta-analysis and the meta-analysis of functional underactivations in the fusiform and supramarginal gyri of the left hemisphere. An overlap between VBM results and the meta-analysis of functional overactivations was found in the left cerebellum. The results of our study provide evidence for consistent grey matter variations bilaterally in the dyslexic brain and substantial overlap of these structural variations with functional abnormalities in left hemispheric regions. PMID:22916214

Prognostic factors associated with the success rates of posterior orthodontic miniscrew implants: A subgroup meta-analysis.

PubMed

Hong, Sung-Bin; Kusnoto, Budi; Kim, Eun-Jeong; BeGole, Ellen A; Hwang, Hyeon-Shik; Lim, Hoi-Jeong

2016-03-01

To systematically review previous studies and to assess, via a subgroup meta-analysis, the combined odds ratio (OR) of prognostic factors affecting the success of miniscrew implants (MIs) inserted into the buccal posterior region. Three electronic searches that were limited to articles on clinical human studies using MIs that were published in English prior to March 2015 were conducted. The outcome measure was the success of MIs. Patient factors included age, sex, and jaw of insertion (maxilla vs. mandible), while the MI factors included length and diameter. A meta-analysis was performed on 17 individual studies. The quality of each study was assessed for non-randomized studies and quantified using the Newcastle-Ottawa Scale. The meta-analysis outcome was a combined OR. Subgroup and sensitivity analyses based on the study design, study quality, and sample size of miniscrews implanted were performed. Significantly higher success rates were revealed for MIs inserted in the maxilla, for patients ≥ 20 years of age, and for long MIs (≥ 8 mm) and MIs with a large diameter (> 1.4 mm). All subgroups acquired homogeneity, and the combined OR of the prospective studies (OR, 3.67; 95% confidence interval [CI], 2.10-6.44) was significantly higher in the maxilla than that in the retrospective studies (OR, 2.10; 95% CI, 1.60-2.74). When a treatment plan is made, these risk factors, i.e. jaw of insertion, age, MI length, and MI diameter, should be taken into account, while sex is not critical to the success of MIs.

The effectiveness of interventions to increase physical activity among adolescent girls: a meta-analysis.

PubMed

Pearson, Natalie; Braithwaite, Rock; Biddle, Stuart J H

2015-01-01

Research has shown that a clear decline in physical activity among girls starting in early adolescence. Therefore, adolescent girls have been identified as a key target population for physical activity behavior change. The quantification of intervention effectiveness for this group has not been previously reported in a meta-analysis, and this therefore was the objective of the current meta-analysis. Included were interventions in which the main component, or 1 of the components, was aimed at promoting physical activity through behavior change in any setting. Interventions had to include a non-physical activity control group or comparison group, and include a quantitative outcome assessment of physical activity behavior in girls aged 12 to 18 years. Science Direct, PubMed, PsychINFO, Web of Science, Cochrane Libraries, and EPPI Centre databases were searched up to and including May 2013. Forty-five studies (k = 34 independent samples) were eligible from an initial 13,747 references. A random-effects meta-analysis was conducted. The average treatment effect for adolescent girls involved in physical activity interventions was significant but small (g = 0.350, 95% confidence interval 0.12, 0.58, P < .001). Moderator analyses showed larger effects for interventions that were theory based, performed in schools, were girls only, with younger girls, used multicomponent strategies, and involved targeting both physical activity and sedentary behavior. Interventions to increase physical activity in adolescent girls show small but significant effects, suggesting that behavior change may be challenging. Results suggest some approaches that appear to be successful. Copyright © 2015 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Meta-Analysis of Workplace Physical Activity Interventions

PubMed Central

Conn, Vicki S.; Hafdahl, Adam R.; Cooper, Pamela S.; Brown, Lori M.; Lusk, Sally L.

2009-01-01

Context Most adults do not achieve adequate physical activity. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from these programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Evidence acquisition Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Evidence synthesis Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21), fitness (0.57), lipids (0.13), anthropometric measures (0.08), work attendance (0.19), and job stress (0.33). The significant effect size for diabetes risk (0.98) is more tentative given small sample sizes. Significant heterogeneity documents intervention effects varied across studies. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on V02max of 3.5 mL/kg/min; for lipids, −0.2 on total cholesterol:HDL; and for diabetes risk, −12.6 mg/dL on fasting glucose. Conclusions These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity. PMID:19765506

Non-resurfacing techniques in the management of the patella at total knee arthroplasty: A systematic review and meta-analysis.

PubMed

Findlay, I; Wong, F; Smith, C; Back, D; Davies, A; Ajuied, A

2016-03-01

Recent meta-analyses support not resurfacing the patella at the time of TKA. Several different modes of intervention are reported for non-resurfacing management of the patella at TKA. We have conducted a systematic review and meta-analysis of non-resurfacing interventions in TKA. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) study methodology and reporting system was adopted, utilising the PRISMA checklist and statement. Classes of patella interventions were defined as: 0. No intervention. 1. Osteophyte excision only. 2. Osteophyte excision, denervation, with soft tissue debridement. 3. Osteophyte excision, denervation, soft tissue debridement, and drilling or micro-fracture of eburnated bone. 4. Patellar resurfacing. A meta-analysis was conducted upon the pre- and post-operative KSS for each technique. Four hundred and twenty-three studies were identified, 12 studies met the inclusion criteria for the systematic review and eight for the meta-analysis. Two studies compared different non-resurfacing patellar techniques, the other studies used the non-resurfacing cohort as controls for their prospective RCTs comparing patellar resurfacing with non-resurfacing. The meta-analysis revealed no significant difference between the techniques. We conclude that there is no significant difference in KSS for differing non-resurfacing patellar techniques, but further trials using patellofemoral specific scores may better demonstrate superior efficacy of specific classes of patella intervention, by virtue of greater sensitivity for patellofemoral pain and dysfunction. I. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Scientific publications on systematic review and meta-analysis from Chinese authors: a 10-year survey of the English literature.

PubMed

Yang, Zhiping; Wu, Qiong; Wu, Kaichun; Fan, Daiming

2012-03-01

Systematic reviews and meta-analyses are playing an increasingly important role in clinical research and practice. This study aimed to measure the scientific production of systematic review and meta-analysis from the three major regions of China: the Mainland (ML), Hong Kong (HK), and Taiwan (TW). English articles on systematic review and meta-analysis from ML, HK, and TW from 2001 to 2010 were retrieved from the PubMed database. The total number of articles, impact factors (IF), and articles published in high-impact journals were conducted for quantity and quality comparisons among the three regions. There were 1 587 published articles from ML (1 292), HK (203), and TW (92) during the past ten years. The annual total numbers of articles in the three regions increased significantly from 2001 to 2010 (from 13 to 677). The number of articles from ML has exceeded that from TW since 2001, and surpassed that from HK in 2003. The accumulated IF of articles from ML (3 488.24) was higher than those from HK (493.16) and TW (216.39). HK had the highest average IF of 3.31, followed by ML of 2.90 and TW of 2.85. Researchers from HK published a larger proportion of papers in high-impact journals than those from ML and TW. The Cochrane Database of Systematic Reviews was the most popular journal in China. Chinese authors have been very active to enhance the systematic review and meta-analysis research over the past ten years, especially in ML. The gap between ML and the other two regions has been narrowed. But there is still considerable room for Chinese authors to improve their studies on systematic review and meta-analysis.

Clinical and structural outcomes after arthroscopic repair of full-thickness rotator cuff tears with and without platelet-rich product supplementation: a meta-analysis and meta-regression.

PubMed

Warth, Ryan J; Dornan, Grant J; James, Evan W; Horan, Marilee P; Millett, Peter J

2015-02-01

The purpose of this study was to perform a systematic review, meta-analysis, and meta-regression of all Level I and Level II studies comparing the clinical or structural outcomes, or both, after rotator cuff repair with and without platelet-rich product (PRP) supplementation. A literature search of the PubMed and EMBASE databases was performed to identify all Level I or II studies comparing the clinical or structural outcomes, or both, after arthroscopic repair of full-thickness rotator cuff tears with (PRP+ group) and without (PRP- group) PRP supplementation. Data included outcome scores (American Shoulder and Elbow Surgeons [ASES], University of California Los Angeles [UCLA], Constant, Simple Shoulder Test [SST] and visual analog scale [VAS] scores) and retears diagnosed with imaging studies. Meta-analyses compared preoperative, postoperative, and gain in outcome scores and relative risk ratios for retears. Meta-regression compared the effect of PRP treatment on outcome scores and retear rates according to 6 covariates. Minimum effect sizes that were detectable with 80% power were also calculated for each study. Eleven studies were included in this review and a maximum of 8 studies were used for meta-analyses according to data availability. There were no statistically significant differences between the PRP+ and PRP- groups for overall outcome scores or retear rates (P > .05). Overall gain in the Constant score was decreased when liquid PRP was injected over the tendon surface compared with PRP application at the tendon-bone interface (-6.88 points v +0.78 points, respectively; P = .046); however, this difference did not reach the previously reported minimum clinically important difference (MCID) for Constant scores. When the initial tear size was greater than 3 cm in anterior-posterior length, the PRP+ group exhibited decreased retear rates after double-row repairs when compared with the PRP- group (25.9% v 57.1%, respectively; P = .046). Sensitivity power analyses revealed that most included studies were only powered to detect large differences in outcome scores between groups. There were no statistically significant differences in overall gain in outcome scores or retear rates between treatment groups. Gain in Constant scores was significantly increased when PRPs were applied at the tendon-bone interface when compared with application over the top of the repaired tendon. Retear rates were significantly decreased when PRPs were used for the treatment of tears greater than 3 cm in anterior-posterior length using a double-row technique. Most of the included studies were only powered to detect large differences in outcome scores between treatment groups. In addition, an increased risk for selection, performance, and attrition biases was found. Level II, meta-analysis of Level I and Level II studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Systematic Reviews in Sports Medicine.

PubMed

DiSilvestro, Kevin J; Tjoumakaris, Fotios P; Maltenfort, Mitchell G; Spindler, Kurt P; Freedman, Kevin B

2016-02-01

The number of systematic reviews published in the orthopaedic literature has increased, and these reviews can help guide clinical decision making. However, the quality of these reviews can affect the reader's ability to use the data to arrive at accurate conclusions and make clinical decisions. To evaluate the methodological and reporting quality of systematic reviews and meta-analyses in the sports medicine literature to determine whether such reviews should be used to guide treatment decisions. The hypothesis was that many systematic reviews in the orthopaedic sports medicine literature may not follow the appropriate reporting guidelines or methodological criteria recommended for systematic reviews. Systematic review. All clinical sports medicine systematic reviews and meta-analyses from 2009 to 2013 published in The American Journal of Sports Medicine (AJSM), The Journal of Bone and Joint Surgery (JBJS), Arthroscopy, Sports Health, and Knee Surgery, Sports Traumatology, Arthroscopy (KSSTA) were reviewed and evaluated for level of evidence according to the guidelines from the Oxford Centre for Evidence-Based Medicine, for reporting quality according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, and for methodological quality according to the Assessment of Multiple Systematic Reviews (AMSTAR) tool. Analysis was performed by year and journal of publication, and the levels of evidence included in the systematic reviews were also analyzed. A total of 200 systematic reviews and meta-analyses were identified over the study period. Of these, 53% included evidence levels 4 and 5 in their analyses, with just 32% including evidence levels 1 and 2 only. There were significant differences in the proportion of articles with high levels of evidence (P < .001) and low levels of evidence (P = .005) by journal. The average PRISMA score was 87% and the average AMSTAR score was 73% among all journals. The average AMSTAR and PRISMA scores were significantly different by journal (P = .002 and .001, respectively) and by year (P = .046 and .019, respectively). Arthroscopy, AJSM, and JBJS all scored higher than Sports Health and KSSTA on the PRISMA and AMSTAR. The average PRISMA score by year varied from 85% to 89%, and the average AMSTAR score varied from 70% to 76%. Systematic reviews and meta-analyses in orthopaedics sports medicine literature relied on evidence levels 4 and 5 in 53% of studies over the 5-year study period. Overall, PRISMA and AMSTAR scores are high and may be better than those in other disciplines. Readers need to be conscious of potential shortcomings when reading systematic reviews and using them in practice. © 2015 The Author(s).

Cumulative meta-analysis: a new tool for detection of temporal trends and publication bias in ecology.

PubMed Central

Leimu, Roosa; Koricheva, Julia

2004-01-01

Temporal changes in the magnitude of research findings have recently been recognized as a general phenomenon in ecology, and have been attributed to the delayed publication of non-significant results and disconfirming evidence. Here we introduce a method of cumulative meta-analysis which allows detection of both temporal trends and publication bias in the ecological literature. To illustrate the application of the method, we used two datasets from recently conducted meta-analyses of studies testing two plant defence theories. Our results revealed three phases in the evolution of the treatment effects. Early studies strongly supported the hypothesis tested, but the magnitude of the effect decreased considerably in later studies. In the latest studies, a trend towards an increase in effect size was observed. In one of the datasets, a cumulative meta-analysis revealed publication bias against studies reporting disconfirming evidence; such studies were published in journals with a lower impact factor compared to studies with results supporting the hypothesis tested. Correlation analysis revealed neither temporal trends nor evidence of publication bias in the datasets analysed. We thus suggest that cumulative meta-analysis should be used as a visual aid to detect temporal trends and publication bias in research findings in ecology in addition to the correlative approach. PMID:15347521

Homeopathy: meta-analyses of pooled clinical data.

PubMed

Hahn, Robert G

2013-01-01

In the first decade of the evidence-based era, which began in the mid-1990s, meta-analyses were used to scrutinize homeopathy for evidence of beneficial effects in medical conditions. In this review, meta-analyses including pooled data from placebo-controlled clinical trials of homeopathy and the aftermath in the form of debate articles were analyzed. In 1997 Klaus Linde and co-workers identified 89 clinical trials that showed an overall odds ratio of 2.45 in favor of homeopathy over placebo. There was a trend toward smaller benefit from studies of the highest quality, but the 10 trials with the highest Jadad score still showed homeopathy had a statistically significant effect. These results challenged academics to perform alternative analyses that, to demonstrate the lack of effect, relied on extensive exclusion of studies, often to the degree that conclusions were based on only 5-10% of the material, or on virtual data. The ultimate argument against homeopathy is the 'funnel plot' published by Aijing Shang's research group in 2005. However, the funnel plot is flawed when applied to a mixture of diseases, because studies with expected strong treatments effects are, for ethical reasons, powered lower than studies with expected weak or unclear treatment effects. To conclude that homeopathy lacks clinical effect, more than 90% of the available clinical trials had to be disregarded. Alternatively, flawed statistical methods had to be applied. Future meta-analyses should focus on the use of homeopathy in specific diseases or groups of diseases instead of pooling data from all clinical trials. © 2013 S. Karger GmbH, Freiburg.

Total hip arthroplasty after a previous pelvic osteotomy: A systematic review and meta-analysis.

PubMed

Shigemura, T; Yamamoto, Y; Murata, Y; Sato, T; Tsuchiya, R; Wada, Y

2018-06-01

There are several reports regarding total hip arthroplasty (THA) after a previous pelvic osteotomy (PO). However, to our knowledge, until now there has been no formal systematic review and meta-analysis published to summarize the clinical results of THA after a previous PO. Therefore, we conducted a systematic review and meta-analysis of results of THA after a previous PO. We focus on these questions as follows: does a previous PO affect the results of subsequent THA, such as clinical outcomes, operative time, operative blood loss, and radiological parameters. Using PubMed, Web of Science, and Cochrane Library, we searched for relevant original papers. The pooling of data was performed using RevMan software (version 5.3, Cochrane Collaboration, Oxford, UK). A p-value<0.05 was judged as significant. Standardized mean differences (SMD) were calculated for continuous data with a 95% confidence interval (CI) was reported. Statistical heterogeneity was assessed based on I 2 using standard χ 2 test. When I 2 >50%, significant heterogeneity was assumed and a random-effects model was applied for the meta-analysis. A fixed-effects model was applied in the absence of significant heterogeneity. Eleven studies were included in this meta-analysis. The pooled results indicated that there was no significant difference in postoperative Merle D'Aubigne-Postel score (I 2 =0%, SMD=-0.15, 95% CI: -0.36 to 0.06, p=0.17), postoperative Harris hip score (I 2 =60%, SMD=-0.23, 95% CI: -0.50 to 0.05, p=0.10), operative time (I 2 =86%, SMD=0.37, 95% CI: -0.09 to 0.82, p=0.11), operative blood loss (I 2 =82%, SMD=0.23, 95% CI: -0.17 to 0.63, p=0.25), and cup abduction angle (I 2 =43%, SMD=-0.08, 95% CI: -0.25 to 0.09, p=0.38) between THA with and without a previous PO. However, cup anteversion angle of THA with a previous PO was significantly smaller than that of without a previous PO (I 2 =77%, SMD=-0.63, 95% CI: -1.13 to -0.13, p=0.01). Systematic review and meta-analysis of results of THA after a previous PO was performed. A previous PO did not affect the results of subsequent THA, except for cup anteversion. Because of the low quality evidence currently available, high-quality randomized controlled trials are required. Level III, meta-analysis of case-control studies. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Role of exercise training in polycystic ovary syndrome: a systematic review and meta-analysis.

PubMed

Benham, J L; Yamamoto, J M; Friedenreich, C M; Rabi, D M; Sigal, R J

2018-06-12

Preliminary evidence suggests exercise in polycystic ovary syndrome (PCOS) may improve reproductive and cardiometabolic parameters. Our primary aim was to determine the impact of exercise training on reproductive health in women with PCOS. Our secondary aim was to determine the effect of exercise training on cardiometabolic indices. A systematic review of published literature was conducted using MEDLINE and EMBASE based on a pre-published protocol (PROSPERO CRD42017065324). The search was not limited by year. Randomized controlled trials, non-randomized controlled trials and uncontrolled trials that evaluated an exercise intervention in women with PCOS and reported reproductive outcomes were included. Reproductive outcomes were analysed semi-quantitatively and a meta-analysis was conducted for reported cardiometabolic outcomes. Of 517 screened abstracts, 14 studies involving 617 women with PCOS were included: seven randomized controlled trials, one non-randomized controlled trial and six uncontrolled trials. There were insufficient published data to describe the effect of exercise interventions on ovulation quantitatively, but semi-quantitative analysis suggested that exercise interventions may improve menstrual regularity, pregnancy and ovulation rates. Our meta-analysis found that exercise improved lipid profiles and decreased waist circumference, systolic blood pressure and fasting insulin. The impact of exercise interventions on reproductive function remains unclear. However, our meta-analysis suggests that exercise interventions may improve cardiometabolic profiles in women with PCOS. © 2018 World Obesity Federation.

Systematic review and meta-analysis of collaborative care interventions for depression in patients with cancer.

PubMed

Li, Madeline; Kennedy, Erin B; Byrne, Nelson; Gérin-Lajoie, Caroline; Katz, Mark R; Keshavarz, Homa; Sellick, Scott; Green, Esther

2017-05-01

Previous systematic reviews have found limited evidence for the effectiveness of pharmacological and psychological interventions for the management of depression in patients with cancer. This paper provides the first meta-analysis of newer collaborative care interventions, which may include both types of treatment, as well as integrated delivery and follow-up. Meta-analyses of pharmacological and psychological interventions are included as a comparison. A search of MEDLINE, EMBASE, PsycINFO, and the Cochrane Library from July 2005 to January 2015 for randomized controlled trials of depression treatments for cancer patients diagnosed with a major depressive disorder, or who met a threshold on a validated depression rating scale was conducted. Meta-analyses were conducted using summary data. Key findings included eight reports of four collaborative care interventions, eight pharmacological, and nine psychological trials. A meta-analysis demonstrated that collaborative care interventions were significantly more effective than usual care (standardized mean difference = -0.49, p = 0.003), and depression reduction was maintained at 12 months. By comparison, short-term (up to 12 weeks), but not longer-term effectiveness was demonstrated for both pharmacological and psychological interventions. Collaborative care interventions have newly emerged as multidisciplinary care delivery models, which may result in more long-term depression remission. This review also updates previous findings of modest evidence for the effectiveness of both pharmacological and psychological interventions for threshold depression in cancer patients. Research designs focusing on combined treatments and delivery systems may best further the limited evidence-base for the management of depression in cancer. Copyright © 2016 John Wiley & Sons, Ltd.

Association between pulmonary ureaplasma colonization and bronchopulmonary dysplasia in preterm infants: updated systematic review and meta-analysis.

PubMed

Lowe, John; Watkins, W John; Edwards, Martin O; Spiller, O Brad; Jacqz-Aigrain, Evelyne; Kotecha, Sarah J; Kotecha, Sailesh

2014-07-01

Previous meta-analyses have reported a significant association between pulmonary colonization with Ureaplasma and development of bronchopulmonary dysplasia (BPD). However, because few studies reporting oxygen dependency at 36 weeks corrected gestation were previously available, we updated the systematic review and meta-analyses to evaluate the association between presence of pulmonary Ureaplasma and development of BPD. Five databases were searched for articles reporting the incidence of BPD at 36 weeks postmenstrual age (BPD36) and/or BPD at 28 days of life (BPD28) in Ureaplasma colonized and noncolonized groups. Pooled estimates were produced using random effects meta-analysis. Meta-regression was used to assess the influence of difference in gestational age between the Ureaplasma-positive and Ureaplasma-negative groups. The effects of potential sources of heterogeneity were also investigated. Of 39 studies included, 8 reported BPD36, 22 reported BPD28 and 9 reported both. The quality of studies was assessed as moderate to good. There was a significant association between Ureaplasma and development of BPD36 (odds ratio = 2.22; 95% confidence intervals: 1.42-3.47) and BPD28 (odds ratio = 3.04; 95% confidence intervals: 2.41-3.83). Sample size influenced the odds ratio, but no significant association was noted between BPD28 rates and difference in gestational age between Ureaplasma colonized and noncolonized infants (P = 0.96). Pulmonary colonization with Ureaplasma continues to be significantly associated with development of BPD in preterm infants at both 36 weeks postmenstrual age and at 28 days of life. This association at BPD28 persists regardless of difference in gestational age.

A Primer on Systematic Reviews and Meta-Analyses.

PubMed

Nguyen, Nghia H; Singh, Siddharth

2018-05-01

With the rapid growth of biomedical literature, there is increasing need to make meaningful inferences from a comprehensive and complex body of evidence. Systematic reviews with or without meta-analyses offer an objective and summative approach to synthesize knowledge and critically appraise evidence to inform clinical practice. Systematic reviews also help identify key knowledge gaps for future investigation. In this review, the authors provide a step-by-step approach to conducting a systematic review. These include: (1) formulating a focused and clinically-relevant question; (2) designing a detailed review protocol with explicit inclusion and exclusion criteria; (3) performing a systematic literature search of multiple databases and unpublished data, in consultation with a medical librarian, to identify relevant studies; (4) meticulous data abstraction by at least two sets of investigators independently; (5) assessing risk of bias in individual studies; (6) quantitative synthesis with meta-analysis; and (7) critically and transparently ascertaining quality of evidence. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Does Intra-articular Platelet-Rich Plasma Injection Provide Clinically Superior Outcomes Compared With Other Therapies in the Treatment of Knee Osteoarthritis? A Systematic Review of Overlapping Meta-analyses.

PubMed

Campbell, Kirk A; Saltzman, Bryan M; Mascarenhas, Randy; Khair, M Michael; Verma, Nikhil N; Bach, Bernard R; Cole, Brian J

2015-11-01

The aims of this study were (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) injection in the treatment of knee joint cartilage degenerative pathology, (2) to provide a framework for analysis and interpretation of the best available evidence to provide recommendations for use (or lack thereof) of PRP in the setting of knee osteoarthritis (OA), and (3) to identify literature gaps where continued investigation would be suggested. Literature searches were performed for meta-analyses examining use of PRP versus corticosteroids, hyaluronic acid, oral nonsteroidal anti-inflammatory drugs, or placebo. Clinical data were extracted, and meta-analysis quality was assessed. The Jadad algorithm was applied to determine meta-analyses that provided the highest level of evidence. Three meta-analyses met the eligibility criteria and ranged in quality from Level II to Level IV evidence. All studies compared outcomes of treatment with intra-articular platelet-rich plasma (IA-PRP) versus control (intra-articular hyaluronic acid or intra-articular placebo). Use of PRP led to significant improvements in patient outcomes at 6 months after injection, and these improvements were seen starting at 2 months and were maintained for up to 12 months. It is unclear if the use of multiple PRP injections, the double-spinning technique, or activating agents leads to better outcomes. Patients with less radiographic evidence of arthritis benefit more from PRP treatment. The use of multiple PRP injections may increase the risk of self-limited local adverse reactions. After application of the Jadad algorithm, 3 concordant high-quality meta-analyses were selected and all showed that IA-PRP provided clinically relevant improvements in pain and function compared with the control treatment. IA-PRP is a viable treatment for knee OA and has the potential to lead to symptomatic relief for up to 12 months. There appears to be an increased risk of local adverse reactions after multiple PRP injections. IA-PRP offers better symptomatic relief to patients with early knee degenerative changes, and its use should be considered in patients with knee OA. Level IV, systematic review of Level II through IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer: Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses

PubMed Central

Khankari, Nikhil K.; Shu, Xiao-Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I.; Easton, Douglas; Gruber, Stephen B.; Haiman, Christopher A.; Hunter, David J.; Chanock, Stephen J.; Pierce, Brandon L.; Zheng, Wei

2016-01-01

Background Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using height-associated genetic variants identified in a genome-wide association study (GWAS), to evaluate the association of adult height with these cancers. Methods and Findings A systematic review of prospective studies was conducted using the PubMed, Embase, and Web of Science databases. Using meta-analyses, results obtained from 62 studies were summarized for the association of a 10-cm increase in height with cancer risk. Mendelian randomization analyses were conducted using summary statistics obtained for 423 genetic variants identified from a recent GWAS of adult height and from a cancer genetics consortium study of multiple cancers that included 47,800 cases and 81,353 controls. For a 10-cm increase in height, the summary relative risks derived from the meta-analyses of prospective studies were 1.12 (95% CI 1.10, 1.15), 1.07 (95% CI 1.05, 1.10), and 1.06 (95% CI 1.02, 1.11) for colorectal, prostate, and lung cancers, respectively. Mendelian randomization analyses showed increased risks of colorectal (odds ratio [OR] = 1.58, 95% CI 1.14, 2.18) and lung cancer (OR = 1.10, 95% CI 1.00, 1.22) associated with each 10-cm increase in genetically predicted height. No association was observed for prostate cancer (OR = 1.03, 95% CI 0.92, 1.15). Our meta-analysis was limited to published studies. The sample size for the Mendelian randomization analysis of colorectal cancer was relatively small, thus affecting the precision of the point estimate. Conclusions Our study provides evidence for a potential causal association of adult height with the risk of colorectal and lung cancers and suggests that certain genetic factors and biological pathways affecting adult height may also affect the risk of these cancers. PMID:27598322

[Quality appraisal of systematic reviews or meta-analysis on traditional Chinese medicine published in Chinese journals].

PubMed

Liu, Jian-ping; Xia, Yun

2007-04-01

To critically assess the quality of literature about systematic review or meta-analysis on traditional Chinese medicine (TCM) published in Chinese journals. Electronic searches in CNKI, VIP and Wanfang data-base were conducted to retrieve the systematic reviews or meta-analysis reports on TCM, including herbal medicine, needling, acupuncture and moxibustion, as well as integrative medicine, they were identified and extracted according to the 18 items of QUOROM (quality of reporting of meta-analyses) Statement and relative information. The appraisal was made taking the indexes mainly including objectives, source of data, methods of data extraction, quality assessment of the included studies, measurement data synthesis, etc. Eighty-two systematic reviews were identified, except 6 reviews were excluded for repeatedly published or didn't comply with the enrolled criterion, 76 reviews concerning 51 kinds of diseases were enrolled for appraisal. Among them, 70 reviews evaluated the efficacy of TCM, mainly on Chinese herbs and 9 on acupuncture and moxibustion. In majority of the reviews, randomised controlled trials were included and the data resources were described, but in 26 reviews only the Chinese databases were searched and the description about data extraction and analysis method were too simple; and 70% of reviews assessed the quality of the included studies; none used flow chart to express the process of selection, inclusion and exclusion of studies. Few reviews or Meta-analysis reports reached the international standard and there is insufficient description of methodology for conducting systematic reviews, so it is hardly to be repeated. The authors suggested that advanced methodological training is necessary for reviewers.

Alcohol Consumption and the Physical Availability of Take-Away Alcohol: Systematic Reviews and Meta-Analyses of the Days and Hours of Sale and Outlet Density.

PubMed

Sherk, Adam; Stockwell, Tim; Chikritzhs, Tanya; Andréasson, Sven; Angus, Colin; Gripenberg, Johanna; Holder, Harold; Holmes, John; Mäkelä, Pia; Mills, Megan; Norström, Thor; Ramstedt, Mats; Woods, Jonathan

2018-01-01

Systematic reviews and meta-analyses were completed studying the effect of changes in the physical availability of take-away alcohol on per capita alcohol consumption. Previous reviews examining this topic have not focused on off-premise outlets where take-away alcohol is sold and have not completed meta-analyses. Systematic reviews were conducted separately for policies affecting the temporal availability (days and hours of sale) and spatial availability (outlet density) of take-away alcohol. Studies were included up to December 2015. Quality criteria were used to select articles that studied the effect of changes in these policies on alcohol consumption with a focus on natural experiments. Random-effects meta-analyses were applied to produce the estimated effect of an additional day of sale on total and beverage-specific consumption. Separate systematic reviews identified seven studies regarding days and hours of sale and four studies regarding density. The majority of articles included in these systematic reviews, for days/hours of sale (7/7) and outlet density (3/4), concluded that restricting the physical availability of take-away alcohol reduces per capita alcohol consumption. Meta-analyses studying the effect of adding one additional day of sale found that this was associated with per capita consumption increases of 3.4% (95% CI [2.7, 4.1]) for total alcohol, 5.3% (95% CI [3.2, 7.4]) for beer, 2.6% (95% CI [1.8, 3.5]) for wine, and 2.6% (95% CI [2.1, 3.2]) for spirits. The small number of included studies regarding hours of sale and density precluded meta-analysis. The results of this study suggest that decreasing the physical availability of take-away alcohol will decrease per capita consumption. As decreasing per capita consumption has been shown to reduce alcohol-related harm, restricting the physical availability of take-away alcohol would be expected to result in improvements to public health.

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

PubMed

Kuiper, Jisca S; Zuidersma, Marij; Zuidema, Sytse U; Burgerhof, Johannes Gm; Stolk, Ronald P; Oude Voshaar, Richard C; Smidt, Nynke

2016-08-01

Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Pre-operative interventions (non-surgical and non-pharmacological) for patients with hip or knee osteoarthritis awaiting joint replacement surgery--a systematic review and meta-analysis.

PubMed

Wallis, Jason A; Taylor, Nicholas F

2011-12-01

To determine if pre-operative interventions for hip and knee osteoarthritis provide benefit before and after joint replacement. Systematic review with meta-analysis of randomised controlled trials (RCTs) of pre-operative interventions for people with hip or knee osteoarthritis awaiting joint replacement surgery. Standardised mean differences (SMD) were calculated for pain, musculoskeletal impairment, activity limitation, quality of life, and health service utilisation (length of stay and discharge destination). The GRADE approach was used to determine the quality of the evidence. Twenty-three RCTs involving 1461 participants awaiting hip or knee replacement surgery were identified. Meta-analysis provided moderate quality evidence that pre-operative exercise interventions for knee osteoarthritis reduced pain prior to knee replacement surgery (SMD (95% CI)=0.43 [0.13, 0.73]). None of the other meta-analyses investigating pre-operative interventions for knee osteoarthritis demonstrated any effect. Meta-analyses provided low to moderate quality evidence that exercise interventions for hip osteoarthritis reduced pain (SMD (95% CI)=0.52 [0.04, 1.01]) and improved activity (SMD (95% CI)=0.47 [0.11, 0.83]) prior to hip replacement surgery. Meta-analyses provided low quality evidence that exercise with education programs improved activity after hip replacement with reduced time to reach functional milestones during hospital stay (e.g., SMD (95% CI)=0.50 [0.10, 0.90] for first day walking). Low to moderate evidence from mostly small RCTs demonstrated that pre-operative interventions, particularly exercise, reduce pain for patients with hip and knee osteoarthritis prior to joint replacement, and exercise with education programs may improve activity after hip replacement. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Nalmefene for the management of alcohol dependence: review on its pharmacology, mechanism of action and meta-analysis on its clinical efficacy.

PubMed

Mann, Karl; Torup, Lars; Sørensen, Per; Gual, Antoni; Swift, Robert; Walker, Brendan; van den Brink, Wim

2016-12-01

Nalmefene, a mu- and delta-opioid receptor (MOR, DOR) antagonist and a partial kappa-opioid receptor (KOR) agonist, is approved in the European Union and other countries for the reduction of alcohol consumption in alcohol dependent patients with a high drinking risk level according to WHO ("target population"). This review presents an overview of nalmefene׳s pharmacology, its mechanisms of action and a meta-analysis on its efficacy in reducing alcohol consumption. The review was based on a systematic search of the literature. Random effects meta-analyses were performed on published and unpublished trials directed at drinking reduction using the changes in heavy drinking days (HDDs) and daily total alcohol consumption (TAC) from baseline to the primary endpoint. For each included study and each dose, Hedges' g was used as an unbiased estimator of the standardised mean differences between nalmefene and placebo. Preclinical data suggests that nalmefene counters alcohol-induced dysregulations of the MOR/endorphine and the KOR/dynorphin system. Evidence further suggests that reduced alcohol consumption is an effective treatment strategy that appeals to patients not ready for abstinence. Finally, meta-analyses confirmed the efficacy of 20mg nalmefene for reducing HDDs in the ITT population (Hedge׳s g=-0.20; 95% CI -0.30 to -0.09) and the target population (Hedge׳s g=-0.33; 95% CI -0.48 to -0.18). Similar results were seen for TAC. Several meta-analyses, including this new meta-analysis, support nalmefene׳s efficacy in reducing alcohol consumption. In conclusion, because it does not require abstinence, this treatment has the potential to motivate more patients for treatment and thus helps to address a major public health concern. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

Putting age-related task activation into large-scale brain networks: A meta-analysis of 114 fMRI studies on healthy aging.

PubMed

Li, Hui-Jie; Hou, Xiao-Hui; Liu, Han-Hui; Yue, Chun-Lin; Lu, Guang-Ming; Zuo, Xi-Nian

2015-10-01

Normal aging is associated with cognitive decline and underlying brain dysfunction. Previous studies concentrated less on brain network changes at a systems level. Our goal was to examine these age-related changes of fMRI-derived activation with a common network parcellation of the human brain function, offering a systems-neuroscience perspective of healthy aging. We conducted a series of meta-analyses on a total of 114 studies that included 2035 older adults and 1845 young adults. Voxels showing significant age-related changes in activation were then overlaid onto seven commonly referenced neuronal networks. Older adults present moderate cognitive decline in behavioral performance during fMRI scanning, and hypo-activate the visual network and hyper-activate both the frontoparietal control and default mode networks. The degree of increased activation in frontoparietal network was associated with behavioral performance in older adults. Age-related changes in activation present different network patterns across cognitive domains. The systems neuroscience approach used here may be useful for elucidating the underlying network mechanisms of various brain plasticity processes during healthy aging. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characteristics and Methodological Quality of Meta-Analyses on Hypertension Treatments-A Cross-Sectional Study.

PubMed

Wu, Xin Yin; Du, Xin Jian; Ho, Robin S T; Lee, Clarence C Y; Yip, Benjamin H K; Wong, Martin C S; Wong, Samuel Y S; Chung, Vincent C H

2017-02-01

Methodological quality of meta-analyses on hypertension treatments can affect treatment decision-making. The authors conducted a cross-sectional study to investigate the methodological quality of meta-analyses on hypertension treatments. One hundred and fifty-eight meta-analyses were identified. Overall, methodological quality was unsatisfactory in the following aspects: comprehensive reporting of financial support (1.9%), provision of included and excluded lists of studies (22.8%), inclusion of grey literature (27.2%), and inclusion of protocols (32.9%). The 126 non-Cochrane meta-analyses had poor performance on almost all the methodological items. Non-Cochrane meta-analyses focused on nonpharmacologic treatments were more likely to consider scientific quality of included studies when making conclusions. The 32 Cochrane meta-analyses generally had good methodological quality except for comprehensive reporting of the sources of support. These results highlight the need for cautious interpretation of these meta-analyses, especially among physicians and policy makers when guidelines are formulated. Future meta-analyses should pay attention to improving these methodological aspects. ©2016 Wiley Periodicals, Inc.

The neurocognitive profile of mood disorders - a review of the evidence and methodological issues.

PubMed

Porter, Richard J; Robinson, Lucy J; Malhi, Gin S; Gallagher, Peter

2015-12-01

Cognitive abnormalities are an established part of the symptomatology of mood disorders. However, questions still exist regarding the exact profile of these deficits in terms of the domains most affected, their origins, and their relationship to clinical subtypes. This review aims to examine the current state of the evidence and to examine ways in which the field may be advanced. Studies examining cognitive function in bipolar disorder (BD) and unipolar major depression (MDD) were examined. Given the number and variability of such studies, particular attention was paid to meta-analyses and to meta-regression analyses which examined the possible mediators of cognitive impairment. Meta-analyses are available for MDD and BD in both depression and euthymia. Several analyses examine mediators. Results do not support the presence of domain specific deficits but rather a moderate deficit across a range of domains in BD and in MDD. The data on clinical mediators is inconsistent, even with regard to the effect of mood state. A two-tiered approach, with the broad-based application of standardized measures on a large-scale, and the refined application of theoretically driven experimental development would significantly further our understanding of neurocognitive processing in mood disorder. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of type 2 diabetes mellitus incidence in different phases of hepatitis B virus infection: A meta-analysis.

PubMed

Shen, Yi; Zhang, Sheng; Wang, Xulin; Wang, Yuanyuan; Zhang, Jian; Qin, Gang; Li, Wenchao; Ding, Kun; Zhang, Lei; Liang, Feng

2017-10-01

Because whether hepatitis B virus infection increases the risk of type 2 diabetes mellitus has been a controversial topic, pair-wise and network meta-analyses of published literature were carried out to accurately evaluate the association between different phases of hepatitis B virus infection and the risk of type 2 diabetes mellitus. A comprehensive literature retrieval was conducted from the PubMed, Embase, Cochrane Library and Chinese Database to identify epidemiological studies on the association between hepatitis B virus infection and the risk of type 2 diabetes mellitus that were published from 1999 to 2015. A pair-wise meta-analysis of direct evidence was performed to estimate the pooled odds ratios and 95% confidence intervals. A network meta-analysis was conducted, including the construction of a network plot, inconsistency plot, predictive interval plot, comparison-adjusted funnel plot and rank diagram, to graphically link the direct and indirect comparisons between different hepatitis B virus infective phases. Eighteen publications (n=113 639) describing 32 studies were included in this meta-analysis. In the pair-wise meta-analysis, the pooled odds ratio for type 2 diabetes mellitus in chronic hepatitis B cirrhosis patients was 1.76 (95% confidence interval: 1.44-2.14) when compared with non-cirrhotic chronic hepatitis B patients. In the network meta-analysis, six comparisons of four hepatitis B virus infectious states indicated the following descending order for the risk of type 2 diabetes mellitus: hepatitis B cirrhosis patients, non-cirrhotic chronic hepatitis B patients, hepatitis B virus carriers and non-hepatitis B virus controls. This study suggests that hepatitis B virus infection is not an independent risk factor for type 2 diabetes mellitus, but the development of cirrhosis may increase the incidence of type 2 diabetes mellitus cirrhosis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[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.

The effect of active video games on cognitive functioning in clinical and non-clinical populations: A meta-analysis of randomized controlled trials.

PubMed

Stanmore, Emma; Stubbs, Brendon; Vancampfort, Davy; de Bruin, Eling D; Firth, Joseph

2017-07-01

Physically-active video games ('exergames') have recently gained popularity for leisure and entertainment purposes. Using exergames to combine physical activity and cognitively-demanding tasks may offer a novel strategy to improve cognitive functioning. Therefore, this systematic review and meta-analysis was performed to establish effects of exergames on overall cognition and specific cognitive domains in clinical and non-clinical populations. We identified 17 eligible RCTs with cognitive outcome data for 926 participants. Random-effects meta-analyses found exergames significantly improved global cognition (g=0.436, 95% CI=0.18-0.69, p=0.001). Significant effects still existed when excluding waitlist-only controlled studies, and when comparing to physical activity interventions. Furthermore, benefits of exergames where observed for both healthy older adults and clinical populations with conditions associated with neurocognitive impairments (all p<0.05). Domain-specific analyses found exergames improved executive functions, attentional processing and visuospatial skills. The findings present the first meta-analytic evidence for effects of exergames on cognition. Future research must establish which patient/treatment factors influence efficacy of exergames, and explore neurobiological mechanisms of action. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Long working hours and depressive symptoms: systematic review and meta-analysis of published studies and unpublished individual participant data.

PubMed

Virtanen, Marianna; Jokela, Markus; Madsen, Ida Eh; Magnusson Hanson, Linda L; Lallukka, Tea; Nyberg, Solja T; Alfredsson, Lars; Batty, G David; Bjorner, Jakob B; Borritz, Marianne; Burr, Hermann; Dragano, Nico; Erbel, Raimund; Ferrie, Jane E; Heikkilä, Katriina; Knutsson, Anders; Koskenvuo, Markku; Lahelma, Eero; Nielsen, Martin L; Oksanen, Tuula; Pejtersen, Jan H; Pentti, Jaana; Rahkonen, Ossi; Rugulies, Reiner; Salo, Paula; Schupp, Jürgen; Shipley, Martin J; Siegrist, Johannes; Singh-Manoux, Archana; Suominen, Sakari B; Theorell, Töres; Vahtera, Jussi; Wagner, Gert G; Wang, Jian Li; Yiengprugsawan, Vasoontara; Westerlund, Hugo; Kivimäki, Mika

2018-05-01

Objectives This systematic review and meta-analysis combined published study-level data and unpublished individual-participant data with the aim of quantifying the relation between long working hours and the onset of depressive symptoms. Methods We searched PubMed and Embase for published prospective cohort studies and included available cohorts with unpublished individual-participant data. We used a random-effects meta-analysis to calculate summary estimates across studies. Results We identified ten published cohort studies and included unpublished individual-participant data from 18 studies. In the majority of cohorts, long working hours was defined as working ≥55 hours per week. In multivariable-adjusted meta-analyses of 189 729 participants from 35 countries [96 275 men, 93 454 women, follow-up ranging from 1-5 years, 21 747 new-onset cases), there was an overall association of 1.14 (95% confidence interval (CI) 1.03-1.25] between long working hours and the onset of depressive symptoms, with significant evidence of heterogeneity (I 2 =45.1%, P=0.004). A moderate association between working hours and depressive symptoms was found in Asian countries (1.50, 95% CI 1.13-2.01), a weaker association in Europe (1.11, 95% CI 1.00-1.22), and no association in North America (0.97, 95% CI 0.70-1.34) or Australia (0.95, 95% CI 0.70-1.29). Differences by other characteristics were small. Conclusions This observational evidence suggests a moderate association between long working hours and onset of depressive symptoms in Asia and a small association in Europe.

Association between HTR2C gene variants and suicidal behaviour: a protocol for the systematic review and meta-analysis of genetic studies.

PubMed

Thelma Beatriz, González-Castro; Isela, Juárez-Rojop; Alma, Genis; María Lilia, López-Narváez; Carlos Alfonso, Tovilla-Zárate

2014-09-04

Suicide is an important public health problem and one of the most common causes of death throughout the world. Suicidal behaviour is complex, and its causes are multifactorial. Case-control studies have reported an association between an alteration of the serotonin system and suicidal behaviour. Recently, it has been suggested that the 5-HTRC2 serotonin receptor gene is involved in the pathogenesis of suicidal behaviour. To evaluate the role of the 5-HTR2C gene in suicidal behaviour, we will perform a systematic review and a meta-analysis of worldwide reports that have investigated the association between the serotonin system and suicidal behaviour. This analysis will be reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Studies deemed fit for inclusion in the systematic review will be scored for methodological quality using the Newcastle-Ottawa Assessment Scale (NOS). The inclusion criteria will be to present independent data, to be case-control studies and to be published in journal peer reviews. To generate more accurate analyses, we will grade the reports using the GRADES scale procedures. This study will describe the association between the HTR2C gene and suicidal behaviour. The results will be reported in a peer-reviewed publication and in scientific presentations in Mexico and throughout the world. PROSPERO CRD42014009213. 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.

Disabling chronic conditions in childhood and socioeconomic disadvantage: a systematic review and meta-analyses of observational studies.

PubMed

Spencer, Nicholas J; Blackburn, Clare M; Read, Janet M

2015-09-03

To determine the association of socioeconomic disadvantage with the prevalence of childhood disabling chronic conditions in high-income countries. Systematic review and meta-analyses. 6 electronic databases, relevant websites, reference lists and experts in the field. 160 observational studies conducted in high-income countries with data on socioeconomic status and disabling chronic conditions in childhood, published between 1 January 1991 and 31 December 2013. Abstracts were reviewed, full papers obtained, and papers identified for inclusion by 2 independent reviewers. Inclusion decisions were checked by a third reviewer. Where reported, ORs were extracted for low versus high socioeconomic status. For studies reporting raw data but not ORs, ORs were calculated. Narrative analysis was undertaken for studies without data suitable for meta-analysis. 126 studies had data suitable for meta-analysis. ORs for risk estimates were: all-cause disabling chronic conditions 1.72 (95% CI 1.48 to 2.01); psychological disorders 1.88 (95% CI 1.68 to 2.10); intellectual disability 2.41 (95% CI 2.03 to 2.86); activity-limiting asthma 2.20 (95% CI 1.87 to 2.85); cerebral palsy 1.42 (95% CI 1.26 to 1.61); congenital abnormalities 1.41 (95% CI 1.24 to 1.61); epilepsy 1.38 (95% CI 1.20 to 1.59); sensory impairment 1.70 (95% CI 1.39 to 2.07). Heterogeneity was high across most estimates (I(2)>75%). Of the 34 studies without data suitable for meta-analysis, 26 reported results consistent with increased risk associated with low socioeconomic status. The findings indicate that, in high-income countries, childhood disabling chronic conditions are associated with social disadvantage. Although evidence of an association is consistent across different countries, the review provides limited evidence to explain the association; future research, using longitudinal data, will be required to distinguish low socioeconomic status as the cause or consequence of childhood disabling chronic conditions and the aetiological pathways and mechanisms. 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.

Effects of intranasal oxytocin on symptoms of schizophrenia: A multivariate Bayesian meta-analysis.

PubMed

Williams, Donald R; Bürkner, Paul-Christian

2017-01-01

Schizophrenia is a heterogeneous disorder in which psychiatric symptoms are classified into two general subgroups-positive and negative symptoms. Current antipsychotic drugs are effective for treating positive symptoms, whereas negative symptoms are less responsive. Since the neuropeptide oxytocin (OT) has been shown to mediate social behavior in animals and humans, it has been used as an experimental therapeutic for treating schizophrenia and in particular negative symptoms which includes social deficits. Through eight randomized controlled trials (RCTs) and three meta-analyses, evidence for an effect of intranasal OT (IN-OT) has been inconsistent. We therefore conducted an updated meta-analysis that offers several advantages when compared to those done previously: (1) We used a multivariate analysis which allows for comparisons between symptoms and accounts for correlations between symptoms; (2) We controlled for baseline scores; (3) We used a fully Bayesian framework that allows for assessment of evidence in favor of the null hypothesis using Bayes factors; and (4) We addressed inconsistencies in the primary studies and previous meta-analyses. Eight RCTs (n=238) were included in the present study and we found that oxytocin did not improve any aspect of symptomology in schizophrenic patients and there was moderate evidence in favor of the null (no effect of oxytocin) for negative symptoms. Multivariate comparisons between symptom types revealed that oxytocin was not especially beneficial for treating negative symptoms. The effect size estimates were not moderated, publication bias was absent, and our estimates were robust to sensitivity analyses. These results suggest that IN-OT is not an effective therapeutic for schizophrenia. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Comparison of the Quick-SOFA and Systemic Inflammatory Response Syndrome Criteria for the Diagnosis of Sepsis and Prediction of Mortality: A Systematic Review and Meta-Analysis.

PubMed

Serafim, Rodrigo; Gomes, José Andrade; Salluh, Jorge; Póvoa, Pedro

2018-03-01

Several studies were published to validate the quick Sepsis-related Organ Failure Assessment (qSOFA), namely in comparison with the systemic inflammatory response syndrome (SIRS) criteria. We performed a systematic review and meta-analysis with the aim of comparing the qSOFA and SIRS in patients outside the ICU. We searched MEDLINE, CINAHL, and the Web of Science database from February 23, 2016 until June 30, 2017 to identify full-text English-language studies published after the Sepsis-3 publication comparing the qSOFA and SIRS and their sensitivity or specificity in diagnosing sepsis, as well as hospital and ICU length of stay and hospital mortality. Data extraction from the selected studies followed the recommendations of the Meta-analyses of Observational Studies in Epidemiology group and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. From 4,022 citations, 10 studies met the inclusion criteria. Pooling all the studies, a total of 229,480 patients were evaluated. The meta-analysis of sensitivity for the diagnosis of sepsis comparing the qSOFA and SIRS was in favor of SIRS (risk ratio [RR], 1.32; 95% CI, 0.40-2.24; P < .0001; I 2  = 100%). One study described the specificity for the diagnosis of infection comparing SIRS (84.4%; 95% CI, 76.2-90.6) with the qSOFA (97.3%; 95% CI < 92.1-99.4); the qSOFA demonstrated better specificity. The meta-analysis of the area under the receiver operating characteristic curve of six studies comparing the qSOFA and SIRS favored the qSOFA (RR, 0.03; 95% CI, 0.01-0.05; P = .002; I 2  = 48%) as a predictor of inhospital mortality. The SIRS was significantly superior to the qSOFA for sepsis diagnosis, and the qSOFA was slightly better than the SIRS in predicting hospital mortality. The association of both criteria could provide a better model to initiate or escalate therapy in patients with sepsis. PROSPERO CRD42017067645. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Defining clinically important perioperative blood loss and transfusion for the Standardised Endpoints for Perioperative Medicine (StEP) collaborative: a protocol for a scoping review.

PubMed

Bartoszko, Justyna; Vorobeichik, Leon; Jayarajah, Mohandas; Karkouti, Keyvan; Klein, Andrew A; Lamy, Andre; Mazer, C David; Murphy, Mike; Richards, Toby; Englesakis, Marina; Myles, Paul S; Wijeysundera, Duminda N

2017-06-30

'Standardised Endpoints for Perioperative Medicine' (StEP) is an international collaboration undertaking development of consensus-based consistent definitions for endpoints in perioperative clinical trials. Inconsistency in endpoint definitions can make interpretation of trial results more difficult, especially if conflicting evidence is present. Furthermore, this inconsistency impedes evidence synthesis and meta-analyses. The goals of StEP are to harmonise definitions for clinically meaningful endpoints and specify standards for endpoint reporting in clinical trials. To help inform this endeavour, we aim to conduct a scoping review to systematically characterise the definitions of clinically important endpoints in the existing published literature on perioperative blood loss and transfusion. The scoping review will be conducted using the widely adopted framework developed by Arksey and O'Malley, with modifications from Levac. We refined our methods with guidance from research librarians as well as researchers and clinicians with content expertise. The electronic literature search will involve several databases including Medline, PubMed-not-Medline and Embase. Our review has three objectives, namely to (1) identify definitions of significant blood loss and transfusion used in previously published large perioperative randomised trials; (2) identify previously developed consensus-based definitions for significant blood loss and transfusion in perioperative medicine and related fields; and (3) describe the association between different magnitudes of blood loss and transfusion with postoperative outcomes. The multistage review process for each question will involve two reviewers screening abstracts, reading full-text articles and performing data extraction. The abstracted data will be organised and subsequently analysed in an iterative process. This scoping review of the previously published literature does not require research ethics approval. The results will be used to inform a consensus-based process to develop definitions of clinically important perioperative blood loss and transfusion. The results of the scoping review will be published in a peer-reviewed scientific journal. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of dietary intervention treatment on children with iron deficiency anemia in China: a meta-analysis.

PubMed

Sun, Jian; Zhang, Lei; Cui, Jing; Li, Shanshan; Lu, Hongting; Zhang, Yong; Li, Haiming; Sun, Jianping; Baloch, Zulqarnain

2018-05-10

Previous studies have shown beneficial effects of dietary approaches for iron deficiency anemia (IDA) control. This study was design to investigate the effect of dietary intervention treatment on children with iron deficiency anemia. We performed a systematic review of published dietary interventions effect on IDA treatment through meta-analysis. CBM, CNKI, Wanfang database, EMBASE, VIP, PubMed and Web of science database were searched to identify studies published between January, 1980 and December, 2016. Statistical analysis was performed by Revmen5.2 software. Initially we retrieved for 373 studies, and then 6 studies with a total of 676 individuals were included in the analysis according to the inclusion and exclusion criteria for meta-analysis. The overall pooled estimate of odds ratio [(OR), 95% confidence intervals (95% CI)] in the dietary intervention on children with iron deficiency anemia was 6.54 (95% CI: 3.48-12.31, Z = 5.82, p<0.001) and funnel plot is symmetric. Our meta-analysis suggested that dietary interventions are effective in improving the iron deficiency in children with iron deficiency anemia (IDA) and should be considered in the overall strategy of IDA management.

Prevention of groin injuries in sports: a systematic review with meta-analysis of randomised controlled trials.

PubMed

Esteve, E; Rathleff, M S; Bagur-Calafat, C; Urrútia, G; Thorborg, K

2015-06-01

Groin injuries are common in football and ice hockey, and previous groin injury is a strong risk factor for future groin injuries, which calls for primary prevention. The aim of this systematic review was to evaluate the effect of specific groin-injury prevention programmes in sports. A comprehensive search was performed in May 2014 yielding 1747 potentially relevant references. Two independent assessors evaluated randomised controlled trials for inclusion, extracted data and performed quality assessments using Cochrane's risk of bias tool. Quantitative analyses were performed in Review Manager 5.3. Seven trials were included: six on football players (four male and two female populations) and one on male handball players. In total there were 4191 participants with a total of 157 injuries. The primary analysis, including all participants, did not show a significant reduction in the number of groin injuries after completing a groin injury prevention programme (relative risk (RR) 0.81; 95% CI 0.60 to 1.09). Subgroup analysis based on type of sports, gender and type of prevention programme showed similar non-significant estimates with RR ranging from 0.48 to 0.81. Meta-analysis revealed a potential clinically meaningful groin injury reduction of 19%, even though no statistical significant reduction in sport-related groin injuries could be documented. PROSPERO registration ID CRD42014009614. 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.

The effects of immunotherapy with intravenous immunoglobulins versus no intervention, placebo, or usual care in patients with recurrent miscarriages: a protocol for a systematic review with meta-analyses, trial sequential analyses, and individual patient data meta-analyses of randomised clinical trials.

PubMed

Egerup, Pia; Lindschou, Jane; Gluud, Christian; Christiansen, Ole Bjarne

2014-08-15

Recurrent miscarriage is generally defined as three or more miscarriages before gestational week 20. Recurrent miscarriage affects 1% of all women and the condition can only be explained by parental chromosome abnormalities, uterine malformations, or endocrine or thrombophilic disturbances to a limited extent. Immunological disturbances are hypothesised to play an important role in recurrent miscarriage and, therefore, various types of immunologically-based therapies have been tested in recurrent miscarriage patients including intravenous immunoglobulins. So far, at least eight randomised placebo-controlled trials, with opposing results, investigating intravenous immunoglobulins with a total of 324 recurrent miscarriage patients have been published. We will include randomised clinical trials irrespective of publication date, publication type, publication language, and publication status investigating infusions with immunoglobulins in relation to pregnancy compared to placebo, no intervention, or treatment as usual for assessments of benefits and harms. The relevant published literature will be searched using the following databases: Cochrane Central Register of Controlled Trials, Medline, Embase, WHO International Clinical Trials Registry Platform, and Ovid Medline In-Process and Other Non-Indexed Citations databases. Two review authors will independently extract data and assess risk of bias. We will undertake meta-analyses according to the recommendations stated in the Cochrane Handbook for Systematic Reviews of Interventions. Further, we will conduct trial sequential analyses and individual patient data meta-analyses. A miscarriage results in great sorrow, loss of life quality, and personal concern. In particular, recurrent miscarriage is extremely stressful and burdensome. It is, therefore, very important to conduct research in this area. There is currently no evidence-based treatment for women with recurrent miscarriage which significantly improves their ability to give live birth. Therefore, a comprehensive up-to-date systematic review is needed. By using individual patient data, it will be possible to provide new knowledge about the benefits and harms of intravenous immunoglobulins and try to identify the subgroup in which the treatment will have the highest impact.This systematic review protocol was registered within the International Prospective Register of Systematic Reviews (PROSPERO) as number CRD42014007112.

Evidence synthesis for medical decision making and the appropriate use of quality scores.

PubMed

Doi, Suhail A R

2014-09-01

Meta-analyses today continue to be run using conventional random-effects models that ignore tangible information from studies such as the quality of the studies involved, despite the expectation that results of better quality studies reflect more valid results. Previous research has suggested that quality scores derived from such quality appraisals are unlikely to be useful in meta-analysis, because they would produce biased estimates of effects that are unlikely to be offset by a variance reduction within the studied models. However, previous discussions took place in the context of such scores viewed in terms of their ability to maximize their association with both the magnitude and direction of bias. In this review, another look is taken at this concept, this time asserting that probabilistic bias quantification is not possible or even required of quality scores when used in meta-analysis for redistribution of weights. The use of such a model is contrasted with the conventional random effects model of meta-analysis to demonstrate why the latter is inadequate in the face of a properly specified quality score weighting method. © 2014 Marshfield Clinic.

Alexithymia in eating disorders: Systematic review and meta-analyses of studies using the Toronto Alexithymia Scale.

PubMed

Westwood, Heather; Kerr-Gaffney, Jess; Stahl, Daniel; Tchanturia, Kate

2017-08-01

The aim of this review was to synthesise the literature on the use of the Toronto Alexithymia Scale (TAS) in eating disorder populations and Healthy Controls (HCs) and to compare TAS scores in these groups. Electronic databases were searched systematically for studies using the TAS and meta-analyses were performed to statistically compare scores on the TAS between individuals with eating disorders and HCs. Forty-eight studies using the TAS with both a clinical eating disorder group and HCs were identified. Of these, 44 were included in the meta-analyses, separated into: Anorexia Nervosa; Anorexia Nervosa, Restricting subtype; Anorexia Nervosa, Binge-Purge subtype, Bulimia Nervosa and Binge Eating Disorder. For all groups, there were significant differences with medium or large effect sizes between the clinical group and HCs, with the clinical group scoring significantly higher on the TAS, indicating greater difficulty with identifying and labelling emotions. Across the spectrum of eating disorders, individuals report having difficulties recognising or describing their emotions. Given the self-report design of the TAS, research to develop and evaluate treatments and clinician-administered assessments of alexithymia is warranted. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Updated Systematic Review and Meta-analysis of the Comparative Data on Colposuspensions, Pubovaginal Slings, and Midurethral Tapes in the Surgical Treatment of Female Stress Urinary Incontinence.

PubMed

Fusco, Ferdinando; Abdel-Fattah, Mohamed; Chapple, Christopher R; Creta, Massimiliano; La Falce, Sabrina; Waltregny, David; Novara, Giacomo

2017-10-01

Retropubic (RP-TVT) and transobturator miurethral (TO-TVT) midurethral sling (MUS) are popular surgical treatments for female stress urinary incontinence. The long-term efficacy and safety of the procedures is still a topic of intense clinical research and several randomised controlled trials (RCTs) have been published in the last years OBJECTIVE: To evaluate the efficacy and safety of MUS compared with other surgical treatments for female stress urinary incontinence. A systematic review and meta-analysis of the literature was performed using the Medline, Scopus, and Web of Science databases to update our previously published analyses. Twenty-eight RCTs were identified. In total, the meta-analyses included 15 855 patients. Patients receiving MUS had significantly higher overall (odds ratio [OR]: 0.59, p=0.0003) and objective (OR: 0.51, p=0.001) cure rates than those receiving Burch colposuspension. Patients undergoing MUS and pubovaginal slings had similar cure rates. Patients treated with RT-TVT had higher subjective (OR: 0.83, p=0.03) and objective (OR: 0.82, p=0.01) cure rates than those receiving TO-TVT. However, the latter had a lower risk of intraoperative bladder or vaginal perforation (OR: 2.4, p=0.0002), pelvic haematoma (OR: 2.61, p=0.002), urinary tract infections (OR: 1.31, p=0.04) and voiding lower urinary tract symptoms (OR: 1.66, p=0.002). Sensitivity analyses limited to RCTs with follow-up durations >60 mo demonstrated similar outcomes for RP-TVT and TO-TVT. No significant differences in efficacy were identified comparing inside-to-out and outside-to-in TO-TVT but vaginal perforations were less common with the former (OR: 0.21, p=0.0002). The present analysis confirms the superiority of MUS over Burch colposuspension. The studies comparing insertion of RT-TVT and TO-TVT showed higher subjective and objective cure rates for the RP-TVT but at the cost of higher risks of some complications and voiding lower urinary tract symptoms. Efficacy of inside-out and outside-in techniques of TO-TVT insertion was similar, although the risk of vaginal perforation was lower in the inside-to-out TO-TVT. Retropubic and transobturator midurethral slings are a popular treatment for female stress urinary incontinence. The available literature suggest that those slings are either more effective or safer than other older surgical procedures. Retropubic tapes are followed with slightly higher continence rates as compared with the transobturator tapes but are associated with higher risk of intra- and postoperative complications. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Meta-analysis of surgical safety checklist effects on teamwork, communication, morbidity, mortality, and safety.

PubMed

Lyons, Vanessa E; Popejoy, Lori L

2014-02-01

The purpose of this study is to examine the effectiveness of surgical safety checklists on teamwork, communication, morbidity, mortality, and compliance with safety measures through meta-analysis. Four meta-analyses were conducted on 19 studies that met the inclusion criteria. The effect size of checklists on teamwork and communication was 1.180 (p = .003), on morbidity and mortality was 0.123 (p = .003) and 0.088 (p = .001), respectively, and on compliance with safety measures was 0.268 (p < .001). The results indicate that surgical safety checklists improve teamwork and communication, reduce morbidity and mortality, and improve compliance with safety measures. This meta-analysis is limited in its generalizability based on the limited number of studies and the inclusion of only published research. Future research is needed to examine possible moderating variables for the effects of surgical safety checklists.

Open access of evidence-based publications: the case of the orthopedic and musculoskeletal literature.

PubMed

Yammine, Kaissar

2015-11-01

The open access model, where researchers can publish their work and make it freely available to the whole medical community, is gaining ground over the traditional type of publication. However, fees are to be paid by either the authors or their institutions. The purpose of this paper is to assess the proportion and type of open access evidence-based articles in the form of systematic reviews and meta-analyses in the field of musculoskeletal disorders and orthopedic surgery. PubMed database was searched and the results showed a maximal number of hits for low back pain and total hip arthroplasty. We demonstrated that despite a 10-fold increase in the number of evidence-based publications in the past 10 years, the rate of free systematic reviews in the general biomedical literature did not change for the last two decades. In addition, the average percentage of free open access systematic reviews and meta-analyses for the commonest painful musculoskeletal conditions and orthopedic procedures was 20% and 18%, respectively. Those results were significantly lower than those of the systematic reviews and meta-analyses in the remaining biomedical research. Such findings could indicate a divergence between the efforts engaged at promoting evidence-based principles and those at disseminating evidence-based findings in the field of musculoskeletal disease and trauma. The high processing fee is thought to be a major limitation when considering open access model for publication. © 2015 Chinese Cochrane Center, West China Hospital of Sichuan University and Wiley Publishing Asia Pty Ltd.

Latest evidence on transcatheter aortic valve implantation vs. surgical aortic valve replacement for the treatment of aortic stenosis in high and intermediate-risk patients.

PubMed

Praz, Fabien; Siontis, George C M; Verma, Subodh; Windecker, Stephan; Jüni, Peter

2017-03-01

The goal of this review is to summarize the current evidence supporting the use of transcatheter aortic valve implantation (TAVI) in high and intermediate-risk patients. The focus is on the five randomized controlled trials comparing TAVI with surgical aortic valve replacement (SAVR) published to date, as well as two recent meta-analyses. TAVI has profoundly transformed the treatment of elderly patients presenting with symptomatic severe aortic stenosis. In experienced hands, the procedure has become well tolerated and the results more predictable. So far, two trials using two different devices [Placement of Aortic Transcatheter Valve (PARTNER) 1A and US CoreValve High Risk] have shown that TAVI is able to compete in terms of mortality with SAVR in high-risk patients. These findings have been extended to the intermediate-risk population in two recently published randomized controlled trials [PARTNER 2 and Nordic Aortic Valve Intervention (NOTION)]. The two meta-analyses suggested improved survival in both high and intermediate-risk patients during the first 2 years following the intervention. The survival benefit was only found in patients treated via the transfemoral access, and appeared more pronounced in women. Individual randomized trials enrolling high and intermediate-risk patients have established the noninferiority of TAVI in comparison with SAVR, whereas subsequent meta-analyses suggest superiority of transfemoral TAVI in terms of a sustained survival benefit 2 years after valve implantation irrespective of the surgical risk category. The benefit of TAVI appears more pronounced in women than in men.

Independent Risk Factors Contributing to Acute Kidney Injury According to Updated Valve Academic Research Consortium-2 Criteria After Transcatheter Aortic Valve Implantation: A Meta-analysis and Meta-regression of 13 Studies.

PubMed

Wang, Jiayang; Yu, Wenyuan; Zhou, Ye; Yang, Yong; Li, Chenglong; Liu, Nan; Hou, Xiaotong; Wang, Longfei

2017-06-01

This study aimed to examine the risk factors for transcatheter aortic valve implantation (TAVI)-associated acute kidney injury (AKI) according to the AKI definition from the Valve Academic Research Consortium-2 (VARC-2). A meta-analysis. A total of 661 patients with post-TAVI AKI according to the VARC-2 definition and 2,012 controls were included in the meta-analysis. Patients undergoing TAVI were included in this meta-analysis. Multiple electronic databases were searched using predefined criteria. The diagnosis of AKI was based on the VARC-2 classification. The authors found that preoperative New York Heart Association class IV (odds ratio [OR], 7.77; 95% confidence interval [CI], 3.81-15.85), previous chronic renal disease (CKD) (OR, 2.81; 95% CI, 1.96-4.03), and requirement for transfusion (OR, 2.03; 95% CI, 1.59-2.59) were associated significantly with an increased risk for post-TAVI AKI. Furthermore, previous peripheral vascular disease (PVD), hypertension, atrial fibrillation, congestive heart failure, diabetes mellitus, and stroke were also risk factors for TAVI-associated AKI. Additionally, transfemoral access significantly correlated with a reduced risk for post-TAVI AKI (OR, 0.43; 95% CI, 0.33-0.57). The potential confounders, including Society of Thoracic Surgeons Score, the logistic European System for Cardiac Operative Risk Evaluation, aortic valve area, mean pressure gradient, left ventricular ejection fraction, age, body mass index, contrast volume, and valve type, had no impact on the association between the risk factors and post-TAVI AKI. Subgroup analysis of the eligible studies presenting multivariate logistic regression analysis on the independent risk factors for post-TAVI AKI revealed that previous CKD, previous PVD, and transapical access were independent risk factors for TAVI-associated AKI. The current meta-analysis suggested that previous CKD, previous PVD, and transapical access may be independent risk factors for TAVI-associated AKI. Copyright © 2017. Published by Elsevier Inc.

Genetic Polymorphisms of Glutathione-Related Enzymes (GSTM1, GSTT1, and GSTP1) and Schizophrenia Risk: A Meta-Analysis

PubMed Central

Kim, Su Kang; Kang, Sang Wook; Chung, Joo-Ho; Park, Hae Jeong; Cho, Kyu Bong; Park, Min-Su

2015-01-01

The association between polymorphisms of glutathione-related enzyme (GST) genes and the risk of schizophrenia has been investigated in many published studies. However, their results were inconclusive. Therefore, we performed a meta-analysis to explore the association between the GSTM1, GSTT1, and GSTP1 polymorphisms and the risk of schizophrenia. Twelve case-control studies were included in this meta-analysis. The odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. Our meta-analysis results revealed that GSTM1, GSTT1, and GSTP1 polymorphisms were not related to risk of schizophrenia (p > 0.05 in each model). Further analyses based on ethnicity, GSTM polymorphism showed weak association with schizophrenia in East Asian population (OR = 1.314, 95% CI = 1.025–1.684, p = 0.031). In conclusion, our meta-analysis indicated the GSTM1 polymorphism may be the only genetic risk factor for schizophrenia in East Asian population. However, more meta-analysis with a larger sample size were needed to provide more precise evidence. PMID:26295386

Reporting of Adverse Events in Published and Unpublished Studies of Health Care Interventions: A Systematic Review

PubMed Central

Golder, Su; Wright, Kath

2016-01-01

Background We performed a systematic review to assess whether we can quantify the underreporting of adverse events (AEs) in the published medical literature documenting the results of clinical trials as compared with other nonpublished sources, and whether we can measure the impact this underreporting has on systematic reviews of adverse events. Methods and Findings Studies were identified from 15 databases (including MEDLINE and Embase) and by handsearching, reference checking, internet searches, and contacting experts. The last database searches were conducted in July 2016. There were 28 methodological evaluations that met the inclusion criteria. Of these, 9 studies compared the proportion of trials reporting adverse events by publication status. The median percentage of published documents with adverse events information was 46% compared to 95% in the corresponding unpublished documents. There was a similar pattern with unmatched studies, for which 43% of published studies contained adverse events information compared to 83% of unpublished studies. A total of 11 studies compared the numbers of adverse events in matched published and unpublished documents. The percentage of adverse events that would have been missed had each analysis relied only on the published versions varied between 43% and 100%, with a median of 64%. Within these 11 studies, 24 comparisons of named adverse events such as death, suicide, or respiratory adverse events were undertaken. In 18 of the 24 comparisons, the number of named adverse events was higher in unpublished than published documents. Additionally, 2 other studies demonstrated that there are substantially more types of adverse events reported in matched unpublished than published documents. There were 20 meta-analyses that reported the odds ratios (ORs) and/or risk ratios (RRs) for adverse events with and without unpublished data. Inclusion of unpublished data increased the precision of the pooled estimates (narrower 95% confidence intervals) in 15 of the 20 pooled analyses, but did not markedly change the direction or statistical significance of the risk in most cases. The main limitations of this review are that the included case examples represent only a small number amongst thousands of meta-analyses of harms and that the included studies may suffer from publication bias, whereby substantial differences between published and unpublished data are more likely to be published. Conclusions There is strong evidence that much of the information on adverse events remains unpublished and that the number and range of adverse events is higher in unpublished than in published versions of the same study. The inclusion of unpublished data can also reduce the imprecision of pooled effect estimates during meta-analysis of adverse events. PMID:27649528

Macrophage migration inhibitory factor gene polymorphisms in inflammatory bowel disease: an association study in New Zealand Caucasians and meta-analysis.

PubMed

Falvey, James D; Bentley, Robert W; Merriman, Tony R; Hampton, Mark B; Barclay, Murray L; Gearry, Richard B; Roberts, Rebecca L

2013-10-21

To investigate the association of macrophage migration inhibitory factor (MIF) promoter polymorphisms with inflammatory bowel disease (IBD) risk. One thousand and six New Zealand Caucasian cases and 540 Caucasian controls were genotyped for the MIF SNP -173G > C (rs755622) and the repeat polymorphism CATT₅₋₈ (rs5844572) using a pre-designed TaqMan SNP assay and capillary electrophoresis, respectively. Data were analysed for single site and haplotype association with IBD risk and phenotype. Meta-analysis was employed, to assess cumulative evidence of association of MIF -173G > C with IBD. All published genotype data for MIF -173G > C in IBD were identified using PubMed and subsequently searching the references of all PubMed-identified studies. Imputed genotypes for MIF -173G > C were generated from the Wellcome Trust Case Control Consortium (and National Institute of Diabetes and Digestive and Kidney Diseases). Separate meta-analyses were performed on Caucasian Crohn's disease (CD) (3863 patients, 6031 controls), Caucasian ulcerative colitis (UC) (1260 patients, 1987 controls), and East Asian UC (416 patients and 789 controls) datasets using the Mantel-Haenszel method. The New Zealand dataset had 93% power, and the meta-analyses had 100% power to detect an effect size of OR = 1.40 at α = 0.05, respectively. In our New Zealand dataset, single-site analysis found no evidence of association of MIF polymorphisms with overall risk of CD, UC, and IBD or disease phenotype (all P values > 0.05). Haplotype analysis found the CATT₅/-173C haplotype occurred at a higher frequency in New Zealand controls compared to IBD patients (0.6 vs 0.01; P = 0.03, OR = 0.22; 95%CI: 0.05-0.99), but this association did not survive bonferroni correction. Meta-analysis of our New Zealand MIF -173G > C data with data from seven additional Caucasian datasets using a random effects model found no association of MIF polymorphisms with CD, UC, or overall IBD. Similarly, meta-analysis of all published MIF -173G > C data from East Asian datasets (416 UC patients, 789 controls) found no association of this promoter polymorphism with UC. We found no evidence of association of MIF promoter polymorphisms with IBD.

Composition differences between organic and conventional meat: a systematic literature review and meta-analysis.

PubMed

Średnicka-Tober, Dominika; Barański, Marcin; Seal, Chris; Sanderson, Roy; Benbrook, Charles; Steinshamn, Håvard; Gromadzka-Ostrowska, Joanna; Rembiałkowska, Ewa; Skwarło-Sońta, Krystyna; Eyre, Mick; Cozzi, Giulio; Krogh Larsen, Mette; Jordon, Teresa; Niggli, Urs; Sakowski, Tomasz; Calder, Philip C; Burdge, Graham C; Sotiraki, Smaragda; Stefanakis, Alexandros; Yolcu, Halil; Stergiadis, Sokratis; Chatzidimitriou, Eleni; Butler, Gillian; Stewart, Gavin; Leifert, Carlo

2016-03-28

Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectively. However, for these and many other composition parameters, for which meta-analyses found significant differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Evidence from controlled experimental studies indicates that the high grazing/forage-based diets prescribed under organic farming standards may be the main reason for differences in FA profiles. Further studies are required to enable meta-analyses for a wider range of parameters (e.g. antioxidant, vitamin and mineral concentrations) and to improve both precision and consistency of results for FA profiles for all species. Potential impacts of composition differences on human health are discussed.

Assessment of Adult Psychopathology: Meta-Analyses and Implications of Cross-Informant Correlations

ERIC Educational Resources Information Center

Achenbach, Thomas M.; Krukowsi, Rebecca A.; Dumenci, Levent; Ivanova, Masha Y.

2005-01-01

Assessment of adult psychopathology relies heavily on self-reports. To determine how well self-reports agree with reports by "informants" who know the person being assessed, the authors examined 51,000 articles published over 10 years in 52 peer-reviewed journals for correlations between self-reports and "informants" reports. Qualifying…

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.

Residential road traffic noise as a risk factor for hypertension in adults: Systematic review and meta-analysis of analytic studies published in the period 2011-2017.

PubMed

Dzhambov, Angel M; Dimitrova, Donka D

2018-05-07

Multiple cross-sectional studies indicated an association between hypertension and road traffic noise and they were recently synthetized in a WHO systematic evidence review. However, recent years have seen a growing body of high-quality, large-scale research, which is missing from the WHO review. Therefore, we aimed to close that gap by conducting an updated systematic review and meta-analysis on the exposure-response relationship between residential road traffic noise and the risk of hypertension in adults. Studies were identified by searching MEDLINE, EMBASE, the Internet, conference proceedings, reference lists, and expert archives in English, Russian, and Spanish through August 5, 2017. The risk of bias for each extracted estimate and the overall quality of evidence were evaluated using a list of predefined safeguards against bias related to different study characteristics and the Grading of Recommendations Assessment, Development and Evaluation system, respectively. The inverse variance heterogeneity (IVhet) model was used for meta-analysis. The possibility of publication bias was evaluated by funnel and Doi plots, and asymmetry in these was tested with Egger's test and the Luis Furuya-Kanamori index, respectively. Sensitivity analyses included leave-one-out meta-analysis, subgroup meta-analysis with meta-regressions, and non-linear exposure-response meta-analysis. Based on seven cohort and two case-control studies (n = 5 514 555; 14 estimates; L den range ≈ 25-90 dB(A)), we found "low" evidence of RR per 10 dB(A)  = 1.018 (95% CI: 0.984, 1.053), moderate heterogeneity (I 2  = 46%), and no publication bias. In the subgroup of cohort studies, we found "moderate" evidence of RR per 10 dB(A)  = 1.018 (95% CI: 0.987, 1.049), I 2  = 31%, and no publication bias. In conclusion, residential road traffic noise was associated with higher risk of hypertension in adults, but the risk was lower than previously reported in the systematic review literature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Maternal body mass index and post-term birth: a systematic review and meta-analysis.

PubMed

Heslehurst, N; Vieira, R; Hayes, L; Crowe, L; Jones, D; Robalino, S; Slack, E; Rankin, J

2017-03-01

Post-term birth is a preventable cause of perinatal mortality and severe morbidity. This review examined the association between maternal body mass index (BMI) and post-term birth at ≥42 and ≥41 weeks' gestation. Five databases, reference lists and citations were searched from May to November 2015. Observational studies published in English since 1990 were included. Linear and nonlinear dose-response meta-analyses were conducted by using random effects models. Sensitivity analyses assessed robustness of the results. Meta-regression and sub-group meta-analyses explored heterogeneity. Obesity classes were defined as I (30.0-34.9 kg m -2 ), II (35.0-39.9 kg m -2 ) and III (≥40 kg m -2 ; IIIa 40.0-44.9 kg m -2 , IIIb ≥ 45.0 kg m -2 ). Searches identified 16,375 results, and 39 studies met the inclusion criteria (n = 4,143,700 births). A nonlinear association between maternal BMI and births ≥42 weeks was identified; odds ratios and 95% confidence intervals for obesity classes I-IIIb were 1.42 (1.27-1.58), 1.55 (1.37-1.75), 1.65 (1.44-1.87) and 1.75 (1.50-2.04) respectively. BMI was linearly associated with births ≥41 weeks: odds ratio is 1.13 (95% confidence interval 1.05-1.21) for each 5-unit increase in BMI. The strength of the association between BMI and post-term birth increases with increasing BMI. Odds are greatest for births ≥42 weeks among class III obesity. Targeted interventions to prevent the adverse outcomes associated with post-term birth should consider the difference in risk between obesity classes. © 2017 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity.

Olympic weightlifting training improves vertical jump height in sportspeople: a systematic review with meta-analysis.

PubMed

Hackett, Daniel; Davies, Tim; Soomro, Najeebullah; Halaki, Mark

2016-07-01

This systematic review was conducted to evaluate the effect of Olympic weightlifting (OW) on vertical jump (VJ) height compared to a control condition, traditional resistance training and plyometric training. Five electronic databases were searched using terms related to OW and VJ. Studies needed to include at least one OW exercise, an intervention lasting ≥6 weeks; a comparison group of control, traditional resistance training or plyometric training; and to have measured VJ height. The methodological quality of studies was assessed using the Downs and Black Checklist. Random and fixed effects meta-analyses were performed to pool the results of the included studies and generate a weighted mean effect size (ES). Six studies (seven articles) were included in the meta-analyses and described a total of 232 participants (175 athletes and 57 physical education students) with resistance training experience, aged 19.5±2.2 years. Three studies compared OW versus control; four studies compared OW versus traditional resistance training; and three studies compared OW versus plyometric training. Meta-analyses indicated OW improved VJ height by 7.7% (95% CI 3.4 to 5.4 cm) compared to control (ES=0.62, p=0.03) and by 5.1% (95% CI 2.2 to 3.0 cm) compared to traditional resistance training (ES=0.64 p=0.00004). Change in VJ height was not different for OW versus plyometric training. OW is an effective training method to improve VJ height. The similar effects observed for OW and plyometric training on VJ height suggests that either of these methods would be beneficial when devising training programmes to improve VJ height. 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/

Visual Task Demands and the Auditory Mismatch Negativity: An Empirical Study and a Meta-Analysis

PubMed Central

Wiens, Stefan; Szychowska, Malina; Nilsson, Mats E.

2016-01-01

Because the auditory system is particularly useful in monitoring the environment, previous research has examined whether task-irrelevant, auditory distracters are processed even if subjects focus their attention on visual stimuli. This research suggests that attentionally demanding visual tasks decrease the auditory mismatch negativity (MMN) to simultaneously presented auditory distractors. Because a recent behavioral study found that high visual perceptual load decreased detection sensitivity of simultaneous tones, we used a similar task (n = 28) to determine if high visual perceptual load would reduce the auditory MMN. Results suggested that perceptual load did not decrease the MMN. At face value, these nonsignificant findings may suggest that effects of perceptual load on the MMN are smaller than those of other demanding visual tasks. If so, effect sizes should differ systematically between the present and previous studies. We conducted a selective meta-analysis of published studies in which the MMN was derived from the EEG, the visual task demands were continuous and varied between high and low within the same task, and the task-irrelevant tones were presented in a typical oddball paradigm simultaneously with the visual stimuli. Because the meta-analysis suggested that the present (null) findings did not differ systematically from previous findings, the available evidence was combined. Results of this meta-analysis confirmed that demanding visual tasks reduce the MMN to auditory distracters. However, because the meta-analysis was based on small studies and because of the risk for publication biases, future studies should be preregistered with large samples (n > 150) to provide confirmatory evidence for the results of the present meta-analysis. These future studies should also use control conditions that reduce confounding effects of neural adaptation, and use load manipulations that are defined independently from their effects on the MMN. PMID:26741815

Meta-analysis of Intravenous Tranexamic Acid in Primary Total Hip Arthroplasty.

PubMed

Moskal, Joseph T; Capps, Susan G

2016-09-01

Previous meta-analyses established that tranexamic acid confers benefits when used during total hip arthroplasty (THA). However, 2 of these meta-analyses included a variety of routes of administration of tranexamic acid in THA (topical, intravenous, oral, and intra-articular), another meta-analysis included a variety of antifibrinolytic drugs (not restricted to a single drug), and the final meta-analysis included nonrandomized controlled trials. This meta-analysis focused on a single medication, tranexamic acid, administered in a specific way, intravenously in patients undergoing primary THA, using data reported only in randomized controlled studies. Outcomes were restricted to blood loss, allogeneic transfusion rates, and complications. Other outcomes, such as return to function or clinical scores, could not be evaluated because of lack of consistent reporting. To better understand the effects of intravenous tranexamic acid in THA on clinical outcomes, such as recovery, return to function, and patient-reported outcome measures, it would be helpful to have more controlled trials examining these measures in a standardized manner. Intravenous tranexamic acid was beneficial for blood loss intraoperatively, blood loss through drains, and total blood loss during hospitalization, in addition to reducing allogeneic transfusion rates. No difference between intravenous tranexamic acid and placebo was found for most complications, except deep venous thrombosis, which showed favorable results with placebo. [Orthopedics.2016; 39(5):e883-e892.]. Copyright 2016, SLACK Incorporated.

Predictors of persistent pain after total knee arthroplasty: a systematic review and meta-analysis.

PubMed

Lewis, G N; Rice, D A; McNair, P J; Kluger, M

2015-04-01

Several studies have identified clinical, psychosocial, patient characteristic, and perioperative variables that are associated with persistent postsurgical pain; however, the relative effect of these variables has yet to be quantified. The aim of the study was to provide a systematic review and meta-analysis of predictor variables associated with persistent pain after total knee arthroplasty (TKA). Included studies were required to measure predictor variables prior to or at the time of surgery, include a pain outcome measure at least 3 months post-TKA, and include a statistical analysis of the effect of the predictor variable(s) on the outcome measure. Counts were undertaken of the number of times each predictor was analysed and the number of times it was found to have a significant relationship with persistent pain. Separate meta-analyses were performed to determine the effect size of each predictor on persistent pain. Outcomes from studies implementing uni- and multivariable statistical models were analysed separately. Thirty-two studies involving almost 30 000 patients were included in the review. Preoperative pain was the predictor that most commonly demonstrated a significant relationship with persistent pain across uni- and multivariable analyses. In the meta-analyses of data from univariate models, the largest effect sizes were found for: other pain sites, catastrophizing, and depression. For data from multivariate models, significant effects were evident for: catastrophizing, preoperative pain, mental health, and comorbidities. Catastrophizing, mental health, preoperative knee pain, and pain at other sites are the strongest independent predictors of persistent pain after TKA. © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effect of PCSK1 variants on waist, waist-hip ratio and glucose metabolism is modified by sex and glucose tolerance status.

PubMed

Gjesing, Anette P; Vestmar, Marie A; Jørgensen, Torben; Heni, Martin; Holst, Jens J; Witte, Daniel R; Hansen, Torben; Pedersen, Oluf

2011-01-01

We aimed to evaluate the effects of the G-allele of rs6232 and the C-allele of rs6235 within PCSK1 on measures of body fat and glucose homeostasis in Danish individuals and to assess interactions of genotypes with age, sex and glucose tolerance status. Data were included in meta-analyses of additional Europeans. Rs6232 and rs6235 were genotyped in 6,164 Danes from the Inter99 study of middle-aged people. Results from these analyses were combined with previously published studies in meta-analyses of a total of 27,786 individuals. The impact of the variants was also investigated in a subset of 62 glucose-tolerant men during a meal challenge including measures of serum incretins. In men we found an effect on body composition in sex-stratified analyses where the rs6235 C-allele conferred an increased waist circumference of 0.8 cm per allele (0.2-1.5, p = 0.008) and increased waist-to-hip ratio of 0.004 (0.0005-0.008, p = 0.027). In the meta-analyses where men and women were combined, the rs6232 G-allele associated with increased waist-to-hip ratio (p = 0.02) and the rs6235 C-allele associated with increased waist circumference (p = 0.01). Furthermore, the rs6235 C-allele was associated nominally with a 0.6% (0.1-1%, p = 0.01) reduction in fasting glucose, it interacted with glucose tolerance status for traits related to glucose metabolism and analysis among individuals having abnormal glucose tolerance revealed a 5% (-0.7-9%, p = 0.02) elevated level of acute insulin response for this variant. Finally, we found that the rs6232 G-allele associated with higher levels of GLP-1, GLP-2 and glucagon and that the rs6235 C-allele associated with higher levels of GIP and glucagon during a meal-test. PCSK1 rs6232 G-allele and rs6235 C-allele have an effect on body composition which may be modified by sex, whereas the effect of rs6235 C-allele on fasting and stimulated circulating plasma glucose and hormone levels may be influenced by glucose tolerance status.

The Effect of PCSK1 Variants on Waist, Waist-Hip Ratio and Glucose Metabolism Is Modified by Sex and Glucose Tolerance Status

PubMed Central

Gjesing, Anette P.; Vestmar, Marie A.; Jørgensen, Torben; Heni, Martin; Holst, Jens J.; Witte, Daniel R.; Hansen, Torben; Pedersen, Oluf

2011-01-01

Background We aimed to evaluate the effects of the G-allele of rs6232 and the C-allele of rs6235 within PCSK1 on measures of body fat and glucose homeostasis in Danish individuals and to assess interactions of genotypes with age, sex and glucose tolerance status. Data were included in meta-analyses of additional Europeans. Methodology/Principal Findings Rs6232 and rs6235 were genotyped in 6,164 Danes from the Inter99 study of middle-aged people. Results from these analyses were combined with previously published studies in meta-analyses of a total of 27,786 individuals. The impact of the variants was also investigated in a subset of 62 glucose-tolerant men during a meal challenge including measures of serum incretins. In men we found an effect on body composition in sex-stratified analyses where the rs6235 C-allele conferred an increased waist circumference of 0.8 cm per allele (0.2–1.5, p = 0.008) and increased waist-to-hip ratio of 0.004 (0.0005–0.008, p = 0.027). In the meta-analyses where men and women were combined, the rs6232 G-allele associated with increased waist-to-hip ratio (p = 0.02) and the rs6235 C-allele associated with increased waist circumference (p = 0.01). Furthermore, the rs6235 C-allele was associated nominally with a 0.6% (0.1–1%, p = 0.01) reduction in fasting glucose, it interacted with glucose tolerance status for traits related to glucose metabolism and analysis among individuals having abnormal glucose tolerance revealed a 5% (−0.7–9%, p = 0.02) elevated level of acute insulin response for this variant. Finally, we found that the rs6232 G-allele associated with higher levels of GLP-1, GLP-2 and glucagon and that the rs6235 C-allele associated with higher levels of GIP and glucagon during a meal-test. Conclusions/Significance PCSK1 rs6232 G-allele and rs6235 C-allele have an effect on body composition which may be modified by sex, whereas the effect of rs6235 C-allele on fasting and stimulated circulating plasma glucose and hormone levels may be influenced by glucose tolerance status. PMID:21935364

β-Blockers in hypertension: studies and meta-analyses over the years.

PubMed

Larochelle, Pierre; Tobe, Sheldon W; Lacourcière, Yves

2014-05-01

β-Blockers are among the most commonly used medications in the treatment of hypertension. However, 45 years after their initial indication for that treatment, their place in the treatment of hypertensive patients is under evaluation and their usefulness has been questioned based on evidence from meta-analyses of clinical trials. The β-blocker class consists of various agents with diverse pharmacokinetic and pharmacodynamic properties including lipo- and hydrophilicity, duration of action, intrinsic sympathomimetic activity, vasodilation, and metabolism linked to genetic polymorphisms. Because of their various properties, some β-blockers are indicated for cardiovascular conditions such as angina, rate control of atrial fibrillation, chronic heart failure, and after myocardial infarction, and other indications such as migraine and essential tremor. There have been more than 17 large trials influencing the recommendations on the use of these agents in the treatment of hypertension. The results of these trials initially led to the widespread recommendation for the use of β-blockers in the management of hypertension. However, the recent multiple meta-analyses using these trials have raised a controversy on their place in that treatment. The Canadian Hypertension Education Program recommendations have included β-blockers as a first-line treatment option for patients younger than 60 years of age based on the evidence from these large trials, and this has been supported by 2 of the meta-analyses. This article reviews these studies to help clinicians better understand the role of β-blockers in managing hypertension. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

A critical review of low-carbohydrate diets in people with Type 2 diabetes.

PubMed

van Wyk, H J; Davis, R E; Davies, J S

2016-02-01

The efficacy of low-carbohydrate diets (LCD) in people with Type 2 diabetes has divided the nutrition community. This review seeks to re-examine the available data to clarify understanding. A comprehensive search of databases was used to identify meta-analyses of LCD in Type 2 diabetes. To improve the quality of the studies analysed, the following inclusion criteria were applied: randomized control trials ≥ 4 weeks in people aged > 18 years with Type 2 diabetes; a carbohydrate intake ≤ 45% of total energy intake per day; and a dietary intake assessment at the end of the study. The resulting studies were subjected to a thematic analysis. Nine meta-analyses were identified containing 153 studies. Twelve studies met our amended inclusion criteria. There were no significant differences in metabolic markers, including glycaemic control, between the two diets, although weight loss with a LCD was greater in one study. Carbohydrate intake at 1 year in very LCD (< 50 g of carbohydrates) ranged from 132 to 162 g. In some studies, the difference between diets was as little as 8 g/day of carbohydrates. Total energy intake remains the dietary predictor of body weight. A LCD appears no different from a high-carbohydrate diet in terms of metabolic markers and glycaemic control. Very LCDs may not be sustainable over a medium to longer term as carbohydrate intake in diets within studies often converged toward a more moderate level. The variable quality of studies included in earlier meta-analyses likely explains the previous inconsistent findings between meta-analyses. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Lack of association between NAT2 polymorphism and prostate cancer risk: a meta-analysis and trial sequential analysis

PubMed Central

Tang, Jingyuan; Xu, Lingyan; Xu, Haoxiang; Li, Ran; Han, Peng; Yang, Haiwei

2017-01-01

Previous studies have investigated the association between NAT2 polymorphism and the risk of prostate cancer (PCa). However, the findings from these studies remained inconsistent. Hence, we performed a meta-analysis to provide a more reliable conclusion about such associations. In the present meta-analysis, 13 independent case-control studies were included with a total of 14,469 PCa patients and 10,689 controls. All relevant studies published were searched in the databates PubMed, EMBASE, and Web of Science, till March 1st, 2017. We used the pooled odds ratios (ORs) with 95% confidence intervals (CIs) to evaluate the strength of the association between NAT2*4 allele and susceptibility to PCa. Subgroup analysis was carried out by ethnicity, source of controls and genotyping method. What's more, we also performed trial sequential analysis (TSA) to reduce the risk of type I error and evaluate whether the evidence of the results was firm. Firstly, our results indicated that NAT2*4 allele was not associated with PCa susceptibility (OR = 1.00, 95% CI= 0.95–1.05; P = 0.100). However, after excluding two studies for its heterogeneity and publication bias, no significant relationship was also detected between NAT2*4 allele and the increased risk of PCa, in fixed-effect model (OR = 0.99, 95% CI= 0.94–1.04; P = 0.451). Meanwhile, no significant increased risk of PCa was found in the subgroup analyses by ethnicity, source of controls and genotyping method. Moreover, TSA demonstrated that such association was confirmed in the present study. Therefore, this meta-analysis suggested that no significant association between NAT2 polymorphism and the risk of PCa was found. PMID:28915684

The Effects of Statins on Infections after Stroke or Transient Ischemic Attack: A Meta-Analysis

PubMed Central

Lin, Shao-Peng; Long, You-Ming; Chen, Xiao-Hui

2015-01-01

Background Previous studies have reported that statins can prevent infections, and these findings were ascribed to the anti-inflammatory and immunomodulatory properties of statins. However, the effects of statins on the risk of infection after stroke or transient ischemic attack (TIA) remain controversial. The aim of this study was to evaluate the relationship between statins and the risk of infection after stroke or TIA by means of a meta-analysis. Methodology and Findings Studies were found by searching major electronic databases using key terms and restricting the results to studies published in English language and human studies. Pooled odds ratio (OR) for the association between infection and statins were analyzed using Stata software. A total of five studies that included 8,791 stroke or TIA patients (3,269 patients in the statin use group and 5,522 in the placebo group) were eligible and abstracted. Pooled analysis demonstrated that statins did not significantly affect the incidence of infection after stroke or TIA compared with a placebo (OR 0.819, 95% CI 0.582–1.151, I2 = 64.2%, p= 0.025). Sensitivity analyses showed that the removal of any single study did not significantly affect the pooled OR. Cumulative meta-analysis showed that the incidence of infection did not vary by publication year. No statistical evidence of publication bias was found among the studies selected, based on the results of Egger’s (p = 1.000) and Begg’s (p = 0.762) tests. Conclusions This meta-analysis does not support the hypothesis that statins reduce the risk of infections in stroke or TIA patients. PMID:26158560

Depression and the risk of coronary heart disease: a meta-analysis of prospective cohort studies.

PubMed

Gan, Yong; Gong, Yanhong; Tong, Xinyue; Sun, Huilian; Cong, Yingjie; Dong, Xiaoxin; Wang, Yunxia; Xu, Xing; Yin, Xiaoxu; Deng, Jian; Li, Liqing; Cao, Shiyi; Lu, Zuxun

2014-12-24

Several systematic reviews and meta-analyses demonstrated the association between depression and the risk of coronary heart disease (CHD), but the previous reviews had some limitations. Moreover, a number of additional studies have been published since the publication of these reviews. We conducted an updated meta-analysis of prospective studies to assess the association between depression and the risk of CHD. Relevant prospective studies investigating the association between depression and CHD were retrieved from the PubMed, Embase, Web of Science search (up to April 2014) and from reviewing reference lists of obtained articles. Either a random-effects model or fixed-effects model was used to compute the pooled risk estimates when appropriate. Thirty prospective cohort studies with 40 independent reports met the inclusion criteria. These groups included 893,850 participants (59,062 CHD cases) during a follow-up duration ranging from 2 to 37 years. The pooled relative risks (RRs) were 1.30 (95% CI, 1.22-1.40) for CHD and 1.30 (95% CI, 1.18-1.44) for myocardial infarction (MI). In the subgroup analysis by follow-up duration, the RR of CHD was 1.36 (95% CI, 1.24-1.49) for less than 15 years follow-up, and 1.09 (95% CI, 0.96-1.23) for equal to or more than 15 years follow-up. Potential publication bias may exist, but correction for this bias using trim-and-fill method did not alter the combined risk estimate substantially. The results of our meta-analysis suggest that depression is independently associated with a significantly increased risk of CHD and MI, which may have implications for CHD etiological research and psychological medicine.

Systematic review with meta-analysis: association between acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) and risk of Crohn's disease and ulcerative colitis exacerbation.

PubMed

Moninuola, O O; Milligan, W; Lochhead, P; Khalili, H

2018-04-05

Unlike acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) have generally been thought to be associated with increased risk of IBD exacerbation. To carry out a systematic review and meta-analysis of previous studies examining the association between acetaminophen and NSAIDs including cyclooxygenase (COX-2) inhibitors use, and risk of Crohn's disease (CD) and ulcerative colitis (UC) exacerbation. We identified published manuscripts and abstracts through 1 March 2017 by systematic search of Medline, Embase, Cochrane and other trial registries. Quality assessment was done using Newcastle-Ottawa scale and random-effect meta-analysis using pooled relative risks (RRs) and 95% CIs were calculated. Eighteen publications between years 1983 and 2016 were identified. For the meta-analysis, pooled RRs of disease exacerbation with NSAIDs use were (1.42, 95% CI, 0.65-3.09), I 2  = 60.3% for CD, and (1.52, 95% CI, 0.87-2.63), I 2  = 56.1% for UC. The corresponding values for acetaminophen use were (1.40, 95% CI, 0.96-2.04), I 2  = 45.6% for UC, and (1.56, 95% CI, 1.22-1.99), I 2  = 0.0% for IBD. Sensitivity analyses limited to studies with low risk of bias showed a significantly increased risk of CD exacerbation (1.53, 95% CI, 1.08-2.16) but not UC (0.94, 95% CI, 0.36-2.42) with NSAIDs use. Contrary to generally accepted belief, we did not find a consistent association between NSAIDs use and risk of CD and UC exacerbation. There was also no consistent evidence for association with acetaminophen although further studies are needed. © 2018 John Wiley & Sons Ltd.

Identification of Common Neural Circuit Disruptions in Cognitive Control Across Psychiatric Disorders.

PubMed

McTeague, Lisa M; Huemer, Julia; Carreon, David M; Jiang, Ying; Eickhoff, Simon B; Etkin, Amit

2017-07-01

Cognitive deficits are a common feature of psychiatric disorders. The authors investigated the nature of disruptions in neural circuitry underlying cognitive control capacities across psychiatric disorders through a transdiagnostic neuroimaging meta-analysis. A PubMed search was conducted for whole-brain functional neuroimaging articles published through June 2015 that compared activation in patients with axis I disorders and matched healthy control participants during cognitive control tasks. Tasks that probed performance or conflict monitoring, response inhibition or selection, set shifting, verbal fluency, and recognition or working memory were included. Activation likelihood estimation meta-analyses were conducted on peak voxel coordinates. The 283 experiments submitted to meta-analysis included 5,728 control participants and 5,493 patients with various disorders (schizophrenia, bipolar or unipolar depression, anxiety disorders, and substance use disorders). Transdiagnostically abnormal activation was evident in the left prefrontal cortex as well as the anterior insula, the right ventrolateral prefrontal cortex, the right intraparietal sulcus, and the midcingulate/presupplementary motor area. Disruption was also observed in a more anterior cluster in the dorsal cingulate cortex, which overlapped with a network of structural perturbation that the authors previously reported in a transdiagnostic meta-analysis of gray matter volume. These findings demonstrate a common pattern of disruption across major psychiatric disorders that parallels the "multiple-demand network" observed in intact cognition. This network interfaces with the anterior-cingulo-insular or "salience network" demonstrated to be transdiagnostically vulnerable to gray matter reduction. Thus, networks intrinsic to adaptive, flexible cognition are vulnerable to broad-spectrum psychopathology. Dysfunction in these networks may reflect an intermediate transdiagnostic phenotype, which could be leveraged to advance therapeutics.

Epidemiology characteristics, reporting characteristics, and methodological quality of systematic reviews and meta-analyses on traditional Chinese medicine nursing interventions published in Chinese journals.

PubMed

Yang, Min; Jiang, Li; Wang, Aihong; Xu, Guihua

2017-02-01

To evaluate the epidemiological characteristics, reporting characteristics, and methodological quality of systematic reviews in the traditional Chinese medicine nursing field published in Chinese journals. The number of systematic reviews in the traditional Chinese medicine nursing field has increased, but their epidemiology, quality, and reporting characteristics have not been assessed completely. We generated an overview of reviews using a narrative approach. Four Chinese databases were searched for systematic reviews from inception to December 2015. The Preferred Reporting Items of Systematic Reviews and Meta-analyses and the Assessment of Multiple Systematic Reviews checklists were adopted to evaluate reporting and methodological quality, respectively. A total of 73 eligible systematic reviews, published from 2005 to 2015, were included. The deficiencies in reporting characteristics mainly lay in the lack of structured abstract or protocol, incomplete reporting of search strategies, study selection, and risk of bias. The deficiencies in methodological quality were reflected in the lack of a priori design and conflict of interest, incomplete literature searches, and assessment of publication bias. The quality of the evaluated reviews was unsatisfactory; attention should be paid to the improvement of reporting and methodological quality in the conduct of systematic reviews. © 2016 John Wiley & Sons Australia, Ltd.

Search strategies in systematic reviews in periodontology and implant dentistry.

PubMed

Faggion, Clovis M; Atieh, Momen A; Park, Stephanie

2013-09-01

To perform an overview of literature search strategies in systematic reviews (SRs) published in periodontology and implant dentistry. Two electronic databases (PubMed and Cochrane Database of SRs) were searched, independently and in duplicate, for SRs with meta-analyses on interventions, with the last search performed on 11 November 2012. Manual searches of the reference lists of included SRs and 10 specialty dental journals were conducted. Methodological issues of the search strategies of included SRs were assessed with Cochrane collaboration guidelines and AMSTAR recommendations. The search strategies employed in Cochrane and paper-based SRs were compared. A total of 146 SRs with meta-analyses were included, including 19 Cochrane and 127 paper-based SRs. Some issues, such as "the use of keywords," were reported in most of the SRs (86%). Other issues, such as "search of grey literature" and "language restriction," were not fully reported (34% and 50% respectively). The quality of search strategy reporting in Cochrane SRs was better than that of paper-based SRs for seven of the eight criteria assessed. There is room for improving the quality of reporting of search strategies in SRs in periodontology and implant dentistry, particularly in SRs published in paper-based journals. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

How standard is standard care? Exploring control group outcomes in behaviour change interventions for young people with type 1 diabetes.

PubMed

Ayling, K; Brierley, S; Johnson, B; Heller, S; Eiser, C

2015-01-01

Poor descriptions of standard care may compromise interpretation of results in randomised controlled trials (RCTs) of health interventions. We investigated quality of standard care in RCTs of behaviour change interventions for young people with type 1 diabetes and consider implications for evaluating trial outcomes. We conducted systematic searches for articles published between 1999 and 2012. We extracted standard care descriptions and contacted trial authors to complete a checklist of standard care activities. The relationship between standard care quality and outcomes was examined via subgroup meta-analyses and meta-regression. Standard care descriptions, standard care quality, and relationships between standard care quality with medical and psychological outcomes. We identified 20 RCTs described across 26 articles. Published descriptions of standard care were limited to service-level features. Author responses indicated standard care provision extended beyond published accounts. Subgroup analyses suggested control groups receiving higher standard care quality showed larger improvements in both medical and psychological outcomes, although standard care quality did not predict outcomes significantly. The quality of care delivered to control group participants can influence outcomes of RCTs. Inadequate reporting exacerbates this issue by masking variations between trials. We argue for increased clarity in reporting standard care in future trials.

Effectiveness of brief interventions in primary health care settings to decrease alcohol consumption by adult non-dependent drinkers: a systematic review of systematic reviews.

PubMed

Álvarez-Bueno, Celia; Rodríguez-Martín, Beatriz; García-Ortiz, Luis; Gómez-Marcos, Manuel Ángel; Martínez-Vizcaíno, Vicente

2015-07-01

To evaluate the effectiveness of brief interventions in the primary health care setting to decrease alcohol consumption in non-alcoholic adult drinkers. Systematic review of systematic reviews and meta-analyses of randomized clinical trials published in English and Spanish and indexed in EMBASE, MEDLINE (PubMed), Web of Science, Scopus, and The Cochrane Library, from their inception to January 2014. The quality of the studies was evaluated with the AMSTAR instrument. Seven studies, published from 1999 to 2011, were included in the review (six meta-analyses, one systematic review). These studies were heterogeneous in terms of design, type and length of interventions analyzed, participants, responsible professionals, and results. Five studies reported a moderate decrease in alcohol consumption and four showed a decrease in the number of participants who consumed alcohol above the established risk level. Brief interventions have a moderate effect on reducing alcohol consumption among excessive drinkers or people who consume excessive amounts of alcohol and as a consequence these interventions increased the number of people drinking alcohol below established limits of risk. Brief interventions with multiple contacts or follow-up sessions are the most effective. Copyright © 2014. Published by Elsevier Inc.

Exercise to prevent falls in older adults: an updated systematic review and meta-analysis.

PubMed

Sherrington, Catherine; Michaleff, Zoe A; Fairhall, Nicola; Paul, Serene S; Tiedemann, Anne; Whitney, Julie; Cumming, Robert G; Herbert, Robert D; Close, Jacqueline C T; Lord, Stephen R

2017-12-01

Previous meta-analyses have found that exercise prevents falls in older people. This study aimed to test whether this effect is still present when new trials are added, and it explores whether characteristics of the trial design, sample or intervention are associated with greater fall prevention effects. Update of a systematic review with random effects meta-analysis and meta-regression. Cochrane Library, CINAHL, MEDLINE, EMBASE, PubMed, PEDro and SafetyLit were searched from January 2010 to January 2016. We included randomised controlled trials that compared fall rates in older people randomised to receive exercise as a single intervention with fall rates in those randomised to a control group. 99 comparisons from 88 trials with 19 478 participants were available for meta-analysis. Overall, exercise reduced the rate of falls in community-dwelling older people by 21% (pooled rate ratio 0.79, 95% CI 0.73 to 0.85, p<0.001, I 2 47%, 69 comparisons) with greater effects seen from exercise programmes that challenged balance and involved more than 3 hours/week of exercise. These variables explained 76% of the between-trial heterogeneity and in combination led to a 39% reduction in falls (incident rate ratio 0.61, 95% CI 0.53 to 0.72, p<0.001). Exercise also had a fall prevention effect in community-dwelling people with Parkinson's disease (pooled rate ratio 0.47, 95% CI 0.30 to 0.73, p=0.001, I 2 65%, 6 comparisons) or cognitive impairment (pooled rate ratio 0.55, 95% CI 0.37 to 0.83, p=0.004, I 2 21%, 3 comparisons). There was no evidence of a fall prevention effect of exercise in residential care settings or among stroke survivors or people recently discharged from hospital. Exercise as a single intervention can prevent falls in community-dwelling older people. Exercise programmes that challenge balance and are of a higher dose have larger effects. The impact of exercise as a single intervention in clinical groups and aged care facility residents requires further investigation, but promising results are evident for people with Parkinson's disease and cognitive impairment. 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/.

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

PubMed

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

2017-01-16

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

Testing for Questionable Research Practices in a Meta-Analysis: An Example from Experimental Parapsychology.

PubMed

Bierman, Dick J; Spottiswoode, James P; Bijl, Aron

2016-01-01

We describe a method of quantifying the effect of Questionable Research Practices (QRPs) on the results of meta-analyses. As an example we simulated a meta-analysis of a controversial telepathy protocol to assess the extent to which these experimental results could be explained by QRPs. Our simulations used the same numbers of studies and trials as the original meta-analysis and the frequencies with which various QRPs were applied in the simulated experiments were based on surveys of experimental psychologists. Results of both the meta-analysis and simulations were characterized by 4 metrics, two describing the trial and mean experiment hit rates (HR) of around 31%, where 25% is expected by chance, one the correlation between sample-size and hit-rate, and one the complete P-value distribution of the database. A genetic algorithm optimized the parameters describing the QRPs, and the fitness of the simulated meta-analysis was defined as the sum of the squares of Z-scores for the 4 metrics. Assuming no anomalous effect a good fit to the empirical meta-analysis was found only by using QRPs with unrealistic parameter-values. Restricting the parameter space to ranges observed in studies of QRP occurrence, under the untested assumption that parapsychologists use comparable QRPs, the fit to the published Ganzfeld meta-analysis with no anomalous effect was poor. We allowed for a real anomalous effect, be it unidentified QRPs or a paranormal effect, where the HR ranged from 25% (chance) to 31%. With an anomalous HR of 27% the fitness became F = 1.8 (p = 0.47 where F = 0 is a perfect fit). We conclude that the very significant probability cited by the Ganzfeld meta-analysis is likely inflated by QRPs, though results are still significant (p = 0.003) with QRPs. Our study demonstrates that quantitative simulations of QRPs can assess their impact. Since meta-analyses in general might be polluted by QRPs, this method has wide applicability outside the domain of experimental parapsychology.

Bayesian meta-analysis of Cronbach's coefficient alpha to evaluate informative hypotheses.

PubMed

Okada, Kensuke

2015-12-01

This paper proposes a new method to evaluate informative hypotheses for meta-analysis of Cronbach's coefficient alpha using a Bayesian approach. The coefficient alpha is one of the most widely used reliability indices. In meta-analyses of reliability, researchers typically form specific informative hypotheses beforehand, such as 'alpha of this test is greater than 0.8' or 'alpha of one form of a test is greater than the others.' The proposed method enables direct evaluation of these informative hypotheses. To this end, a Bayes factor is calculated to evaluate the informative hypothesis against its complement. It allows researchers to summarize the evidence provided by previous studies in favor of their informative hypothesis. The proposed approach can be seen as a natural extension of the Bayesian meta-analysis of coefficient alpha recently proposed in this journal (Brannick and Zhang, 2013). The proposed method is illustrated through two meta-analyses of real data that evaluate different kinds of informative hypotheses on superpopulation: one is that alpha of a particular test is above the criterion value, and the other is that alphas among different test versions have ordered relationships. Informative hypotheses are supported from the data in both cases, suggesting that the proposed approach is promising for application. Copyright © 2015 John Wiley & Sons, Ltd.

Does the Theory of Planned Behaviour Explain Condom Use Behaviour Among Men Who have Sex with Men? A Meta-analytic Review of the Literature.

PubMed

Andrew, Benjamin J; Mullan, Barbara A; de Wit, John B F; Monds, Lauren A; Todd, Jemma; Kothe, Emily J

2016-12-01

The aim of this meta-analysis was to explore whether the constructs in the theory of planned behaviour (TPB; i.e., attitude, subjective norm, perceived behavioural control, intention) explain condom use behaviour among men who have sex with men (MSM). Electronic databases were searched for studies that measured TPB variables and MSM condom use. Correlations were meta-analysed using a random effects model and path analyses. Moderation analyses were conducted for the time frame of the behavioural measure used (retrospective versus prospective). Attitude, subjective norm and perceived behavioural control accounted for 24.0 % of the variance in condom use intention and were all significant correlates. Intention and PBC accounted for 12.4 % of the variance in condom use behaviour. However, after taking intention into account, PBC was no longer significantly associated with condom use. The strength of construct relationships did not differ between retrospective and prospective behavioural assessments. The medium to large effect sizes of the relationships between the constructs in the TPB, which are consistent with previous meta-analyses with different behaviours or target groups, suggest that the TPB is also a useful model for explaining condom use behaviour among MSM. However, the research in this area is rather small, and greater clarity over moderating factors can only be achieved when the literature expands.

Behavioral treatments for speech in Parkinson's disease: meta-analyses and review of the literature.

PubMed

Atkinson-Clement, Cyril; Sadat, Jasmin; Pinto, Serge

2015-01-01

Parkinson's disease (PD) results from neurodegenerative processes leading to alteration of motor functions. Most motor symptoms respond well to pharmacological and neurosurgical treatments, except some axial symptoms such as speech impairment, so-called dysarthria. However, speech therapy is rarely proposed to PD patients. This review aims at evaluating previous research on the effects of speech behavioral therapies in patients with PD. We also performed two meta-analyses focusing on speech loudness and voice pitch. We showed that intensive therapies in PD are the most effective for hypophonia and can lead to some improvement of voice pitch. Although speech therapy is effective in handling PD dysarthria, behavioral speech rehabilitation in PD still needs further validation.

A methodological systematic review of what's wrong with meta-ethnography reporting.

PubMed

France, Emma F; Ring, Nicola; Thomas, Rebecca; Noyes, Jane; Maxwell, Margaret; Jepson, Ruth

2014-11-19

Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality of meta-ethnography reporting, particularly the analysis and synthesis processes. Our aim was to investigate the application and reporting of methods in recent meta-ethnography journal papers, focusing on the analysis and synthesis process and output. Methodological systematic review of health-related meta-ethnography journal papers published from 2012-2013. We searched six electronic databases, Google Scholar and Zetoc for papers using key terms including 'meta-ethnography.' Two authors independently screened papers by title and abstract with 100% agreement. We identified 32 relevant papers. Three authors independently extracted data and all authors analysed the application and reporting of methods using content analysis. Meta-ethnography was applied in diverse ways, sometimes inappropriately. In 13% of papers the approach did not suit the research aim. In 66% of papers reviewers did not follow the principles of meta-ethnography. The analytical and synthesis processes were poorly reported overall. In only 31% of papers reviewers clearly described how they analysed conceptual data from primary studies (phase 5, 'translation' of studies) and in only one paper (3%) reviewers explicitly described how they conducted the analytic synthesis process (phase 6). In 38% of papers we could not ascertain if reviewers had achieved any new interpretation of primary studies. In over 30% of papers seminal methodological texts which could have informed methods were not cited. We believe this is the first in-depth methodological systematic review of meta-ethnography conduct and reporting. Meta-ethnography is an evolving approach. Current reporting of methods, analysis and synthesis lacks clarity and comprehensiveness. This is a major barrier to use of meta-ethnography findings that could contribute significantly to the evidence base because it makes judging their rigour and credibility difficult. To realise the high potential value of meta-ethnography for enhancing health care and understanding patient experience requires reporting that clearly conveys the methodology, analysis and findings. Tailored meta-ethnography reporting guidelines, developed through expert consensus, could improve reporting.

Risk assessment for juvenile justice: a meta-analysis.

PubMed

Schwalbe, Craig S

2007-10-01

Risk assessment instruments are increasingly employed by juvenile justice settings to estimate the likelihood of recidivism among delinquent juveniles. In concert with their increased use, validation studies documenting their predictive validity have increased in number. The purpose of this study was to assess the average predictive validity of juvenile justice risk assessment instruments and to identify risk assessment characteristics that are associated with higher predictive validity. A search of the published and grey literature yielded 28 studies that estimated the predictive validity of 28 risk assessment instruments. Findings of the meta-analysis were consistent with effect sizes obtained in larger meta-analyses of criminal justice risk assessment instruments and showed that brief risk assessment instruments had smaller effect sizes than other types of instruments. However, this finding is tentative owing to limitations of the literature.

The influence of stereotype threat on immigrants: review and meta-analysis

PubMed Central

Appel, Markus; Weber, Silvana; Kronberger, Nicole

2015-01-01

In many regions around the world students with certain immigrant backgrounds underachieve in educational settings. This paper provides a review and meta-analysis on one potential source of the immigrant achievement gap: stereotype threat, a situational predicament that may prevent students to perform up to their full abilities. A meta-analysis of 19 experiments suggests an overall mean effect size of 0.63 (random effects model) in support of stereotype threat theory. The results are complemented by moderator analyses with regard to circulation (published or unpublished research), cultural context (US versus Europe), age of immigrants, type of stereotype threat manipulation, dependent measures, and means for identification of immigrant status; evidence on the role of ethnic identity strength is reviewed. Theoretical and practical implications of the findings are discussed. PMID:26217256

Sleep spindles and cognitive performance across adolescence: A meta-analytic review.

PubMed

Reynolds, C M; Short, M A; Gradisar, M

2018-07-01

Higher sleep spindle activity generally relates to better cognitive performance in adults, while studies in children often show the opposite. As children become young adults, there is rapid brain maturation and development of higher-order cognitive functions, and therefore investigations within this age group may elucidate the relationship between spindles and cognition in this developmental period. Twelve studies published between 2009 and 2016 were identified. Meta-analyses revealed a positive relationship between spindles and cognition overall (r = 0.27), however effects varied depending on cognitive domain. Moderate positive relationships were seen for fluid IQ (r = 0.44), working memory/executive function (r = 0.40) and speed/accuracy (r = 0.33), while full IQ/verbal IQ was not significantly associated (r = -0.05). Meta-regressions indicated cognitive domain and spindle characteristic had a small influence over effect sizes, while age and gender did not have a significant influence. The relationship between spindles and cognition in adolescents is likely influenced by individual neural makeup and brain maturation. Copyright © 2018 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls.

PubMed

Medema, Suzanne; Mocking, Roel J T; Koeter, Maarten W J; Vaz, Frédéric M; Meijer, Carin; de Haan, Lieuwe; van Beveren, Nico J M; Kahn, René; de Haan, Lieuwe; van Os, Jim; Wiersma, Durk; Bruggeman, Richard; Cahn, Wiepke; Meijer, Carin; Myin-Germeys, Inez

2016-03-01

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder. For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups. Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings. We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Meta-analysis: Problems with Russian Publications.

PubMed

Verbitskaya, E V

2015-01-01

Meta-analysis is a powerful tool to identify Evidence Based medical technologies (interventions) for use in every day practice. Meta-analysis uses statistical approaches to combine results from multiple studies in an effort to increase power (over individual studies), improve estimates of the size of the effect and/or to resolve uncertainty when reports disagree. Meta-analysis is a quantitative, formal study design used to systematically assess previous research studies to derive conclusions from this research. Meta-analysis may provide more precise estimate of the effect of treatment or risk factor for a disease, or other outcomes, than any individual study contributing to the pooled analysis.We have quite a substantial number of Russian medical publications, but not so many Meta-Analyses published in Russian. Russian publications are cited in English language papers not so often. A total of 90% of clinical studies included in published Meta-Analyses incorporate only English language papers. International studies or papers with Russian co-authors are published in English language. The main question is: what is the problem with inclusion of Russian medical publications in Meta-Analysis? The main reasons for this are the following: 1) It is difficult to find Russian papers, difficult to work with them and to work with Russian journals:a. There are single Russian Biomedical Journals, which are translated into English and are included in databases (PubMed, Scopus and other), despite the fact that all of them have English language abstracts.b. The majority the meta-analyses authors use in their work different citation management software such as the Mendeley, Reference Manager, ProCite, EndNote, and others. These citation management systems allow scientists to organize their own literature databases with internet searches and have adds-on for the Office programs what makes process of literature citation very convenient. The Internet sites of the majority of International Journals have built-in tools for saving citations to reference manager software. The majority of articles in Russian journals cannot be captured by citation management systems: they do not have special coding of articles descriptors.c. Some journals still have PDF files of the whole journal issue without dividing it into articles and do not provide any descriptors, making manual time-consuming input of information the only possibility. Moreover the context search of the article content is unavailable for search engines.2) The quality of research. This problem has been discussed for more than twenty years already. Still we have too many publications of poor quality of study design and statistical analysis. With the exception of pharmacological clinical tails, designed and supervised by international Pharma industry, many interventional studies, conducted in Russia, have methodological flaws inferring a high risk of bias:a. Absence of adequate control,b. No standard endpoints, duration of therapy and follow up,c. Absence of randomization and blinding,d. Low power of studies: sample sizes are calculated (if calculated at all) in such a way, that the main goal is to have as small sample size as possible. Very often statisticians have to solve the problem how to substantiate a small number of subjects, that sponsor could afford, instead of calculating the needed sample size to reach enough power.e. No standards of statistical analysis.f. Russian journals do not have standards for description and presentation of study results, in particular, results of statistical analysis (a reader even cannot see what is presented: standard deviation (SD) or standard error of the mean (SEM).We have a long standing experience in analysis of methodological and statistical quality of Russian biomedical publications and have found up to 80% publications with statistical and methodological errors and high risk of bias.In our practice, we had tried to perform two Meta-analyses for two local pharmaceutical products for prevention of stroke recurrence. For the first product, we did not found even two single Russian language studies suitable for the analysis (incomparable populations, different designs, endpoints, doses etc.). For the second product, only four studies had comparable populations and standard internationally approved scales for effectiveness analysis. However, the combinations of scales, the length of treatment and follow up differed widely, so that we could combine the results of only 2 or 3 studies for each end point. Russian researchers have to follow internationally recognised standards in study design, selection of endpoint, timelines and therapy regimens, data analysis and presentation of results. Russian journals need to develop consolidate rules for authors of clinical trials and epidemiological research of result reporting close to international standards. In this case the international Network EQUATOR (Enhancing the QUAlity and Transparency Of health Research http://www.equator-network.org/) is one to be taken into account. In addition, Russian Journals have to improve their online information for better interaction with search engines and citation managers.

Liver elastography, comments on EFSUMB elastography guidelines 2013

PubMed Central

Cui, Xin-Wu; Friedrich-Rust, Mireen; Molo, Chiara De; Ignee, Andre; Schreiber-Dietrich, Dagmar; Dietrich, Christoph F

2013-01-01

Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography. The document is intended to form a reference and to guide clinical users in a practical way. They give practical advice for the use and interpretation. Liver disease forms the largest section, reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography. In this review comments and illustrations on the guidelines are given. PMID:24151351

The Herd Mentality: Strength in Numbers, and Combining Studies.

PubMed

Jupiter, Daniel C

2016-01-01

Although clinicians may have the best of intentions in terms of keeping up with the medical literature, the overwhelming volume of published studies and the press of clinical responsibilities can make this difficult. A medical version of the Reader's Digest(©) would thus be a valuable asset. This is something of the role that systematic reviews and meta-analyses play: synthesis and summary of the information in the literature. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Daily potassium intake and sodium-to-potassium ratio in the reduction of blood pressure: a meta-analysis of randomized controlled trials.

PubMed

Binia, Aristea; Jaeger, Jonathan; Hu, Youyou; Singh, Anurag; Zimmermann, Diane

2015-08-01

To evaluate the efficacy of daily potassium intake on decreasing blood pressure in non-medicated normotensive or hypertensive patients, and to determine the relationship between potassium intake, sodium-to-potassium ratio and reduction in blood pressure. Mixed-effect meta-analyses and meta-regression models. Medline and the references of previous meta-analyses. Randomized controlled trials with potassium supplementation, with blood pressure as the primary outcome, in non-medicated patients. Fifteen randomized controlled trials of potassium supplementation in patients without antihypertensive medication were selected for the meta-analyses (917 patients). Potassium supplementation resulted in reduction of SBP by 4.7 mmHg [95% confidence interval (CI) 2.4-7.0] and DBP by 3.5 mmHg (95% CI 1.3-5.7) in all patients. The effect was found to be greater in hypertensive patients, with a reduction of SBP by 6.8 mmHg (95% CI 4.3-9.3) and DBP by 4.6 mmHg (95% CI 1.8-7.5). Meta-regression analysis showed that both increased daily potassium excretion and decreased sodium-to-potassium ratio were associated with blood pressure reduction (P < 0.05). Increased total daily potassium urinary excretion from 60 to 100 mmol/day and decrease of sodium-to-potassium ratio were shown to be necessary to explain the estimated effect. Potassium supplementation is associated with reduction of blood pressure in patients who are not on antihypertensive medication, and the effect is significant in hypertensive patients. The reduction in blood pressure significantly correlates with decreased daily urinary sodium-to-potassium ratio and increased urinary potassium. Patients with elevated blood pressure may benefit from increased potassium intake along with controlled or decreased sodium intake.

Systematic Review of Universal Resilience-Focused Interventions Targeting Child and Adolescent Mental Health in the School Setting.

PubMed

Dray, Julia; Bowman, Jenny; Campbell, Elizabeth; Freund, Megan; Wolfenden, Luke; Hodder, Rebecca K; McElwaine, Kathleen; Tremain, Danika; Bartlem, Kate; Bailey, Jacqueline; Small, Tameka; Palazzi, Kerrin; Oldmeadow, Christopher; Wiggers, John

2017-10-01

To examine the effect of universal, school-based, resilience-focused interventions on mental health problems in children and adolescents. Eligible studies were randomized controlled trials (RCTs) of universal, school-based interventions that included strategies to strengthen a minimum of 3 internal resilience protective factors, and included an outcome measure of mental health problems in children and adolescents aged 5 to 18 years. Six databases were searched from 1995 to 2015. Results were pooled in meta-analyses by mental health outcome (anxiety symptoms, depressive symptoms, hyperactivity, conduct problems, internalizing problems, externalizing problems, and general psychological distress), for all trials (5-18 years). Subgroup analyses were conducted by age (child: 5-10 years; adolescent: 11-18 years), length of follow-up (short: post-≤12 months; long: >12 months), and gender (narrative). A total of 57 included trials were identified from 5,984 records, with 49 contributing to meta-analyses. For all trials, resilience-focused interventions were effective relative to a control in reducing 4 of 7 outcomes: depressive symptoms, internalizing problems, externalizing problems, and general psychological distress. For child trials (meta-analyses for 6 outcomes), interventions were effective for anxiety symptoms and general psychological distress. For adolescent trials (meta-analyses for 5 outcomes), interventions were effective for internalizing problems. For short-term follow-up, interventions were effective for 2 of 7 outcomes: depressive symptoms and anxiety symptoms. For long-term follow-up (meta-analyses for 5 outcomes), interventions were effective for internalizing problems. The findings may suggest most promise for using universal resilience-focused interventions at least for short-term reductions in depressive and anxiety symptoms for children and adolescents, particularly if a cognitive-behavioral therapy-based approach is used. The limited number of trials providing data amenable for meta-analysis for some outcomes and subgroups, the variability of interventions, study quality, and bias mean that it is not possible to draw more specific conclusions. Identifying what intervention qualities (such as number and type of protective factor) achieve the greatest positive effect per mental health problem outcome remains an important area for future research. Systematic Review of Universal Resilience Interventions Targeting Child and Adolescent Mental Health in the School Setting; http://dx.doi.org/10.1186/s13643-015-0172-6; PROSPERO CRD42015025908. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Associations of occupational standing with musculoskeletal symptoms: a systematic review with meta-analysis.

PubMed

Coenen, Pieter; Willenberg, Lisa; Parry, Sharon; Shi, Joyce W; Romero, Lorena; Blackwood, Diana M; Maher, Christopher G; Healy, Genevieve N; Dunstan, David W; Straker, Leon M

2018-02-01

Given the high exposure to occupational standing in specific occupations, and recent initiatives to encourage intermittent standing among white-collar workers, a better understanding of the potential health consequences of occupational standing is required. We aimed to review and quantify the epidemiological evidence on associations of occupational standing with musculoskeletal symptoms. A systematic review was performed. Data from included articles were extracted and described, and meta-analyses conducted when data were sufficiently homogeneous. Electronic databases were systematically searched. Peer-reviewed articles on occupational standing and musculoskeletal symptoms from epidemiological studies were identified. Of the 11 750 articles screened, 50 articles reporting 49 studies were included (45 cross-sectional and 5 longitudinal; n=88 158 participants) describing the associations of occupational standing with musculoskeletal symptoms, including low-back (39 articles), lower extremity (14 articles) and upper extremity (18 articles) symptoms. In the meta-analysis, 'substantial' (>4 hours/workday) occupational standing was associated with the occurrence of low-back symptoms (pooled OR (95% CI) 1.31 (1.10 to 1.56)). Evidence on lower and upper extremity symptoms was too heterogeneous for meta-analyses. The majority of included studies reported statistically significant detrimental associations of occupational standing with lower extremity, but not with upper extremity symptoms. The evidence suggests that substantial occupational standing is associated with the occurrence of low-back and (inconclusively) lower extremity symptoms, but there may not be such an association with upper extremity symptoms. However, these conclusions are tentative as only limited evidence was found from high-quality, longitudinal studies with fully adjusted models using objective measures of standing. 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/.

Television watching and risk of childhood obesity: a meta-analysis.

PubMed

Zhang, Gang; Wu, Lei; Zhou, Lingling; Lu, Weifeng; Mao, Chunting

2016-02-01

Over the last few decades, there has been a worldwide epidemic of childhood obesity. An important step in successful prevention in paediatrics is the identification of modifiable risk factors of childhood obesity. Many studies have evaluated the associations between television (TV) watching and childhood obesity but yielded inconsistent results. To help elucidate the role of TV watching, PubMed and Embase databases were searched for published studies on associations between TV watching and childhood obesity. Random-effects models and dose-response meta-analyses were used to pool study results. Fourteen cross-sectional studies with 24 reports containing 106 169 subjects were included in the meta-analysis. Subgroup analyses were conducted by the available characteristics of studies and participants. The multivariable-adjusted overall OR of the childhood obesity for the highest vs. the lowest time of TV watching was 1.47 [95% confidence interval (95% CI): 1.33-1.62]. A linear dose-response relationship was also found for TV watching and childhood obesity (P < 0.001), and the risk increased by 13% for each 1 h/day increment in TV watching. Subgroup analysis showed a basically consistent result with the overall analysis. The association is observed in both boys and girls (for boys, OR 1.30, 95% CI 1.16-1.45; for girls, OR 1.26, 95% CI 1.11-1.41). our meta-analysis suggested that increased TV watching is associated with increased risk of childhood obesity. And restricting TV time and other sedentary behaviour of children may be an important public health strategy to prevent childhood obesity. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

The interpersonal theory of suicide: A systematic review and meta-analysis of a decade of cross-national research.

PubMed

Chu, Carol; Buchman-Schmitt, Jennifer M; Stanley, Ian H; Hom, Melanie A; Tucker, Raymond P; Hagan, Christopher R; Rogers, Megan L; Podlogar, Matthew C; Chiurliza, Bruno; Ringer, Fallon B; Michaels, Matthew S; Patros, Connor H G; Joiner, Thomas E

2017-12-01

Over the past decade, the interpersonal theory of suicide has contributed to substantial advances in the scientific and clinical understanding of suicide and related conditions. The interpersonal theory of suicide posits that suicidal desire emerges when individuals experience intractable feelings of perceived burdensomeness and thwarted belongingness and near-lethal or lethal suicidal behavior occurs in the presence of suicidal desire and capability for suicide. A growing number of studies have tested these posited pathways in various samples; however, these findings have yet to be evaluated meta-analytically. This paper aimed to (a) conduct a systematic review of the unpublished and published, peer-reviewed literature examining the relationship between interpersonal theory constructs and suicidal thoughts and behaviors, (b) conduct meta-analyses testing the interpersonal theory hypotheses, and (c) evaluate the influence of various moderators on these relationships. Four electronic bibliographic databases were searched through the end of March, 2016: PubMed, Medline, PsycINFO, and Web of Science. Hypothesis-driven meta-analyses using random effects models were conducted using 122 distinct unpublished and published samples. Findings supported the interpersonal theory: the interaction between thwarted belongingness and perceived burdensomeness was significantly associated with suicidal ideation; and the interaction between thwarted belongingness, perceived burdensomeness, and capability for suicide was significantly related to a greater number of prior suicide attempts. However, effect sizes for these interactions were modest. Alternative configurations of theory variables were similarly useful for predicting suicide risk as theory-consistent pathways. We conclude with limitations and recommendations for the interpersonal theory as a framework for understanding the suicidal spectrum. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Identifying psychosocial predictors of medication non-adherence following acute coronary syndrome: A systematic review and meta-analysis.

PubMed

Crawshaw, Jacob; Auyeung, Vivian; Norton, Sam; Weinman, John

2016-11-01

Medication non-adherence following acute coronary syndrome (ACS) is associated with poor clinical outcomes. A systematic review and meta-analysis were undertaken to identify psychosocial factors associated with medication adherence in patients with ACS. A search of electronic databases (Cochrane Library, Medline, EMBASE, PsycINFO, Web of Science, International Pharmaceutical Abstracts, CINAHL, ASSIA, OpenGrey, EthOS and WorldCat) was undertaken to identify relevant articles published in English between 2000 and 2014. Articles were screened against our inclusion criteria and data on study design, sample characteristics, predictors, outcomes, analyses, key findings and study limitations were abstracted. Our search identified 3609 records, of which 17 articles met our inclusion criteria (15 independent studies). Eight out of ten studies found an association between depression and non-adherence. A meta-analysis revealed that depressed patients were twice as likely to be non-adherent compared to patients without depression (OR=2.00, 95% CI 1.57-3.33, p=0.015). Type D personality was found to predict non-adherence in both studies in which it was measured. Three out of three studies reported that treatment beliefs based on the Necessity-Concerns Framework predicted medication non-adherence and there was some evidence that social support was associated with better adherence. There was insufficient data to meta-analyse all other psychosocial factors identified. There was some evidence that psychosocial factors, particularly depression, were associated with medication adherence following ACS. Targeting depressive symptoms, screening for Type D personality, challenging maladaptive treatment beliefs, and providing better social support for patients may be useful strategies to improve medication adherence. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Step training improves reaction time, gait and balance and reduces falls in older people: a systematic review and meta-analysis.

PubMed

Okubo, Yoshiro; Schoene, Daniel; Lord, Stephen R

2017-04-01

To examine the effects of stepping interventions on fall risk factors and fall incidence in older people. Electronic databases (PubMed, EMBASE, CINAHL, Cochrane, CENTRAL) and reference lists of included articles from inception to March 2015. Randomised (RCT) or clinical controlled trials (CCT) of volitional and reactive stepping interventions that included older (minimum age 60) people providing data on falls or fall risk factors. Meta-analyses of seven RCTs (n=660) showed that the stepping interventions significantly reduced the rate of falls (rate ratio=0.48, 95% CI 0.36 to 0.65, p<0.0001, I 2 =0%) and the proportion of fallers (risk ratio=0.51, 95% CI 0.38 to 0.68, p<0.0001, I 2 =0%). Subgroup analyses stratified by reactive and volitional stepping interventions revealed a similar efficacy for rate of falls and proportion of fallers. A meta-analysis of two RCTs (n=62) showed that stepping interventions significantly reduced laboratory-induced falls, and meta-analysis findings of up to five RCTs and CCTs (n=36-416) revealed that stepping interventions significantly improved simple and choice stepping reaction time, single leg stance, timed up and go performance (p<0.05), but not measures of strength. The findings indicate that both reactive and volitional stepping interventions reduce falls among older adults by approximately 50%. This clinically significant reduction may be due to improvements in reaction time, gait, balance and balance recovery but not in strength. Further high-quality studies aimed at maximising the effectiveness and feasibility of stepping interventions are required. CRD42015017357. 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/.

Integrated care programmes for adults with chronic conditions: a meta-review.

PubMed

Martínez-González, Nahara Anani; Berchtold, Peter; Ullman, Klara; Busato, André; Egger, Matthias

2014-10-01

To review systematic reviews and meta-analyses of integrated care programmes in chronically ill patients, with a focus on methodological quality, elements of integration assessed and effects reported. Meta-review of systematic reviews and meta-analyses identified in Medline (1946-March 2012), Embase (1980-March 2012), CINHAL (1981-March 2012) and the Cochrane Library of Systematic Reviews (issue 1, 2012). Methodological quality assessed by the 11-item Assessment of Multiple Systematic Reviews (AMSTAR) checklist; elements of integration assessed using a published list of 10 key principles of integration; effects on patient-centred outcomes, process quality, use of healthcare and costs. Twenty-seven systematic reviews were identified; conditions included chronic heart failure (CHF; 12 reviews), diabetes mellitus (DM; seven reviews), chronic obstructive pulmonary disease (COPD; seven reviews) and asthma (five reviews). The median number of AMSTAR checklist items met was five: few reviewers searched for unpublished literature or described the primary studies and interventions in detail. Most reviews covered comprehensive services across the care continuum or standardization of care through inter-professional teams, but organizational culture, governance structure or financial management were rarely assessed. A majority of reviews found beneficial effects of integration, including reduced hospital admissions and re-admissions (in CHF and DM), improved adherence to treatment guidelines (DM, COPD and asthma) or quality of life (DM). Few reviews showed reductions in costs. Systematic reviews of integrated care programmes were of mixed quality, assessed only some components of integration of care, and showed consistent benefits for some outcomes but not others. © The Author 2014. Published by Oxford University Press in association with the International Society for Quality in Health Care.