Journal ArticleDOI
How should meta-regression analyses be undertaken and interpreted?
TLDR
The examples considered in this paper show the tension between the scientific rationale for using meta-regression and the difficult interpretative problems to which such analyses are prone.Abstract:
SUMMARY Appropriate methods for meta-regression applied to a set of clinical trials, and the limitations and pitfalls in interpretation, are insuciently recognized. Here we summarize recent research focusing on these issues, and consider three published examples of meta-regression in the light of this work. One principal methodological issue is that meta-regression should be weighted to take account of both within-trial variances of treatment eects and the residual between-trial heterogeneity (that is, heterogeneity not explained by the covariates in the regression). This corresponds to random eects meta-regression. The associations derived from meta-regressions are observational, and have a weaker interpretation than the causal relationships derived from randomized comparisons. This applies particularly when averages of patient characteristics in each trial are used as covariates in the regression. Data dredging is the main pitfall in reaching reliable conclusions from meta-regression. It can only be avoided by prespecication of covariates that will be investigated as potential sources of heterogeneity. However, in practice this is not always easy to achieve. The examples considered in this paper show the tension between the scientic rationale for using meta-regression and the dicult interpretative problems to which such analyses are prone. Copyright ? 2002 John Wiley & Sons, Ltd.read more
Citations
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Journal ArticleDOI
The PRISMA Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions: Explanation and Elaboration
Alessandro Liberati,Douglas G. Altman,Jennifer Tetzlaff,Cynthia D. Mulrow,Peter C Gøtzsche,John P. A. Ioannidis,Mike Clarke,Mike Clarke,Philip J. Devereaux,Jos Kleijnen,David Moher +10 more
TL;DR: An Explanation and Elaboration of the PRISMA Statement is presented and updated guidelines for the reporting of systematic reviews and meta-analyses are presented.
Book
Cochrane Handbook for Systematic Reviews of Interventions
Julian P T Higgins,Sally Green +1 more
TL;DR: The Cochrane Handbook for Systematic Reviews of Interventions is the official document that describes in detail the process of preparing and maintaining Cochrane systematic reviews on the effects of healthcare interventions.
Journal ArticleDOI
The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration
Alessandro Liberati,Douglas G. Altman,Jennifer Tetzlaff,Cynthia D. Mulrow,Peter C Gøtzsche,John P. A. Ioannidis,Mike Clarke,Philip J. Devereaux,Jos Kleijnen,David Moher +9 more
TL;DR: The meaning and rationale for each checklist item is explained, and an example of good reporting is included and, where possible, references to relevant empirical studies and methodological literature are included.
Journal ArticleDOI
The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration
Alessandro Liberati,Douglas G. Altman,Jennifer Tetzlaff,Cynthia D. Mulrow,Peter C Gøtzsche,John P. A. Ioannidis,Mike Clarke,Mike Clarke,Philip J. Devereaux,Jos Kleijnen,David Moher +10 more
TL;DR: This Explanation and Elaboration document explains the meaning and rationale for each checklist item and includes an example of good reporting and, where possible, references to relevant empirical studies and methodological literature.
Journal ArticleDOI
The Worldwide Prevalence of ADHD: A Systematic Review and Metaregression Analysis
Guilherme V. Polanczyk,Maurício Silva de Lima,Bernardo L. Horta,Joseph Biederman,Luis Augusto Rohde +4 more
TL;DR: The findings suggest that geographic location plays a limited role in the reasons for the large variability of ADHD/HD prevalence estimates worldwide and that this variability seems to be explained primarily by the methodological characteristics of studies.
References
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Journal ArticleDOI
Bias in meta-analysis detected by a simple, graphical test
TL;DR: Funnel plots, plots of the trials' effect estimates against sample size, are skewed and asymmetrical in the presence of publication bias and other biases Funnel plot asymmetry, measured by regression analysis, predicts discordance of results when meta-analyses are compared with single large trials.
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Pharmacological interventions for somatoform disorders in adults.
Maria Kleinstäuber,Michael Witthöft,Andrés Steffanowski,Harm W.J. van Marwijk,Wolfgang Hiller,Michael J. Lambert +5 more
TL;DR: A systematic review and meta-analysis of placebo-controlled studies examined the efficacy and tolerability of different types of antidepressants, the combination of an antidepressant and an antipsychotic, antipsychotics alone, or natural products in adults with somatoform disorders in adults to improve optimal treatment decisions.
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Statistical Methods for Meta-Analysis
Larry V. Hedges,Ingram Olkin +1 more
TL;DR: In this article, the authors present a model for estimating the effect size from a series of experiments using a fixed effect model and a general linear model, and combine these two models to estimate the effect magnitude.
Journal ArticleDOI
A simulation study of the number of events per variable in logistic regression analysis.
Peter Peduzzi,John Concato,John Concato,Elizabeth Kemper,Elizabeth Kemper,Theodore R. Holford,Alvan R. Feinstein,Alvan R. Feinstein +7 more
TL;DR: Findings indicate that low EPV can lead to major problems, and the regression coefficients were biased in both positive and negative directions, and paradoxical associations (significance in the wrong direction) were increased.
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Multilevel Statistical Models
TL;DR: In this article, the authors present a general classification notation for multilevel models and a discussion of the general structure and maximum likelihood estimation for a multi-level model, as well as the adequacy of Ordinary Least Squares estimates.