Investigating clinical heterogeneity in systematic reviews: a methodologic review of guidance in the literature

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

2009 • 78,446 citations

Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement

2009 • 53,927 citations

Measuring inconsistency in meta-analyses

2003 • 53,662 citations

Meta-analysis in clinical trials

1986 • 36,193 citations

Cochrane Handbook for Systematic Reviews of Interventions

2008 • 18,785 citations

The Effect of Riding as an Alternative Treatment for Children with Cerebral Palsy: A Systematic Review and Meta-Analysis

2015 • 18,140 citations

Introduction to Meta‐Analysis

2009 • 11,635 citations

Introduction to Meta‐Analysis

2021 • 8,727 citations

Regression Modeling Strategies

2001 • 8,706 citations

A simulation study of the number of events per variable in logistic regression analysis

1996 • 7,351 citations

Cochrane Handbook for Systematic Reviews of Interventions, Version 5.1.0. The Cochrane Collaboration

2013 • 5,537 citations

Systematic reviews: CRD's guidance for undertaking reviews in health care

2010 • 2,620 citations

How should meta‐regression analyses be undertaken and interpreted?

2002 • 2,618 citations

Quantitative Synthesis in Systematic Reviews

1997 • 2,428 citations

Updated Method Guidelines for Systematic Reviews in the Cochrane Collaboration Back Review Group

2003 • 2,060 citations

Group-Based Trajectory Modeling in Clinical Research

2010 • 1,982 citations

Systematic reviews in health care: Investigating and dealing with publication and other biases in meta-analysis

2001 • 1,976 citations

Avoidable waste in the production and reporting of research evidence

2009 • 1,916 citations

Importance of events per independent variable in proportional hazards regression analysis II. Accuracy and precision of regression estimates

1995 • 1,854 citations

Methods for Meta-Analysis in Medical Research

2000 • 1,803 citations

Meta-Analysis: Recent Developments in Quantitative Methods for Literature Reviews

2001 • 1,731 citations

Explaining heterogeneity in meta-analysis: a comparison of methods

1999 • 1,666 citations

Improved tests for a random effects meta‐regression with a single covariate

2003 • 1,563 citations

2009 Updated Method Guidelines for Systematic Reviews in the Cochrane Back Review Group

2009 • 1,552 citations

Advanced methods in meta‐analysis: multivariate approach and meta‐regression

2002 • 1,495 citations

Controlling the risk of spurious findings from meta‐regression

2004 • 1,157 citations

Systematic Reviews and Meta-Analysis

2008 • 1,137 citations

Systematic Review: Why sources of heterogeneity in meta-analysis should be investigated

1994 • 947 citations

A Consumer's Guide to Subgroup Analyses

1992 • 910 citations

Meta‐Analysis Of Controlled Clinical Trials

2002 • 811 citations

A random‐effects regression model for meta‐analysis

1995 • 805 citations

Invited Review: Integrating Quantitative Findings from Multiple Studies Using Mixed Model Methodology

2001 • 780 citations

Importance of events per independent variable in proportional hazards analysis I. Background, goals, and general strategy

1995 • 700 citations

Statistical heterogeneity in systematic reviews of clinical trials: a critical appraisal of guidelines and practice

2002 • 643 citations

Methodologic guidelines for systematic reviews of randomized control trials in health care from the potsdam consultation on meta-analysis

1995 • 581 citations

Avoidable Waste in the Production and Reporting of Research Evidence

2009 • 576 citations

What is missing from descriptions of treatment in trials and reviews?

2008 • 576 citations

Recent developments in meta‐analysis

2007 • 572 citations

Interpretation of tests of heterogeneity and bias in meta‐analysis

2008 • 550 citations

BORROWING STRENGTH FROM EXTERNAL TRIALS IN A META-ANALYSIS

1996 • 543 citations

Meta-analysis of individual patient data from randomized trials: a review of methods used in practice

2005 • 522 citations

A graphical method for exploring heterogeneity in meta‐analyses: application to a meta‐analysis of 65 trials

2002 • 504 citations

Impact of allocation concealment on conclusions drawn from meta-analyses of randomized trials

2007 • 443 citations

An international registry of systematic-review protocols

2010 • 439 citations

Individual patient‐ versus group‐level data meta‐regressions for the investigation of treatment effect modifiers: ecological bias rears its ugly head

2002 • 413 citations

Understanding heterogeneity in meta-analysis: the role of meta-regression

2009 • 388 citations

A comparison of summary patient-level covariates in meta-regression with individual patient data meta-analysis

2002 • 378 citations

Bayesian methods in health technology assessment: a review.

2000 • 340 citations

A case study of multiple-treatments meta-analysis demonstrates that covariates should be considered

2009 • 288 citations

Bayesian random effects meta‐analysis of trials with binary outcomes: methods for the absolute risk difference and relative risk scales

2002 • 268 citations

Meta‐analysis of continuous outcome data from individual patients

2001 • 263 citations

Flexible Meta-Regression Functions for Modeling Aggregate Dose-Response Data, with an Application to Alcohol and Mortality

2004 • 260 citations

Meta‐analysis of continuous outcomes combining individual patient data and aggregate data

2007 • 258 citations

Systematic reviews of trials and other studies.

1998 • 247 citations

How to review the evidence: systematic identification and review of the scientific literature

2000 • 238 citations

Systematic reviews of adverse effects: framework for a structured approach

2007 • 232 citations

Methods for Exploring Heterogeneity in Meta-Analysis

2001 • 232 citations

Meta-regression detected associations between heterogeneous treatment effects and study-level, but not patient-level, factors

2004 • 231 citations

An empirical study of the effect of the control rate as a predictor of treatment efficacy in meta-analysis of clinical trials

1998 • 213 citations

Systematic Reviews to Support Evidence-Based Medicine: How to Review and Apply Findings of Healthcare Research.

2004 • 207 citations

Taking healthcare interventions from trial to practice

2010 • 203 citations

Investigating causes of heterogeneity in systematic reviews

2002 • 195 citations

Meta-analysis: Beyond the grand mean?

1997 • 175 citations

Covariate heterogeneity in meta‐analysis: Criteria for deciding between meta‐regression and individual patient data

2006 • 172 citations

Can meta-analysis help target interventions at individuals most likely to benefit?

2005 • 164 citations

A model for integrating fixed-, random-, and mixed-effects meta-analyses into structural equation modeling.

2008 • 164 citations

Meta-analysis and the exploration of causal mediating processes: A primer of examples, methods, and issues.

1996 • 164 citations

Investigating heterogeneity in an individual patient data meta-analysis of time to event outcomes

2005 • 158 citations

Using mixed treatment comparisons and meta‐regression to perform indirect comparisons to estimate the efficacy of biologic treatments in rheumatoid arthritis

2006 • 150 citations

Tips for learners of evidence-based medicine: 4. Assessing heterogeneity of primary studies in systematic reviews and whether to combine their results

2005 • 149 citations

Meta-analysis of individual patient data versus aggregate data from longitudinal clinical trials

2009 • 130 citations

Attention should be given to multiplicity issues in systematic reviews

2008 • 129 citations

THE POPULATION RISK AS AN EXPLANATORY VARIABLE IN RESEARCH SYNTHESIS OF CLINICAL TRIALS

1996 • 128 citations

The Way in Which Intervention Studies Have “Personality” and why it is Important to Meta-Analysis

2001 • 125 citations

Inter‐study differences: How should they influence the interpretation and analysis of results?

1987 • 111 citations

Systematic reviews and knowledge translation

2006 • 111 citations

Analysing the relationship between treatment effect and underlying risk in meta-analysis: comparison and development of approaches

2000 • 106 citations

Method guidelines for Cochrane Musculoskeletal Group systematic reviews.

2006 • 104 citations

Exploratory or analytic meta-analysis: Should we distinguish between them?

1995 • 93 citations

Resolving conflicting clinical trials: Guidelines for meta-analysis

1988 • 93 citations

Can meta-analysis help target interventions at individuals most likely to benefit?

2005 • 91 citations

Consensus-based recommendations for investigating clinical heterogeneity in systematic reviews

2013 • 91 citations

Comparative Effectiveness Review Methods: Clinical Heterogeneity

2010 • 88 citations

Multilevel models for meta-analysis, and their application to absolute risk differences

2001 • 85 citations

Variation in baseline risk as an explanation of heterogeneity in meta-analysis

1997 • 82 citations

Baseline risk as predictor of treatment benefit: three clinical meta-re-analyses

2000 • 82 citations

Exploring Heterogeneity in Meta-Analysis

1999 • 73 citations

Knowledge for knowledge translation: The role of the Cochrane Collaboration

2006 • 73 citations

MULTIPLE-OUTCOME META-ANALYSIS OF CLINICAL TRIALS

1996 • 70 citations

Bench-to-bedside review: Avoiding pitfalls in critical care meta-analysis – funnel plots, risk estimates, types of heterogeneity, baseline risk and the ecologic fallacy

2008 • 68 citations

Guides for Reading and Interpreting Systematic Reviews

1998 • 67 citations

Interpreting and Evaluating Meta-Analysis

1995 • 66 citations

A Note on Variance Estimation in Random Effects Meta-Regression

2005 • 63 citations

Mediation Analyses: Applications in Nutrition Research and Reading the Literature

2010 • 60 citations

Two cheers for meta-analysis: problems and opportunities in aggregating results of clinical trials.

1988 • 57 citations

An overview of statistical issues and methods of meta-analysis

1991 • 55 citations

Summaries of findings, descriptions of interventions, and information about adverse effects would make reviews more informative

2006 • 50 citations

Predictive modeling and heterogeneity of baseline risk in meta-analysis of individual patient data

2001 • 48 citations

An overview of methods and empirical comparison of aggregate data and individual patient data results for investigating heterogeneity in meta‐analysis of time‐to‐event outcomes

2005 • 47 citations

Diagnostic statistical procedures in medical meta-analyses

1999 • 39 citations

Creating clinically relevant knowledge from systematic reviews: the challenges of knowledge translation

2007 • 37 citations

Exploring heterogeneity in meta‐analyses: needs, resources and challenges

2008 • 35 citations

Random effects survival models gave a better understanding of heterogeneity in individual patient data meta-analyses

2005 • 34 citations

Assessing treatment-time interaction in clinical trials with time to event data: a meta-analysis of hypertension trials

1998 • 33 citations

Meta-analysis: when and how.

1999 • 32 citations

Meta‐analysis of binary data: which within study variance estimate to use?

2001 • 30 citations

Multilevel models for meta-analysis, and their application to absolute risk differences

2001 • 29 citations

Subgroup effects despite homogeneous heterogeneity test results

2010 • 28 citations

DERIVING TREATMENT RECOMMENDATIONS FROM EVIDENCE WITHIN RANDOMIZED TRIALS The Role and Limitation of Meta-Analysis

1999 • 28 citations

A systematic review of analytical methods used to study subgroups in (individual patient data) meta-analyses

2007 • 28 citations

Clinical heterogeneity was a common problem in Cochrane reviews of physiotherapy and occupational therapy

2006 • 27 citations

An empirical study using permutation-based resampling in meta-regression

2012 • 25 citations

CoPlot: A tool for visualizing multivariate data in medicine

2007 • 24 citations

Use of hierarchical models for meta-analysis: experience in the metabolic ward studies of diet and blood cholesterol

1999 • 22 citations

Evaluation of underlying risk as a source of heterogeneity in meta-analyses: A simulation study of Bayesian and frequentist implementations of three models

2007 • 18 citations

Principles of metaanalysis.

2000 • 17 citations

A Logistic Model for Trend in 2 x 2 x K Tables with Applications to Meta- Analyses

1997 • 16 citations

Semi‐parametric modelling of the distribution of the baseline risk in meta‐analysis

2007 • 12 citations

Meta‐regression with partial information on summary trial or patient characteristics

2010 • 12 citations

Intervention Effects in the Case of Heterogeneity between Three Subgroups

2010 • 7 citations

Heterogeneity can impair the results of Cochrane meta‐analyses despite accordance with statistical guidelines

2008 • 7 citations

Assessing heterogeneity in meta‐analyses of Helicobacter pylori infection‐related clinical studies: a critical appraisal

2004 • 6 citations

Deleted Work

1955 • 0 citations