Michael Borenstein is the Director of Biostat, a leading developer of statistical software. He is the primary developer of Comprehensive Meta-Analysis (CMA), the world's most widely used program for meta-analysis. He is the recipient of numerous grants from the NIH to develop methods, software, and educational materials for meta-analysis. He has lectured widely on meta-analysis, including at the NIH, CDC, and FDA.

Larry V. Hedges is Board of Trustees Professor of Statistics and Education and Social Policy, Professor of Psychology, Professor of Medical Social Sciences, and IPR Fellow, Northwestern University, USA. He is a national leader in the fields of educational statistics and evaluation and is an elected member of many leading associations.

Julian P.T. Higgins is Professor of Evidence Synthesis at the University of Bristol, UK, and a National Institute for Health Research (NIHR) Senior Investigator. He has had numerous core roles in the Cochrane Collaboration, including editing its methodological Handbook since 2003. His many contributions to meta-analysis include the foundation of network meta-analysis, methods for describing and explaining heterogeneity and a general framework for individual participant data meta-analysis. He is a Highly Cited Researcher with over a quarter of a million citations to his work and has been a recipient of the Ingram Olkin Award for distinguished lifetime achievement in research synthesis methodology.

Hannah R. Rothstein is Professor of Management at Baruch College and the Graduate Center of the City University of New York. She is a Fellow of the American Psychological Association and a past President of the Society for Research Synthesis Methodology. She is former Editor-in-Chief of Research Synthesis Methods and serves on the editorial boards of Psychological Bulletin, Psychological Methods, and Organizational Research Methods. Professor Rothstein is a co-developer of the Comprehensive Meta-Analysis software and has published numerous systematic reviews and meta-analyses.

List of Tables xv

List of Figures xix

Acknowledgements xxv

Preface xxvii

Preface to the Second Edition xxxv

Website xxxvii

Part 1: Introduction

1 How a Meta-Analysis Works 3

2 Why Perform a Meta-Analysis 9

Part 2: Effect Size and Precision

3 Overview 17

4 Effect Sizes Based On Means 21

5 Effect Sizes Based On Binary Data (2 × 2 Tables) 33

6 Effect Sizes Based On Correlations 39

7 Converting Among Effect Sizes 43

8 Factors That Affect Precision 49

9 Concluding Remarks 55

Part 3: Fixed-Effect Versus Random-Effects Models

10 Overview 59

11 Fixed-Effect Model 61

12 Random-Effects Model 65

13 Fixed-Effect Versus Random-Effects Models 71

14 Worked Examples (Part 1) 81

Part 4: Heterogeneity

15 Overview 97

16 Identifying and Quantifying Heterogeneity 99

17 Prediction Intervals 119

18 Worked Examples (Part 2) 127

19 An Intuitive Look At Heterogeneity 139

20 Classifying Heterogeneity As Low, Moderate, Or High 155

Part 5: Explaining Heterogeneity

21 Subgroup Analyses 161

22 Meta-Regression 197

23 Notes On Subgroup Analyses and Meta-Regression 213

Part 6: Putting It All In Context

24 Looking At the Whole Picture 223

25 Limitations of the Random-Effects Model 233

26 Knapp-Hartung Adjustment 243

Part 7: Complex Data Structures

27 Overview 253

28 Independent Subgroups Within a Study 255

29 Multiple Outcomes or Time-Points Within A Study 263

30 Multiple Comparisons Within a Study 277

31 Notes On Complex Data Structures 281

Part 8: Other Issues

32 Overview 287

33 Vote Counting - A New Name For An Old Problem 289

34 Power Analysis For Meta-Analysis 295

35 Publication Bias 313

Part 9: Issues Related To Effect Size

36 Overview 335

37 Effect Sizes Rather Than P-Values 337

38 Simpson's Paradox 343

39 Generality of the Basic Inverse-Variance Method 349

Part 10: Further Methods

40 Overview 361

41 Meta-Analysis Methods Based On Direction and P-Values 363

42 Further Methods For Dichotomous Data 369

43 Psychometric Meta-Analysis 377

Part 11: Meta-Analysis In Context

44 Overview 391

45 When Does It Make Sense To Perform a Meta-Analysis? 393

46 Reporting The Results of a Meta-Analysis 401

47 Cumulative Meta-Analysis 407

48 Criticisms of Meta-Analysis 413

49 Comprehensive Meta-Analysis Software 425

50 How To Explain the Results of An Analysis 443

Part 12: Resources

51 Software For Meta-Analysis 471

52 Web Sites, Societies, Journals, and Books 473

Web sites 473

Professional societies 476

Journals 476

Special issues dedicated to meta-analysis 477

Books on systematic review methods and meta-analysis 477

References 479

Index 491