Evidence in Medicine (eBook)

Iain K Crombie is Emeritus Professor of Public Health at Dundee University, UK. He has published more than 160 research papers as well as books on critical appraisal, research methods, grant applications, and clinical audits. He has extensive experience teaching both undergraduate and postgraduate courses in epidemiology, medical statistics, and research methods.

Preface 4

Aims of this book 5

Chapter 1 The rationale for treatment: a brief history 7

Conclusion 14

References 15

Chapter 2 Sources of bias in randomised controlled trials 18

Method of treatment allocation 18

Problems in measuring the outcome 20

Follow-up and missing outcomes 22

Missing outcome data and intention to treat 23

Other methodological concerns 24

Conclusions 26

References 27

Chapter 3 Wasted and unhelpful trials 34

Wasted Studies 34

Neglected areas of research 35

Unhelpful outcome measures 35

Lack of generalisability 37

Weak and misleading evidence 39

Conclusion 40

References 40

Chapter 4 Can the analysis bias the findings? 46

The p-value problem 46

Questionable research practices 48

Ensuring high quality analysis: the Statistical Analysis Plan 50

Conclusions 51

References 52

Chapter 5 Systematic reviews and Meta-analysis 56

Introduction 56

Identifying relevant trials 57

Extracting trial data 59

The quality of primary trials 61

Pooling effect sizes across trials 62

Other methodological issues 63

Conclusions 65

References 66

Chapter 6 Fabrication, falsification and spin 73

Fabrication 73

Falsification 75

Questionable Research Practices 76

Spin 76

Retractions 78

Discussion 78

References 79

Chapter 7 Why do researchers falsify data or manipulate study findings? 83

The research environment 83

Research oversight 86

Conflict of interest 88

Individual level explanations for research misconduct 90

How honest people rationalise misconduct 91

Discussion 93

References 94

Chapter 8 Developing a strategy to prevent poor quality and misleading research 103

Research environment 103

Research transparency 105

Research oversight 106

Research integrity 107

Essential elements of a transformational strategy 108

Implementing a programme for action 112

References 113

Appendix 1 Summary of the key findings on poor quality research 118

Problems in the design, conduct, analysis and reporting of studies 118

Frequency of data fabrication and falsification 120

The causes of poor quality and misleading research 120

The findings in perspective 121

References 122

Appendix 2 Initiatives to improve the quality of research 123

Change the research environment 123

Improve training 125

Increase research transparency 126

Quality of trial methodology 128

Trial registration 130

Reporting of the methods of systematic reviews 130

Increasing access to and use of reporting guidelines 132

Implement vigorous research oversight 132

Promote research integrity 136

Examples of coordinated initiatives 140

References 141

Index

"Evidence in Medicine: The Common Flaws, Why They Occur and How to Prevent Them will open your eyes to the squishy underbelly of clinical research. Given the numerous pitfalls for the unwary -- and overly ingenious -- investigator, it is no surprise that "possibly 85 percent of clinical research is wasted."' - Journal of Clinical Research Best Practices