Acknowledgements ix
Preface to the First Edition xi
Preface to the Second Edition xiii
Chapter 1 Introduction to Critical Appraisal 1
The aims of critical appraisal 1
Three stages of critical appraisal 2
Chapter 2 Do Not Read the Paper 4
The initial interrogation 5
The in-depth interrogation 6
Chapter 3 Identifying the Research Design 7
Surveys 7
Cohort studies 9
Case-control studies 10
RCTs 11
Cohort studies that evaluate the effectiveness of interventions 12
Systematic reviews 14
Chapter 4 Interpreting the Results 16
The effect size 17
Taking the play of chance into account 19
Factors that distort the effect size 22
Questionable research practices 24
Conclusion 25
Chapter 5 The In-Depth Interrogation 26
Bias 26
Critical questions for bias 27
Important questions for bias 27
Indicative questions for bias 33
Questions about value 36
Conclusion 39
Chapter 6 Appraising Surveys 40
The critical bias questions for bias 40
The complete list for appraising surveys* 43
Chapter 7 Appraising Cohort Studies 45
The critical questions for bias 45
The important questions for bias 49
The indicative questions for risk of bias 50
The complete list for the appraisal of cohort studies* 51
Chapter 8 Appraising Case-Control Studies 53
The critical questions for bias 53
The important questions for bias 55
The complete list for the appraisal of case-control studies* 58
Chapter 9 Appraising Randomised Controlled Trials 60
The critical questions for bias 60
The important questions for bias 64
The questions of value 67
The complete list for the appraisal of clinical trials* 68
Chapter 10 Cohort Studies That Evaluate the Effectiveness of Interventions 70
Overview of advantages of cohort treatment studies and challenges for critical appraisal 71
The critical questions for bias 72
The important questions for bias 76
The questions of value 78
Conclusion 78
The complete list for the appraisal of cohort studies that evaluate interventions 79
Chapter 11 Appraising Systematic Reviews 81
The critical questions for risk of bias 81
The important questions for risk of bias 86
The questions of value 88
The complete list for the appraisal of systematic reviews* 89
Chapter 12 Summarising Risk of Bias 91
Identify the risk of bias of the research designs 91
Review the biases in study design, conduct, and interpretation 92
Derive an overall rating 93
Summary 95
Chapter 13 Certainty of Evidence 96
The nature of certainty of evidence 96
Downgrading the certainty of evidence 97
Factors that increase certainty 100
Overall assessment of certainty 102
Conclusion 103
Chapter 14 Assessing Value 104
Measuring potential benefit 105
Harm and the balance between benefit and harm 106
Costs and cost effectiveness 107
Feasibility of implementation of a treatment 109
Health equity 109
Summary 111
Appendix: Further Reading 113
Index 131
