Chapter Contents Scope of the Problem 108 Consequences of Poor Recruitment 108 Trial Abandonment 108 Power 108 External Validity 108 Ethical Concerns 109 Great Expectations? 109 Recruitment Terminology 109 Keeping…
Chapter Contents Likelihood Ratios for Tests With Two Outcomes 96 Why Bother? 97 Shift Happens 98 Choosing Cut Points 98 Fagan Nomogram 99 Two-Step Fagan Nomogram 100 Nomogram Alternatives 100…
Chapter Contents Ethical Implications 85 What are the Potential Harms of Screening? 85 Criteria for Screening 86 If a Test is Available, Should it be Used? 86 Assessment of Test…
Chapter Contents False Claims 71 Amateurs at Work 72 Administrative Databases 74 Weak Associations: Size Matters 75 Porous Peer Review 76 Fraud 77 Conclusion 78 Observational research dominates the biomedical…
Chapter Contents Aim of Controls 60 Where to Find Controls? 62 Controls From a Known Group 62 Random-Digit Dialling 63 Controls From an Unknown Group 64 Neighbourhood Controls 64 Hospital…
Chapter Contents Basic Case-Control Study Design 52 Advantages and Disadvantages 53 Selection of Case and Control Groups 54 Case Group 54 Control Group 54 Measurement of Exposure Information 56 Control…
Chapter Contents Data Collection: Forwards and Backwards 40 Advantages of Cohort Studies 41 Disadvantages of Cohort Studies 42 What to Look for in Cohort Studies 43 Who is at Risk?…
Chapter Contents Internal and External Validity 26 Bias 26 Selection Bias 27 Are the Groups Similar in all Important Respects? 27 Information Bias 28 Has Information Been Gathered in the…
Chapter Contents The Descriptive Triad—Or Pentad? 14 Five ‘W’ Questions 14 Types of Descriptive Studies 15 Case Report 16 Case-Series Report 16 Cross-Sectional (Prevalence) Studies 16 Surveillance 17 Ecological Correlational…
Chapter Contents A Taxonomy of Clinical Research 2 What Studies Can and Cannot Do 4 Descriptive Study 4 Cross-Sectional Study: A Snapshot in Time 4 Cohort Study: Looking Forward in…
