chapter NATURAL HISTORY OF DISEASE -- chapter DETERMINING CAUSATION -- chapter OUTCOME MEASURES -- chapter FORMULATING CLINICAL QUESTIONS -- chapter HIERARCHY OF EVIDENCE -- chapter SYSTEMATIC REVIEWS -- chapter META-ANALYSES -- chapter RANDOMIZED CONTROLLED TRIALS -- chapter OTHER TRIALS FOR COMPARISON OF INTERVENTIONS -- chapter COHORT STUDIES -- chapter CASE-CONTROL STUDIES -- chapter CROSS-SECTIONAL (PREVALENCE) SURVEYS -- part CASE REPORTS AND CASE SERIES -- chapter QUALITATIVE RESEARCH -- chapter SCREENING -- chapter QUESTIONNAIRES -- chapter SOURCES OF INFORMATION -- chapter SITES OF INTEREST ON THE WORLD WIDE WEB -- chapter Search strategies for electronic databasesa -- chapter THE COCHRANE COLLABORATION -- chapter CRITICAL APPRAISAL -- chapter STATISTICAL METHODS (OVERVIEW) -- chapter THE P VALUE -- chapter RELATIVE RISK, RELATIVE RISK REDUCTION AND ODDS RATIO -- chapter RISK REDUCTION AND THE NUMBER NEEDED TO TREAT (NNT) -- chapter CONFIDENCE INTERVALS -- part SENSITIVITY AND SPECIFICITY -- chapter LIKELIHOOD RATIOS -- chapter NEGATIVE AND POSITIVE PREDICTIVE VALUES -- chapter STRATIFICATION AND MINIMIZATION -- chapter BIAS AND CONFOUNDERS -- chapter INTENTION TO TREAT -- part THE POWER OF STUDIES -- chapter REPRODUCIBILITY -- chapter REGRESSION ANALYSIS -- part SUBGROUP ANALYSIS -- chapter HEALTH STATUS MEASUREMENT -- chapter HEALTH ECONOMICS -- chapter QALYs -- chapter SAMPLING AND APPLICABILITY -- chapter AUDIT -- chapter GUIDELINES -- chapter DECISION ANALYSIS -- chapter IMPROVING PROFESSIONAL PRACTICE -- chapter EXPLAINING RISK TO PATIENTS -- part LIMITATIONS OF EBM -- chapter THE FUTURE OF EBM.