Clinical Trials

Clinical Trials: A Practical Guide ■❚❙❘objectives, 7–8patient population, 8patient selection, 48, 51, 51–52regression result interpretation, 247–248result interpretation, 248sample size calculation, 9study design, 8trial reporting, 11–12Cardiac Arrythmia Suppression Trial (CAST),surrogate endpoints, 43‘carryover effects,’ crossover trials, 97case record form (CRF), 34case series studies, 18case studies, 18CAST (Cardiac Arrythmia Suppression Trial),surrogate endpoints, 43categorical variables, 172centers, 3patient selection, 49–50selection, multicenter trials, 161single-center, 3CF-WISE (Withdrawal of Inhaled SteroidsEvaluation Study in Patients with CysticFibrosis), 71CHARM see Candesartan in Heart failure –Assessment of Reduction in Mortality andmorbidity (CHARM)children, 52Chi-squared (χ 2 ) test, 222–224, 232assumptions, 224calculation, 223critical values, 224chronic airways limitation (CAL) trial, 198–200raw data, 199statistics, 199clarity, CONSORT statement, 371clinical equivalence trials, 115definition, 114clinical event review committee,protocol development, 35Clopidogrel in Unstable Angina to PreventRecurrent Events (CURE), 40cluster effect, cluster randomized trials, 146cluster randomized trials, 141–151advantages, 143, 149, 149analysis, 146–147bias, 147, 147–148definition, 3design, 142–144cluster effect, 142–143confounding, 143–144selection bias, 143ethical issues, 148–149example, 144, 145limitations, 149, 149randomization units, 143reporting, 148sample size, 144–145C max, bioequivalence trials, 122coherence, CONSORT statement, 371column chart, 412comparisonmeans see means, comparison ofproportions see proportions, comparison ofcomplete crossover clinical trials, 94compliance, factorial design, 111complicated factorial design, 109–110composite endpoints, 40–42advantages, 41limitations, 41–42multiplicity, 336confidence intervalscalculation, bioequivalence trials,127–129, 128, 128definition, 454statistical significance, 404tables, 403confirmatory trial, 4confounding, 5–6, 295–304, 297causes, 297–298cluster randomized trials, 143–144controlanalysis, 301–302study design, 300–301critical appraisal of reports, 431–432definition, 296detection of, 298–299non-treatment causation assessment, 299outcome predictor assessment, 299, 299treatment group association, 298, 298evaluation, 299–300example, 297–298see also hormone replacement trialinteraction vs, 297–298, 303negative, 300positive vs, 296positive, 300negative vs, 296469