Clinical Trials

❘❙❚■ IndexQqualitative interaction, 307–308, 308quality-adjusted life-years (QALYs),as endpoint measure, 44quality assessment, meta-analysis, 443quantitative interaction, 307–308, 308, 310RRALES (Randomized Aldactone EvaluationStudy), 374random-effects model, meta-analysis, 446–448, 447random error, 6–7false-positive rate, 6sampling error, 6randomization, 65–74bias minimization, 66common techniques, 67–73block, 68–70, 69minimization, 72, 72–73simple, 67–68, 68stratified, 70–71, 71CONSORT statement, 369factorial design, 104multicenter trials, 161protocol development, 31reporting, 372selection bias, 57technique choice, 66–67use, 66Randomized Aldactone Evaluation Study(RALES), 374randomized clinical trials (RCTs), 1–13center number, 3–4definition, 1example, 7–13see also Candesartan in Heart failure –Assessment of Reduction in Mortalityand morbidity (CHARM)reliability, 4–7types, 2–4range, definition, 173rate of change, repeated measurements,322, 326, 327recruitment rate, critical appraisal of reports,430–431recruitment targets, multicenter trials, 159referencesprotocol development, 34tables, 402regression analysis, 6, 273–285baseline variables adjustment, 282classification, 275definition, 456determining diagnostic models, 283–284hazards regression, 279–281example, 280, 280–281logistic regression, 277–279, 278, 292example, 277, 278–279Gruppo Italiano per lo Studio dellaStreptochinasi nell’Infarto Miocardico(GISSI)-Prevenzione trial, 312models, 281–284multiple linear regression, 275–277assumptions and interpretations, 284example, 276, 277outcome predictor identification, 282prognostic factor identification, 282–283prognostic model establishment, 283uses of, 281–284regression coefficient, definition, 276regression lines, repeated measurements, 327regression modeling, confounding, 302regulatory changes, reporting, 372–373regulatory requirements, 24protocol development, 32relative frequency, definition, 170relative risk, definition, 455relevance, reports, 429repeated measurements, 317–328analysis methods, 319–321predefined time point, 319statistical models, 320summary measures see belowtime-by-time analysis, 319–320data considerations, 319definitions, 318example, 318mean, 323multiplicity, 332–333summary measure approach, 320–326, 322area under the curve, 324–325maximum, 322–323, 323mean, 321–322, 322, 323rate of change, 326, 327regression lines, 327time to maximum, 322, 323variable range, 322, 325see also statistics476