RCT = gold standard. Systematic review = highest evidence level. Meta-analysis = statistical pooling. Blinding: single (participant), double (+ researcher), triple (+ analyst).

PICO: Population, Intervention, Comparison, Outcome. NNT = 1/ARR. CONSORT = RCTs. STROBE = observational. PRISMA = systematic reviews. Cochrane = gold standard database.

Type I error (α) = false positive. Type II (β) = false negative. Power = 1-β. Linear regression = continuous. Logistic = binary. Kaplan-Meier = survival. ROC = diagnostic test.

4 principles: Autonomy, Beneficence, Non-maleficence, Justice. Informed consent = mandatory. DCI = regulatory. Consumer Protection Act = negligence. Vicarious liability = employer responsible.