방법 비교

	사례-대조 연구	무작위 임상시험 (RCT)
분야	역학	역학
계열	Process / pipeline	Process / pipeline
기원 연도	1950s (formal methodology); precursors in the 1920s	1948 (first rigorously conducted RCT — MRC streptomycin trial)
창시자	Janet Lane-Claypon (early precursors, 1926); formalized by Brian MacMahon and Jerome Cornfield in the 1950s–1960s	Austin Bradford Hill; MRC Streptomycin Trial team
유형	Observational analytic study design	Interventional experimental study
원전	Schlesselman, J.J. (1982). Case-Control Studies: Design, Conduct, Analysis. Oxford University Press. ISBN: 978-0195027860	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2015). Fundamentals of Clinical Trials (5th ed.). Springer. ISBN: 978-3319185385
별칭	case-referent study, case-control design, retrospective case-control, case-control analysis	RCT, randomized controlled trial, randomised controlled trial, clinical randomized trial
관련	6	6
요약	A case-control study is a retrospective observational design in which individuals who have developed a disease or outcome of interest (cases) are compared with individuals who have not (controls) to determine whether prior exposure to a putative risk factor differs between the two groups. The primary measure of association is the odds ratio, which approximates the relative risk when the outcome is rare. Case-control studies are especially efficient for investigating rare diseases and generating etiological hypotheses.	A randomized clinical trial (RCT) is an experimental study design in which participants are randomly assigned to an intervention group or a control group, then followed prospectively to compare outcomes. Random allocation is the defining feature: it distributes known and unknown confounders across groups by chance, making the RCT the strongest individual study design for establishing causal efficacy of a treatment or intervention under controlled conditions.