مقایسهٔ روش‌ها

	طرح مطالعه کوهورت	طراحی مطالعه مورد-شاهدی
حوزه	پژوهش بالینی	پژوهش بالینی
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1970s-1980s	1950s-1970s
پدیدآور	Donald Acheson, Olli Miettinen, and others in modern epidemiology	Jerome L. Schlesselman, Brian MacMahon, Thomas Pugh
نوع	Research Design	Research Design
منبع بنیادین	Miettinen, O. S. (1976). Estimability and estimation in case-referent studies. American Journal of Epidemiology, 103(2), 226–235.	Schlesselman, J. J. (1982). Case-Control Studies: Design, Conduct, Analysis. Oxford University Press. ISBN: 978-0195027815
نام‌های دیگر	prospective study, follow-up study, longitudinal study, cohort study	case-control study, retrospective study, matched case-control, nested case-control
مرتبط	2	2
خلاصه	A cohort study follows a group of individuals forward in time from exposure to outcome. Exposed and unexposed participants (or participants with differing exposure levels) are enrolled at baseline, characterized, and observed prospectively until the outcome occurs or the study ends. Cohort studies are fundamental to epidemiology and are the design of choice for establishing causal associations when randomized trials are infeasible or unethical.	A case-control study identifies individuals with a disease or outcome (cases) and a comparison group without the outcome (controls), then measures prior exposure retrospectively. Developed in the 1950s–1970s by epidemiologists like Schlesselman and MacMahon, case-control studies are especially efficient for rare diseases, as they sample cases enriched for the outcome, avoiding the need for enormous cohorts. They are a mainstay of clinical epidemiology, observational research, and outbreak investigations.