विधियों की तुलना करें

	पूर्वव्यापी केस-कंट्रोल अध्ययन	पूर्वव्यापी कोहॉर्ट अध्ययन
क्षेत्र	महामारी विज्ञान	महामारी विज्ञान
परिवार	Process / pipeline	Process / pipeline
उद्भव वर्ष	1950s–1960s (formal methodology)	Mid-20th century (widely formalized 1950s–1970s)
प्रवर्तक	Jerome Cornfield; formalized by Brian MacMahon and others in mid-20th-century epidemiology	Systematic use attributed to early 20th-century occupational epidemiology; formalized in modern epidemiological theory by Brian MacMahon and others
प्रकार	Observational analytical study	Observational analytic study
मौलिक स्रोत	Schlesselman, J. J. (1982). Case-Control Studies: Design, Conduct, Analysis. Oxford University Press. ISBN: 978-0195029338	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
उपनाम	case-control study, retrospective case-referent study, case-referent design, trohoc study	historical cohort study, non-concurrent cohort study, retrospective follow-up study, historical prospective study
संबंधित	5	6
सारांश	A retrospective case-control study identifies individuals who already have an outcome of interest (cases) and a comparable group without it (controls), then looks backward in time using existing records to determine prior exposure to a suspected risk factor. The primary measure of association is the odds ratio. This design is especially efficient for studying rare diseases or outcomes with long latency periods, since the outcome has already occurred before the study begins.	A retrospective cohort study assembles a group of individuals who share a common starting point and reconstructs their exposure history and subsequent outcomes entirely from pre-existing records. Because the data have already been collected before the study begins, the design is far faster and cheaper than a prospective cohort; however, the researcher must work with whatever information was recorded at the time rather than collecting purpose-built measurements.