เปรียบเทียบวิธี

	Retrospective case-control study	การศึกษากลุ่มควบคุมที่ซ้อนกัน (Nested Case-Control Study)
สาขาวิชา	ระบาดวิทยา	ระบาดวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1950s–1960s (formal methodology)	1973–1977
ผู้ริเริ่ม	Jerome Cornfield; formalized by Brian MacMahon and others in mid-20th-century epidemiology	Nathan Mantel (1973); D. C. Thomas (1977 formalization)
ประเภท	Observational analytical study	Hybrid observational study design
แหล่งต้นตำรับ	Schlesselman, J. J. (1982). Case-Control Studies: Design, Conduct, Analysis. Oxford University Press. ISBN: 978-0195029338	Thomas, D. C. (1977). Addendum to: Methods of cohort analysis: Appraisal by application to asbestos mining. Journal of the Royal Statistical Society, Series A, 140(4), 469–491.
ชื่อเรียกอื่น	case-control study, retrospective case-referent study, case-referent design, trohoc study	NCC study, nested CC design, case-control within cohort, density sampling case-control
ที่เกี่ยวข้อง	5	6
สรุป	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 nested case-control study is an efficient observational design embedded within a defined cohort. For each participant who develops the outcome of interest (a case), a small number of matched controls are sampled from those still at risk at the same point in time. This density-sampling strategy yields odds ratios that approximate incidence-rate ratios from the full cohort at a fraction of the data-collection cost — making it the preferred alternative when measuring exposures for all cohort members would be prohibitively expensive or technically demanding.