قارن الطرق

	دراسة الأتراب المتطابقة (Matched Cohort Study)	دراسة الحالة والشاهد المتداخلة (Nested Case-Control Study)
المجال	علم الأوبئة	علم الأوبئة
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	Mid-20th century; propensity-score variant 1983	1973–1977
صاحب الطريقة	Established practice; propensity-score matching formalized by Rosenbaum & Rubin (1983)	Nathan Mantel (1973); D. C. Thomas (1977 formalization)
النوع	Observational analytic study design	Hybrid observational study design
المصدر التأسيسي	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	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.
الأسماء البديلة	matched follow-up study, paired cohort study, propensity-matched cohort, matched prospective study	NCC study, nested CC design, case-control within cohort, density sampling case-control
ذات صلة	5	6
الملخص	A matched cohort study is an observational design in which each exposed participant is paired with one or more unexposed counterparts who share key characteristics — such as age, sex, or comorbidity status — before both groups are followed forward in time to compare incident outcomes. Matching controls for measured confounders at the design stage, reducing bias that would otherwise require statistical adjustment alone.	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.