قارن الطرق

	دراسة الحالة والشاهد المتداخلة المستقبلية	دراسة الأتراب
المجال	علم الأوبئة	علم الأوبئة
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1977	Mid-20th century (formal epidemiological design codified ~1950s)
صاحب الطريقة	D.C. Thomas (formal description); building on Mantel (1973) and Liddell, McDonald & Thomas (1977)	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
النوع	Observational analytic design	Observational longitudinal study design
المصدر التأسيسي	Thomas, D.C. (1977). Addendum to: Methods of cohort analysis: Appraisal by application to asbestos mining. By F.D.K. Liddell, J.C. McDonald, and D.C. Thomas. Journal of the Royal Statistical Society, Series A, 140(4), 469-491.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
الأسماء البديلة	prospective NCC, nested case-control within prospective cohort, prospective case-control within cohort, incident NCC	longitudinal study, follow-up study, panel study, incidence study
ذات صلة	5	6
الملخص	A prospective nested case-control study enrolls a cohort before disease onset, follows participants forward in time, and then — once cases develop — samples matched controls from those still at risk at the time each case occurs. By embedding the case-control comparison inside a prospective cohort, the design combines the causal clarity of longitudinal follow-up with the cost efficiency of analysing only a fraction of the cohort's stored specimens or records.	A cohort study assembles a group of individuals who share a common starting point — typically freedom from the outcome of interest — and follows them over time to observe who develops the outcome. By comparing incidence rates between exposed and unexposed subgroups, researchers can estimate relative risk and absolute risk differences. Cohort studies are the gold-standard observational design for measuring disease incidence and establishing temporal relationships between exposure and outcome.