So sánh phương pháp

	Nghiên cứu thuần tập	Nghiên cứu dịch tễ học cắt ngang
Lĩnh vực	Dịch tễ học	Dịch tễ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Mid-20th century (formal epidemiological design codified ~1950s)	1960s (formal codification); widely practiced since mid-20th century
Người khởi xướng	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Classical epidemiology tradition; systematized by Brian MacMahon and Thomas Pugh (1960s)
Loại	Observational longitudinal study design	Observational, descriptive/analytic epidemiological design
Công trình gốc	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	Kelsey, J. L., Whittemore, A. S., Evans, A. S., & Thompson, W. D. (1996). Methods in Observational Epidemiology (2nd ed.). Oxford University Press. ISBN: 978-0195080407
Tên gọi khác	longitudinal study, follow-up study, panel study, incidence study	prevalence study, cross-sectional survey, transversal study, cross-sectional design
Liên quan	6	6
Tóm tắt	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.	A cross-sectional epidemiological study measures the exposure(s) and outcome(s) of interest simultaneously in a defined population at a single point in time (or over a short period). Because there is no follow-up, it is the most efficient observational design for estimating disease prevalence and for generating hypotheses about associations between risk factors and health outcomes.