手法を比較

	コホート研究	横断疫学研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	Mid-20th century (formal epidemiological design codified ~1950s)	1960s (formal codification); widely practiced since mid-20th century
提唱者	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Classical epidemiology tradition; systematized by Brian MacMahon and Thomas Pugh (1960s)
種類	Observational longitudinal study design	Observational, descriptive/analytic epidemiological design
原典	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
別名	longitudinal study, follow-up study, panel study, incidence study	prevalence study, cross-sectional survey, transversal study, cross-sectional design
関連	6	6
概要	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.