手法を比較

	実用的な生態学的研究	コホート研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1967–1982 (pragmatic concept 1967; ecological study formalized ~1982)	Mid-20th century (formal epidemiological design codified ~1950s)
提唱者	Morgenstern (ecological study framework); Schwartz & Lellouch (pragmatic design concept)	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
種類	Observational ecological study with pragmatic framing	Observational longitudinal study design
原典	Morgenstern, H. (1982). Uses of ecologic analysis in epidemiologic research. American Journal of Public Health, 72(12), 1336–1344.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
別名	real-world ecological study, effectiveness ecological study, population-level pragmatic study, pragmatic ecologic design	longitudinal study, follow-up study, panel study, incidence study
関連	5	6
概要	A pragmatic ecological study is an observational epidemiological design that examines associations between exposures and outcomes at the population or group level — using routinely collected, real-world data — with the explicit goal of informing practical public health decisions under everyday conditions. Rather than controlling every variable in a laboratory-like manner, it embraces the complexity and heterogeneity of natural settings to answer effectiveness questions relevant to policy.	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.