手法を比較

	リスク調整済み生態学的研究	コホート研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1980s–1990s	Mid-20th century (formal epidemiological design codified ~1950s)
提唱者	Extension of ecological study methodology; risk adjustment concepts formalized by Morgenstern (1982) and developed further in health outcomes research	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
種類	Observational ecological design with statistical confounding control	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	risk-adjusted ecological analysis, confounder-adjusted ecological study, ecological regression with risk adjustment, adjusted area-level study	longitudinal study, follow-up study, panel study, incidence study
関連	4	6
概要	A risk-adjusted ecological study is an observational epidemiological design that examines associations between exposures and outcomes measured at the group or area level — such as regions, hospitals, or countries — while statistically controlling for known risk factors also measured at that level. By incorporating risk adjustment through ecological regression or standardization, the design reduces (though cannot eliminate) confounding from group-level variables, enabling more valid comparisons across populations or settings.	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.