手法を比較

	回顧的生態学的研究	後ろ向きコホート研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	20th century (formalized ~1980s–1990s)	Mid-20th century (widely formalized 1950s–1970s)
提唱者	Epidemiological tradition; formalized by Morgenstern and others	Systematic use attributed to early 20th-century occupational epidemiology; formalized in modern epidemiological theory by Brian MacMahon and others
種類	Observational epidemiological design	Observational analytic study
原典	Morgenstern, H. (1998). Ecologic studies. In K. J. Rothman & S. Greenland (Eds.), Modern Epidemiology (2nd ed., pp. 459–480). Lippincott-Raven.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
別名	retrospective aggregate study, historical ecological study, retrospective correlational ecological design, population-level retrospective study	historical cohort study, non-concurrent cohort study, retrospective follow-up study, historical prospective study
関連	5	6
概要	A retrospective ecological study examines associations between exposures and outcomes using pre-existing aggregate data from defined populations or geographic units. Rather than following individual subjects, the unit of analysis is a group — a country, region, or time period — and all measurements come from historical records already collected before the study began. It is a rapid, low-cost way to generate hypotheses about environmental, social, or policy determinants of disease at the population level.	A retrospective cohort study assembles a group of individuals who share a common starting point and reconstructs their exposure history and subsequent outcomes entirely from pre-existing records. Because the data have already been collected before the study begins, the design is far faster and cheaper than a prospective cohort; however, the researcher must work with whatever information was recorded at the time rather than collecting purpose-built measurements.