השוואת שיטות

	מחקר אקולוגי רב-מרכזי	מחקר עוקבה
תחום	אפידמיולוגיה	אפידמיולוגיה
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1980s–1990s (formal methodological description)	Mid-20th century (formal epidemiological design codified ~1950s)
הוגה השיטה	Epidemiological tradition; methodologically articulated by Morgenstern (1982) and Susser (1994)	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
סוג	Observational epidemiological study design	Observational longitudinal study design
מקור מכונן	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
כינויים	multi-site ecological study, multinational ecological study, pooled ecological analysis, multicenter aggregate study	longitudinal study, follow-up study, panel study, incidence study
קשורות	6	6
תקציר	A multicenter ecological study is an observational epidemiological design in which the units of analysis are groups — such as cities, regions, or countries — rather than individuals, and data are pooled from two or more distinct centers or geographic areas. The approach links aggregate exposure measures (e.g., average pollution levels, vaccination coverage rates) to aggregate outcome rates (e.g., disease incidence per 100,000) across multiple populations, enabling comparisons that would be infeasible within any single site.	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.