手法を比較

	生態学的研究	メタアナリシス生態学的研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	19th century (Snow 1854); formalised mid-20th century	1990s
提唱者	Various; foundational work by John Snow (1854) and systematised in modern form by Brian MacMahon and colleagues	Morgenstern, Blettner, and colleagues in epidemiology methodology
種類	Observational epidemiological study	Quantitative synthesis design
原典	Morgenstern, H. (1995). Ecologic studies in epidemiology: concepts, principles, and methods. Annual Review of Public Health, 16(1), 61–81.	Blettner, M., Sauerbrei, W., Schlehofer, B., Scheuchenpflug, T., & Friedenreich, C. (1999). Traditional reviews, meta-analyses and pooled analyses in epidemiology. International Journal of Epidemiology, 28(1), 1–9.
別名	aggregate study, correlational study, ecological correlation study, population-level study	ecological meta-analysis, aggregate-level meta-analysis, meta-analytic ecologic design, population-level meta-analysis
関連	5	2
概要	An ecological study is an observational epidemiological design in which the unit of analysis is a group or population — a country, region, city, or time period — rather than an individual. Exposures and outcomes are measured as aggregates (rates, proportions, or means) and then correlated across groups to generate or evaluate hypotheses about population-level associations between risk factors and disease.	A meta-analytic ecological study synthesises data from multiple populations or geographic units — rather than from individual patients — to estimate associations between exposures and health outcomes. By pooling aggregate-level statistics across studies or regions, it extends the reach of ecological reasoning to a wider evidence base, enabling detection of exposure-outcome relationships that single-population ecological analyses may miss due to limited variability or sample size.