So sánh phương pháp

	Nghiên cứu sinh thái tiềm cứu	Nghiên cứu thuần tập
Lĩnh vực	Dịch tễ học	Dịch tễ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1950s–1970s (ecological epidemiology); prospective variant widely applied from 1980s onward	Mid-20th century (formal epidemiological design codified ~1950s)
Người khởi xướng	Ecological study design formalised in epidemiology mid-20th century; prospective variant established through environmental and chronic disease research	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
Loại	Observational epidemiological study design	Observational longitudinal study design
Công trình gốc	Morgenstern, H. (1998). Ecological 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
Tên gọi khác	prospective ecologic study, prospective aggregate-level study, prospective group-level study, ecological cohort study	longitudinal study, follow-up study, panel study, incidence study
Liên quan	4	6
Tóm tắt	A prospective ecological study is an observational epidemiological design in which groups — not individuals — serve as the unit of analysis, and exposure data are collected going forward in time before outcomes are measured. Investigators define geographically, politically, or socially bounded populations, characterise their aggregate exposures at baseline, then ascertain group-level outcomes (disease rates, mortality rates) at one or more later time points. Because exposure precedes outcome measurement, this design provides stronger temporal evidence than retrospective ecological studies.	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.