手法を比較

	ケースクロスオーバーデザイン	コホート研究	ネステッドケースコントロール研究
分野	疫学	疫学	疫学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1991	Mid-20th century (formal epidemiological design codified ~1950s)	1973–1977
提唱者	Malcolm Maclure	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Nathan Mantel (1973); D. C. Thomas (1977 formalization)
種類	Observational epidemiological study design	Observational longitudinal study design	Hybrid observational study design
原典	Maclure, M. (1991). The case-crossover design: A method for studying transient effects on the risk of acute events. American Journal of Epidemiology, 133(2), 144–153.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	Thomas, D. C. (1977). Addendum to: Methods of cohort analysis: Appraisal by application to asbestos mining. Journal of the Royal Statistical Society, Series A, 140(4), 469–491.
別名	case-crossover study, CCO design, self-matched case study, within-person crossover case study	longitudinal study, follow-up study, panel study, incidence study	NCC study, nested CC design, case-control within cohort, density sampling case-control
関連	3	6	6
概要	The case-crossover design is an observational epidemiological method that estimates whether a transient exposure triggers an acute event by comparing each case's exposure during a brief hazard window immediately before the event to their own exposure during earlier control periods. Because each person serves as their own control, all stable personal characteristics are automatically adjusted for, making the design especially powerful for studying intermittent exposures and sudden-onset outcomes such as myocardial infarction, stroke, or injury.	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.	A nested case-control study is an efficient observational design embedded within a defined cohort. For each participant who develops the outcome of interest (a case), a small number of matched controls are sampled from those still at risk at the same point in time. This density-sampling strategy yields odds ratios that approximate incidence-rate ratios from the full cohort at a fraction of the data-collection cost — making it the preferred alternative when measuring exposures for all cohort members would be prohibitively expensive or technically demanding.