手法を比較

	前向き症例対照研究	ケースクロスオーバーデザイン
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1970s–1990s (formalized alongside nested case-control methods)	1991
提唱者	Evolved from classical retrospective case-control methodology; prospective embedding attributed to modern epidemiological practice (Rothman, Greenland, and others, late 20th century)	Malcolm Maclure
種類	Observational analytic study design	Observational epidemiological study design
原典	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	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.
別名	prospective case-control design, ambidirectional case-control, bidirectional case-control, nested case-control (prospective variant)	case-crossover study, CCO design, self-matched case study, within-person crossover case study
関連	6	3
概要	A prospective case-control study embeds the case-control logic within a defined cohort followed forward in time. Cases are identified as they occur, rather than looked up in records after the fact, and controls are sampled from the same prospectively monitored base population. This forward-looking approach allows collection of exposure data before outcome ascertainment, reducing recall bias — the principal weakness of the classic retrospective case-control design — while retaining the efficiency gains of sampling controls rather than enrolling a full cohort.	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.