手法を比較

	前向き症例集積研究	コホート研究
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	Late 19th century onward; formalized in modern clinical epidemiology by the 1970s–1980s	Mid-20th century (formal epidemiological design codified ~1950s)
提唱者	Evolved from clinical case reporting traditions in 19th–20th century medicine	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
種類	Observational study design	Observational longitudinal study design
原典	Meinert, C. L. (1996). Clinical Trials: Design, Conduct, and Analysis. Oxford University Press. ISBN: 978-0195035681	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
別名	prospective case series study, forward-looking case series, prospective uncontrolled study, prospective observational case series	longitudinal study, follow-up study, panel study, incidence study
関連	5	6
概要	A prospective case series is an observational study design in which a group of patients with a particular condition, exposure, or intervention is identified in advance and followed forward in time according to a pre-specified protocol. Data on outcomes, adverse events, and clinical course are collected as they occur, yielding higher data quality and temporal clarity than retrospective designs. No control group is included, so causal inference is limited, but the design is valuable for characterizing natural disease history, early safety signals, and feasibility of new interventions.	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.