Vertaile menetelmiä

	Tapaustutkimus	Kohorttitutkimus
Tieteenala	Epidemiologia	Epidemiologia
Menetelmäperhe	Process / pipeline	Process / pipeline
Syntyvuosi	Longstanding; systematized in 20th century clinical research	Mid-20th century (formal epidemiological design codified ~1950s)
Kehittäjä	Historical clinical practice; formalized in modern evidence-based medicine literature	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
Tyyppi	Observational descriptive study	Observational longitudinal study design
Alkuperäislähde	Case series. Wikipedia.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
Rinnakkaisnimet	case series report, clinical case series, consecutive case series, patient series	longitudinal study, follow-up study, panel study, incidence study
Liittyvät	5	6
Tiivistelmä	A case series is a descriptive observational study that documents the characteristics, clinical course, and outcomes of a group of patients who share a common condition, exposure, or intervention. Unlike case reports, which focus on a single patient, a case series aggregates data across multiple patients (typically three or more) to identify patterns, generate hypotheses, and characterize rare or novel conditions — without a concurrent control group.	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.