Vertaile menetelmiä

	Prospektiivinen satunnaistettu kontrolloitu tutkimus	Kohorttitutkimus
Tieteenala	Epidemiologia	Epidemiologia
Menetelmäperhe	Process / pipeline	Process / pipeline
Syntyvuosi	1948 (landmark MRC streptomycin trial)	Mid-20th century (formal epidemiological design codified ~1950s)
Kehittäjä	Austin Bradford Hill / Medical Research Council	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
Tyyppi	Experimental / interventional study design	Observational longitudinal study design
Alkuperäislähde	Medical Research Council (1948). Streptomycin treatment of pulmonary tuberculosis: a Medical Research Council investigation. British Medical Journal, 2(4582), 769–782.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
Rinnakkaisnimet	Prospective RCT, randomized controlled trial, RCT, controlled clinical trial	longitudinal study, follow-up study, panel study, incidence study
Liittyvät	5	6
Tiivistelmä	A prospective randomized clinical trial (RCT) is an experimental study in which participants are assigned to intervention or control groups by chance before any outcomes are observed, then followed forward in time. Random allocation eliminates systematic selection bias, making this design the gold standard for establishing causal efficacy of treatments in medicine and clinical research.	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.