Linganisha mbinu

	Utafiti wa Kesi-udhibiti	Utafiti wa Cohort
Nyanja	Epidemiolojia	Epidemiolojia
Familia	Process / pipeline	Process / pipeline
Mwaka wa asili	1950s (formal methodology); precursors in the 1920s	Mid-20th century (formal epidemiological design codified ~1950s)
Mwanzilishi	Janet Lane-Claypon (early precursors, 1926); formalized by Brian MacMahon and Jerome Cornfield in the 1950s–1960s	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
Aina	Observational analytic study design	Observational longitudinal study design
Chanzo asilia	Schlesselman, J.J. (1982). Case-Control Studies: Design, Conduct, Analysis. Oxford University Press. ISBN: 978-0195027860	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
Majina mbadala	case-referent study, case-control design, retrospective case-control, case-control analysis	longitudinal study, follow-up study, panel study, incidence study
Zinazohusiana	6	6
Muhtasari	A case-control study is a retrospective observational design in which individuals who have developed a disease or outcome of interest (cases) are compared with individuals who have not (controls) to determine whether prior exposure to a putative risk factor differs between the two groups. The primary measure of association is the odds ratio, which approximates the relative risk when the outcome is rare. Case-control studies are especially efficient for investigating rare diseases and generating etiological hypotheses.	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.