방법 비교

	적응형 4상 연구	코호트 연구
분야	역학	역학
계열	Process / pipeline	Process / pipeline
기원 연도	1990s–2000s (regulatory formalization of adaptive Phase IV designs)	Mid-20th century (formal epidemiological design codified ~1950s)
창시자	Adaptive design principles developed by multiple statisticians; Phase IV framework established by regulatory bodies (FDA, EMA) in the late 20th century	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
유형	Adaptive post-marketing clinical study design	Observational longitudinal study design
원전	Chow, S. C., & Chang, M. (2008). Adaptive Design Methods in Clinical Trials. Chapman and Hall/CRC. ISBN: 978-1584889625	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
별칭	adaptive post-marketing surveillance study, adaptive pharmacovigilance study, adaptive Phase IV trial, adaptive post-approval study	longitudinal study, follow-up study, panel study, incidence study
관련	6	6
요약	An Adaptive Phase IV study is a post-marketing surveillance study conducted after a drug or intervention has received regulatory approval, augmented with pre-specified adaptive design elements that allow pre-planned modifications to the study protocol in response to accumulating data. These modifications may include sample size re-estimation, endpoint adjustments, or population enrichment, all governed by statistical rules set before the study begins, preserving scientific integrity while increasing efficiency.	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.