방법 비교

	실용적 증례 시리즈	후향적 증례 시리즈
분야	역학	역학
계열	Process / pipeline	Process / pipeline
기원 연도	Pragmatic framing formalized 1967; case series practice predates 20th century	Long-standing practice; codified in EBM frameworks during 1990s–2000s
창시자	Pragmatic framework: Schwartz & Lellouch (1967); case series design: longstanding clinical tradition	Clinical medicine tradition (no single originator); formalized in evidence-based medicine literature
유형	Observational descriptive study	Observational descriptive study design
원전	Schwartz, D., & Lellouch, J. (1967). Explanatory and pragmatic attitudes in therapeutical trials. Journal of Chronic Diseases, 20(8), 637–648.	Kooistra, B., Dijkman, B., Einhorn, T. A., & Bhandari, M. (2009). How to design a good case series. Journal of Bone and Joint Surgery, 91(Suppl 3), 21–26.
별칭	real-world case series, pragmatic observational case series, practice-based case series	retrospective case series, chart review case series, historical case series, medical records case series
관련	5	4
요약	A pragmatic case series is an observational study that documents consecutive or purposively selected patients receiving a clinical intervention or presenting with a condition under routine, real-world practice conditions — without randomization, a control group, or the highly controlled eligibility criteria characteristic of explanatory trials. It is used to describe treatment patterns, outcomes, and adverse events as they occur in everyday clinical settings.	A retrospective case series is an observational study that systematically describes the clinical features, treatments, and outcomes of a defined group of patients by examining pre-existing medical records or administrative data. It looks backward in time — data have already been recorded before the study begins. With no control group, no randomization, and no prospective follow-up, it sits near the base of the evidence hierarchy but remains one of the most practical and frequently published study designs in clinical medicine.