So sánh phương pháp

	Nghiên cứu chuỗi ca bệnh hồi cứu	Nghiên cứu đoàn hệ hồi cứu
Lĩnh vực	Dịch tễ học	Dịch tễ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Long-standing practice; codified in EBM frameworks during 1990s–2000s	Mid-20th century (widely formalized 1950s–1970s)
Người khởi xướng	Clinical medicine tradition (no single originator); formalized in evidence-based medicine literature	Systematic use attributed to early 20th-century occupational epidemiology; formalized in modern epidemiological theory by Brian MacMahon and others
Loại	Observational descriptive study design	Observational analytic study
Công trình gốc	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.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
Tên gọi khác	retrospective case series, chart review case series, historical case series, medical records case series	historical cohort study, non-concurrent cohort study, retrospective follow-up study, historical prospective study
Liên quan	4	6
Tóm tắt	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.	A retrospective cohort study assembles a group of individuals who share a common starting point and reconstructs their exposure history and subsequent outcomes entirely from pre-existing records. Because the data have already been collected before the study begins, the design is far faster and cheaper than a prospective cohort; however, the researcher must work with whatever information was recorded at the time rather than collecting purpose-built measurements.