So sánh phương pháp

	Chuỗi ca bệnh	Nghiên cứu thuần tập
Lĩnh vực	Dịch tễ học	Dịch tễ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Longstanding; systematized in 20th century clinical research	Mid-20th century (formal epidemiological design codified ~1950s)
Người khởi xướng	Historical clinical practice; formalized in modern evidence-based medicine literature	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)
Loại	Observational descriptive study	Observational longitudinal study design
Công trình gốc	Case series. Wikipedia.	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641
Tên gọi khác	case series report, clinical case series, consecutive case series, patient series	longitudinal study, follow-up study, panel study, incidence study
Liên quan	5	6
Tóm tắt	A case series is a descriptive observational study that documents the characteristics, clinical course, and outcomes of a group of patients who share a common condition, exposure, or intervention. Unlike case reports, which focus on a single patient, a case series aggregates data across multiple patients (typically three or more) to identify patterns, generate hypotheses, and characterize rare or novel conditions — without a concurrent control group.	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.