เปรียบเทียบวิธี

	รายงานผู้ป่วยย้อนหลัง	Case Series
สาขาวิชา	ระบาดวิทยา	ระบาดวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	19th century (formalized ~2013 with CARE guidelines)	Longstanding; systematized in 20th century clinical research
ผู้ริเริ่ม	Case reporting tradition in medicine (formalized by CARE guidelines, Riley et al., 2013)	Historical clinical practice; formalized in modern evidence-based medicine literature
ประเภท	Observational descriptive study	Observational descriptive study
แหล่งต้นตำรับ	Gagnier, J. J., Kienle, G., Altman, D. G., Moher, D., Sox, H., & Riley, D. (2013). The CARE guidelines: consensus-based clinical case reporting guideline development. Journal of Medical Case Reports, 7(1), 223.	Case series. Wikipedia.
ชื่อเรียกอื่น	retrospective case study, post-hoc case report, retrospective clinical case, case report	case series report, clinical case series, consecutive case series, patient series
ที่เกี่ยวข้อง	4	5
สรุป	A retrospective case report is a detailed, structured narrative of a single patient's clinical presentation, diagnosis, management, and outcome, assembled from existing medical records after the clinical events have occurred. It is the most granular and accessible observational design in clinical medicine, serving primarily to document rare presentations, unexpected outcomes, novel treatments, or unusual drug reactions that would not otherwise enter the published literature.	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.