เปรียบเทียบวิธี

	การศึกษาทางคลินิกระยะที่ IV แบบหลายศูนย์	การศึกษาเฟส 4
สาขาวิชา	ระบาดวิทยา	ระบาดวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1980s–1990s (formalized with post-marketing requirements in modern drug regulation)	Formalised 1970s–1990s (ICH E3 guideline 1994)
ผู้ริเริ่ม	Regulatory agencies and pharmaceutical industry (ICH E2E, FDA, EMA post-marketing frameworks)	Regulatory agencies and pharmaceutical industry (ICH, FDA, EMA frameworks)
ประเภท	Observational or interventional post-marketing study	Post-marketing observational or interventional study
แหล่งต้นตำรับ	Strom, B. L., & Kimmel, S. E. (Eds.). (2005). Textbook of Pharmacoepidemiology. John Wiley & Sons. ISBN: 978-0470029619	International Conference on Harmonisation (ICH). (1994). ICH Harmonised Tripartite Guideline: Structure and Content of Clinical Study Reports E3. ICH Secretariat.
ชื่อเรียกอื่น	multicenter post-marketing study, multicenter pharmacovigilance study, multi-site phase IV study, post-authorization safety study	post-marketing surveillance study, post-approval study, Phase 4 study, PMS study
ที่เกี่ยวข้อง	6	5
สรุป	A multicenter Phase IV study is a post-marketing surveillance investigation conducted simultaneously at two or more clinical or research sites after a drug, device, or intervention has received regulatory approval. By pooling real-world data from diverse patient populations and geographic regions, it detects rare adverse events, evaluates long-term effectiveness, characterizes safety in subgroups, and fulfills regulatory post-authorization commitments that single-site studies cannot achieve.	A Phase IV study is a post-marketing surveillance study conducted after a drug, device, or intervention has received regulatory approval. Its primary purpose is to monitor long-term safety, detect rare adverse events, assess effectiveness in routine clinical practice, and explore new indications or populations not adequately represented in earlier trials. Phase IV evidence accumulates continuously throughout a product's commercial life.