เปรียบเทียบวิธี

	การทดลองทางคลินิกระยะที่ 3	การศึกษาเฟส 4
สาขาวิชา	ระบาดวิทยา	ระบาดวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1962 (Kefauver-Harris Amendment formalised phased drug development)	Formalised 1970s–1990s (ICH E3 guideline 1994)
ผู้ริเริ่ม	FDA regulatory framework / ICH guidelines	Regulatory agencies and pharmaceutical industry (ICH, FDA, EMA frameworks)
ประเภท	Confirmatory randomised controlled trial	Post-marketing observational or interventional study
แหล่งต้นตำรับ	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2015). Fundamentals of Clinical Trials (5th ed.). Springer. ISBN: 978-3319185385	International Conference on Harmonisation (ICH). (1994). ICH Harmonised Tripartite Guideline: Structure and Content of Clinical Study Reports E3. ICH Secretariat.
ชื่อเรียกอื่น	Phase 3 trial, confirmatory trial, pivotal trial, Phase III RCT	post-marketing surveillance study, post-approval study, Phase 4 study, PMS study
ที่เกี่ยวข้อง	6	5
สรุป	A Phase III clinical trial is a large-scale, confirmatory randomised controlled trial designed to establish the efficacy and safety of an intervention in the target patient population before regulatory submission. It builds on the signal identified in Phase II, tests the intervention at its proposed dose under controlled conditions, and provides the primary evidence base for marketing authorisation or guideline adoption.	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.