手法を比較

	第IV相試験	ランダム化比較試験 (RCT)
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	Formalised 1970s–1990s (ICH E3 guideline 1994)	1948 (first rigorously conducted RCT — MRC streptomycin trial)
提唱者	Regulatory agencies and pharmaceutical industry (ICH, FDA, EMA frameworks)	Austin Bradford Hill; MRC Streptomycin Trial team
種類	Post-marketing observational or interventional study	Interventional experimental study
原典	International Conference on Harmonisation (ICH). (1994). ICH Harmonised Tripartite Guideline: Structure and Content of Clinical Study Reports E3. ICH Secretariat.	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
別名	post-marketing surveillance study, post-approval study, Phase 4 study, PMS study	RCT, randomized controlled trial, randomised controlled trial, clinical randomized trial
関連	5	6
概要	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.	A randomized clinical trial (RCT) is an experimental study design in which participants are randomly assigned to an intervention group or a control group, then followed prospectively to compare outcomes. Random allocation is the defining feature: it distributes known and unknown confounders across groups by chance, making the RCT the strongest individual study design for establishing causal efficacy of a treatment or intervention under controlled conditions.