手法を比較

	ランダム化比較試験 (RCT)	フェーズII臨床試験 ― 初期有効性と用量評価
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1948 (first rigorously conducted RCT — MRC streptomycin trial)	1960s–1970s (formalised in US federal drug regulation)
提唱者	Austin Bradford Hill; MRC Streptomycin Trial team	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)
種類	Interventional experimental study	Interventional clinical study design
原典	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	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2015). Fundamentals of Clinical Trials (5th ed.). Springer. ISBN: 978-3319185392
別名	RCT, randomized controlled trial, randomised controlled trial, clinical randomized trial	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial
関連	6	6
概要	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.	A Phase II clinical trial is the second stage in the drug or intervention development pipeline, conducted after Phase I safety testing. Its primary goal is to assess whether the intervention shows preliminary efficacy signals in a relevant patient population at the dose established in Phase I, while continuing to characterise the safety and tolerability profile. Phase II trials are generally smaller than Phase III confirmatory trials and serve as critical go/no-go decision points before large-scale investment.