مقایسهٔ روش‌ها

	کارآزمایی بالینی چندمرکزی فاز III	آزمایش بالینی فاز II
حوزه	اپیدمیولوژی	اپیدمیولوژی
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1940s–1990s (formalized through ICH harmonization ~1990s)	1960s–1970s (formalised in US federal drug regulation)
پدیدآور	Codified through ICH E9 guideline (1998) and decades of regulatory practice (FDA, EMA)	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)
نوع	Confirmatory interventional study design	Interventional clinical study design
منبع بنیادین	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
نام‌های دیگر	Phase III multicenter RCT, confirmatory multicenter trial, Phase 3 multicenter study, pivotal multicenter trial	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial
مرتبط	6	6
خلاصه	A multicenter Phase III clinical trial is the definitive confirmatory study that tests whether a new intervention produces a clinically meaningful benefit over a comparator in a large, representative patient population enrolled at two or more independent research sites. It is the primary evidence basis for regulatory approval by agencies such as the FDA and EMA, combining the statistical power of large samples with the external validity gained from geographic and demographic diversity across sites.	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.