قارن الطرق

	التجربة العشوائية العنقودية	تصميم التجربة التكيفي
المجال	البحوث السريرية	البحوث السريرية
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1999-2000	1990s-2000s
صاحب الطريقة	Campbell, Grimshaw, Elbourne et al.	Stephen Pocock, Christopher Jennison, and statistical methodologists; FDA formalized guidance 2019
النوع	Research Design	Research Design
المصدر التأسيسي	Campbell, M. K., Grimshaw, J. M., & Elbourne, D. R. (2000). Intracluster correlation coefficients in cluster randomized trials: empirical insights into how should they be reported. BMC Medical Research Methodology, 4, 30.	Pocock, S. J. (2005). Current issues in the design and interpretation of clinical trials. BMJ, 330(7500), 1118–1121.
الأسماء البديلة	CRT, cluster RCT, cluster trial, group randomization	adaptive trial, adaptive design, response-adaptive randomization, RAR
ذات صلة	3	1
الملخص	A cluster randomized trial (CRT) randomizes intact groups—schools, clinics, villages, or hospital wards—rather than individuals. Developed by Campbell, Grimshaw, and colleagues in the late 1990s to address real-world settings where intervention delivery or contamination occurs at the group level, CRTs are now standard for evaluating population-level, community-based, and policy interventions.	An adaptive trial design allows pre-specified modifications to the trial based on interim data—such as sample size re-estimation, stopping for futility or efficacy, dropping ineffective arms, or shifting randomization ratios toward better-performing treatments. Developed systematically in the 1990s–2000s by statisticians like Pocock and Jennison, and formalized by the FDA in 2019, adaptive designs accelerate drug development, reduce exposure to ineffective treatments, and improve efficiency without inflating false-positive rates when properly executed.