השוואת שיטות

	מחקר עוקבה רב-מרכזי	ניסוי קליני רב-מרכזי אקראי
תחום	אפידמיולוגיה	אפידמיולוגיה
משפחה	Process / pipeline	Process / pipeline
שנת המקור	Mid-to-late 20th century (widespread adoption 1970s–1990s)	1970s–1980s (widespread adoption for large-scale efficacy trials)
הוגה השיטה	Developed incrementally through large collaborative epidemiological projects (e.g., Framingham Heart Study consortium expansions, 1948 onward; EPIC study, 1992)	Evolved from single-center RCT methodology; consolidated through landmark trials such as the MRC streptomycin trial (1948) and large cardiovascular mega-trials of the 1970s–1980s
סוג	Observational longitudinal study	Interventional experimental design
מקור מכונן	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	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
כינויים	multisite cohort study, multi-centre cohort, collaborative cohort study, pooled cohort study	multi-site RCT, multicenter RCT, multinational randomized trial, multicenter controlled trial
קשורות	6	6
תקציר	A multicenter cohort study follows defined groups of participants at two or more geographically or institutionally distinct sites over time to estimate incidence, identify risk factors, and quantify associations between exposures and outcomes. By pooling data from multiple centers, it achieves statistical power and population diversity that single-site designs cannot match, making it the workhorse of large-scale epidemiological and clinical research.	A multicenter randomized clinical trial (RCT) is an experimental study in which eligible participants are randomly assigned to intervention or control arms simultaneously across two or more clinical sites. By combining the rigor of randomization with enrollment from geographically or institutionally diverse centers, this design produces large samples and externally valid effect estimates that single-center trials rarely achieve. It is the regulatory gold standard for confirmatory efficacy and safety evaluation of new treatments.