ABSTRACT
Randomized controlled trials (RCTs) are the gold standard evaluation design for validly comparing the effects of alternative interventions for a problem. The rst randomized trial ever published tested a drug, streptomycin, against tuberculosis in hospitalized patients, but increasingly, RCTs are also being used to test many other interventions besides pharmacotherapeutics, including, in order of increasing degree of complexity-implantable devices, surgical interventions, counseling, and other psychological interventions aimed at individuals, families, or groups; knowledge translation interventions aimed at providing post-professional training to clinicians; task-shifting interventions aimed at downloading physician or high skilled professional tasks to less scarce cadres of health workers, health nancing changes; and interventions aimed at changing the nancing, or the organization of healthcare.
