Abstract
Randomized controlled trials (RCTs) are considered the first level of evidence to assess the efficacy of novel interventions/therapies. Proper design and implementation of an RCT can result in convincing causal inferences. RCTs often represent the gold standard for clinical trials when appropriately designed, conducted and reported. However, there are limitations in implementation of RCTs, including sufficiency of randomized allocation (especial for allocation concealment), implementing standard intervention, maintaining follow-up and statement of conflicting interests. Therefore, the basic principles of RCTs are outlined here so that pediatric investigators can further understand what is the best evidence based on RCTs. More importantly, the quality of pediatric RCTs may be improved by following challenges in pediatric clinical trials outlined here.