Objective: Conduct of clinical trials is perceived to be more challenging in children than in adults. This study aimed to evaluate the impact of the age of participants on completion rates of randomized controlled trials (RCTs).
Study design and setting: A cross-sectional study on RCTs registered in the ClinicalTrials.gov database. All RCTs registered up to December 31, 2016, were extracted and were classified according to their recruitment status: active, completed, or discontinued and according to the age of participants: children (<17 years), adults (≥18 years), and mixed-age population. A logistic regression model was applied to assess the impact of participant's age category on trial completion while controlling for other relevant trial features.
Results: A total of 65,095 registered RCTs were identified. Among pediatric trials, 49.9% were completed and 8.5% were discontinued. Among adult and mixed age RCTs, respectively, 49.7% and 47.9% were completed whereas, 10.2% and 9.4% were discontinued. Overall, pediatric and mixed age RCTs were more likely to be registered as completed than adult RCTs (odds ratio: 1.16, 95% CI: 1.02-1.30; odds ratio: 1.15, 95% CI: 1.04-1.27, respectively). Also, funding source, type of intervention under evaluation, primary trial purpose, use of a blinding procedure, use of a placebo, and participants' assignment model were identified as independent predictors of RCT completion.
Conclusion: Contrary to current perceptions and despite several specific challenges, recruitment of children and adolescents is not a limiting factor to completing a RCT. Other study features such as funding source, impact completeness and should be carefully considered before initiating research.
Keywords: Completion rates; Pediatric research; Premature discontinuation; Randomized controlled trials.
Copyright © 2018 Elsevier Inc. All rights reserved.