Randomized controlled trials in pediatric patients had higher completion rates than adult trials: a cross-sectional study Edouard Dufetelle a,b , Geert W. ‘t Jong c , Florentia Kaguelidou a,b,d, * a Department of Pediatric Pharmacology and Pharmacogenetics, APHP, Robert Debre Hospital, Paris, France b Center of Clinical Investigations, INSERM CIC1426, Paris, France c Children’s Hospital Research Institute (CHRIM), University of Manitoba, Winnipeg, Manitoba, Canada d Universite Paris 7-Diderot, Sorbonne Paris Cite EA08, Paris, France Accepted 20 April 2018; Published online 26 April 2018 Abstract 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 ac- cording 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: 1.02e1.30; odds ratio: 1.15, 95% CI: 1.04e1.27, 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. Ó 2018 Elsevier Inc. All rights reserved. Keywords: Randomized controlled trials; Completion rates; Premature discontinuation; Pediatric research 1. Introduction Reducing waste has been identified as an important chal- lenge in clinical research [1,2]. Specifically, premature discontinuation of randomized controlled trials (RCTs) concerns almost 25% of planned RCTs and raises both re- sources wasting and ethical concerns. It also contributes to creating a body of medical literature that potentially misguides clinical practice as more than half of discontin- ued trials remain unpublished and valuable, mostly nega- tive information is lost [3,4]. Reasons for premature RCT discontinuation have been studied in various medical fields in adults and overall, fail- ure to achieve planned sample size and issues in trial design account for most cases of trial discontinuation [5e10]. In pediatrics, completion of RCTs is perceived to be more challenging than in adults. This is mainly related to the low prevalence of pediatric diseases and therefore, the scar- city of potential participants and the need for multicenter studies but also the ethical considerations pertaining to vulnerable populations [11e14]. Indeed, obtaining both parents’ written informed consent while respecting the child’s autonomy and the requisite implication of parents in research may eventually prevent or at least delay chil- dren’s participation. Moreover, methodological challenges regarding the choice of trial design and that of comparators Funding: This study was not supported by any external funds or grants. Conflict of Interest: The authors have no conflicts of interest to disclose. * Corresponding author. Department of Pediatric Pharmacology and Pharmacogenetics, Clinical Investigations Center, Universite Paris Diderot, Sorbonne Paris Cite, Inserm CIC1426 H^opital Robert Debre 48 boulevard Serurier, Paris 75019, France. Tel.: þ33 1 4003 4142; fax: þ33 1 4003 2424. E-mail address: florentia.kaguelidou@aphp.fr (F. Kaguelidou). https://doi.org/10.1016/j.jclinepi.2018.04.018 0895-4356/Ó 2018 Elsevier Inc. All rights reserved. Journal of Clinical Epidemiology 100 (2018) 53e60