#10 Publication Of Randomized Controlled Trials In Child Health Research: A Follow-Up Study
Leah Crockett, University of Manitoba; Terry Klassen, University of Manitoba
First referred to as the ‘file-drawer’ problem four decades ago, non-publication of trial findings is an ongoing issue that results in research waste and compromises medical evidence and the safety of interventions for children. The objectives of this study were to examine the impact of ethical, editorial and legislative mandates to register and publish findings by replicating the methods of our 2002 study which measured subsequent publication of randomized controlled trials (RCTs) presented at a major pediatric scientific meeting and predictors of publication.
Abstracts accepted to the PAS meetings (2008-2011) were screened in duplicate to identify phase-III RCTs enrolling pediatric populations. Subsequent publication was ascertained by searching electronic databases. Study quality was measured using Cochrane Risk of Bias, Jadad Scale and allocation concealment, and key variables (eg. trial design, study stage) were extracted. Pearson X2, t-tests and Wilcoxon rank sum tests were used to examine association between variables and publication status. Logistic regression, rank correlation and Egger regression were used to assess predictors of publication, time to publication and publication bias.
Fewer studies remained unpublished since the 2002 study (27.9% vs 40.9%, p=.007). Abstracts with higher sample sizes (p=0.01) and those registered in ClinicalTrials.gov were more likely to be published (p<.0001). There were no differences in quality measures or in preference for positive results (p=0.36) between published and unpublished studies. Mean time to publication was 26.5 months and did not differ between groups. Asymmetric distribution in the funnel plot (p=0.04) suggests a reduced but ongoing existence of publication bias.
Our results suggest a promising trend towards a reduction in publication bias over time and positive impacts of trial registry. Yet, despite heightened legislative safeguards and editorial policy changes in recent decades, publication bias remains commonplace and presents a threat to assessing the effectiveness of interventions in child health.