Introduction: Non-publication of trial findings results in research waste and compromises medical evidence and the safety of interventions in child health. The objectives of this study were to replicate, compare and contrast findings of a previous study (Klassen et al., 2002) to determine the impact of ethical and editorial mandates to register and publish findings. Methods: Abstracts accepted to the Pediatric Academic Societies meetings (2008-2011) were screened in duplicate to identify Phase-III RCTs enrolling pediatric populations. Subsequent publication was ascertained through a search of electronic databases. Study internal validity was measured using Cochrane Risk of Bias and Jadad Scale, and key variables (e.g., 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, log-rank tests, rank correlation and Egger regression were used to assess predictors of publication, time to publication and publication bias, respectively. Results: Compared to our previous study, fewer studies remained unpublished (27.9% vs 40.9%, p=.007).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no differences in quality measures/risk of bias or in preference for positive results (p=0.36) between published and unpublished studies. Mean time to publication was 26.5 months and published manuscripts appeared most frequently in Pediatrics, the Journal of Pediatrics, and Pediatric Emergency Care. The funnel plot (p=0.04) suggests a reduced but ongoing existence of publication bias among published studies. Overall, we observed a reduction in publication bias and in preference for positive findings, and an increase in study size and publication rates over time. Conclusion: Despite heightened safeguards and editorial policy changes in recent decades, publication bias remains commonplace and presents a threat to assessing the efficacy and effectiveness of interventions in child health. Our results suggest a promising trend towards a reduction in publication bias over time and positive impacts of trial registration. Further efforts are needed to ensure the entirety of evidence can be accessed when assessing treatment effectiveness.
