A study comparing trial registry entries of randomized controlled trials with publications of their results in a high impact factor journal: The Journal of the American Medical Association

Purpose: The International Committee of Medical Journal Editors mandates trial registration as a precondition for publication. Growing evidence indicates that information in registry may not correlate with eventual publication. The present study was carried out with the objective of comparing content of Randomized Controlled Trials (RCTs) published in one year in the Journal of the American Medical Association (JAMA), with the information contained in trial registries. Methods: All RCTs published in JAMA in 2013 were included. 11 data set items were matched for content between registry entry and published RCT: Title, Primary and Secondary Objectives, Study type, Inclusion and Exclusion Criteria, Treatment Age Group, Follow up, Sample Size, Primary and Secondary Outcomes. A fully correct match was scored 2, partially correct 1 and incorrect 0. Thus, maximum possible score for each paper was number of items multiplied by 2, i.e., 22. Results: The median [range] total score achieved by RCTs was 15. No RCT achieved a perfect score of 22. The largest proportion of RCTs reported secondary objectives, study type, treatment age group, follow up, sample size and primary outcomes fully correctly. However, only 13.5 %, 12 % and 13.5 % of RCTs were a perfect match with registry entries in terms of title, primary objective and secondary outcomes respectively. Almost three quarters did not match perfectly in selection criteria. Conclusion: There exist discrepancies between trial registration and published paper even in a high impact factor journal. Both authors and editors should adhere to CONSORT guidelines to ensure transparency of published research.