Transparency of outcome reporting and trial registration of randomized controlled trials in top psychosomatic and behavioral health journals: A 5-year follow-up

Abstract

Objective: The extent that randomized controlled trials (RCTs) accurately reflect intervention effectiveness depends on the completeness and accuracy of published results. A previous study found that only 40% of 63 RCTs published in top behavioral health journals in 2008-2009 clearly declared primary and secondary outcomes and only 21% were registered. The objective of this study was to conduct a five-year follow-up to assess outcome reporting clarity, proportion of registered trials, and adequacy of outcome registration in RCTs in top behavioral health journals.

Method: Eligible studies were RCTs published in Annals of Behavioral Medicine, Health Psychology, Journal of Psychosomatic Research, and Psychosomatic Medicine from January 2013 to October 2014.

Results: Of 76 RCT publications reviewed, only 25 (32.9%) adequately declared primary or secondary outcomes, whereas 51 (67.1%) had multiple primary outcomes or did not define outcomes. Of the 76 trials, 40 (52.6%) had been registered. Only 3 studies registered a single primary outcome and time point of assessment prior to enrolling patients, and registered and published outcomes were discrepant in 1 of the 3 studies. No studies were adequately registered as per Standard Protocol Items: Recommendation for Interventional Trials guidelines. Compared to 5 years prior, the proportion of published trials with adequate outcome declaration decreased from 39.7% to 32.9% (p=0.514). The proportion of registered trials increased from 20.6% to 52.6% (p<0.001).

Conclusion: The quality of published outcome declarations and trial registrations remains largely inadequate. Greater attention to trial registration and outcome definition in published reports is needed.

Keywords: Behavioral medicine; Bias; Randomized controlled trials; Selective outcome reporting; Trial registration.