Publication and non-publication of clinical trials in PTSD: an overview

BACKGROUND: Although a large number of clinical trials on interventions demonstrating efficacy (or lack thereof) are conducted annually, much of this evidence is not accessible to scientists and clinicians. OBJECTIVES: We aimed to determine the publication rate of posttraumatic stress disorder (PTSD) trials that have been registered in clinical trial registries, and the factors associated with publication. METHODS: Trials, completed on January 15, 2015, were identified via the US National Institutes of Health clinical trials registry, the European Union Clinical Trials Register and the WHO International Clinical Trials Registry Platform. A systematic search for publications (published by the end of March 2018) related to each of the registered trials were then performed. RESULTS: Four hundred and thirty-eight of 1982 potentially eligible trials were included. Only 34% of interventional trials were registered prior to initiation, 9% were registered within 2 months of starting and 20% after trial completion. Of the 438 included trials, 72% had generated peer-reviewed publications, while an additional 7% had disseminated results in some other form (such as on the trial database), 26 months after trial completion. Randomisation of a trial was the only factor individually associated with publication, in logistic regression analysis (p < 0.001). Intervention type, university as sponsor and study registration prior to completion were factors that influenced the time to publication, using Cox regression (p < 0.001). CONCLUSIONS: This study underscores the importance of timely and accurate publication and dissemination of trial results, in order to avoid the potential waste of resources and to ensure research integrity and patient safety. We suggest that authors and journal editors adhere to conditions set out by the International Committee of Medical Journal Editors and that more diligent data sharing is encouraged through prospective trial registration and trial reporting websites.