Background: The purpose of the present study was to systematically evaluate the completeness of trial registration and the extent of outcome-reporting bias in modern randomized controlled trials (RCTs) relating to the treatment of distal radial fracture.
Methods: With use of 4 databases (PubMed, Cochrane CENTRAL, Embase, and PEDro), this systematic review identified all RCTs of distal radial fracture treatment published from January 1, 2010, to December 31, 2015. We independently determined the registration status of these trials in a public trial registry and compared the characteristics of registered and non-registered trials. We assessed the quality and consistency of primary outcome measure (POM) reporting between the registration data and the final published studies.
Results: Ninety studies met the inclusion criteria. Of those, only 28 (31%) were registered, and only 3 (3%) were "appropriately registered" (i.e., prospectively registered and identifying and fully describing the POM). Registered trials had larger sample sizes and were more likely to be multicenter, to report funding sources, and to be published in higher-impact-factor journals. Sixteen (18%) of the 90 registered RCTs named a POM in the registry; 7 (44%) of those 16 registered RCTs stated a different POM, an additional POM, or no POM at all in the final publication than was stated in the registry data. Additionally, 13 (81%) of those 16 registered RCTs had discrepancies in the time point reported for the POM.
Conclusions: In an attempt to address publication and outcome-reporting bias, prospective trial registration in a public registry has been deemed a condition for publication by the International Committee of Medical Journal Editors (ICMJE) since 2005. This study shows poor registration rates as well as inconsistencies in the reporting of POMs of recent trials relating to the treatment of distal radial fracture, one of the most common and most investigated injuries in orthopaedic practice.
Clinical relevance: The problems of registration and outcome-reporting bias in RCTs are important to highlight and address, and to find a solution will require the cooperation of researchers, reviewers, and journal editors. Increasing the transparency and consistency of reporting will help to increase the quality of research, which can impact patient care through evidence-based guidelines.