Discrepancy review: a feasibility study of a novel peer review intervention to reduce undisclosed discrepancies between registrations and publications

Undisclosed discrepancies often exist between study registrations and their associated publications. Discrepancies can increase risk of bias, and when undisclosed, they disguise this increased risk of bias from readers. To remedy this issue, we developed an intervention called discrepancy review. We provided journals with peer reviewers specifically assigned to check for undisclosed discrepancies between registrations and manuscripts submitted to journals. We performed discrepancy review on 18 manuscripts submitted to Nicotine and Tobacco Research and three manuscripts submitted to the European Journal of Personality. We iteratively refined the discrepancy review process based on feedback from discrepancy reviewers, editors and authors. Authors addressed the majority of discrepancy reviewer comments, and there was no opposition to running a trial from authors, editors or discrepancy reviewers. Outcome measures for a trial of discrepancy review could include the presence of primary or secondary outcome discrepancies, whether publications that are not the primary report from a clinical trial registration are clearly described as such, whether registrations are permanent, and an overarching subjective assessment of the impact of discrepancies in published articles. We found that discrepancy review could feasibly be introduced as a regular practice at some journals interested in this process. A full trial of discrepancy review would be needed to evaluate its impact on reducing undisclosed discrepancies.