Two prognostic indicators of the publication rate of clinical studies were available during ethical review

Objective: To identify prognostic indicators of the publication rate of clinical studies, available to research ethics committees (RECs) during review.

Study design and setting: Retrospective survival study of a random sample of 100 studies, approved by a Dutch academic REC, with follow-up information by questionnaire and bibliographic searches. Multivariate Cox regression analysis of the association between publication rate and seven factors available during review: six study characteristics and the number of letters sent by the committee during review representing the length of the review process.

Results: Two factors were associated with publication rate: studies with possible therapeutic benefit to participants were less likely to be published than nontherapeutic studies (adjusted hazard ratio [AHR]: 0.16; 95% confidence interval [CI]: 0.03-0.54); with every letter sent, publication was less likely (AHR: 0.46 per letter; 95% CI: 0.17-0.98). Possibly, studies with more-than-minimal burdens to participants were more likely to be published than studies with minimal burdens (AHR: 3.90, 95% CI: 1.03-16.64).

Conclusion: We identified two prognostic indicators of publication rate. After suitable replication, RECs might explore using prognostic indicators, such as these, to target study protocols at high risk for nonpublication. Discussing the risk of nonpublication with investigators could help prevent nonpublication.