Reporting bias in breast reconstruction clinical trials: Which and when clinical trials get published

Reporting bias refers to the phenomenon in which the reporting of research findings is influenced by the nature of the results. Without the totality of evidence, clinical practice may be misguided. The objective of this work was to examine the extent of reporting bias in clinical trials of breast reconstruction surgery.

We searched and extracted data from all completed breast reconstruction clinical trials published in ClinicalTrials.gov from database inception to August 2020. Investigators sought to identify published full manuscripts of the registered trials. The primary outcome was classified as positive or nonpositive and trials were classified as industry or nonindustry funded. Time to publication in a peer-reviewed journal was computed and compared using time-to-event analysis. Trial characteristics associated with publication were evaluated using logistic regression.

A total of 156 clinical trials were identified, of which, 53 trials were published. The median time to publication was 22 months (IQR, 13-35 months). Industry-funded studies were associated with a longer time to publication (HR = 2.4, p = 0.023) and publication in lower-impact journals (OR = 3.7, p = 0.048). Randomized clinical trials were associated with faster times to publication than nonrandomized studies (aHR = 3.2, p = 0.030). Statistical significance and the effect size were not associated with time to publication.

We found no evidence that industry-funded trials were more likely to report a positive primary outcome. However, industry-funded trials were associated with a longer time to publication and publication in lower-impact journals.