Positive Results Bias and Impact Factor in Retina Clinical Trials 2016-2019.

PURPOSE To assess for a positive results bias in recently published randomized controlled trials (RCTs) in the field of vitreoretinal disease.Methods: A bibliometric analysis was conducted examining RCTs published in the field of retina between January 1, 2016, and December 31, 2019. Studies were classified as positive result or negative result based on the statistical significance of their primary outcome. Publication date and sample size were documented. These variables were compared against Journal Citation Reports Impact Factor in the year of publication.Results: 288 RCTs from 64 unique journals were included and analyzed. 185 (64.2%) studies were classified as positive result, and 103 (35.8%) studies were classified as negative result. There was no association between impact factor and positive result. Studies classified as positive result had larger sample sizes, and higher sample size was associated with higher impact factor. CONCLUSION These results do not support the presence of a recent positive results bias in retina RCTs. This is reassuring, although several factors could be contributing to this finding including studies that were conducted but never submitted and selective reporting of outcomes. Thus, it will be important to remain cognizant of potential publication biases moving forward.