Publication Rates and Patterns of Registered Glaucoma Trials.

Purpose: To examine the publication rates and patterns of registered glaucoma trials.

Design: Cross-sectional analysis.

Participants: All registered glaucoma trials from ClinicalTrials.gov.

Methods: The National Institutes of Health ClinicalTrials.gov was queried in August 2024 for all registered glaucoma trials. Study characteristics and time from study start date to primary completion date were extracted, and verification of publication in peer-reviewed journals was confirmed using PubMed.gov, ClinicalTrials.gov, and Google Scholar.

Main Outcome Measures: Publication status and characteristics associated with publication.

Results: A total of 969 trials were identified, of which 510 (53%) were published, 222 (23%) were published within the mandated reporting period of 12 to 24 months by the Food and Drug Administration (FDA), and 312 (32%) had results available on ClinicalTrials.gov. Of the evaluated trials, 575 (59%) were nonsurgical (did not focus on surgical procedures), 748 were interventional (77%), 518 were international (54%), and 512 were industry sponsored (53%). The average time from study start date to primary completion date was 24 months, with a delay of primary completion date to publication date of another 34 months. In the overall cohort, non-US-based compared with US-based studies and nonindustry compared with industry sponsorships were more likely to be published (P < 0.05 for both). Industry-sponsored trials were more likely to be interventional (investigator assigned participants to an intervention or no intervention) than observational (participants may receive interventions as part of a study group but not specifically assigned by investigators) (88% vs. 65%, P < 0.01), to be medical rather than surgical (71% vs. 46%, P < 0.01), to be based in the United States (58% vs. 34%, P < 0.01), to have results available on ClinicalTrials.gov (45% vs. 18%, P < 0.01), and to be completed sooner (22 vs. 32 months, P < 0.01). For both industry- and nonindustry-sponsored trials, interventional trials were more likely to be published compared with observational trials (P = 0.04, P = 0.02, respectively).

Conclusions: Only about half of all registered glaucoma trials from ClinicalTrials.gov were published, with less than 25% complying with the mandated FDA report period of 1 to 2 years and overall, a significant delay of nearly 3 years from study primary completion date to publication date. This suggests potential bias in information dissemination of glaucoma trials.

Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references.