Publication rates of registered clinical trials in macular degeneration.

Purpose: The purpose of this study was to evaluate the rate of publication of registered clinical trials concerning age-related macular degeneration (AMD).

Methods: The National Institutes of Health's ClinicalTrials.gov registry was searched to identify all trials concerning AMD. Trials that were actively recruiting, not interventional, terminated, or did not actually concern AMD were excluded. Only trials completed 2 or more years before this analysis was started were included, to allow for adequate time to pass before publication was expected to occur. PubMed.gov was then searched to evaluate the publication status of each study.

Results: Three hundred and eight-six studies were initially identified, and 64 (16.5%) were included in the final evaluation. Three hundred and twenty-one studies were not included for the following reasons: 171 did not involve AMD or were not interventional; 141 were not completed by January 1, 2007; and 9 trials were terminated. Of the 64 trials included, 35 (54%) were published. Early phase trials were published at a lower rate (41.6% [15/36]) than late-phase trials (71.4% [20/28]). This difference was statistically significant (P = 0.02). The sponsor type, date of study initiation, and location did not influence the publication rate.

Conclusion: Using broad study parameters, 54% of registered interventional clinical trials in AMD have been reported in the peer-reviewed literature.