Establishing comparability between measured outcomes in clinical trials poses a significant obstacle for systematic reviewers. Core outcome sets (COSs) were developed to address this issue. The macular degeneration (MD) COS is designed to standardise outcome measurement across clinical trials for MD. This study investigates the uptake of the MD COS in standardising outcome measurement across clinical trials.

Cross-sectional analysis

We conducted a search on ClinicalTrials.gov to locate MD clinical trials that were registered 5 years prior to COS publication through the search date of 26 June 2023 and obtained a pool of 2152 registered studies. After applying various inclusion and exclusion criteria, we analysed 159 trials. We then analysed the COS uptake using an interrupted time series analysis (ITSA) and performed performed analyses of variance (ANOVAs) and Pearson correlations to evaluate associations between trial characteristics and outcome measurement.

ITSA showed no significant change in uptake following the MD COS (2016): mean percentage of completion of the COS increased by 0.24% per month before publication (p=0.27) and by 0.07% per month after publication (p=0.62), indicating no meaningful post-publication slope change in COS use. For context, visual acuity was most commonly measured, while several patient-reported and disutility domains were infrequently captured.

No discernible patterns in COS usage for MD trials were observed. We recommend further collaboration between regulators and COS developers to help with COS uptake. Additionally, we suggest that further studies analyse adherence to COSs in respect to regulatory recommendations.