Discontinuation and loss to follow-up rates in clinical trials of intravitreal anti-vascular endothelial growth factor injections.

Abstract

Clinical trials are often designed to include homogenous, highly specific patient populations with many resources to reduce patient dropout. Results may not translate to real-world settings. We evaluated discontinuation and loss to follow-up (LTFU) rates in clinical trials of anti-vascular endothelial growth factor (anti-VEGF) injections for diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO). Retrospective meta-epidemiological study. The authors queried ClinicalTrials.gov for all completed trials of anti-VEGF injections for DME, AMD, or RVO. Of 658 trials identified, 582 were excluded for being non-interventional, <100 patients, terminating early, or missing study results. The remaining 76 trials of 27,823 patients were analyzed for discontinuation and LTFU rates. Mean discontinuation rate was 12.44% (SD 8.12%, range 0-54.12%), with higher rates among control (18.87%) than treatment arms (10.78%, p = .006). Mean LTFU rate was 1.84% (SD 1.78%, range 0-7.76%), with no differences by disease, treatment type, or treatment frequency. Discontinuation rates of major intravitreal anti-VEGF clinical trials were highly variable, suggesting even trials struggle with overall patient retention. Though trial LTFU rates were low, real-world outcomes may differ due to higher reported LTFU rates, which should be considered when extrapolating trial results to clinical practice.