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

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.