Abstract
Purpose :
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 performed a retrospective meta-epidemiological study to evaluate discontinuation and loss to follow-up (LTFU) rates in clinical trials of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections for diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO).
Methods :
Clinicaltrials.gov was queried for all completed trials of anti-VEGF injections for DME, AMD, or RVO. Of the 658 trials identified, 582 were excluded for being non-interventional (n = 90), having fewer than 100 patients (n = 207), terminating early (n = 6), or missing study results (n = 279). The remaining 76 trials (DME n = 33, AMD n = 33, RVO n = 10) of 27,823 patients were analyzed for discontinuation and LTFU rates.
Results :
Mean discontinuation rate was 12.44% (SD 8.12%, range 0 – 54.12%) (Figure 1A), with higher rates among control (18.87%) than treatment arms (10.78%, p = .006). Subject withdrawal was the most common reason for discontinuation, followed by adverse events and LTFU (Table 1). Mean LTFU rate was 1.84% (SD 1.78%, range 0 – 7.76%) (Figure 1B), with no significant differences when stratified by disease, treatment type, or treatment frequency.
Conclusions :
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.
This is a 2021 ARVO Annual Meeting abstract.