Abstract
INTRODUCTION: There is little understanding of long-term treatment persistence in patients receiving anti-vascular endothelial growth factor (anti-VEGF) injections for diabetic macular edema (DME), particularly relating to treatment intervals. The aim of this study was to investigate the association between treatment interval and discontinuation rate after 24 months of unilateral anti-VEGF treatment in patients with DME under routine clinical care in the USA. METHODS: This was a non-interventional, retrospective cohort study to review the health insurance claims of adults with DME linked with the IBM MarketScan(®) Commercial and Medicare Supplemental databases, who were continuously enrolled in a health plan for at least 6 months prior to their first anti-VEGF treatment and for a duration of at least 24 months between July 2011 and June 2017. Patients were grouped on the basis of the injection interval they achieved at 24 months of treatment. Discontinuation rate beyond 24 months and its association with treatment intervals at 24 months was estimated using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: The overall discontinuation rate among the 1702 eligible patients from 24 to 60 months after treatment initiation was 30%. At 60 months, patients were more likely to remain on treatment in shorter (75.3% [4-week interval group]) versus longer treatment interval groups (62.1% [> 12-week interval group], difference = 13.2%, [95% confidence interval (CI) 1.06, 2.06], p = 0.01). Patients on a > 12-week interval were twice as likely to discontinue treatment compared with those on an 8-week interval (hazard ratio = 2.01 [95% CI 1.43, 2.82], p < 0.001). CONCLUSION: Patients with DME on longer anti-VEGF treatment intervals at 24 months consistently had higher discontinuation rates in the following years than those on shorter treatment intervals.