Determinants in Initial Treatment Choice for Diabetic Macular Edema

Abstract

To assess how patient choices (out-of-pocket costs, insurance plan, geographic region) impact initiation of therapy for diabetic macular edema (DME). Retrospective cohort study using administrative medical claims data from a large, national insurer. All patients newly diagnosed with DME from 2013 through 2016 were observed for 90 days after diagnosis or until first treatment was received. Multivariate logistic regression was used to create odds ratios comparing different baseline demographic and patient-related factors. The primary outcome was the odds of receiving the different possible initial treatments for DME (anti-vascular endothelial growth factor [VEGF], focal laser treatment, steroids, or observation), no treatment, and not following up. Of the 6220 newly diagnosed DME patients, 3010 (48.4%) underwent a follow-up examination within 90 days of diagnosis, and of those, 1453 patients (48.3%) received treatment in the observation window, including 614 (20.4%) with bevacizumab, 191 (6.3%) with ranibizumab or aflibercept, 560 (18.6%) with focal laser, 38 (1.3%) with steroid injection, and 50 (1.7%) with an injection of an unspecified drug. Having a copay (vs. $0) lowered the odds of receiving any treatment (odds ratio [OR] = 0.60; 95% confidence interval [CI], 0.51-0.71; P<0.001) and of receiving each treatment individually (anti-VEGF treatment: OR = 0.72; 95% CI, 0.59-0.88; bevacizumab: OR = 0.73; 95% CI, 0.59-0.91; ranibizumab or aflibercept: OR, 0.70; 95% CI, 0.49-0.99; focal laser: OR = 0.44; 95% CI, 0.35-0.55; P < 0.001). Contrary to having a copay, having a high deductible and type of insurance plan were not associated with initiating treatment (P > 0.41 for all comparisons). Patients in the Northeast showed lower odds of initiating anti-VEGF treatment (OR = 0.60; 95%CI, 0.44-0.82; P < 0.001) and specifically bevacizumab (OR = 0.47; 95% CI, 0.33-0.67; P < 0.001). Furthermore, Northeast patients who were treated with anti-VEGF showed a higher odds of receiving ranibizumab or aflibercept compared with bevacizumab (OR = 2.39; 95% CI, 1.31-4.37; P < 0.001). Southern Midwest patients showed a higher odds of treatment (anti-VEGF: OR = 1.35; 95%CI, 1.02-1.77; P < 0.001; bevacizumab: OR = 1.40; 95% CI, 1.04-1.87; focal laser: OR = 1.39; 95% CI, 1.01-1.89; P < 0.001). Patient choices such as copays and where they live are important factors in determining the initial choice of treatment for DME.