PDB130 - Treatment patterns of anti-vascular endothelial growth factor (VEGF) and laser therapy among patients with diabetic macular edema (DME)

Abstract

BACKGROUND: Diabetic macular edema (DME) is a form of diabetic retinopathy caused by continued leakage from retinal blood vessels. The use of antivascular endothelial growth factor (VEGF) injections has gained in popularity in the treatment of DME due to satisfactory efficacy, while laser photocoagulation is still the first-line therapy. Examining anti-VEGF treatment patterns may improve understanding of real-world medication-taking behaviors. OBJECTIVES: To (a) compare demographic and clinical characteristics and treatment patterns of anti-VEGF (bevacizumab, ranibizumab, and pegaptanib) and laser therapies among DME patients and (b) determine predictors of switching and anti-VEGF therapy initiation. METHODS: A retrospective cohort analysis was conducted with Texas Medicaid medical and prescription claims (January 1, 2008-December 31, 2012) for patients who were aged 18-63 years, continuously enrolled 1 year pre- and post-index, diagnosed with DME and treated with anti-VEGF or laser therapies. Treatment patterns included treatment frequency and switching between anti-VEGF and laser therapies. Logistic regression and multinomial analysis were used to determine factors associated with switching and initiation of anti-VEGF therapy, while controlling for demographic and clinical characteristics. RESULTS: DME patients (N = 2,201) were aged 54.7 (SD ± 7.9) years; 63.1% were female; 59.1% were Hispanic; and 10.3% were visually impaired. CCI mean score was 6.5 (SD ± 3.1), and patients were on 2.6 (SD ± 3.3) unique prescription medications. Anti-VEGF users had significantly (P < 0.0001) fewer prescriptions compared with laser users (1.9 [SD ± 3.1) vs. 2.8 [SD ± 3.3], respectively). Laser was the most commonly used (84.9%) therapy from 2009 to 2011; however, anti-VEGF use increased from 11.7% in 2009 to 21.8% in 2011 (P < 0.0001). Patients received 1.5 (SD ± 0.7) laser surgeries compared with 1.7 (SD ± 1.1) anti-VEGF injections per eye annually. Switching from laser to anti-VEGF injections was 9.7%, while switching from anti-VEGF injections to laser surgery was 42.2%. Patients who switched from antiVEGF injections to laser surgery were more likely to be Hispanic (OR = 1.415, 95% CI = 1.037-1.930); male (OR = 1.341, 95% CI = 1.053-1.709); have fewer prescriptions (OR = 0.944, 95% CI = 0.905-0.985); and less likely to have no visual impairment (OR = 0.641, 95% CI = 0.449-0.915). Multinomial regression results showed anti-VEGF users were more likely to remain on the same therapy if they had more prescriptions (OR = 1.094, 95% CI = 1.029-1.172) or were female (OR = 1.441, 95% CI = 1.024-2.041). Anti-VEGF initiators had fewer prescriptions (OR = 0.917, 95% CI = 0.868-0.947) and initiated in 2011 vs. 2009 (OR = 2.363, 95% CI = 1.777-3.141). CONCLUSIONS: Although anti-VEGF use is increasing, laser use is still more prevalent. Over 40% of patients who initiated on anti-VEGF injections switched to laser surgery. Additional research should be conducted to determine factors associated with this high rate of switching.