Treatment Patterns of Anti-Vascular Endothelial Growth Factor and Laser Therapy Among Patients with Diabetic Macular Edema.

backgroundDiabetic macular edema (DME) is a form of diabetic retinopathy caused by continued leakage from retinal blood vessels. The use of anti-vascular 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.

objectivesTo (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.

methodsA 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.

resultsDME 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  less than  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  less than  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 anti-VEGF 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).

conclusionsAlthough 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.