Abstract
Purpose :
The efficacy of generic latanoprost compared to that of brand-name latanoprost in treating primary open-angle glaucoma (POAG) has not been widely established. To better understand differences in their respective abilities to treat POAG, we assessed a cohort of incident POAG patients taking branded or generic latanoprost using a national claims database to determine the risk of needing a second intraocular pressure (IOP) medication or surgical intervention.
Methods :
This was a retrospective cohort study using medical claims data from a large, national U.S. insurer. Cohorts were created using all incident POAG patients (defined as a new ICD9 for POAG and a prescription fill for either generic or branded latanoprost within 30 days of diagnosis) from 2000-2013. Index date was considered the date of diagnosis. Exclusion criteria included less than 2 years of time in the plan prior to diagnosis, any previous use of a glaucoma medication or any diagnosis of any form of glaucoma other than POAG prior to or after the index date. Outcomes of interest were need for a second IOP-lowering medication and need for surgical intervention. Cox proportional hazard models were used to calculate covariate-adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for comparing medication and procedure outcomes in the generic vs. branded drug groups. Covariates of interest were age, sex, race, education level and financial net worth.
Results :
A total of 1,853 patients met the criteria for study eligibility (948 treated with generic; 905 treated with branded). The rate of secondary IOP prescription was 19.6% for generic vs. 25.2% for branded (HR: 0.82, 95% CI: 0.66, 1.02). The rate of procedural intervention was 5.5% for generic and 8.6% for branded (HR: 0.68, 95% CI: 0.46, 1.01). Combined, the rate of secondary IOP prescription and/or procedural intervention was 22.2% in for generic and 29.2% for branded (HR: 0.80, 95% CI: 0.65, 0.98).
Conclusions :
Generic latanoprost was no less efficacious in preventing the need for a second IOP medication or surgical intervention than its brand-name counterpart. Further work will be needed to understand why the results suggest that the generic form is more effective than its branded counterpart.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.