Glaucoma Medications and Mortality: A Retrospective Cohort Study

PURPOSE: This study presents a retrospective, cohort analysis to estimate the 4-year rate of all-cause risk-adjusted mortality for veterans who were dispensed glaucoma medications. The main outcome measures was hazard of death according to glaucoma medication exposure. METHODS: Beneficiaries 40 years and older enrolled in Veterans Health Administration (VHA) with International Disease Classification diagnoses of glaucoma. VHA clinical and pharmacy data sets were linked with a national VHA mortality registry. Patients were identified with a primary diagnosis of glaucoma were then put into one of two groups, glaucoma medication exposure or nonexposure medication group. Four-Year survival analysis using the Cox proportional hazard method was adjusted for comorbidities using pertinent demographic characteristics and hierarchical condition categories from the Centers for Medicare and Medicaid Services. RESULTS: Of 214,971 beneficiaries with glaucoma or suspected glaucoma, 25,148 (11.7%) died during the study period. Compared to unexposed patients with glaucoma, the use of any class of glaucoma medication was associated with a statistically significant 7% reduced hazard of death (adjusted hazard ratio, 0.93; 95% confidence interval: 0.90-0.95). Reduced risk of death was found for multiple topical medication use, but not individual glaucoma agents. CONCLUSIONS: The seemingly inexplicable protective effect of glaucoma agents on all-cause mortality may best be explained by unmeasured confounding variables involved in the clinical decision of whether or not to treat patients with limited life expectancy for glaucoma. Ann Epidemiol 2010;20:917-923. Published by Elsevier Inc.