Risk of Noninfectious Uveitis with Female Hormonal Therapy in a Large Healthcare Claims Database.

PURPOSE: To determine if female hormonal therapy (FHT) increases the incidence of noninfectious uveitis. DESIGN: Retrospective cohort study. PARTICIPANTS: Women exposed to FHT and matched women unexposed to FHT enrolled in a national insurance plan. METHODS: Estimation of noninfectious uveitis incidence used multivariable Cox proportional hazards regression. To account for differences between the exposed and unexposed cohorts, a propensity score for being prescribed FHT was created using logistic regression, and inverse probability of treatment weighting was performed. MAIN OUTCOME MEASURES: Incidence of noninfectious uveitis. For the primary outcome, incident noninfectious uveitis was defined as a new diagnosis code for noninfectious uveitis followed by a second instance of a noninfectious uveitis code within 120 days. For the alternative outcome definition, a corticosteroid prescription or code for an ocular corticosteroid injection within 120 days of the uveitis diagnosis code was used instead of the second uveitis diagnosis code. RESULTS: There were 217 653 women exposed to FHT and 928 408 women not unexposed to FHT. For the primary outcome, the hazard ratio (HR) for incident noninfectious uveitis was not significantly different between the FHT and unexposed cohorts (HR, 0.99; 95% confidence interval [CI], 0.83-1.17; P = 0.87). With the alternative outcome definition, the FHT cohort was more likely to develop uveitis (HR, 1.21; 95% CI, 1.04-1.41; P = 0.01). When examined by anatomic subtype, for anterior uveitis there was a greater likelihood of incident uveitis in the exposed cohort (HR, 1.23; 95% CI, 1.05-1.45; P = 0.01) for the alternative outcome definition but not for the primary outcome. With age stratification, women exposed to FHT aged ≥45 years at the time of FHT prescription were more likely to develop uveitis (HR, 1.23; 95% CI, 1.03-1.47; P = 0.03) for the alternative outcome definition. A similar HR (1.22) was seen for women aged ≤44 years at the time of prescription, but this association did not meet statistical significance (P = 0.20). CONCLUSIONS: Exposure to FHT increases the rate of incident noninfectious uveitis when uveitis is defined on the basis of both diagnostic codes and documentation of corticosteroid treatment. However, the risk is modest and FHT is likely safe with regard to noninfectious uveitis risk in the majority of patients exposed to these drugs.