Two-Year Retrospective Economic Evaluation of Three Dual-Controller Therapies Used in the Treatment of Asthma

Abstract

To compare asthma-related health-care utilization and expenditures for patients prescribed one of three dual-controller therapies: fluticasone plus salmeterol, inhaled corticosteroids (ICS) [excluding fluticasone] plus salmeterol, and ICS plus a leukotriene modifier (LTM). Asthma-related medical claims from two major health plans were obtained for the 12 months before and after the initiation of dual therapy. A total of 1,325 patients > or = 12 years old with no claims for COPD or respiratory tract cancer were selected from the approximately 3.5 million lives covered. Multivariable regression was used to assess differences in asthma-related expenditures. To compensate for positive skew, all cost variables were log-transformed. Risk-adjusted total asthma-related costs for the fluticasone-plus-salmeterol cohort (n = 121), the ICS-plus-salmeterol cohort (n = 844), and the ICS-plus-LTM cohort (n = 360) [corrected] were $975, $1,089, and $1,268, respectively. Risk-adjusted pharmacy costs were $813, $841, and $996, respectively. Generalized linear modeling, controlling for baseline covariates, indicated that compared to ICS-plus-LTM therapy, fluticasone-plus-salmeterol therapy was associated with a significant reduction in asthma-related total (p = 0.0014) and pharmacy (p = 0.001) costs. Similar results were found when the ICS-plus-salmeterol group and the ICS-plus-LTM group were compared (p = 0.0001). The number of inpatient, outpatient, and emergency department visits and their corresponding costs were lower for the fluticasone-plus-salmeterol cohort, but were not statistically significant (p > 0.05). Results from managed-care practice suggest that treatment with fluticasone plus salmeterol, and more broadly ICS plus salmeterol, yield important cost savings when compared to treatment with ICS plus LTM.