Risk of hospitalizations/emergency department visits and treatment costs associated with initial maintenance therapy using fluticasone propionate 500 µg/salmeterol 50 µg compared with ipratropium for chronic obstructive pulmonary disease in older adults

Abstract

Background: Cost-effective treatments for chronic obstructive pulmonary disease (COPD) are needed to reduce the burden on the Medicare system. Objectives: The objectives of this retrospective study were to compare the effects of fluticasone propionate 500 µg/salmeterol 50 µg (FSC 500/50) with those of ipratropium (IPR) in older adult patients with COPD on the following factors: (1) the risk of all-cause and COPD-related hospitalization and emergency department (ED) visits; and (2) all-cause and COPD-related treatment costs. Methods: This retrospective, observational cohort study assessed commercially insured patients aged ≥65 years (Medicare eligible) with COPD-related medical costs ( International Classification of Diseases, Ninth Revision, Clinical Modification codes 490.xx, 491.xx, 492.xx, or 496.xx), 18 months of continuous enrollment (12 months' pre-study and 6 months' poststudy), and ≥1 prescription claim (ie, the index event) for FSC 500/50 or IPR between January 2, 2001, and August 12, 2003. Exacerbation events (hospitalizations/ED visits) were assessed using Cox proportional hazards regression models controlling for baseline factors and preindex events. Treatment costs were estimated using multivariate generalized linear models to adjust for baseline characteristics and preindex utilization and costs. A propensity-matched comparison was conducted as a sensitivity analysis. Results: A total of 1051 patients (540 women, 511 men) were identified: 952 in the IPR group (mean age, 74.26 years) and 99 in the FSC 500/50 group (mean age, 72.38 years). Treatment with FSC 500/50 was not associated with a reduction in the risk of all-cause hospitalization or ED visit compared with IPR (adjusted hazards ratio [HR], 0.913 [95% CI, 0.673-1.238]); however, FSC 500/50 was associated with a significantly lower risk (45%) of a COPD-related event (adjusted HR, 0.547 [95% CI, 0.301-0.995]). Although treatment with FSC 500/50 was associated with significantly lower annual mean all-cause medical costs compared with IPR ($18,642 vs $25,556, P < 0.05), the use of FSC 500/50 was also associated with significantly higher annual all-cause pharmacy costs ($2813 vs $2244, P < 0.05). Compared with the IPR cohort, the FSC 500/50 cohort had lower mean annual COPD-related medical costs (-$464 [ P = NS]) and higher COPD-related pharmacy costs ($260 [ P < 0.01]). However, increased pharmacy costs may be compensated for by decreased medical costs in both all-cause and COPD-related services. Results from the sensitivity analysis with the propensity score-matched sample of 194 patients were similar. Conclusions: Compared with the IPR cohort, the FSC 500/50 cohort was 45% less likely to have a COPD-related exacerbation event and had similar medical costs. FSC 500/50 was a more effective initial maintenance therapy than IPR for this Medicare population, and, despite the $260 increase in COPD-related pharmacy costs, there was no significant difference in COPD-related medical costs.