ABSTRACT
OBJECTIVE: The aim of this work was to compare rates of asthma-related health service utilization for Medicaid-eligible pediatric and adult patients with asthma treated with fixed-dose fluticasone propionate/salmeterol (FSC) or fluticasone propionate (FP) monotherapy. METHODS: A retrospective, observational claims analysis was conducted with Medicaid enrollees aged ≥4 years with ≥1 diagnosis code for asthma and a prescription fill for FSC or FP between January 1, 2002, and November 1, 2005. The end date allowed a follow-up period of ≥60 days; Medicaid data were available through December 31, 2005, and were obtained from 2 sources: a large US-managed Medicaid provider affiliated with i3 Innovus, and the Thomson Medstat Marketscan (Ann Arbor, Michigan) Medicaid claims database. Patients were new or continuing users of asthma controllers, but were new users of FSC or FP. Outcome measures included postindex use of systemic corticosteroid drugs and short-acting ß-agonists (SABAs), asthma-related utilization, and costs. Descriptive and multivariate techniques were used, adjusting for differences in baseline demographics and length of follow-up time in the study population. Patients were grouped into cohorts according to age: 4 to 17 or ≥18 years. RESULTS: The final study population was 50,428 patients, including 30,071 patients (59.6%) aged <18 years and 20,357 patients (40.4%) aged ≥18 years. Mean number of days of follow-up was 290.4, and 55.1% of patients (n = 27,793) were followed for ≥1 year after the index date. Among those aged <18 years, FSC treatment was associated with decreased adjusted risk of asthma-related emergency department (ED) visits (adjusted hazard ratio [HR] = 0.917; 95% CI, 0.855-0.984) and combined ED/inpatient (IP) visits (HR = 0.922; 95% CI, 0.860-0.988). Among those aged ≥18 years, FSC treatment was associated with decreased adjusted risk of asthma-related ED visits (HR = 0.907; 95% CI, 0.849-0.969) and combined ED/IP visits (HR = 0.907; 95% CI, 0.850-0.968). FSC treatment was also associated with significantly fewer prescription fills for SABAs compared with FP treatment in both age groups (aged <18 years: incident rate ratio [IRR] = 0.960 [95% CI, 0.929-0.992]; aged ≥18 years: IRR = 0.950 [95% CI, 0.905-0.998]). Total mean (SD) unadjusted asthma costs were $579 ($2429) for FSC and $551 ($3151) for FP in the <18-year age group and were $1764 ($10,006) for FSC and $1512 ($5543) for FP in the ≥18-year age group. CONCLUSION: In this retrospective database analysis, Medicaid-eligible patients who initiated FSC therapy experienced better asthma control compared with patients who initiated FP monotherapy, as measured by asthma-related ED/IP visits and use of SABAs.