Administrative Claims Analysis of Asthma-Related Health Care Utilization for Patients Who Received Inhaled Corticosteroids With Either Montelukast or Salmeterol as Combination Therapy

OBJECTIVES: To compare asthma-related health care resource utilization among a matched cohort of asthma patients using inhaled corticosteroids (ICSs) plus either montelukast (MON) or salmeterol (SAL) as combination therapy for asthma, during a time prior to the availability of fixed-dose combinations of ICS/SAL. METHODS: A retrospective analysis using the PHARMetrics patient-centric claims database was conducted for the period preceding the market introduction of combination fluticasone-SAL in September 2000. Patients had to meet the following criteria for inclusion in the study: they had to be between the ages of 4 and 55 years; they had to have been continuously enrolled for 2 years; they had to have initiated ICS/MON or ICS/SAL therapy between July 1, 1998, and June 30, 1999; and they had to have had either (a) a diagnosis of asthma (based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes of 493.xx) for 2 outpatient visits, 1 or more emergency department (ED) visits, or 1 or more hospitalizations within 1 year or (b) pharmacy claim records that contained a National Drug Code for an antiasthma medication (betaagonist, theophylline, ICS, cromolyn, or leukotriene) 2 or more times within 1 year. ICS/MON and ICS/SAL patients were matched 1 to 1 on age and propensity score. Outcomes included asthma-related hospitalizations and ED visits with ICD-9-CM codes of 493.xx, and oral corticosteroid (OCS) fills and short-acting beta-agonist (SABA) fills. Multivariate regression analyses were performed. Subgroup analyses based on sequential or concurrent initiation of combination therapy were also conducted. RESULTS: A total of 1,216 patients were matched (ICS/MON=608; ICS/SAL= 608). Decreased odds of ED visits and/or hospitalizations were observed with ICS/MON (adjusted odds ratio [OR]=0.58; 95% confidence interval [CI], 0.35-0.98) versus ICS/SAL. The odds of postindex OCS fills were not different for ICS/MON and ICS/SAL patients (adjusted OR=1.04; 95% CI, 0.79-1.38). Postindex pharmacy claims for SABAs were significantly higher among ICS/MON patients versus ICS/SAL patients (adjusted relative risk [RR]=1.33; 95% CI, 1.17-1.52), and this difference remained regardless of prior use or no prior use of ICSs. In subgroup analyses, mean change in SABA fills varied by how combination therapy was initiated, with sequential addition of asthma controllers leading to a reduction in SABA fills in both groups. For patients with concurrent initiation of combination therapy, the odds of ED visits/hospitalizations were significantly lower in patients initiating ICS/MON (adjusted OR=0.25; 95% CI, 0.08-0.79). CONCLUSIONS: In this matched cohort, use of ICS/MON compared with ICS/SAL resulted in similar odds of OCS fills, decreased odds of ED visits and asthma related hospitalizations, but higher utilization of SABA.