An observational study using pharmacy and medical claims was used to determine whether there are differences in asthma care cost between patients that are newly started on montelukast and low-dose fluticasone propionate. Patients were identified who had at least one ICD-9 (493.XX) claim for asthma and were newly prescribed inhaled fluticasone propionate 44 microg (FP) or montelukast 5 or 10 mg (MON). Subjects could not have had a claim for any inhaled corticosteroid or oral leukotriene modifier in 9 months prior to the first prescription claim for either FP or MON. They were subsequently followed for 9 months. Multi-variate regression analysis was used to determine the influence of these single-controller therapies on post-index asthma related costs. Positively skewed cost variables were log-transformed prior to their inclusion into the multi-variate model. Asthma-related costs were adjusted for age, gender, health plan, co-morbidities, pre-index asthma medication use and pre-index asthma care costs. Multivariate regression analysis, adjusting for baseline covariates, indicated that compared to treatment with montelukast, treatment with FP had significantly (P<0.001) lower post-index total asthma related costs. Adjusted least squares mean total asthma care costs for the 9-month post-index period were $US649 for FP 44 microg compared to $US1028 for montelukast
