AB041. Effectiveness and cost impact evaluation of fluticasone propionate/formoterol compared to fluticasone propionate/salmeterol

Background: Treatment of asthmatics with an inhaled corticosteroid (ICS) and long-acting beta agonist (LABA) is recommended for maintenance treatment according to Step 3 in the GINA guidelines. Fixed-dose combination (FDC) inhalers simplify the dosing regimen and may improve adherence over their separate components. However, the effectiveness and cost impact of FDC devices containing fluticasone propionate/formoterol (FP/FOR) compared to fluticasone/salmeterol (FP/SAL) in asthma patients who initiate or switch to FDC ICS/LABA inhalers have not been studied in real-life patients in the United Kingdom. To determine whether FP/FOR is non-inferior to FP/SAL in patients who initiate or switch to a FDC ICS/LABA therapy with respect to decreasing the occurrence of asthma exacerbations and overall cost impact.

Methods: This study used a matched, historical cohort design to compare the two FDC ICS/LABA treatments using the Optimal Patient Care Database. Based on a 1-year exploratory analysis of baseline variables such as comorbidities, current treatment, demographics and clinical measurements, cohorts were matched to ensure similar patients were compared over a 1-year outcome. Two cohorts of patients were studied: one of patients initiated on combination therapy (either FP/FOR or FP/SAL) and one of patients either switched from FP/SAL to FP/FOR or who remained on FP/SAL. The primary outcome studied non-inferiority in terms of percentage of patients who were free from severe asthma exacerbations (defined by ATS/ERS position statements) for patients prescribed FP/FORversusFP/SAL in the outcome year. Secondary outcomes included the rate of asthma exacerbations, clinical exacerbations, asthma control, treatment stability, and lower respiratory tract hospitalisations. Cost impact outcomes included a comparison of resource costs, drug costs and combined drug and resource costs.

Results: The study included 2,472 patients (618 patients in FP/FOR and 1,854 patients in FP/SAL cohorts) in total. A total of 696 patients (FP/FOR, 174; FP/SAL, 522) were in the ‘initiation cohort’ and 1776 patients (FP/FOR, 444; FP/SAL, 1,332) were in the ‘switch cohort’. The percentage of patients who had ‘no asthma exacerbations’ was non-inferior for the combined FP/FOR sub-cohort compared with the combined FP/SAL sub-cohort. Clinical asthma exacerbations were associated with a lower number for patients prescribed FP/FOR compared with patients prescribed FP/SAL (rate, 0.82; 95% CI, 0.71–0.94). The overall cost impact associated with prescription of FP/FOR compared to FP/SAL in the outcome period was also significantly lower (£406 vs. £487; P<0.001).

Conclusions: Patients switching to or initiating FP/FOR achieve comparable asthma control (in terms of prevention of severe exacerbations) at a lower mean cost compared with patients continuing or initiating treatment with FP/SAL.

Keywords: Asthma; effectiveness; cost; fixed-dose combination (FDC); inhaled corticosteroid (ICS)