Cost-effectiveness of initiating extrafine- or standard size-particle inhaled corticosteroid for asthma in two health-care systems: a retrospective matched cohort study

BACKGROUND: Real-life studies are needed to determine the cost-effectiveness of asthma therapies in clinical practice. AIM: To compare the cost-effectiveness of extrafine-particle inhaled corticosteroid (ICS) with standard size-particle ICS in the United Kingdom (UK) and United States (US). METHODS: These retrospective matched cohort analyses used large electronic databases to study asthma-related outcomes for patients in the UK (12–60 years old; n=1730) and US (12–80 years; n=10,312) prescribed extrafine beclomethasone or fluticasone as their first ICS therapy for asthma. Patients were matched on demographic characteristics and asthma severity during 1 baseline year, and asthma control and asthma-related costs were compared during 1 outcome year. RESULTS: In both the UK and US, adjusted odds of risk-domain asthma control were similar, whereas the odds of overall control (no hospitalisation or oral steroids for asthma, no antibiotics for lower respiratory infection, limited reliever use) were greater for extrafine ICS in both countries (UK odds ratio, 1.23; 95% confidence interval (CI), 1.01–1.50). Asthma-related annual costs, adjusted for baseline, were significantly lower for extrafine-particle ICS cohorts in both countries (UK difference, −£66 (95% CI,−93 to −37)). Cost-effectiveness analyses using the two measures of asthma control found 92 and 98% probabilities of extrafine-particle ICS being the preferred treatment strategy (less costly and more effective than standard size-particle ICS) in the UK, and 84 and 100% probabilities in the US. CONCLUSIONS: Initiating ICS therapy for asthma as extrafine-particle ICS seems the dominant treatment option (less costly and more effective) compared with standard size-particle ICS in both the UK and the US.