Increased use of inhaled corticosteroids among young Danish adult asthmatics: An observational study

Abstract

This population-based longitudinal study aimed to investigate trends in use of inhaled corticosteroids (ICS) and determinants of ICS use in young Danish adults with asthma. 106 757 users, aged 18-44 years, of anti-asthmatic drugs were identified in the Danish Register of Medical Product Statistics during 1997-2006. One year prevalences of ICS use were calculated in categories of gender, age, and annual consumption of inhaled beta-2-agonists (IBA) in defined daily doses (DDD) per year. Determinants of ICS use were estimated by logistic regression models. The one year prevalence of ICS use was constant, approximately 64%, during 1997-2000. An annual increase was observed from 67% in 2001 to 77% in 2006. This trend also existed when stratifying on gender, age and IBA use. Using 1997 as baseline, the adjusted odds ratios (ORs) of ICS use in 2000 was 0.98 (95% CI 0.96-1.01) compared to 1.12 (95% CI 1.09-1.15) in 2001, and 1.81 (95% CI 1.75-1.87) in 2006. Other determinants of high ICS use were female gender, young age, and high annual IBA consumption. Among those using at least 400 DDD of IBA per year (corresponding to 4.4 powder inhalations daily), nearly 20% had no ICS prescriptions in 2006. Treatment with ICS among young Danish adult asthmatics has increased since 2001. This apparent improvement was associated with the introduction of fixed dose combination inhalers with ICS and inhaled long-acting beta-2-agonists. However, there is still room for improvement.