Regional variation in intensity of inhaled asthma medication and oral corticosteroid use in Denmark, Finland, and Sweden

Abstract

Oral corticosteroids (OCS) are often prescribed to patients with asthma that remains uncontrolled with maintenance therapy. We performed a real-world analysis to describe the geographic distributions of patients with asthma and OCS dispensed in Nordic countries. This observational, retrospective study examined patient-level data from nationally prescribed drug registries from January to December 2018 for individuals aged ≥12 years in Denmark, Finland, and Sweden. Using an algorithm based on asthma treatment combinations defined by the Global Initiative for Asthma (GINA), we identified patients with asthma, those on GINA Step 4–5 treatments, and those being dispensed ≥2 courses of OCS and determined volumes of OCS dispensed to these patients over the 1-year analysis period. Data were plotted geographically within each country using colour-coded heat maps. The overall asthma prevalence rates were 7.4% in Denmark, 11.6% in Finland, and 8.1% in Sweden. In Denmark, Finland, and Sweden, respectively, the frequencies of patients on GINA Step 4–5 treatments were 19%, 15%, and 16%; among whom 10%, 23%, and 5% received ≥2 courses of OCS. The rates of patients on GINA Step 4–5 treatments who were dispensed OCS in each country were 23%, 30%, and 46%, of which 22%, 17%, and 10% were dispensed doses averaging ≥5 mg/day over the year. Heat maps revealed considerable heterogeneity in geographic densities of patients with asthma and OCS claims within each country. Taken together, these results demonstrate regional variations in estimated asthma severity, control, and OCS dispensed within and between countries. Patterns of medication use suggest that a high proportion of patients in Denmark, Finland, and Sweden are on GINA Step 4–5 treatments, many of whom are dispensed OCS; this poses a considerable corticosteroid burden to these patients. Geographic differences in medication use within and between Nordic countries may reflect variations in population characteristics and/or treatment approaches.