Regional variation in prevalence of difficult-to-treat asthma and oral corticosteroid use for patients in Australia: heat map analysis.

BACKGROUND: In Australia, the regional prevalence of difficult-to-treat asthma is unknown. We aimed to describe regional variation in difficult-to-treat asthma prevalence and oral corticosteroid (OCS) use. METHODS: In this retrospective, observational, longitudinal study using data from March 2018-February 2019 in the NostraData longitudinal database, prescriptions dispensed for obstructive airway disease were processed through a high-level algorithm to identify patients with asthma. Difficult-to-treat asthma was defined by ≥2 high-dosage inhaled corticosteroids plus long-acting beta-agonist prescriptions over 6 months. Patients who additionally received OCS prescriptions sufficient to treat ≥2 exacerbations over 6 months were classified as having uncontrolled difficult-to-treat asthma. Patient-level data were analyzed across 340 geographic areas in Australia to determine regional prevalence of difficult-to-treat asthma, uncontrolled difficult-to-treat asthma, and OCS use. RESULTS: Of 1 851 129 people defined as having asthma, 440 800 (24%) were classified as having difficult-to-treat disease. Of those difficult-to-treat asthma patients, 96 338 (22%) were considered to have uncontrolled disease. Between 29% and 48% of patients had difficult-to-treat asthma in 49 geographic areas, most frequently located in Western Australia. Between 26% and 67% of patients had uncontrolled difficult-to-treat asthma in 29 geographic areas (mostly in Eastern Australia). Overall, a wide variability of asthma severity and control was observed among regions. CONCLUSIONS: Despite global and national guidelines, regional differences in the prevalence of difficult-to-treat asthma and uncontrolled difficult-to-treat asthma and OCS use exist in Australia. Understanding these regional variations should inform policy and target management in the areas with the greatest unmet need.

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

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.