Change in asthma control and pharmacological asthma treatment – 17 years follow up

Introduction: Many asthma patients have symptoms that affect their daily lives. This longitudinal study intended to assess asthma control and asthma-related quality of life over an 18-year follow up of a cohort of adult patients with asthma. As asthma control is dependent on sufficient anti-inflammatory treatment, we have studied how asthma treatment has changed in this cohort during the study period. Methods: Patients with doctor-diagnosed asthma, aged 18–75 years were randomly selected from 14 hospitals and 56 primary healthcare centres in Sweden in 2005. The patients answered questionnaires about symptoms, pharmacological treatment and the Mini-Asthma Quality of Life Questionnaire (Mini-AQLQ) in 2005 (n=1,210), 2012 (n=749) and 2022 (n=437). Only patients that participated in all surveys were included (n=437). A simplified definition of asthma control was created. Optimal asthma control was defined as no nocturnal asthma symptoms, use of reliever medication twice or less during the previous week, and no exacerbations last six months. Results: There was no notable difference in number of patients with optimal asthma control (39.1% vs. 39.2%, p=0.80) or mean mini-AQLQ score (5.5±1.2 vs. 5.6±1.2, p=0.69). Inhaled corticosteroids (ICS) in combination with long-acting β2-agonists increased from 40.3% in 2005 to 46.6% in 2022 (p=0.009), but the overall use of ICS decreased (78.0% vs. 70.4%, p=0.0007). In 2023, 15.1% used leukotriene antagonists, compared with 9.4% in 2005, p=0.003). The overall use of reliever medication more often than twice during the previous week did not change (48.3% vs. 51.6%, p=0.24). Discussion: The proportion of patients with controlled asthma remained low and use of reliever medication high over this time period. The overall use of ICS decreased. According to the recommended guidelines, early ICS treatment in asthma is of critical importance in improving asthma control. Implications should include emphasizing the role of airway inflammation in asthma in patient education.