Objective: Despite access to effective therapies many asthma patients still do not have well-controlled disease. This is possibly related to underuse of inhaled corticosteroids (ICS) and overuse of short-acting β2-agonists (SABA). Our aim was to investigate longitudinal trends and associated factors in asthma treatment.
Methods: Two separate cohorts of adults with physician-diagnosed asthma were randomly selected from 14 hospitals and 56 primary health centers in Sweden in 2005 (n = 1182) and 2015 (n = 1225). Information about symptoms, maintenance treatment, and use of rescue medication was collected by questionnaires. Associations between treatment and sex, age, smoking, education, body mass index (BMI), physical activity, allergic asthma, and symptom control were analyzed using Pearson's chi2-test. Odds ratios (ORs) were calculated using logistic regression.
Results: Maintenance treatment with ICS together with long-acting β2-agonists (LABA) and/or montelukast increased from 39.2% to 44.2% (p = 0.012). The use of ICS + LABA as-needed increased (11.1-18.9%, p < 0.001), while SABA use decreased (46.4- 41.8%, p = 0.023). Regular treatment with ICS did not change notably (54.2-57.2%, p = 0.14). Older age, former smoking, and poor symptom control were related to treatment with ICS + LABA/montelukast. In 2015, 22.7% reported daily use of SABA. A higher step of maintenance treatment, older age, obesity, shorter education, current smoking, allergic asthma, low or very high physical activity, and a history of exacerbations were associated with daily SABA use.
Conclusions: The use of ICS + LABA both for maintenance treatment and symptom relief has increased over time. Despite this, the problem of low use of ICS and high use of SABA remains.
Keywords: LABA; Longitudinal study; SABA; inhaled corticosteroids; long-acting β2-agonists; short-acting β2-agonists.