The Association Between Beliefs and Adherence to Inhaled Controller Medication Among Older Adults with Asthma: A Cross-Sectional Study in Primary Care

BACKGROUND: While illness perceptions and medication beliefs have been shown to be associated with inhaled corticosteroid (ICS) adherence in younger adults with asthma, their impact on older adults is less understood. This study aimed to determine the prevalence of ICS adherence among older Asian adults and to assess the association between ICS adherence, illness perceptions and medication beliefs. METHODS: A questionnaire survey on older multi-ethnic Asian patients, aged ≥60 years, with physician-diagnosed asthma, was conducted in two Singapore public primary care clinics. The scores of the Medication Adherence Report Scale for asthma (MARS) were computed to determine the adherence to ICS alone or in combination with LABA. Illness perceptions and medication beliefs were assessed by the scores from the Brief-Illness Perception Questionnaire (B-IPQ) and Beliefs about Medications Questionnaire (BMQ), respectively. Logistic regression analyses were used to identify factors associated with ICS adherence. RESULTS: Analyses of 323 participants (57% males; Chinese 73.7%, Malay 12.7%, Indian 12.4%; mean age 71.5 years) showed that 40.9% of them had good adherence to ICS (mean MARS score≥4.5). Good adherence to ICS was associated with perception of asthma as a chronic illness (OR=1.22; 95% CI=1.10–1.35; p<0.001), belief of ICS as an essential medication (2.67; 1.76–4.06; p<0.001) and fewer concerns about its use (0.39; 0.26–0.60; p<0.001). Patients on combined ICS-LABA therapy had higher adherence (2.50; 1.41–4.44; p=0.02) than those on ICS monotherapy. CONCLUSION: Four in ten older patients with asthma were adherent to ICS. Perception of medication necessity, chronicity of illness, concerns and use of ICS-LABA medication were associated with adherence.