Cognition, symptom perception, and medication non-adherence in older adults with asthma.

ABSTRACT

BACKGROUND: Cognitive impairment (CI) is highly prevalent in elderly asthmatics and is associated with worse asthma self-management (SM) and outcomes. CI may also explain why older adults may under-perceive asthma symptoms. We hypothesized that CI would be associated with low medication adherence and asthma symptom under-perception (ASP). We also hypothesized that ASP would mediate the relationship between CI and medication adherence. METHODS: Participants of this longitudinal cohort study were asthmatics (N = 334) ≥60 years (51% Hispanic, 25% Black). Cognitive measures assessed general cognition, attention, processing speed, executive functioning, memory, and language. Measures of SM were self-reported and electronically measured adherence to controller medications. ASP was assessed for 6 weeks by participants entering estimates of peak expiratory flow (PEF) into a programmable peak flow meter, followed by PEF blows. Participants were blinded to actual PEF values. Percentage of time that participants were in the over-perception zone was calculated as an average. RESULTS: In regression analyses, those with impairments in memory and general cognition had lower odds ratios (OR) for self-reported non-adherence (OR 0.96, 95% CI 0.93 - 0.98 & OR 0.90, 95% CI 0.83 - 0.96, respectively). CI was not associated with electronically measured non-adherence or ASP. In structural equation modeling, while CI was associated with adherence (ß = 0.04, SE = 0.021, p = 0.04), ASP did not mediate this relationship. CONCLUSIONS: While results confirmed the importance of cognition in asthma SM, these findings were not linked to ASP. Future analyses are needed to understand the role of confounding factors.