We sought to investigate the degree to which cognitive skills explain associations between health literacy and asthma-related medication use among older adults with asthma.
Patients aged 60 years and older receiving care at 8 outpatient clinics (primary care, geriatrics, pulmonology, allergy and immunology) in New York, NY and Chicago, IL were recruited to participate in structured, in-person interviews as part of the Asthma Beliefs and Literacy in the Elderly (ABLE) study (n=425). Behaviors related to medication use were investigated, including adherence to prescribed regimens, metered dose inhaler (MDI) technique, and dry powder inhaler (DPI) technique. Health literacy was measured using the Short Test of Functional Health Literacy in Adults (S-TOFHLA). Cognitive function was assessed in terms of fluid (working memory, processing speed, executive function) and crystallized (verbal) ability.
The mean age of participants was 68 years; 40% were Hispanic, 30% African American. More than a third (38%) were adherent to their controller medication, 53% demonstrated proper DPI technique, and 38% demonstrated correct MDI technique. In multivariable analyses, limited literacy was associated with poorer adherence to controller medication (OR, 2.3; 95% CI, 1.29-4.08), incorrect DPI (OR, 3.51; 95% CI, 1.81-6.83) and MDI techniques (OR, 1.64; 95% CI, 1.01-2.65). Fluid and crystallized abilities were independently associated with medication behaviors. However, when fluid abilities were added to the model, literacy associations were reduced.
Among older asthmatics, interventions to promote proper medication use should seek to simplify tasks and patient roles in order to overcome cognitive load and suboptimal performance in self-care.