How does health literacy affect health in adults with asthma?

Published Online: April 15, 2103

Low health literacy is common, especially among those with low socioeconomic status, the elderly, and those whose primary language is not English, reflecting limited educational opportunities. The severity and complexity of asthma tends to be high in these same patients. One theory explaining poor asthma outcomes among disadvantaged patients is that health literacy affects their ability to manage one or more health problems like asthma.

In this study, published in The Journal of Allergy and Clinical Immunology (JACI), Apter et al examine how health literacy is related to asthma self-management. Patients with moderate-severe asthma were recruited from clinics serving low-income urban neighborhoods. Health literacy was measured by a standard test of reading and understanding medical information (print literacy) and a test of numerical concepts needed for patient to manage asthma (numeracy). Then participants’ subsequent management of medications, measured as electronically recorded use of inhaled steroid medication, and asthma status were assessed prospectively for 26 weeks. Two hundred eighty-four patients participated in the study. The average age was 48, most were female, most were African American, and baseline measurement of lung function (FEV1) showed moderately severe asthma. Almost one third had been hospitalized and more than half had required an Emergency Department visit for asthma in the previous year. Most patients had adequate reading scores and answered between 2 and 3 out of 4 numeracy questions correctly. On average patients took about 66% of prescribed inhaled steroid doses during the study.

Higher health literacy scores, whether measured as numeracy or print literacy, were associated with better adherence to prescribed medication, fewer symptoms, and better quality of life from asthma when controlling for age and sex. These associations were diminished somewhat when adjusting for race/ethnicity that was highly correlated with household income and educational status. That is, the effect of minority status which was associated with poorer outcomes could not be separated from the effect of poverty and limited educational opportunities on asthma outcomes.

This study shows the relationship between literacy and health is complex and supports the importance of considering health literacy when clinicians communicate with patients. Finding ways to account for and address the literacy needs of patients may improve asthma outcomes. In the long-term addressing poverty and educational opportunities is essential for better health.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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