Association of brief health literacy screening and blood pressure in primary care

Health literacy impacts health outcomes. However, the relationship to blood pressure is inconsistent. This study aimed to determine whether health literacy, assessed by clinic staff, is associated with blood pressure among patients with hypertension. The design was a cross-sectional study of a large sample of primary care patient encounters in 3 academic medical center clinics in Nashville, Tennessee. Health literacy was assessed using the Brief Health Literacy Screen, with higher scores indicating higher health literacy. Blood pressure was extracted from the electronic health record. Using 23,483 encounters in 10,644 patients, the authors examined the association of health literacy with blood pressure in multivariable analyses, adjusting for age, gender, race, education, and clinic location. Independent of educational attainment, 3-point increases in health literacy scores were associated with 0.74 mmHg higher systolic blood pressure (95% CI [0.38, 1.09]) and 0.30 mmHg higher diastolic blood pressure (95% CI [0.08, 0.51]). No interaction between education and health literacy was observed (p = .91). In this large primary care population of patients with hypertension, higher health literacy, as screened in clinical practice, was associated with a small increase in blood pressures. Future research is needed to explore this unexpected finding.