Association of Health Literacy With Diabetes Outcomes

To examine the association between health literacy and diabetes outcomes among patients with type 2 diabetes. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional observational study of 408 English- and Spanish-speaking patients who were older than 30 years and had type 2 diabetes identified from the clinical database of 2 primary care clinics of a university-affiliated public hospital in San Francisco, Calif. Participants were enrolled and completed questionnaires between June and December 2000. We assessed patients' health literacy by using the short-form Test of Functional Health Literacy in Adults (s-TOFHLA) in English or Spanish. MAIN OUTCOME MEASURES: Most recent hemoglobin A(1c) (HbA(1c)) level. Patients were classified as having tight glycemic control if their HbA(1c) was in the lowest quartile and poor control if it was in the highest quartile. We also measured the presence of self-reported diabetes complications.

After adjusting for patients' sociodemographic characteristics, depressive symptoms, social support, treatment regimen, and years with diabetes, for each 1-point decrement in s-TOFHLA score, the HbA(1c) value increased by 0.02 (P =.02). Patients with inadequate health literacy were less likely than patients with adequate health literacy to achieve tight glycemic control (HbA(1c) or = 9.5%; adjusted OR, 2.03; 95% CI, 1.11-3.73; P =.02) and to report having retinopathy (adjusted OR, 2.33; 95% CI, 1.19-4.57; P =.01).