Racial disparities in health literacy in a primary care setting

The ability to calculate is an important aspect of health literacy and essential for many chronic disease self-care activities. The Newest Vital Sign (NVS) assesses numeracy skills in a face-to-face interview. The NVS uses a nutrition food label to ask 4 items requiring basic math skills and 2 reading items. In this study, we used the NVS as part of a self-administered questionnaire (SAQ) examining hypertension self-care. We hypothesized that participants would have higher health literacy scores because they could use paper and pencil to make calculations. Logistic regression was performed to determine odds ratios (OR) and 95% confidence intervals (CIs). Eligible participants had hypertension (n=196) and were recruited from a primary care clinic. Participants were 77% Black, 67% women, and they had an average age of 56. Only 48% of the participants attempted all 6 NVS items. Blacks had 60% reduced odds of completing the full NVS (OR=0.40; 95% CI=0.17-0.93). “Don't know” responses were more frequent for math-related items (16.1% to 28.8%) than reading-related items (9.8% to 10.1%). Mean NVS scores for Blacks were significantly lower than Whites' scores (1.97 versus 3.33, p=.003). After adjusting for confounders, Blacks had 83% reduced odds of having adequate to good numeracy skills (OR=0.17; 95% CI=0.07-0.40) as compared to Whites. Administering the NVS as a SAQ resulted in lower health literacy scores for Blacks than have previously been reported; however, we were unable to control for participants' education level. Recommendations for modifying the NVS based on additional qualitative findings will be presented.