Performance of a brief survey to assess health literacy in patients receiving hemodialysis

BACKGROUND Health literacy is associated with important outcomes among patients with kidney disease, but widely used measures of health literacy can be burdensome. In an effort to make a practical assessment available, we compared the performance of the three-item brief health literacy screen (BHLS) to other widely used measures of health literacy among patients with end-stage renal disease (ESRD). METHODS Adult hemodialysis patients (n = 150) from four urban dialysis facilities participated in a cross-sectional study from 2009 to 2012. Three health literacy measures were administered including (i) the rapid estimate of adult literacy in medicine (REALM), (ii) the short test of functional health literacy in adults (S-TOFHLA) and (iii) the three-item BHLS. The mini-mental state exam assessed cognitive status, and the chronic hemodialysis knowledge survey (CHeKS) and perceived kidney disease knowledge survey (PiKS) assessed kidney knowledge. Spearman's ρs and area under the receiver-operating curves examined relationships between the aforementioned variables. RESULTS Participants had received dialysis for a mean of 4.6 years. They were 49% female, 73% African American and averaged 52 years of age. Less education and less cognitive capacity were each associated (P < 0.05) with lower health literacy for all three health literacy measures. Performance on the BHLS was significantly associated with the REALM [0.35 (95% confidence interval (95% CI): 0.20-0.49); P < 0.001] and S-TOFHLA [0.49 (95% CI: 0.35-0.69); P < 0.001], the CHeKS [0.43 (95% CI: 0.28-0.55); P < 0.001] and PiKS [0.41 (95% CI: 0.27-0.54); P < 0.001]. CONCLUSIONS The BHLS demonstrates evidence of construct validity among ESRD patients. Furthermore, health literacy was associated with kidney knowledge, supporting it as a potential intervention target to improve outcomes among patients with lower health literacy.