Prevalence and associations of limited health literacy in chronic kidney disease: a systematic review.

BACKGROUND Health literacy (HL) is important in chronic disease. This review aimed to evaluate the literature evidence on prevalence and associations of limited HL in chronic kidney disease (CKD). METHODS Seven databases were searched using terms for CKD and HL. Studies were included that ascertained the prevalence of limited HL using a validated tool in adults with CKD of any stage. The primary outcome was an objectively measured prevalence of limited HL in a population with CKD. The secondary outcome was associations of limited HL. Two reviewers assessed study inclusion and quality. Prevalence values were combined using a random-effect model to give overall prevalence. RESULTS Eighty-two studies were identified from searching, of which six met the inclusion criteria. The total number of people in all studies was 1405. Five studies were in dialysis or transplant populations, and all were from the USA. There was a significant heterogeneity in the prevalence of limited HL [9-32% (median 25%, inter-quartile range 16%)]. The pooled prevalence of limited HL in all studies was 22.7% (95% confidence interval 20.6-24.8%), but study heterogeneity limited the generalizability of this combined prevalence. The review identified associations between limited HL and socio-economic factors (lower education attainment, lower income), and certain process and outcome measures (lower likelihood of referral for transplant, higher mortality). CONCLUSIONS Limited HL is common among people with CKD and independently associated with socio-economic factors and health outcomes. It may represent an important determinant of inequality in CKD.