Relationship between Health Literacy and Kidney Function.

AIM: Low health literacy (HL) may contribute to poor self-management of chronic kidney disease (CKD) and poor kidney function. This study aimed to assess the relationship between HL and estimated glomerular filtration rate (eGFR).

METHODS: A cross-sectional observational study was conducted among consecutive eligible adult patients with CKD stages 1-4 attending an outpatient nephrology clinic. HL was assessed using Newest Vital Sign (NVS). eGFR was estimated using the Modification of Diet in Renal Disease equation. CKD self-management behaviour knowledge was assessed using a study instrument (CKD self-management knowledge (SMKT)).

RESULTS: One hundred fifty patients participated in the study (83% participation rate). The prevalence of high likelihood of limited HL was 32.7%. Participants' eGFRs ranged from 17 to 152 mL/min / 1.73 m(2) , with over 80% of the eGFRs below 60 mL/min / 1.73 m(2) . HL was associated with eGFR after controlling for all demographics except age, race and gender (which are included in eGFR equation) (P = 0.05). Every unit increase in NVS score was associated with a 1.9% increase (95% confidence interval = 0 to 3.86%) in eGFR (model R square = 0.23, P = 0.002), which remained significant after controlling for CKD-SMKT (P = 0.05; model R square = 0.28, P < 0.001). The relationship was non-significant after controlling for age, although it remained significant after controlling for other demographics including gender and race.

CONCLUSIONS: There is a small but significant association between HL and eGFR. Providers should use HL-tailored communication strategies in CKD patients. Larger multicentre studies are needed to substantiate this relationship.