Medication-related health literacy in patients on hemodialysis assessed with the RALPH interview guide

To study medication-related health literacy (HL) among patients on hemodialysis using phosphate-binding medication (PBM) and explore its association with medication adherence.

This planned sub-study was part of a prospective intervention study in patients on hemodialysis with a high serum phosphate concentration and high PBM pill burden. Functional, communicative, and critical medication-related HL were assessed using the Recognizing and Addressing Limited Pharmaceutical Literacy interview guide, and self-reported PBM adherence was evaluated using the MARS-5 (Medication Adherence Report Scale-5) questionnaire. Primary outcome was the proportion of patients who perceived difficulties in ≥ 1 HL domain, secondary outcome was the prevalence of perceived difficulties within the HL domains. Exploratory outcome was the association between medication-related HL and self-reported adherence to PBM. Data analysis was performed using descriptive statistics and univariable and multivariable logistic regression. Covariates for logistic regression were age, gender, number of medications, and PBM and total pill burden.

Of the 75 patients, 81 % perceived difficulties, mainly in the critical domain. Around 65 % of the patients experienced difficulties assessing the applicability and reliability of information. 26.7 % of the patients had a MARS-5 score ≤ 22 and were classified as non-adherent. No association was found between medication-related HL in general and medication adherence (OR 1.13, 95 %CI 0.31-4.10). However, age was significantly associated with adherence (OR 1.05, 95 %CI 1.02-1.09).

Over 80 % of patients on hemodialysis using PBM experience difficulties in using and applying medication and treatment information. These results suggest that patients on hemodialysis need more support to effectively use this information.

Healthcare professionals should guide patients in the adequate use and application of treatment information, to improve the effective use of PBM. Universal use of HL-sensitive communication strategies in patients on dialysis, including the teach-back method, could enhance patient understanding and engagement, potentially improving self-management and medication adherence.