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

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.