The effect of health literacy, depression, and pill burden on medication nonadherence in patients with kidney disease including kidney failure requiring dialysis

Abstract

Abstract Aim To identify independent contributors to medication nonadherence in chronic kidney disease (CKD) and kidney failure (KF) patients on dialysis.Background Medication nonadherence is common in chronic diseases, including CKD and KF patients. Identification of independent contributors may enable the development of targeted strategies to improve adherence.Methods Cross-sectional design. We assessed self-reported medication adherence (using Morisky Medication Adherence Scale), demographic factors, comorbidities, pill burden, cognitive function (using Modified mini-mental scale, Trail-making test A & B and Stroop task), health literacy (HL) (using a multi-dimensional instrument, Health Literacy Questionnaire), and depression (using Beck depression inventory 2) in a cohort of CKD and KF patients. Multivariable logistic regression (LR) models with covariates chosen from univariate analyses used to identify independent predictors of treatment nonadherence.Results Compared to CKD (N = 113) patients, KF patients on dialysis (N = 107) were significantly younger (65.3 ± 12.1 vs 68.0 ± 11.0years), had higher vascular disease burden, heavier pill burden (mean 21.8 vs 9.7 pills daily) and lower self-reported adherence. In multivariate LR analysis, nonadherence was significantly associated with younger age (OR 0.65 for older age, p = 0.002), KF status (OR 1.82, p = 0.044), lower HL relevant to patient-health care provider engagement (HLQ6) (OR 2.33, p = 0.023) and depression (OR 2.52, p = 0.008). When pill burden was included in the multivariate model, the significance of association between KF status and nonadherence became marginal (OR1.88, p = 0.084), while age, HLQ6 and depression retained significant independent association.Conclusion Medication nonadherence is significantly worse in KF patients. Strategies to improve nonadherence should target younger patients, implement strategies to enhance patient-provider engagement and address depression.