Association between medication adherence and clinical outcomes in patients with chronic kidney disease: a prospective cohort study

Abstract

Background: There is limited evidence of medication adherence related to progression of chronic kidney disease (CKD) worldwide. The aim of this study was to determine associations between medication adherence and the progression of CKD in outpatients with CKD. Methods: This cohort study recruited 339 Thai patients with stages 3–5 CKD. Patients with a glomerular disease or receiving renal replacement therapy before recruitment were excluded. 295 were followed up regarding their serum creatinine, blood pressure, glycated hemoglobin, and low-density lipoprotein cholesterol over 12 months. Medication adherence was measured at baseline using the Thai version of the 8-Item Morisky Medication Adherence Scale®. The primary outcome was the progression of CKD. The progression of CKD was defined as either a decline in estimated glomerular filtration rate of at least 3 ml/min/1.73 m2/year or initiation of renal replacement therapy. Univariate and multivariate analyses were performed using Chi-squared tests and multiple logistic regressions. Results: Twenty-one percent had poor adherence. Younger patients were more likely to have poor adherence (adjusted OR 2.81, 95 % CI 1.45–5.43). Anti-hypertensive agents were the most frequently reported as not being taken (52 %). Patients with poor adherence were associated with the progression of CKD (adjusted OR 1.96, 95 % CI 1.02–3.76). Those with poor adherence were less likely to control their blood pressure, than moderate-to-high adherence group (p < 0.01). Conclusion: The findings suggest that CKD patients with poor medication adherence are more likely to have progression of CKD. Health care providers should acknowledge these findings and provide effective strategies to deal with this issue. © 2016, Japanese Society of Nephrology.