Choosing Not to Take Phosphate Binders : The Role of Dialysis Patients' Medication Beliefs

Abstract

Objective: Patients with end-stage renal disease (ESRD) receiving haemodialysis are at risk of cardiovascular disease and bone disorders related to high levels of serum phosphate (PO(4)). Phosphate binders are an important treatment; however, non-adherence remains a significant issue. This study investigates whether patients' beliefs about medicines predict intentional non-adherence to phosphate binders. Method: This was a cross-sectional study of ESRD patients (n = 76). Non-adherence was measured in two ways: (1) the self-report Medication Adherence Questionnaire (MAQ) and (2) 3-month average level of serum phosphate. The Beliefs about Medicines questionnaire was used to assess general and specific beliefs towards phosphate medicines. Results: Eleven (14.5% of 76) patients reported being intentionally non-adherent to phosphate binders. Patients' beliefs that phosphate binders were less necessary were significantly associated with intentional self-reported non- adherence. Furthermore, patients with greater concerns about phosphate binders had higher serum phosphate levels. Conclusion: Assessing patient beliefs about medicines is a reliable indicator of intentional non-adherence to treatment with phosphate binders. These findings may help in identifying ways in which adherence rates to phosphate binders can be improved.