Phosphate Binder Compliance Study in Patients with End-Stage Kidney Disease

Introduction: ~600k US end-stage kidney disease patients undergo dialysis, and >43% have serum phosphorus >5.5mg/dL, increasing bone disorder and mortality. Recent studies report phosphate binder (PB) non-adherence rates up to 78%. Objective: Understanding patient perspectives on PB therapy challenges to improve adherence and outcomes. Methods: 20-minute online survey was conducted (2/15-5/16/24) with patients from the National Kidney Foundation email list. Eligibility: on dialysis (in-center or home), ≥40 years old, using ≥1 phosphate management treatment, and insured. The survey assessed patient perspectives on daily pill burden, PB-related challenges, non-adherence drivers, and impact of PB attributes on compliance. Results: 200 patients surveyed. PBs had the highest daily pill requirements (4.8 pills/day) vs. diabetes, high cholesterol, high blood pressure, and depression medications (1.2-2.6 pills or injections/day). Among non-compliant group (≤80% compliant), 58% rated taking PBs as directed as “extremely important,” vs. 67%-100% for other medications. PB non-compliance was ~3-fold higher vs. other medications (37% of patients vs. 12-18%, p≤0.05). Self-reported non-compliant patients were 2.6-times more likely to report uncontrolled phosphate levels. Among 126 patients with <100% compliance, top barriers were forgetting to take PBs, too many pills, and large pill size. Patients were 4- and 2-times more likely to be compliant with fewer and smaller pills, respectively. Conclusion: PBs had the highest pill burden and lowest compliance. Pill number and size were two of the top barriers. Patients preferred regimens with fewer, smaller pills. Reducing pill burden and enhancing the perceived importance of phosphate control may improve adherence and phosphate management.