Phosphate binder use in patients undergoing centre‐based haemodialysis within the Metro North Kidney Health Service

Abstract

Reducing polypharmacy directly improves quality use of medicines, a key arm of the Australian National Medicines Policy. Numerous studies have illustrated that a reduction in pill burden improves patient compliance, reduces drug economics and minimizes therapy-related adverse effects. Phosphate binders are the single largest contributor to the daily pill burden in chronic kidney disease patients undergoing renal replacement therapy. The aim of this study was to examine the relationship between pill burden and cost of phosphate binders with biochemical parameters in patients undergoing centre-based haemodialysis within the Kidney Health Service of the Metro North Hospital and Health Service. Centre-based haemodialysis patients from three geographically different kidney units in Queensland, Australia, underwent a single, cross-sectional assessment of total daily pill burden from phosphate binders between May 2015 and August 2015. The total number of phosphate binder pills per week comprised of calcium carbonate, aluminium hydroxide, sevelamer hydrochloride, lanthanum and cinacalcet. The urea reduction ratio, serum albumin, serum calcium, serum phosphate and serum parathyroid hormone (PTH) were averaged across this period. Of the 138 patients in this study, 62 (44.9%) patients were from the Royal Brisbane and Women’s Hospital (RBWH), 40 (29.0%) patients were from Redcliffe Satellite Unit and 36 (26.1%) patients were from the Northlakes Satellite Unit. Eighty-two (59.4%) were male and the mean age was 66 (standard deviation 15) years. Between hospital comparisons of baseline co-morbidities revealed significant difference in hypertension (P = 0.014) only. Sevelamer hydrochloride was most commonly used at RBWH at 41%, followed by calcium carbonate (32%) and aluminium hydroxide (22%). In contrast, both Northlakes and Redcliffe had similar phosphate binder use with calcium carbonate being most popular (36% and 58% respectively), followed by sevelamer hydrochloride (33% and 15% respectively) and aluminium hydroxide (8% and 14% respectively). Forty-two percent of RBWH patients, 45% of Redcliffe patients and 58% of Northlakes patients were taking two or more classes of phosphate binders. There were no statistically significant differences across the three kidney health services in relation to total pill burden (P = 0.17), weekly phosphate binder cost (P = 0.13), or serum calcium (P = 0.35), serum phosphate (P = 0.61) and serum PTH (P = 1.00). Comparison of weekly phosphate binder cost between the three sites revealed no significant difference (P = 0.12) with RBWH $41.58 (1.89–84.58), Redcliffe $5.32 (1.89–46.52) and Northlakes $44.87 (5.20–87.52). No appreciable differences in the pill burden and phosphate binder cost per week were associated with biochemical outcomes between the RBWH, Northlakes and Redcliffe kidney health service. Several studies have recently emerged regarding the lack of efficacy and survival benefit of phosphate binders in patients undergoing centre-based haemodialysis. This study reinforces ongoing concerns regarding the minimal biochemical and economic improvement associated with phosphate binder use in this group of dialysis patients. Future studies should compare the cost and pill burden of phosphate binders in other Australian centres and ascertain whether any biochemical and economic changes occur in patients undergoing haemodialysis in the home environment.