Economic evaluation of sevelamer for the treatment of hyperphosphatemia in chronic kidney disease patients not on dialysis in the United Kingdom

Abstract

Objectives:To determine the cost effectiveness of sevelamer vs calcium carbonate in patients with chronic kidney disease and not on dialysis (CKD-ND) from the perspective of the National Health Service (NHS) in the UK.Methods:A Markov decision analytic model was developed to estimate (1) total life years (LYs), quality-adjusted life years (QALYs), and costs for patients treated with sevelamer or calcium carbonate; and (2) incremental costs per LY gained (LYG) and per QALY gained for sevelamer vs calcium carbonate. Data informing probability transitions to all-cause death and dialysis inception in CKD-ND patients were taken directly from the INDEPENDENT-CKD study and were extrapolated beyond the 3-year clinical trial using Weibull regression analysis. Estimates of health utility and costs (in £2011) were derived from the published literature.Results:Over a lifetime horizon, sevelamer treatment resulted in a gain of 2.05 LYs and 1.56 QALYs per patient, an increase of £37,282 in total costs per patient vs calcium carbonate (3.5% discount), and a per-patient cost of £18,193/LYG and £23,878/QALY gained. Results were robust to alternative assumptions in key parameters; results were most sensitive to alternative assumptions regarding the mean daily dose of sevelamer, impact of sevelamer on dialysis initiation, cost of dialysis, and health utility estimates. The probabilistic sensitivity analysis showed that sevelamer was cost-effective vs calcium carbonate in 93% of simulations at a willingness-to-pay threshold of £30,000/QALY gained.Limitations:While the model simulated a real-world clinical setting, this analysis was subject to limitations common to all decision analytic models, in that it used a mix of data sources and relied on several assumptions. Not all variables that impact real-world outcomes and costs were included in this model.Conclusions:Sevelamer is a cost-effective option compared to calcium carbonate for the first-line treatment of hyperphosphatemia in CKD-ND patients in the UK.