Wee1 within the cinacalcet arm. Transition Probabilities The initial transition probabilities to 4 PTH categories in both treatment arms were estimated using patient level data derived from a clinical trial of cinacalcet conducted in Japan22. The proportion of withdrawal from cinacalcet was obtained from this trial22 and another dose finding study.23 Transition to higher PTH categories was assumed to occur at a rate of 10% per year in the conventional treatment arm. This assumption was not applied to patients treated with cinacalcet based on the report that cinacalcet can effectively exert long term control of PTH levels without dose escalation.27 A transition probability of an event occurring over a time interval was calculated using a rate according to the following formula: P 1 exp.28 Table 2 lists the input parameters used to calculate the probabilities of clinical outcomes. The incidence of non CV death and relative risk by PTH category were derived from a nationwide registry of Japanese dialysis patients.12,29 The incidence of CV events was derived from the Q Cohort Study, a large scale prospective observational study of 3,170 hemodialysis enzalutamide patients in Kyushu, Japan.30 The rate of death after CV events also was derived from the Q Cohort Study.
The relative risk of CV events by PTH category was derived from the 5-HT Receptor Japan Dialysis Outcomes and Practice Patterns Study.11 Because cinacalcet decreases not only PTH levels, but also serumCosting was undertaken from the perspective of the third party health care payer in Japan. Drug costs were obtained from the 2010 National Health Insurance Price List set by the Ministry of Health, Labor, and Welfare in Japan.36 Costs of cinacalcet per cycle were calculated using the doses of cinacalcet used for patients who had intact PTH levels 500 pg/mL at baseline in the long term study.24 Costs for conventional treatment were calculated using data from a baseline analysis of the Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients.37 We assumed that costs of active vitamin D and phosphate binders do not change during treatment with cinacalcet, based on data from an interim analysis of the MBD 5D.38 We explored Candesartan whether this assumption affects the cost effectiveness of cinacalcet in the sensitivity analysis.
Surgical costs for parathyroidectomy with autotransplant were calculated by a clinical combination of fee for service and a per diem inclusive rate set by the Diagnosis Procedure Combination.39 Because intravenous active vitamin D treatment usually is discontinued after successful parathyroidectomy, we assumed that costs for medications to treat SHPT substantially decrease after surgery. Given the lack of data for costs for CV events and fracture for dialysis patients, we used data from other populations. Costs for CV events were derived from an economic analysis of Japanese patients with hypertension,40 with a weighted average according to frequencies reported in the Q Cohort Study.30 Costs for fracture were derived from a study of patients with hip fracture in Japan.41 Dialysis costs were derived from the report by the Japanese Association of Dialysis Physicians,42 but were not included in the base case analysis. All costs were calculated in JapaneseYen and converted into US dollars.