This health-economic analysis investigated the cost, cost-effectiveness and cost-utility of intravenous paricalcitol compared with oral calcitriol and oral and intravenous alfacalcidol. The main finding was that intravenous paricalcitol demonstrated clear advantages with respect to costs, effectiveness and utilities compared with treatment with oral calcitriol and intravenous alfacalcidol (see Table V ).
The unit-cost data were based on German retail pharmacy prices, fixed in a tariff of charges with Germany-wide validity. The alfacalcidol products Doss® and Bondiol® and the calcitriol-product Osteotriol® were not chosen as comparators because of their primary indication for osteoporosis, which might explain the relatively high market share based on 4 million (Doss®) and 3.6 million (Bondiol®) defined daily doses (DDD) in 2003.
For oral alfacalcidol and calcitriol, a constant dosage of 0.5μg per patient per day with 100% compliance and no change in initial doses was assumed. Since intravenous paricalcitol is administered during the dialysis session, compliance with this medication was not an issue. However, the effectiveness of oral calcitriol and alfacalcidol is dependent upon patient compliance, which favours the use of paricalcitol.
The sensitivity analysis showed a strong influence of the G-DRG used. Nevertheless, all suitable G-DRGs associated with secondary hyperparathyroidism resulted in cost savings with use of paricalcitol compared with calcitriol and alfacalcidol, demonstrating the robustness of the results.
Reference to a real-world database, namely 875 million single prescriptions in Germany in 2003, shows that the administration costs per day for alfacalcidol and calcitriol were even higher than those estimated by our analytical approach. Based on 2.5 million DDD of Rocaltrol® in 2003, the average daily costs for calcitriol were reported as 3.28, which is equivalent to yearly costs of 1197. If this value were used for one day of treatment or one dialysis session with calcitriol, this would result in even higher benefit ratios for paricalcitol compared with calcitriol and alfacalcidol.
A limitation of this analysis is that the cost of adverse events has not been calculated. However, any additional cost beyond hospitalisations would potentially favour the use of paricalcitol, since a randomised controlled trial of calcitriol and paricalcitol showed a nearly 40% relative increase in the incidence of hypercalcaemia with calcitriol (9.2% and 6.7%, respectively) compared with paricalcitol.[3,24,45]
The number of hospitalisations per year was obtained from real-world clinical dialysis settings, including 11433 haemodialysis patients treated with paricalcitol (n = 4611) or calcitriol (n = 6832). As the discharges per 100000 population for Germany are 20% higher than the corresponding rates for the US, a conservative modelling approach was used (i.e. a premium rate was not used). The study by Dobrez et al. did not provide any information about disease-specific hospitalisations in the monotherapy subpopulation. Since disease-specific hospitalisations were not reported, all-cause hospitalisations were used in this analysis.
The survival rates of patients treated either with paricalcitol or calcitriol were obtained from patients who received the same therapy for the duration of follow-up. The robustness of these data may offset the uncertainty resulting from missing information regarding patients´ time of entry to the study and withdrawal.
The external validity of the Teng et al. study is supported by a second retrospective study of haemodialysis patients from a different dialysis facility commenced on either intravenous paricalcitol or intravenous calcitriol between 1999 and 2004. This study found the mortality rate (deaths/100 patient-years) was higher among patients receiving calcitriol than in those receiving paricalcitol, namely 19.6 (95% CI 18.2, 21.1) versus 15.3 (95% CI 13.6, 16.9), respectively (p = 0.0001). In addition, an international prospective observational study of haemodialysis patients showed a significantly lower mortality rate with vitamin D therapy compared with no vitamin D. This study also demonstrated that mortality with intravenous paricalcitol compared with no vitamin D was associated with the lowest mortality rate compared with oral vitamin D, intravenous calcitriol or any vitamin D versus no vitamin D, after adjusting for baseline demographics and co-morbidities, and time-varying laboratory values. However, intravenous paricalcitol was not compared with intravenous calcitriol in this study. Furthermore, the US Renal Data System has shown an overall reduction in mortality rates in a current dialysis population, and suggested this phenomenon may be associated with increased use of paricalcitol and other changes in overall medical practice.
Clin Drug Invest. 2006;26(11):629-638. © 2006 Adis Data Information BV
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Cite this: Health-Economic Comparison of Paricalcitol, Calcitriol and Alfacalcidol for the Treatment of Secondary Hyperparathyroidism during Haemodialysis - Medscape - Nov 01, 2006.