Analytical approach:
A Markov model was constructed to estimate the clinical and economic outcomes accrued over 10 years, by a hypothetical cohort of CKD patients with secondary hyperparathyroidism. The authors stated that the perspective was that of the UK NHS. A societal perspective was also considered.
Effectiveness data:
The data were from published literature, including paricalcitol clinical trials and observational studies. The main sources for the clinical inputs were two large cohort studies. The main efficacy outcomes were the reductions in secondary hyperparathyroidism, proteinuria, complications, and mortality.
Monetary benefit and utility valuations:
The utilities came from two sources. One study provided UK estimates for patients with severe CKD (stage five; haemodialysis, peritoneal dialysis, and transplantation) and the other provided US population estimates for CKD stages two, three, and four, using the time trade-off method.
Measure of benefit:
Life-years and quality-adjusted life-years (QALYs) were the benefit measures. These were discounted at an annual rate of 3.5%.
Cost data:
The costs included those of renal failure (particularly dialysis and transplantation in CKD stage five), complications, medications, and routine monitoring. The unit costs came from published sources. All costs were in UK pounds sterling (£) and the price year was 2005 to 2006. A discount rate of 3.5% per annum was applied to all future costs.
Analysis of uncertainty:
The assessment of parameter uncertainty was undertaken using univariate and probabilistic sensitivity analyses. For the univariate analyses, the ranges selected were presented and justified. For the probabilistic analyses the results were presented in a cost-effectiveness acceptability curve. Several alternative scenarios were evaluated, including the consideration of indirect costs (work productivity losses; societal perspective) and a lifetime horizon.