Cost utility analysis of prophylactic pamidronate for the prevention of skeletal related events in patients with advanced breast cancer

Metastatic bone disease is a common complication of advanced breast cancer. Recently, the results of a large randomized placebo-controlled trial demonstrated that monthly pamidronate infusions reduce the incidence of skeletal related events in these patients. In the current study, a cost-utility analysis was performed from a Canadian health care system perspective to estimate the incremental cost-effectiveness of pamidronate in patients with advanced breast cancer. Twenty-five advanced breast cancer patients who were bisphosphonate naive and had developed skeletal related complications were identified. Total hospital resource consumption was then collected for all patients. This included direct costs for hospitalization and costs for radiation treatment to bone, surgery, analgesics, blood products, diagnostic imaging, paramedical services and all related physician fees. Treatment preferences were estimated from a random sample of 25 women selected from the general population and 25 female health care professionals, using the Time Trade-Off technique. The outcomes were then generated through a decision-analytic model. Over a 12-month period, total costs in the pamidronate arm were approximately 44% higher than those in the no-treatment alternative (Can$ 9,180 vs Can$ 6,380). When treatment preferences were incorporated into the analysis, the results of the decision model revealed an incremental pamidronate cost of $18,700 per quality-adjusted life year gained. The results of the sensitivity analysis suggested that this estimate was dependent on the cost of treating skeletal related events, particularly bone surgery. Even though pamidronate has a high drug acquisition cost, the results of the cost-utility analysis suggest that this agent does provide patients with substantial quality-adjusted survival benefit at a reasonable cost to the Canadian health care system.