RESUMO
OBJECTIVES: To evaluate two of the various treatment strategies of bone metastasis- single-fraction radiotherapy and multiple-fraction radiotherapy. METHODS: A multistage Markov decision model was applied to assess the incremental costs per quality-adjusted life-year (QALY) gained of single fraction against multiple fractions. The model had a monthly cycle length over a lifetime horizon with 1000 hypothetical cohort samples. The EuroQol five-dimensional questionnaire was used to estimate the health-related quality of life in patients. To cope with parameters of uncertainty, we conducted a probabilistic sensitivity analysis using a Monte-Carlo simulation technique. Both cost and utility variables were discounted by 3% in the base model. Strategies were assessed considering a willingness-to-pay threshold of US $6578 per QALY gained. RESULTS: The expected mean cost and quality-adjusted life-years were, respectively, US $447.28 and 5.95 months for patients receiving single-fraction radiotherapy and US $1269.66 and 7.87 months for those receiving multiple-fraction radiotherapy. The incremental cost-utility ratio was US $428.38 per QALY. Considering the Iranian gross domestic product per capita (US $6578) as the recommended willingness to pay for 1 QALY gained, the multiple-fraction method was found to be a cost-effective strategy. CONCLUSIONS: Policymakers should advocate the multiple-fraction method instead of the single-fraction method in the treatment of patients with painful bone metastases.