Cost-Effectiveness of Intervention Thresholds for the Treatment of Osteoporosis Based on FRAX(®) in Portugal.

Abstract

Cost-effective intervention thresholds (ITs) based on FRAX(®) were determined for Portugal. Assuming a willingness to pay (WTP) of €32,000 per quality-adjusted life years (QALYs), treatment with generic alendronate is cost effective for men and women aged 50years or more, with 10-year probabilities for major osteoporotic fractures and hip above 8.8 and 2.5%, respectively. The aim of the present study was to identify the 10-year probabilities of a major and hip osteoporotic fracture using FRAX(®) validated for Portugal, above which pharmacologic interventions become cost effective in the Portuguese context. A previously developed and validated state transition Markov cohort model was populated with epidemiologic, economic and quality-of-life fracture data from Portugal. Cost-effectiveness of FRAX(®)-based ITs was calculated for generic alendronate and proprietary zoledronic acid, denosumab and teriparatide were compared to "no intervention", assuming a WTP of €32,000 (two times national Gross Domestic Product per capita) per QALYs. In the Portuguese epidemiological and economic context, treatment with generic alendronate was cost effective for men and women aged 50years or more, with 10-year probabilities at or above 8.8% for major osteoporotic fractures and 2.5% for hip fractures. Cost-effective threshold 10-year probabilities for major osteoporotic and hip fractures were higher for zoledronic acid (20.4 and 10.1%), denosumab (34.9 and 10.1%) and teriparatide (77.8 and 62.6%), respectively. A tool is provided to perform the calculation of cost-effective ITs for different medications, according to age group and diverse levels of WTP. Cost-effective ITs, for different medications, age groups and WTP, based on 10-year probabilities of major and hip fracture probabilities calculated with FRAX are provided.