1. A Markov state-transition model was used to determine osteoporosis treatment thresholds in osteoporotic Hong Kong postmenopausal women, using local data of hip, vertebral, and wrist fracture incidence and mortality.
2. The lifetime costs and quality-adjusted life years (QALYs) for the treated (osteoporosis treatment for 5 years) and untreated cohorts were estimated from a societal perspective.
3. The incremental cost-effectiveness ratio for treatment in women around age 50 years was estimated to be approximately HK$3.6 million per QALY. This decreased with increasing age and fell below the cost-effectiveness threshold of $333 840 from the age of 70 years.
4. Probabilistic sensitivity analysis showed that treatment for those aged ≥70 years had a 75% likelihood of being cost-effective, even at a QALY value of only about $250 000.
5. The cost-effectiveness model can be used together with the World Health Organization fracture risk assessment algorithm to determine whether treatment is likely to be cost-effective at a given QALY value for any individual.