Cost-effectiveness of osteoporosis screening strategies for hip fracture prevention in older Chinese people: a decision tree modeling study in the Mr. OS and Ms. OS cohort in Hong Kong.

Despite the high costs of hip fracture, many governments provide limited support for osteoporosis screening. We demonstrated that osteoporosis screening by dual-energy X-ray absorptiometry (DXA) with or without pre-screening by Fracture Risk Assessment Tool (FRAX) or calcaneal ultrasound are more cost-effective than no screening in Chinese people aged 65 or over in Hong Kong.

INTRODUCTION: To examine the cost-effective potential osteoporosis screening strategies for hip fracture prevention in Hong Kong.

METHODS: Decision tree models were constructed to evaluate the cost per quality-adjusted life years (QALYs) of the different osteoporosis screening strategies followed by subsequent 5-year treatment with alendronate compared to no screening (but treat if a hip fracture occurs). The multiple osteoporosis screening strategies were composed of alternative tests and initiation age groups were evaluated with a 10-year horizon, and treatment were assigned if central dual-energy X-ray absorptiometry (DXA) T-score (at either the hip or spine) is - 2.5 or less. Strategies included DXA for all people and pre-screening with the Fracture Risk Assessment Tool (FRAX) at specific thresholds or by calcaneal quantitative ultrasonography (QUS) before taking DXA examination. All the model inputs were based on the Mr. OS and Ms. OS Hong Kong cohort; data are obtained from the Social Welfare Department or the published literature.

RESULTS: All of the screening strategies, including the universal screening with DXA and the pre-screening with FRAX or QUS before DXA, were consistently more cost-effective than no screening for people aged 65 years old or over. One-way sensitivity analysis with a more optimistic assumption on treatment adherence or inclusion of other major osteoporotic fractures did not change the results materially. Probabilistic sensitivity analyses showed a dominant role of pre-screening with FRAX followed by subsequent osteoporosis drug treatment in people aged 70 years old or over in Hong Kong.

CONCLUSIONS: Osteoporosis screening strategies based on DXA with or without pre-screening are more cost-effective compared to no screening for Chinese people aged 65 or over in Hong Kong.