Cost-effectiveness of single-dose zoledronic acid for nursing home residents with osteoporosis in the USA

Objective To evaluate the cost-effectiveness of routine administration of single-dose zoledronic acid for nursing home residents with osteoporosis in the USA. Design Markov cohort simulation model based on published literature from a healthcare sector perspective over a lifetime horizon. Setting Nursing homes. Participants A hypothetical cohort of nursing home residents aged 85 years with osteoporosis. Interventions Two strategies were compared: (1) a single intravenous dose of zoledronic acid 5mg and (2) usual care (supplementation of calcium and vitamin D only). Primary and secondary outcome measures Incremental cost-effectiveness ratio (ICER), as measured by cost per quality-adjusted life year (QALY) gained. Results Compared with usual care, zoledronic acid had an ICER of $207400 per QALY gained and was not cost-effective at a conventional willingness-to-pay threshold of $100000 per QALY gained. The results were robust to a reasonable range of assumptions about incidence, mortality, quality-of-life effects and the cost of hip fracture and the cost of zoledronic acid. Zoledronic acid had a potential to become cost-effective if a fracture risk reduction with zoledronic acid was higher than 23% or if 6-month mortality in nursing home residents was lower than 16%. Probabilistic sensitivity analysis showed that the zoledronic acid would be cost-effective in 14%, 27% and 44% of simulations at willingness-to-pay thresholds of $50 000, $100000 or $200000 per QALY gained, respectively. Conclusions Routine administration of single-dose zoledronic acid in nursing home residents with osteoporosis is not a cost-effective use of resources in the USA but could be justifiable in those with a favourable life expectancy.