30th Annual Meeting of the Society for Medical Decision Making (October 19-22, 2008): COST-EFFECTIVENESS OF SUPPLEMENTATION WITH VITAMIN K FOR THE PRIMARY PREVENTION OF OSTEOPOROTIC FRACTURES IN POSTMENOPAUSAL WOMEN

Sunday, October 19, 2008

Columbus A-C (Hyatt Regency Penns Landing)

Olga Gajic-Veljanoski, MD, MSc, University of Toronto, Department of Health Policy, Management and Evaluation, Toronto, ON, Canada, Angela M. Cheung, MD, PhD, FRCP(C), Osteoporosis Program, University Health Network, Toronto, ON, Canada, Kamran Khan, MD, MPH, FRCPC, Centre for Research on Inner City Health, Toronto, ON, Canada, George Tomlinson, PhD, University of Toronto, Department of Health Policy Management and Evaluation, Toronto, ON, Canada and Ahmed M. Bayoumi, MD, MSc, Centre for Research on Inner City Health, the Keenan Research Centre in the Li Ka Shing Knowledge Institute, Toronto, ON ON ON, Canada Canada Canada

Purpose: While current guidelines recommend vitamin D3 and calcium for the prevention of osteoporosis in postmenopausal women, vitamin K may be an effective alternative. We evaluated the cost-effectiveness of oral vitamin K2 for the primary prevention of osteoporotic fractures in young postmenopausal women.

Methods: We developed a microsimulation model to compare the following strategies: 1) vitamin K2 concurrent with vitamin D3 and calcium; 2) vitamin D3 and calcium only; and 3) no supplementation. The base case was a 50-year-old postmenopausal woman with a normal bone mineral density or osteopenia and no prior fractures. Our model incorporated age-specific hip, clinical vertebral and wrist fracture rates and mortality rates. The model’s perspective was societal and the time horizon was the patient’s lifetime. We modeled fracture risk, including changing risks over time and assumed that osteoporosis therapy with alendronate was initiated after a fracture. We estimated the efficacy of vitamin K2 from a published meta-analysis and the efficacy of vitamin D3 and calcium from our systematic review and meta-analysis of the literature. Outcomes were expressed as survival, quality-adjusted life years (QALYs), and costs, lifetime costs and incremental cost-effectiveness ratios. We discounted costs and QALYs at 3%. We estimated second-order uncertainty by simulating 1000 trials, each of 1000 patients.
Results: Compared to no supplementation, lifetime supplementation with vitamin D and calcium was associated with an increased survival of 0.29 years (95% credible interval [CrI] -0.38 to 0.99), 0.27 QALYs (95% CrI: -0.35 to 0.93), and incremental costs of $11,891 (95% CrI: $9,564 to $14,349). Compared to vitamin D and calcium, vitamin K was associated with further gains of 3.55 years (95% CrI 1.31 to 5.49) and 3.31 QALYs (95% CrI: 1.21 to 5.14), and incremental costs of $3,417 (95% CrI 854 to 4,579). The vitamin D and calcium strategy was eliminated by extended dominance. Compared to no treatment, the incremental cost-effectiveness of vitamin K was $3,986/life year and $4,494/QALY. At a societal willingness-to-pay (WTP) threshold of $20,000/QALY, there was a 99.1% probability that the vitamin K strategy was cost-effective. At a WTP of $50,000/QALY, the per-person expected value of perfect information was $24.63.

Conclusions: Adding vitamin K to currently recommended supplementation with vitamin D3 and calcium is highly cost-effective for the lifetime prevention of fractures in postmenopausal women.

See more of: Poster Session I

See more of: 30th Annual Meeting of the Society for Medical Decision Making (October 19-22, 2008)

7CEA COST-EFFECTIVENESS OF SUPPLEMENTATION WITH VITAMIN K FOR THE PRIMARY PREVENTION OF OSTEOPOROTIC FRACTURES IN POSTMENOPAUSAL WOMEN