Table 4.
The results of cost-effectiveness analysis with different assumptions of the cumulative persistence rates
| Cumulative persistence rates, first, second, and third year (%) | Age 65 | Age 70 | Age 75 | Age 80 | ||
|---|---|---|---|---|---|---|
| Denosumab | ZA | |||||
|
Base case (ages 65, 70, 75, or 80) |
81, 55, 37 | 100, 52, 36 | ZA: cost-saving | ZA: cost-saving | ZA: cost-saving | ZA: cost-saving |
|
Sensitivity analysis 1* (ages 65, 70, 75, or 80) |
85, 63, 43 | 100, 52, 36 | ICER of D/A $980,400/QALY | ICER of D/A $699,300/QALY | ICER of D/A $537,000/QALY | ZA: cost-saving |
| Sensitivity analysis 2** (ages 65, 70, or 75) | 94, 92, 87 | 100, 52, 36 | ICER of D/A $87,200/QALY | ICER of D/A $29,000/QALY | ICER of D/A $6,400/QALY | N/A |
| Sensitivity analysis 3*** (ages 65, 70, or 75) | 94, 92, 87 | 100, 87, 85 | ICER of D/A $176,300/QALY | ICER of D/A $111,300/QALY | ICER of D/A $60,900/QALY | N/A |
| Sensitivity analysis 2** (age 80) | 83, 71, 59 | 100, 52, 36 | N/A | N/A | N/A | ICER of D/A $50,500/QALY |
| Sensitivity analysis 3*** (age 80) | 83, 71, 59 | 100, 67, 57 | N/A | N/A | N/A | ZA: cost-saving |
ZA, zoledronic acid; D/A, sequential denosumab/alendronate; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-years
The predetermined thresholds of willingness-to-pay were $47,500 (¥5 million) or $95,000 (¥10 million) per quality-adjusted life-year
*Scenario based on the upper bound of the 95% credible interval of a meta-analysis and our own assumption[21]
**Scenario based on a small retrospective observational study at a single institution in Japan (n = 102)[23]
***Scenario where in addition to higher cumulative persistence rates of denosumab based on a small observational study in Japan, higher cumulative persistence rates of zoledronic acid were modeled, assuming that the same ratios of the cumulative persistence rates of zoledronic acid to denosumab based on a meta-analysis were applied[21, 23]