Table 3. One-way sensitivity analyses of the base-case analysis of the incidence parameter in an economic evaluation of wastewater surveillance combined with clinical COVID-19 screening tests, Japan*.
| Incidence† | Relative value of option 2 |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Option 1 |
Option 2 |
Incremental cost§ | Incremental benefit¶ | Relative ROI# | |||||||
| Cost | Benefit | ROI‡ | Cost | Benefit | ROI‡ | ||||||
| 10 | $67.04 | $1.39 | 0.02 | $53.60 | $1.14 | 0.02 | –$13.44 | –$0.25 | 54 | ||
| 50 | $67.04 | $7.03 | 0.10 | $53.61 | $5.94 | 0.11 | –$13.44 | –$1.09 | 12 | ||
| 100 | $67.05 | $14.09 | 0.21 | $53.61 | $11.94 | 0.22 | –$13.43 | –$2.15 | 6 | ||
| 400 | $67.07 | $56.43 | 0.84 | $53.66 | $47.94 | 0.89 | –$13.41 | –$8.49 | 1.58 | ||
| 445 | $67.08 | $62.78 | 0.94 | $53.67 | $53.34 | 0.99 | –$13.41 | –$9.44 | 1.42 | ||
| 450 | $67.08 | $63.49 | 0.95 | $53.67 | $53.94 | 1.01 | –$13.41 | –$9.54 | 1.40 | ||
| 475 | $67.08 | $67.01 | 0.999 | $53.67 | $56.94 | 1.06 | –$13.41 | –$10.07 | 1.33 | ||
| 480 | $67.08 | $67.72 | 1.010 | $53.67 | $57.54 | 1.07 | –$13.41 | –$10.18 | 1.32 | ||
| 500 | $67.08 | $70.54 | 1.05 | $53.68 | $59.94 | 1.12 | –$13.40 | –$10.60 | 1.26 | ||
| 600 | $67.09 | $84.65 | 1.26 | $53.69 | $71.94 | 1.34 | –$13.40 | –$12.71 | 1.05 | ||
| 630 | $67.09 | $88.89 | 1.32 | $53.70 | $75.54 | 1.41 | –$13.39 | –$13.35 | 1.004 | ||
| 635 | $67.09 | $89.59 | 1.34 | $53.70 | $76.14 | 1.42 | –$13.39 | –$13.45 | 0.996 | ||
| 700 | $67.10 | $98.77 | 1.47 | $53.71 | $83.94 | 1.56 | –$13.39 | –$14.83 | 0.90 | ||
| 1,000 | $67.12 | $141.11 | 2 | $53.75 | $119.94 | 2 | –$13.37 | –$21.16 | 0.63 | ||
| 2,000 | $67.20 | $282.23 | 4 | $53.91 | $239.95 | 4 | –$13.29 | –$42.29 | 0.31 | ||
| 5,000 | $67.45 | $705.62 | 10 | $54.37 | $599.96 | 11 | –$13.07 | –$105.66 | 0.12 | ||
| 10,000 | $67.85 | $1,411.26 | 21 | $55.14 | $1,199.97 | 22 | –$12.71 | –$211.29 | 0.06 | ||
*Option 1 is clinical tests only; option 2 is wastewater surveillance and clinical tests. If an option is cost-saving compared with its comparator, the option’s ROI is estimated to exceed 1. The comparator of options 1 and 2 is do-nothing. All monetary values were expressed in 2022 US dollars. ROI, return on investment. †Disease incidence per day per 1 million residents in the area. ‡ROI is benefit divided by cost for each option. §Incremental cost is the cost of option 2 minus cost of option 1. A negative value of incremental cost indicates that option 2 has a lower cost or is cost-saving, compared with option 1. This could be interpreted as option 2’s relative benefit. ¶Incremental benefit is the benefit of option 2 minus benefit of option 1. A negative value of incremental benefit indicates that option 2 has a lower benefit compared with option 1, which could be interpreted as option 2’s relative cost. #Relative ROI is incremental cost divided by incremental benefit.