Table 1. Key parameters of benefit-cost model of four case-finding strategies, India.
| Parameter | Point estimate | Distribution and parameters for probabilistic sensitivity analysis |
|---|---|---|
| Discount rate | 3%16 | Uniform, 0%–8%32 |
| Avoided loss in employment (moderate or severe visual impairment or blind) | 30.2% reduction in employment for those aged 15–643,8 | Uniform, 19.5%–43.5%32 |
| Avoided mortality (moderate or severe visual impairment) | 1.26: 10-year all-cause mortality risk ratio relative to no visual impairment3,33 | Gaussian, mean: 1.26; SD: 0.063,33 |
| Avoided mortality (blind) | 1.90: 10-year all-cause mortality risk ratio relative to no visual impairment3,33 | Gaussian mean: 1.90; SD: 0.263,33 |
| Improved productivity in employment | Avoided 20% productivity loss9,34–36 | Uniform: 17%–23%9 |
| Avoided caregiver costs (moderate or severe visual impairment) | 5% of productive time for one person37 | Uniform: 2.5%–10.0% |
| Avoided caregiver costs (blind) | 10% of productive time for one person37 | Assumed as twice the draw for moderate or severe visual impairment |
| Productivity improvement in domestic work (moderate or severe visual impairment or blind) | 20% loss of productivity in household, non-market activities with value of loss estimated at 50% of wages38 | Productivity loss equal to draw from productivity loss in employment; value of time: uniform: 25%–75%38 |
| Increase in test scores from the provision of eyeglasses | 0.18 standard deviation improvement11–13 | Uniform: 0.11–0.2311–13 |
| Compliance rate of eyeglasses use, adults | 0.639 | Uniform: 0.4–0.8 |
| Compliance rate of eyeglasses use, children | 0.340 | Uniform: 0.2–0.4 |
| Patient costs per screening, US$ | 1.241 | Gaussian mean: 1.2; SD: 0.1841 |
| Patient costs per cataract surgery, US$ | 19.942 | Gaussian mean: 19.9; SD: 4.7742 |
| Provider costs, case finding (US$ per treatment initiated) | 8.0–29.3, varies by intervention and condition31 | Follows probabilistic sensitivity analysis in Wong et al.31 |
| Provider costs, one pair of eyeglasses, US$ | 4.831 | Uniform: 3.3–5.631 |
| Provider costs per cataract surgery, US$ | 71.031 | Uniform: 42.6–106.531 |
SD: standard deviation; US$: United States dollars.
Notes: Summary of key parameters used in the benefit-cost model. Any reported currencies are in 2020 figures.