Table 4.
Selected sensitivity analysis outcomes for incidence of 0.013.
| Variable | Variable low-end |
Base- case 5 yrs |
Variable high-end |
Elasticity† | ||||
|---|---|---|---|---|---|---|---|---|
| Years with HIV incidence | 5 years | -- | -- | -- | n/a | -- | ||
| Ave. CD4 decline/yr, untreated | 22 cells/µL/yr | 7.5 yrs | 6 yrs | -- | -- | 4 yrs | 75 cells/µL/yr | 0.459 |
| Time to detect virologic failure | 3 mo. | -- | -- | -- | -- | -- | 24 mo. | 0.025 |
| Reduction in transmission due to diagnosis | 0% | 7.5 yrs | 6 yrs | -- | -- | 4 yrs | 50% | 0.734 |
| VCT cost, per tester | $2 | 2 yrs | 4 yrs | -- | 7.5 yrs | 15 yrs | $50 | 0.047 |
| 1st-line HAART cost, per patient-year | $50 | 7.5 yrs | 7.5 yrs | -- | -- | -- | $1000 | 0.383 |
| 2nd-line HAART cost, per patient-year | $200 | 6 yrs | 6 yrs | -- | -- | -- | $2000 | 0.326 |
| Linkage from diagnosis to care* | 30% + | 7.5 yrs | 6 yrs | -- | -- | -- | 100% | 0.048 |
| Mortality rate, on effective ART | ½ base | -- | -- | -- | -- | 6 yrs | 2 × base | −0.047 |
| Failure rates on 1st-line HAART* | 1% + | 6 yrs | 6 yrs | -- | -- | -- | 40% + | 0.191 |
| Failure rates on 2nd-line HAART* | 1% + | -- | -- | -- | -- | 6 yrs | 40% + | 0.052 |
| HIV transmission rates, no treatment (reproductive number) | R0 = 0.5 | 6 yrs | 6 yrs | -- | -- | -- | R0 = 1.2 | −0.369 |
| HIV transmissions, on ART (per person-year) | 0.001 | -- | -- | -- | -- | -- | 0.045 | 0.019 |
| Quality of life values** | Small differential | 6 yrs | -- | -- | -- | 4 yrs | Large differential | −0.458 |
| Maximal rise in CD4 count due to suppressive HAART | ½ base | -- | -- | -- | 6 yrs | 6 yrs | 1.5 × base | -- |
| Length of follow-up after year 30 (base = 15 years) | n/a | -- | -- | -- | 40 yrs | -- | ||
The center column represents the base-case, represented with a dash. Outer columns represent the variable low and high values, while the columns between the base-case and outer extremes represent an intermediate value. Dashes indicate that the most cost-effective frequency is the same as for the base-case; otherwise, the frequency is indicated. Secondary infections averted were accounted for in the comparison of testing frequencies.
Linkage to care starts at 30% linked to care in the first year after diagnosis and 3% each year thereafter. The failure rates from HAART range from 1% failure each year, to 40% failure during the first year with 15% failing each year thereafter.
Quality of life differentials refers to the magnitude of the difference between the values for the highest CD4 strata (>350) and lowest (<200).
The elasticity refers to the ratio of a percent change in the CE ratio (with secondary infections accounted for) to a corresponding percent change in the parameter.