Table 2.
Base case results and selected sensitivity analyses of an HIV screening analysis in South Africa.
| HIV Screening Frequency | ||||
|---|---|---|---|---|
| Current Practice* |
One-time | Every 5 years |
Annually | |
| Base Case, South Africa | ||||
| Prevalence 16.9%, Annual Incidence 1.3% | ||||
| HIV+ Population | ||||
| Undiscounted per person quality-adjusted life expectancy (months) | 285.6 | 291.9 | 298.3 | 317.2 |
| Discounted per person quality-adjust life expectancy (months) | 180.6 | 184.9 | 187.6 | 197.2 |
| Mean CD4 at detection (/µl) | ||||
| Prevalent cases | 195 | 233 | 235 | 259 |
| Incident cases | 337 | 337 | 357 | 410 |
| General Population | ||||
| Undiscounted per person quality-adjusted life expectancy (months) | 354.3 | 357.6 | 361.0 | 371.2 |
| Discounted per person quality-adjusted life expectancy (months) | 213.7 | 215.7 | 216.8 | 221.0 |
| Per person costs ($) | 2,330 | 2,570 | 2,740 | 3,330 |
| Cost-effectiveness ratio ($/QALY)§‖ | ----- | dominated† | 1,570 | 1,720 |
| Sensitivity Analysis, Western Cape | ||||
| Prevalence 5.3%, Annual Incidence 0.4% | ||||
| HIV+ Population | ||||
| Undiscounted per person quality-adjusted life expectancy (months) | 314.9 | 320.2 | 326.3 | 344.6 |
| Discounted per person life expectancy (months) | 194.7 | 198.0 | 199.7 | 209.6 |
| General Population | ||||
| Undiscounted per person life expectancy (months) | 420.3 | 421.2 | 422.2 | 424.7 |
| Discounted per person life expectancy (months) | 243.4 | 243.9 | 244.1 | 245.1 |
| Per person costs ($) | 830 | 910 | 980 | 1,220 |
| Cost-effectiveness ratio ($/QALY)§‖ | ----- | 1,650 | dominated† | 3,090 |
| Sensitivity Analysis, KwaZulu Natal | ||||
| Prevalence 25.8%, Annual Incidence 2.0% | ||||
| HIV+ Population | ||||
| Undiscounted per person life expectancy (months) | 264.6 | 271.9 | 277.9 | 297.2 |
| Discounted per person life expectancy (months) | 170.1 | 175.0 | 176.6 | 187.9 |
| General Population | ||||
| Undiscounted per person life expectancy (months) | 313.5 | 318.1 | 321.7 | 334.2 |
| Discounted per person life expectancy (months) | 194.4 | 197.5 | 198.3 | 204.8 |
| Per person costs ($) | 3,240 | 3,610 | 3,830 | 4,630 |
| Cost-effectiveness ratio ($/QALY)§‖ | ----- | dominated† | dominated† | 1,590 |
QALY: Quality-adjusted life-year
In the absence of routine screening, HIV infection is detected via background screening (on average, every ten years) or with the development of one of the following severe opportunistic infections: Isosporiasis, Mycobacterium avium complex, Toxoplasmosis, Pneumocystis jirovecii pneumonia (PCP), and other WHO stage 4-defining non-bacterial diseases.
“dominated” strategies are eliminated because they cost more and deliver fewer years of life saved than the comparative combination of strategies.14
In order to accentuate the effects of HIV-related stigma, it is assumed that all health states prior to HIV testing have quality of life equivalent to perfect health. Quality of life decrements are then applied only to states involving either an HIV test or time spent living with an HIV diagnosis.
Cost-effectiveness ratios were calculated prior to rounding quality-adjusted life expectancy and costs.