TABLE 2a.
Base case results for screening and treatment strategies in Washington DC.
| Strategy (Performance index = 9.4%)* |
CD4 at detection (cells/μl) Prevalent cases | CD4 at detection (cells/μl) Incident cases | HIV-infected Life expectancy (years) | Total HIV- infected follow-up time at 5 yr|| | Follow-up time yrs (%) with HIV RNA >500 copies/ml (5yr) | % reduction in time with transmissible viral load (5yr)‡ | |
|---|---|---|---|---|---|---|---|
| Test frequency | ART initiation (CD4 count) | ||||||
| No regular screen | No ART | 162 | 352 | 15.8 | 8,850 | 8,150 (92.1%) | +25.6 |
| † No regular screen | ≤ 350/μl | 162 | 352 | 23.9 | 10,100 | 6,500 (64.3%) | -- |
| Once | ≤ 350/μl | 171 | 352 | 24.0 | 10,140 | 6,370 (62.8%) | −1.9 |
| Every 3 years | ≤ 350/μl | 173 | 366 | 24.2 | 10,140 | 6,320 (62.4%) | −2.5 |
| Annually | ≤ 350/μl | 180 | 388 | 24.7 | 10,180 | 6,170 (60.6%) | −4.9 |
| Once | At diagnosis | 171 | 352 | 24.3 | 10,150 | 5,860 (57.8%) | −9.6 |
| Every 3 years | At diagnosis | 173 | 366 | 24.6 | 10,160 | 5,780 (56.8%) | −11.0 |
| † Annually | At diagnosis | 180 | 388 | 25.0 | 10,210 | 5,530 (54.2%) | −14.7 |
| Annually | § Optimized ART at diagnosis | 180 | 388 | 25.6 | 10,280 | 4,720 (46.0%) | −27.3 |
Performance index is the per encounter joint probability of test offer*accept*linkage to care. In part a, the performance index is 9.4%, derived from test offer 31%, test acceptance 60%, and linkage to care 50% [29]. In part b, the performance index is 38%, derived from test offer 80%, test acceptance 60%, and linkage to care 80%. In part c, the performance index is 73%, derived from 90% test offer, test acceptance 90%, and linkage to care 90%. See methods for details.
We assume that the no regular screen and ART initiation at CD4 ≤ 350/μl strategy represents current practice. The test and treat strategy is represented by annual screen and ART upon diagnosis. These two strategies are presented in bold.
The percent reduction in time spent with HIV RNA >500 copies/ml is computed in comparison to current practice (i.e., the no regular screen and ART initiation at CD4 ≤ 350/μl strategy), as reported in the second row of the table.
ART efficacy is under “optimized ART” inflates, for all 6 ART regimens, virologic suppression by 15% above the base case (Table 1).
Follow-up time includes the entire HIV-infected population, both diagnosed and undiagnosed.