Table 3.
Switching among patients with treatment failure under different monitoring strategies.
| Monitoring Strategy | ||||||||
|---|---|---|---|---|---|---|---|---|
| Clinical | CD4 cell count | Targeted viral load | Routine viral load | |||||
| No. of patients with failure |
Percent switched to second-line ART at 2 years (95% CI) |
No. of patients with failure |
Percent switched to second-line ART at 2 years (95% CI) |
No. of patients with failure |
Percent switched to second-line ART at 2 years (95% CI) |
No. of patients with failure |
Percent switched to second-line ART at 2 years (95% CI) |
|
| Virological failure | ||||||||
| Single value | 98 | 32·7% (22·4–46·3%) |
465 | 57·5% (52·2–63·1%) |
6952 | 55·8% (54·3–57·3%) |
11346 | 36·5% (35·3–37·6%) |
| Confirmed | 13 | 0% | 56 | 62·2% (48·7–75·7%) |
1279 | 65·5% (62–68·9%) |
5102 | 56·1% (54·4–57·8%) |
| Immunological failure | ||||||||
| Single value | 1587 | 6·2% (4·9–7·8%) |
14261 | 9·9% (9·3–10·5%) |
27074 | 12·5% (12–13%) |
7694 | 19·5% (18·4–20·7%) |
| Confirmed | 285 | 9·2% (5·9–14%) |
3656 | 17·2% (15·7–18·7%) |
9452 | 19·4% (18·4–20·4%) |
2499 | 23·1% (21·1–25·2%) |
| Any evidence of treatment failure | 1636 | 6·7% (5·4–8·3%) |
14381 | 10·1% (9·5–10·7%) |
29532 | 15% (14·5–15·6%) |
14866 | 27·7% (26·8–28·7%) |
ART: Antiretroviral therapy; CI: Confidence Interval
Estimates of the proportion who switched to second line ART up to 2 years after treatment failure from Kaplan-Meier life-table analyses.
Patients were classified according to the monitoring strategy used in their ART programme at the time of treatment failure. Routine VL monitoring was assumed if at least 75 VL tests had been done per 100 person-years. CD4 monitoring was assumed if at least 75 CD4 counts had been done per 100 person-years. Targeted VL monitoring was assumed if in addition to CD4 monitoring at least 5 but less than 75 VL measurements were done per 100 person-years. A site was considered to use clinical monitoring if it did not meet the criteria for any other monitoring strategy.
Immunologic failure was defined according to the World Health Organization (WHO)16 as CD4 count below 100 cells/ µl after six months of therapy, a return to, or a fall below the pre-therapy CD4 baseline after six months of therapy, or a 50% decline from the on-treatment peak CD4 value. Virological failure was defined as a viral load value >1,000 copies/ml.