Table 5. Baseline Phenotypic HIV-1 Drug Resistance as a Predictor of Virologic Failure.
| Parameter | N | Odds Ratio for Virologic Failure by Week 16 (95% CI) |
|---|---|---|
| Abacavir sensitivity a | ||
| all subjects | 202 | 1.19 (0.62, 2.26) |
| subjects receiving ABC | 109 | 1.00 (0.44, 2.32) |
| subjects not receiving ABC | 93 | 1.60 (0.56, 4.57) |
| Abacavir log10 IC50 fold change b | ||
| all subjects | 202 | 0.60 (0.27, 1.31) |
| subjects receiving ABC | 109 | 0.89 (0.30, 2.60) |
| subjects not receiving ABC | 93 | 0.35 (0.10, 1.21) |
| Abacavir IC50 fold change | ||
| all subjects | 202 | |
| 0.0 - <4.0 | 145 | 1.00 |
| 4.0 - <8.0 | 43 | 0.59 (0.26, 1.33) |
| ≥ 8.0 | 14 | 0.61 (0.16, 2.28) |
| subjects receiving ABC | 109 | |
| 0.0 - <4.0 | 79 | 1.00 |
| 4.0 - <8.0 | 23 | 0.57 (0.19, 1.70) |
| ≥ 8.0 | 7 | 0.82 (0.15, 4.49) |
| subjects not receiving ABC | 93 | |
| 0.0 - <4.0 | 66 | 1.00 |
| 4.0 - <8.0 | 20 | 0.62 (0.18, 2.09) |
| ≥ 8.0 | 7 | 0.41 (0.05, 3.66) |
| Overall Sensitivity Score c | 202 | 1.32 (0.72, 2.45) |
a
Odds ratio reported is for virologic failure for a subject having an IC 50 fold-change ≤ 3.0 as compared to a subjects having an IC 50 fold-change > 3.0 for ABC.
b
Odds ratio for virologic failure for a one-unit increase in log 10 (IC 50 fold change) for ABC
c
Odds ratio for a one-unit increase in overall sensitivity score, which is the total number of drugs in the regimen to which a subject's virus is sensitive (range 1-3).