Table 4 Performance of pill count adherence in determining viral load suppression
Pill count adherence | Viral load unsuppressed (≥400 copies/ml) | Viral load suppressed (< 400 copies/ml) | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) |
|---|---|---|---|---|---|---|
Year 1 on ART (n = 268) | ||||||
 < 95% | 2 (1%) | 9 (3%) | 97% (94–98) | 22% (3–60) | 97% (94–99) | 18% (2–52) |
 ≥ 95% | 7 (3%) | 250 (93%) | ||||
Year 2 on ART (n = 201) | ||||||
 < 95% | 1 (1%) | 4 (2%) | 98% (95–99) | 10% (0–45) | 95% (91–98) | 20% (1–72) |
 ≥ 95% | 9 (4%) | 187 (93%) | ||||
Year 3 on ART (n = 166) | ||||||
 < 95% | 3 (2%) | 4 (2%) | 97% (94–99) | 33% (7–70) | 96% (92–99) | 43% (10–82) |
 ≥ 95% | 6 (4%) | 153 (92%) | ||||
Year 4 on ART (n = 243) | ||||||
  < 95% | 0 | 4 (2%) | 98% (96–100) | 0 | 95% (91–97) | 0 |
  ≥ 95% | 13 (5%) | 226 (93%) | ||||
Year 5 on ART (n = 233) | ||||||
 < 95% | 1 (1%) | 11 (5%) | 95% (91–98) | 9% (0–41) | 95% (92–98) | 8% (0–38) |
 ≥ 95% | 10 (4%) | 211 (90%) | ||||