Table 1 The sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of WHO clinical stage and plasma viral load against CD4 count for the assessment of eligibility to ART.
CD4 count × 106/l (no. of subjects) | Sensitivity | Specificity | PPV | NPV | ||
|---|---|---|---|---|---|---|
All subjects screened | <200 | ≥ 200 | Percent (95% CI) | |||
WHO clinical stage | ||||||
III, IV | 1163 | 648 | 52 (50, 54) | 68 (66, 70) | 64 (62, 66) | 56 (54, 58) |
I, II | 1091 | 1400 | ||||
<250 | ≥ 250 | |||||
III, IV | 1320 | 491 | 52 (50,53) | 72 (70, 74) | 73 (71, 75) | 50 (48, 52) |
I, II | 1241 | 1250 | ||||
<350 | ≥ 350 | |||||
III, IV | 1515 | 296 | 48 (46–50) | 74 (72–77) | 84 (82–85) | 34 (32–36) |
I, II | 1640 | 851 | ||||
Subjects enrolled in the trial | <200 | ≥ 200 | ||||
WHO clinical stage | ||||||
III, IV | 708 | 83 | 54 (51, 56) | 37 (29, 46) | 90 (87, 92) | 7 (6, 10) |
I, II | 613 | 49 | ||||
advanced III, IV | 561 | 70 | 42 (40, 45) | 47 (38, 56) | 89 (86, 91) | 8 (6, 10) |
I, II, early III | 760 | 62 | ||||
IV | 102 | 17 | 8 (6, 9) | 87 (80, 92) | 86 (78, 91) | 9 (7, 10) |
I, II, III | 1219 | 115 | ||||
Plasma RNA viral load, copies per ml Ω | ||||||
≥ 100,000 | 878 | 60 | 66 (64, 69) | 55 (46, 63) | 94 (92, 95) | 14 (11, 17) |
<100,000 | 443 | 72 | ||||
Plasma viral load, copies per ml tested within 30 days of CD4 test | ||||||
≥ 100,000 | 411 | 19 | 66 (62, 70) | 68 (55, 80) | 96 (93, 97) | 16 (12, 22) |
<100,000 | 209 | 41 | ||||