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





Ω Median (IQR) interval between the CD4 count and plasma viral load tests was 32 (28–45) days.

Note: the subjects enrolled in the trial were a subset of all subjects screened.

Jaffar et al. AIDS Research and Therapy 2008 5:4   doi:10.1186/1742-6405-5-4