TABLE III.
Diagnostic accuracy of the CD4/CD8 ratio in the P2C2 HIV and PACTS (validation data) cohorts at 3 months of age
| CD4/CD8 ratio |
Percentage of HIV-positive subjects below cutoff point |
Percentage of HIV-negative subjects below cutoff point |
Sensitivity (%) |
Specificity (%) |
DLR+ | Posttest probability* (%) |
DLR− | Posttest probability† (%) |
|---|---|---|---|---|---|---|---|---|
| 1.00 | 86 (79) | 14 (21) | 32 (26) | 99 (98) | 32.3 (16.7) | 87 (79) | 0.7 (0.8) | 12 (14) |
| 1.20 | 79 (68) | 21 (32) | 38 (33) | 98 (97) | 19.4 (9.4) | 80 (68) | 0.6 (0.7) | 11 (13) |
| 1.40 | 63 (57) | 37 (43) | 46 (41) | 95 (93) | 8.9 (6.1) | 65 (57) | 0.6 (0.6) | 11 (12) |
| 1.60 | 53 (51) | 47 (49) | 52 (51) | 91 (89) | 5.7 (4.7) | 54 (51) | 0.5 (0.6) | 10 (11) |
| 1.80 | 46 (42) | 54 (58) | 61 (57) | 86 (83) | 4.4 (3.4) | 47 (42) | 0.5 (0.5) | 9 (10) |
| 2.00 | 38 (38) | 62 (62) | 65 (68) | 80 (76) | 3.2 (2.8) | 40 (38) | 0.4 (0.4) | 8 (8) |
| 2.20 | 36 (33) | 64 (67) | 73 (74) | 74 (67) | 2.9 (2.2) | 37 (33) | 0.4 (0.4) | 7 (8) |
| 2.40 | 32 (29) | 68 (71) | 81 (79) | 67 (58) | 2.5 (1.9) | 33 (30) | 0.3 (0.4) | 5 (7) |
| 2.60 | 29 (27) | 71 (73) | 82 (82) | 60 (51) | 2.1 (1.6) | 30 (27) | 0.3 (0.4) | 6 (7) |
| 2.80 | 26 (25) | 74 (75) | 90 (86) | 51 (44) | 1.8 (1.5) | 27 (25) | 0.2 (0.3) | 4 (7) |
| 3.00 | 24 (24) | 76 (76) | 92 (90) | 44 (38) | 1.7 (1.4) | 25 (24) | 0.2 (0.3) | 3 (6) |
The pretest probabilities for P2C2 data and validation data sets are 17% and 18%, respectively. For each column, the first number is based on the P2C2 data set, and the number within parentheses is calculated from the validation data set (PACTS).
*
Posttest probability for a positive test result.
†
Posttest probability for a negative test result.