TABLE 3.
Resolved sensitivity, specificity, and positive and negative predictive values of the COBAS AMPLICOR test calculated separately for each specimena
| Specimen source and type | Site | Sensitivity (%)b | Specificity (%)c | PPV (%)d | NPV (%)e |
|---|---|---|---|---|---|
| Females | |||||
| Swab | Meaux | 100.0 (1/1) | 100.0 (176/176) | 100.0 (1/1) | 100.0 (176/176) |
| Montreal | 95.8 (23/24) | 99.5 (782/786) | 85.2 (23/27) | 99.9 (782/783) | |
| Groningen | 96.7 (59/61) | 99.2 (954/962) | 88.1 (59/67) | 99.8 (954/956) | |
| All | 96.5 (83/86) | 99.4 (1912/1924) | 87.4 (83/95) | 99.8 (1912/1915) | |
| Urine | Meaux | 100.0 (1/1) | 99.4 (163/164) | 50.0 (1/2) | 100.0 (163/163) |
| Montreal | 95.2 (20/21) | 99.7 (743/745) | 90.9 (20/22) | 99.9 (743/744) | |
| Groningen | 94.7 (18/19) | 100.0 (298/298) | 100.0 (18/18) | 99.7 (298/299) | |
| All | 95.1 (39/41) | 99.8 (1204/1207) | 92.9 (39/42) | 99.8 (1204/1206) | |
| Males | |||||
| Swab | Meaux | 100.0 (3/3) | 96.3 (26/27) | 75.0 (3/4) | 100.0 (26/26) |
| Montreal | 100.0 (4/4) | 99.1 (110/111) | 80.0 (4/5) | 100.0 (110/110) | |
| Groningen | 100.0 (34/34) | 98.4 (189/192) | 91.9 (34/37) | 100.0 (189/189) | |
| All | 100.0 (41/41) | 98.5 (325/330) | 89.1 (41/46) | 100.0 (325/325) | |
| Urine | Meaux | 100.0 (3/3) | 100.0 (28/28) | 100.0 (3/3) | 100.0 (28/28) |
| Montreal | 100.0 (5/5) | 100.0 (110/110) | 100.0 (5/5) | 100.0 (110/110) | |
| Groningen | 90.0 (9/10) | 100.0 (98/98) | 100.0 (9/9) | 99.0 (98/99) | |
| All | 94.4 (17/18) | 100.0 (236/236) | 100.0 (17/17) | 99.6 (236/237) |
Sensitivity and specificity were calculated by taking the IC results into account. Results for all specimens that were initially COBAS AMPLICOR negative and IC negative for C. trachomatis were interpreted as positive, negative, or inhibitory on the basis of the result of the repeat COBAS AMPLICOR test. PPV, positive predictive value; NPV, negative predictive value.
Values in parentheses are true positive/(true positive + false negative).
Values in parentheses are true negative/(true negative + false positive).
Values in parentheses are true positive/(true positive + false positive).
Values in parentheses are true negative/(true negative + false negative).