TABLE 2.
Clinical performance of Cobas versus PIS by symptomatic status for C. trachomatisa
| Sex, sample type | Symptom status | Total | % sensitivity (no. of samples positive/total no. tested) | 95% CI for sensitivity | % specificity (no. of samples positive/total no. tested) | 95% CI | Prevalence (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|---|---|---|---|---|
| Women | |||||||||
| Urine | Symptomatic | 1,441 | 96.0 (119/124) | 90.9–98.3 | 99.8 (1,315/1,317) | 99.4–100.0 | 8.6 | 98.3 | 99.6 |
| Asymptomatic | 2,418 | 95.2 (140/147) | 90.5–97.7 | 99.6 (2,262/2,271) | 99.2–99.8 | 6.1 | 94.0 | 99.7 | |
| Overall | 3,859 | 95.6 (259/271) | 92.4–97.4 | 99.7 (3,577/3,588) | 99.5–99.8 | 7.0 | 95.9 | 99.7 | |
| CC vaginal swab | Symptomatic | 711 | 100.0 (63/63) | 94.3–100.0 | 99.2 (643/648) | 98.2–99.7 | 8.9 | 92.6 | 100.0 |
| Asymptomatic | 1,225 | 97.6 (83/85) | 91.8–99.4 | 99.0 (1,129/1,140) | 98.3–99.5 | 6.9 | 88.3 | 99.8 | |
| Overall | 1,936 | 98.6 (146/148) | 95.2–99.6 | 99.1 (1,772/1,788) | 98.6–99.4 | 7.6 | 90.1 | 99.9 | |
| SC vaginal swab | Symptomatic | 720 | 100.0 (59/59) | 93.9–100.0 | 98.8 (653/661) | 97.6–99.4 | 8.2 | 88.1 | 100.0 |
| Asymptomatic | 1,186 | 98.4 (60/61) | 91.3–99.7 | 99.2 (1,116/1,125) | 98.5–99.6 | 5.1 | 87.0 | 99.9 | |
| Overall | 1,906 | 99.2 (119/120) | 95.4–99.9 | 99.0 (1,769/1,786) | 98.5–99.4 | 6.3 | 87.5 | 99.9 | |
| PreservCyt | Symptomatic | 1,438 | 95.1 (116/122) | 89.7–97.7 | 99.5 (1,309/1,316) | 98.9–99.7 | 8.5 | 94.3 | 99.5 |
| Asymptomatic | 2,413 | 90.3 (131/145) | 84.4–94.2 | 99.7 (2,261/2,268) | 99.4–99.9 | 6.0 | 94.9 | 99.4 | |
| Overall | 3,851 | 92.5 (247/267) | 88.7–95.1 | 99.6 (3,570/3,584) | 99.3–99.8 | 6.9 | 94.6 | 99.4 | |
| Endocervical swab | Symptomatic | 1,433 | 95.9 (116/121) | 90.7–98.2 | 99.1 (1,300/1,312) | 98.4–99.5 | 8.4 | 90.6 | 99.6 |
| Asymptomatic | 2,410 | 91.1 (133/146) | 85.4–94.7 | 99.5 (2,253/2,264) | 99.1–99.7 | 6.1 | 92.4 | 99.4 | |
| Overall | 3,843 | 93.3 (249/267) | 89.6–95.7 | 99.4 (3,553/3,576) | 99.0–99.6 | 6.9 | 91.5 | 99.5 | |
| Men, urine | Symptomatic | 305 | 100.0 (63/63) | 94.3–100.0 | 99.6 (241/242) | 97.7–99.9 | 20.7 | 98.4 | 100.0 |
| Asymptomatic | 887 | 100.0 (55/55) | 93.5–100.0 | 99.8 (830/832) | 99.1–99.9 | 6.2 | 96.5 | 100.0 | |
| Overall | 1,192 | 100.0 (118/118) | 96.8–100.0 | 99.7 (1,071/1,074) | 99.2–99.9 | 9.9 | 97.5 | 100.0 | |
| Overall | 16,587 | 95.5 (1,138/1,191) | 94.2–96.6 | 99.5 (15,312/15,396) | 99.3–99.6 | 7.2 | 93.1 | 99.7 |
a
CC, clinician collected; Cobas, Cobas CT/NG test for use on the Cobas 6800/8800 systems; NPV, negative predictive value; PIS, patient infected status; PPV, positive predictive value; PreservCyt, cervical sample collected in PreservCyt cytology medium; SC, self-collected.