TABLE 5.
Clinical performance of Cobas versus PIS by symptomatic status for N. gonorrhoeaea
| 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 for specificity | Prevalence (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|---|---|---|---|---|
| Women | |||||||||
| Urine | Symptomatic | 1,535 | 96.7 (59/61) | 88.8–99.1 | 99.8 (1,471/1,474) | 99.4–99.9 | 4.0 | 95.2 | 99.9 |
| Asymptomatic | 2,519 | 93.2 (68/73) | 84.9–97.0 | 100.0 (2,446/2,446) | 99.8–100.0 | 2.9 | 100.0 | 99.8 | |
| Overall | 4,054 | 94.8 (127/134) | 89.6–97.4 | 99.9 (3,917/3,920) | 99.8–100.0 | 3.3 | 97.7 | 99.8 | |
| CC vaginal swab | Symptomatic | 711 | 100.0 (11/11) | 74.1–100.0 | 99.7 (698/700) | 99.0–99.9 | 1.5 | 84.6 | 100.0 |
| Asymptomatic | 1,225 | 100.0 (17/17) | 81.6–100.0 | 99.8 (1,205/1,208) | 99.3–99.9 | 1.4 | 85.0 | 100.0 | |
| Overall | 1,936 | 100 (28/28) | 87.9–100.0 | 99.7 (1,903/1,908) | 99.4–99.9 | 1.4 | 84.8 | 100.0 | |
| SC vaginal swab | Symptomatic | 720 | 100.0 (14/14) | 78.5–100.0 | 99.7 (704/706) | 99.0–99.9 | 1.9 | 87.5 | 100.0 |
| Asymptomatic | 1,187 | 100.0 (14/14) | 78.5–100.0 | 99.7 (1,169/1,173) | 99.1–99.9 | 1.2 | 77.8 | 100.0 | |
| Overall | 1,907 | 100.0 (28/28) | 87.9–100.0 | 99.7 (1,873/1,879) | 99.3–99.9 | 1.5 | 82.4 | 100.0 | |
| PreservCyt | Symptomatic | 1,486 | 97.9 (44/48) | 89.1–99.6 | 99.9 (1,437/1,438) | 99.6–100.0 | 3.2 | 97.9 | 99.9 |
| Asymptomatic | 2,436 | 95.1 (39/41) | 83.9–98.7 | 100.0 (2,394/2,395) | 99.8–100.0 | 1.7 | 97.5 | 99.9 | |
| Overall | 3,922 | 96.6 (86/89) | 90.6–98.8 | 99.9 (3,831/3,833) | 99.8–100.0 | 2.3 | 97.7 | 99.9 | |
| Endocervical swab | Symptomatic | 1,484 | 100.0 (45/45) | 92.1–100.0 | 99.9 (1,438/1,439) | 99.6–100.0 | 3.0 | 97.8 | 100.0 |
| Asymptomatic | 2,464 | 94.5 (52/55) | 85.1–98.1 | 100.0 (2,408/2,409) | 99.8–100.0 | 2.2 | 98.1 | 99.9 | |
| Overall | 3,948 | 97.0 (97/100) | 91.5–99.0 | 99.9 (3,846/3,848) | 99.8–100.0 | 2.5 | 98.0 | 99.9 | |
| Men, urine | Symptomatic | 305 | 100.0 (82/82) | 95.5–100.0 | 98.7 (220/223) | 96.1–99.5 | 26.9 | 96.5 | 100.0 |
| Asymptomatic | 887 | 100.0 (5/5) | 56.6–100.0 | 99.7 (879/882) | 99.0–99.9 | 0.6 | 62.5 | 100.0 | |
| Overall | 1,193 | 100.0 (87/87) | 95.8–100.0 | 99.5 (1,099/1,105) | 98.8–99.8 | 7.3 | 93.5 | 100.0 | |
| Overall | 16,959 | 97.2 (453/466) | 95.3–98.4 | 99.9 (16,469/16,493) | 99.8–99.9 | 2.7 | 95.0 | 99.9 |
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.