Table 2.
Comparison of self taken vulvovaginal swabs with clinician taken endocervical swabs as diagnostic samples for detection of Chlamydia trachomatis infection among 3867 women recruited at a sexual health centre. Values are numbers of women unless stated otherwise
| Chlamydia infection status | Total | % Sensitivity (95% CI) | P value* | ||
|---|---|---|---|---|---|
| Positive | Negative | ||||
| Whole cohort | |||||
| Endocervical swab: | 88 (85 to 91) | <0.00001 | |||
| Positive | 350 | 0 | 350 | ||
| Negative | 46 | 3471 | 3517 | ||
| Total | 396 | 3471 | 3867 | ||
| Vulvovaginal swab: | 97 (95 to 98) | ||||
| Positive | 384 | 2 | 386 | ||
| Negative | 12 | 3469 | 3481 | ||
| Total | 396 | 3471 | 3867 | ||
| Women with symptoms suggestive of bacterial sexually transmitted infection | |||||
| Endocervical swab: | 88 (83 to 92) | 0.0008 | |||
| Positive | 187 | 0 | 187 | ||
| Negative | 26 | 1421 | 1447 | ||
| Total | 213 | 1421 | 1634 | ||
| Vulvovaginal swab: | 97 (93 to 98) | ||||
| Positive | 206 | 1 | 207 | ||
| Negative | 7 | 1420 | 1427 | ||
| Total | 213 | 1421 | 1634 | ||
| Women without symptoms suggestive of bacterial sexually transmitted infection | |||||
| Endocervical swab: | 89 (84 to 93) | 0.0025 | |||
| Positive | 163 | 0 | 163 | ||
| Negative | 20 | 2050 | 2070 | ||
| Total | 183 | 2050 | 2233 | ||
| Vulvovaginal swab: | 97 (94 to 99) | ||||
| Positive | 178 | 1 | 179 | ||
| Negative | 5 | 2049 | 2054 | ||
| Total | 183 | 2050 | 2233 | ||
| Women suitable for asymptomatic screen | |||||
| Endocervical swab: | 89 (81 to 95) | 0.2668 | |||
| Positive | 68 | 0 | 68 | ||
| Negative | 8 | 1271 | 1279 | ||
| Total | 76 | 1271 | 1347 | ||
| Vulvovaginal swab: | 95 (87 to 98) | ||||
| Positive | 72 | 1 | 73 | ||
| Negative | 4 | 1270 | 1274 | ||
| Total | 76 | 1271 | 1347 | ||
*Endocervical swab compared with vulvovaginal swab.