Table 1.
Risk of testing PCR positive for HPV at each visit given vaginal pH measurement, stratified by age at visit
| Vaginal pH Level | N | Percent with PCR Positive HPV | Odds of Testing HPV Positivea (95% CI) | p-value (trend) |
|---|---|---|---|---|
| All Womenb | ||||
| 4.0 | 2,139 | 19.1 | 0.7 (0.7-0.8) | |
| 4.5 | 17,201 | 23.8 | refc | |
| 5.0 | 7,246 | 25.6 | 1.2 (1.1-1.3) | |
| 5.5 | 1,976 | 25.2 | 1.2 (1.1-1.4) | < 0.001 |
| Age at Visit | ||||
| < 25 years | ||||
| 4.0 | 114 | 22.8 | 0.5 (0.3-0.8) | |
| 4.5 | 1,417 | 38.3 | ref | |
| 5.0 | 404 | 40.8 | 1.1 (0.9-1.4) | 0.009 |
| 5.5 | 82 | 41.5 | 1.1 (0.7-1.8) | |
| 25-34 years | ||||
| 4.0 | 798 | 22.7 | 0.8 (0.7-1.0) | |
| 4.5 | 5,436 | 26.5 | ref | |
| 5.0 | 1,517 | 29.8 | 1.2 (1.0-1.3) | |
| 5.5 | 240 | 29.2 | 1.1 (0.9-1.5) | 0.007 |
| 35-44 years | ||||
| 4.0 | 842 | 17.5 | 0.9 (0.7-1.1) | |
| 4.5 | 5,244 | 19.6 | ref | |
| 5.0 | 1,407 | 21.4 | 1.1 (1.0-1.3) | |
| 5.5 | 194 | 16.0 | 0.8 (0.5-1.1) | 0.088 |
| 45-54 years | ||||
| 4.0 | 310 | 13.6 | 0.8 (0.5-1.1) | |
| 4.5 | 2,912 | 17.2 | ref | |
| 5.0 | 1,432 | 19.8 | 1.2 (1.0-1.4) | |
| 5.5 | 372 | 18.0 | 1.1 (0.8-1.4) | 0.051 |
| 55-64 years | ||||
| 4.0 | 48 | 12.5 | 0.4 (0.2-1.0) | |
| 4.5 | 1,253 | 25.1 | ref | |
| 5.0 | 1,194 | 23.3 | 0.9 (0.7-1.1) | |
| 5.5 | 481 | 23.9 | 0.9 (0.7-1.2) | 0.209 |
| 65+ years | ||||
| 4.0 | 27 | 22.2 | 0.7 (0.3-1.9) | |
| 4.5 | 939 | 27.7 | ref | |
| 5.0 | 1,292 | 29.1 | 1.1 (0.9-1.3) | |
| 5.5 | 607 | 29.7 | 1.1 (0.8-1.4) | 0.773 |
a Generalized estimating equation models with an independent correlation structure were used to estimate the odds of testing positive for HPV given pH measurements at each visit
b Adjusted for age at visit
c A pH of 4.5 was used as the referent category because it provided the most stable comparison