Table 3.
Multivariate and univariate analysis for risk (HR, HR) of developing cervical intraepithelial neoplasia grade 3 (CIN3) or adenocarcinoma in situ (AIS) according to baseline Chlamydia trachomatis and high-risk human papillomavirus (hrHPV) DNA status
| N | C trachomatis positive at day 1 (N=354) | C trachomatis negative at day 1 (N=8087) | Multivariate model | Univariate model | |||||||
| n | No of women with a CIN3/AIS lesion due to any HPV type | Rate* | n | No of women with a CIN3/AIS lesion due to any HPV type | Rate* | HR† (95% CI) | p-value‡ | HR† (95% CI) | p-value‡ | ||
| CIN3/AIS due to any HPV type | |||||||||||
| Total | 8441 | 354 | 20 | 1.71 | 8087 | 267 | 0.96 | 1.31 (0.83 to 2.06) | 0.253 | 1.74 (1.10 to 2.74) | 0.017 |
| Negative for HPV16 and 18 | 7382 | 268 | 10 | 1.09 | 7114 | 163 | 0.66 | 1.44 (0.76 to 2.73) | 0.265 | 1.61 (0.85 to 3.05) | 0.146 |
| Positive for HPV16 and/or 18 | 965 | 81 | 10 | 4.3 | 884 | 103 | 3.71 | 1.19 (0.62 to 2.28) | 0.601 | 1.15 (0.60 to 2.21) | 0.666 |
| N | n | No of women with a CIN3/AIS lesion due to hrHPV type§ | Rate* | n | No of women with a CIN3/AIS lesion due to hrHPV type§ | Rate* | HR† (95% CI) | p-value‡ | HR† (95% CI) | p-value‡ | |
| CIN3/AIS due to hrHPV§ type | |||||||||||
| Total | 8441 | 354 | 20 | 1.71 | 8087 | 256 | 0.92 | 1.10 (0.69 to 1.76) | 0.693 | 1.82 (1.15 to 2.87) | 0.010 |
| Negative for all 12 tested§ hrHPV types | 5689 | 143 | 3 | 0.6 | 5546 | 77 | 0.39 | 1.43 (0.45 to 4.55) | 0.540 | 1.50 (0.47 to 4.77) | 0.488 |
| Positive for ≥1 of 12 tested§ hrHPV types | 2629 | 204 | 16 | 2.48 | 2425 | 179 | 2.25 | 1.05 (0.63 to 1.75) | 0.851 | 1.09 (0.65 to 1.81) | 0.750 |
N: Total number of women with non-missing Chlamydia status and respective PCR status and at least one follow-up visit.
n: Number of women with positive/negative Chlamydia status and positive/negative PCR status and at least one follow-up visit.
Number of women with a lesion per 100 person-years at risk.
HR associated with being positive versus negative to Chlamydia at baseline for each model. For the ‘univariate—total’ estimates, HR is calculated using the full data. For the ‘univariate—negative/positive’ estimates, HR is calculated using data from each stratified HPV baseline status data. For the ‘multivariate—total’ estimates, HR is calculated after adjusting for HPV baseline status (positive or negative), age at study entry, number of lifetime sexual partners, and smoking status (current smoker, former smoker, never smoked). Interactions between baseline HPV status and Chlamydia status were tested and proven to be insignificant (P-values of interactions are 0.683 and 0.628 in the models of CIN3/AIS due to any HPV type and CIN3/AIS due to any hrHPV type, respectively). For the ‘multivariate—negative/positive’ estimates, HR is estimated within each HPV baseline status group after including the interaction term between baseline Chlamydia status and baseline HPV status and adjusting for age at study entry, number of lifetime sexual partners, and smoking status.
p Value shows how significantly the estimated HRs differ from 1.
Includes HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59.