Chlamydia prevalence by key demographic and clinical variables
| Chlamydia prevalence (N/N) | Relative risk (95% confidence interval) | p Value | |
|---|---|---|---|
| *χ2 test of linear trend p<0.001, departure from linear trend p=0.1 | |||
| **χ2 test of linear trend p=0.9, departure from linear trend p=0.9 | |||
| ***Number of symptoms reported, ie if entry was missing or unknown then no symptom assumed. | |||
| Base | 998 | ||
| Age group | (n=998) | ||
| <20 | 10.8% (26/240) | 1 | <0.001* |
| 20–24 | 11.5% (33/288) | 1.06 (0.65 to 1.72) | |
| 25–34 | 3.9% (14/360) | 0.36 (0.19 to 0.67) | |
| >34 years | 1.8% (2/110) | 0.17 (0.04 to 0.69) | |
| Race/ethnicity | (n=896) | ||
| White | 8.1% (66/817) | 1 | 0.1 |
| Black | 0% (0/34) | 0 (–) | |
| Asian | 0% (0/35) | 0 (–) | |
| Other | 10.0% (1/10) | 1.24 (0.19 to 8.06) | |
| Willing to pay £20 for test | (n=998) | ||
| No | 8.1% (53/653) | 1 | 0.3 |
| Yes | 6.4% (22/345) | 0.79 (0.49 to 1.27) | |
| Previous chlamydia test | (n=998) | ||
| No | 7.5% (69/921) | 1 | 0.9 |
| Yes | 7.8% (6/77) | 1.04 (0.47 to 2.31) | |
| Previous positive chlamydia test | (n=961) | ||
| Yes | 23.5% (4/17) | 1 | 0.02 |
| No | 0% (0/23) | 0.00 (–) | |
| Never tested | 7.5% (69/921) | 0.32 (0.13 to 0.77) | |
| Previous treated infection | (n=998) | ||
| Yes | 20.0% (3/15) | 1 | 0.01 |
| Unknown | 50.0% (1/2) | 2.50 (0.45 to 13.91) | |
| Not applicable | 7.2% (71/981) | 0.36 (0.12 to 1.02) | |
| Partner change in last year | (n=651) | ||
| No | 7.6% (41/538) | 1 | 0.6 |
| Yes | 6.2% (7/113) | 1.23 (0.57 to 2.67) | |
| Vaginal discharge | (n=760) | ||
| No | 7.8% (41/525) | 1 | 0.5 |
| Yes | 9.4% (22/235) | 1.20 (0.73 to 1.97) | |
| Pelvic pain | (n=712) | ||
| No | 8.3% (48/581) | 1 | 0.6 |
| Yes | 6.9% (9/131) | 0.83 (0.42 to 1.65) | |
| Cystitis | (n=692) | ||
| No | 8.8% (51/582) | 1 | 0.4 |
| Yes | 6.4% (7/110) | 0.74 (0.35 to 1.60) | |
| Irregular bleeding | (n=675) | ||
| No | 8.76 (51/582) | 1 | 0.1 |
| Yes | 4.3% (4/93) | 0.49 (0.18 to 1.32) | |
| Number of symptoms*** | (n=998) | ||
| 0 | 6.4% (45/606) | 1 | 0.96** |
| 1 | 7.8% (20/257) | 1.05 (0.63 to 1.74) | |
| 2 | 8.1% (8/99) | 1.09 (0.53 to 2.24) | |
| 3 | 6.7% (2/30) | 0.90 (0.23 to 3.53) | |
| 4 | 0% (0/6) | 0.00 (–) | |
| Number of children | (n=998) | ||
| 0 | 7.7% (45/584) | 1 | 0.8 |
| 1 | 8.7% (15/172) | 1.13 (0.65 to 1.98) | |
| 2 | 6.4% (10/157) | 0.93 (0.43 to 1.60) | |
| 3 or more | 5.9% (5/85) | 0.76 (0.31 to 1.87) | |
| Number of miscarriages | (n=998) | ||
| 0 | 7.4% (65/880) | 1 | 0.6 |
| 1 | 9.5% (9/95) | 1.28 (0.66 to 2.49) | |
| 2 or more | 4.4% (1/23) | 0.59 (0.09 to 4.06) | |
| Number of previous TOP | (n=998) | ||
| 0 | 8.4% (63/752) | 1 | 0.2 |
| 1 | 4.4% (9/206) | 0.52 (0.26 to 1.03) | |
| 2 or more | 7.5% (3/40) | 0.90 (0.29 to 2.73) | |