The roles of sexual mixing and partnership type in explaining ethnic and gender differences in acute STI diagnosis
| Men | Women | Comparisons by gender | ||||||||||
| BC % (95% CI) | WBI % (95% CI) | OR: BC compared with WBI (95% CI) | P value | BC % | WBI % | OR: BC compared with WBI (95% CI) | P value | Among BC attendees | Among WBI attendees | |||
| OR: men compared with women (95% CI) | P value | OR: men compared with women (95% CI) | P value | |||||||||
| Denominator (participants) * | 149 | 364 | 319 | 664 | ||||||||
| ‘Acute STI’: Bacterial STI and/or trichomoniasis diagnosis/es† within ±6 weeks of clinic attendance (95% CI) | 26.8% (15.2% to 42.9%) | 20.1% (15.9% to 25.0%) | 16.0% (9.9%–24.7%) | 7.7% (5.4%–10.9%) | ||||||||
| Unadjusted OR (95% CI) | 1.46 (0.69 to 3.10) | 0.294 | 2.29 (1.23 to 4.27) | 0.014 | 1.93 (1.26 to 2.96) | 0.006 | 3.02 (1.95 to 4.68) | <0.001 | ||||
| aOR1: adjusted for age and number of recent partners‡ (95% CI) | 1.36 (0.63 to 2.93) | 0.402 | 2.31 (1.28 to 4.14) | 0.009 | 1.82 (1.14 to 2.92) | 0.017 | 2.76 (1.81 to 4.21) | <0.001 | ||||
| aOR2: adjusted for the above variables, and sexual mixing and partnership type§ (95% CI) | 1.53 (0.57 to 4.06) | 0.367 | 2.15 (1.06 to 4.38) | 0.037 | 2.01 (1.21 to 3.33) | 0.011 | 2.70 (1.61 to 4.51) | <0.001 | ||||
*Denominators: participants (SHC attendees) identifying as male, and who reported only female partners in the past year; and participants identifying as female who reported only male partners in the past year.
†The following bacterial STIs: chlamydia, gonorrhoea, syphilis, chancroid, lymphogranuloma venereum (LGV), non-specific genital infection (NSGI), Mycoplasma genitalium infection, shigellosis, non-specific pelvic inflammatory disease (PID), donovanosis (no one in the sample was diagnosed with the latter); and also trichomoniasis, caused by the flagellated protozoan parasite Trichomonas vaginalis.
‡Adjusted for: age as a continuous variable, and number of opposite-sex partners in the past 3 months (0, 1, 2+).
§Adjusted for: age as a continuous variable, and number of opposite-sex partners in the past 3 months (0, 1, 2+), and the following (all derived from questions about the (up to) three most recent partners within the past 3 months): any committed partners within the past 3 months, any uncommitted regular partners within the past 3 months, any casual partners within the past 3 months; and the following sexual mixing variables: any age-mixing* among partners within the past 3 months, any ethnic-mixing among partners within the past 3 months. (*We repeated this analysis replacing ‘any age-mixing’ with a variable for any age-mixing in which the man was ≥5 years older. Results were very similar, as shown in online supplementary table 5.)
BC, Black Caribbean; SHC, sexual health clinic; WBI, White British/Irish; aOR, adjusted OR.