Objective: To determine independent risks with predictive value for specific sexually transmitted diseases in women.
Design: A prospective study of reported sexual behaviour in patients who presented for screening and diagnosis of sexually transmitted diseases.
Setting: A genitourinary medicine clinic at the West London Hospital.
Subjects: 1025 consecutive newly attending patients who completed a sexual behaviour questionnaire between February and June 1982.
Main outcome measures: Sexual behaviour reported by standardised self-administered questionnaire and sexually transmitted diseases diagnosed by routine clinical and laboratory methods.
Results: Independent risks for gonorrhoea were teenage (RR 2.0), black race (RR 2.0), more than two partners in the past year (RR 2.2) and previous pregnancy (RR 2.1). Trichomoniasis (RR 2.5), chlamydial infection (RR 1.8) and pelvic inflammatory disease (RR 4.8) also had significant predictive value. Conversely, gonorrhoea proved a risk for chlamydial infection (RR 2.1) together with age under 25 years (RR 2.3) and more than five partners in the previous year (RR 2.2). Ano-genital herpes was predicted by a total of more than 10 sexual partners (RR 2.6) and by both anal (RR 2.2) and oral intercourse (RR 2.9). Age under 25 years was the only independent risk for ano-genital warts (RR 2.0). We found no evidence that either vaginal candidosis or bacterial vaginosis were sexually transmitted. The risk for any genital infection was increased by more than one sexual partner in the preceding year (RR 1.7) and black race (RR 2.0).
Conclusions: Sexually transmitted diseases show both similarities and differences in the risk factors associated with their transmission. These risk profiles facilitate the targeting of health education measures for those sections of the community at greatest risk and form a baseline for the future assessment of the effects of condom protected sexual intercourse and other safer sexual practices.