A prospective cross sectional study of sexual behaviour reported by a standardised self administered questionnaire in new patients who presented for screening and diagnosis.
SETTING: A genitourinary medicine clinic in west London.
SUBJECTS: 957 consecutive newly attending heterosexual men who completed a sexual behaviour questionnaire in 1993/94.
MAIN OUTCOME MEASURES: We found that the 65% of men who reported non-regular sexual partners were more likely to be white collar class (d = 7.5%, 95% CI = 1.3, 13.7) and to have had sexual intercourse with non-United Kingdom born women (d = 7.8%, 95% CI = 3.5, 12.2). They also reported coitarche before 16 years of age (d = 13.4%, 95% CI = 8.0, 18.8) and many more sexual partners both in the last year (d = 13.1%, 95% CI = 10.2, 16.0) and in their lifetime (d = 27.9%, 95% CI = 21.6, 34.2). They were significantly more likely to practise anal intercourse (d = 8.7%, 95% CI = 3.3, 14.1), to
smoke (d = 16.3%, 95% CI = 9.8, 22.6), to drink alcohol (d = 4.9%, 95% CI = 1.2, 8.6), and to have chlamydial
infection (d = 5.7%, 95% CI = 2.2, 9.2), of which 30% was subclinical. Increasing
condom use with regular partners correlated with decreasing incidence of urethral
infection (gonorrhoeal and/or chlamydial
infection) (p < 0.03) and candidal
balanitis (p < 0.03) and a greater likelihood of no
infection being detected (p = 0.0002). Use of
condoms with non-regular partners was much more frequent than with regular partners (d = 21.4%, 95% CI = 16.7, 26.1). However, we found evidence of oral transmission of urethral gonorrhoea and chlamydial
infection among men who reported always using
condoms.
HIV infection was found in only two men (0.2%), both of whom reported intercourse with non-United Kingdom born women.
CONCLUSIONS: Heterosexual men who reported non-regular sexual relationships compensated for their increased risk lifestyle by using
condoms more frequently and showed only an increased incidence of chlamydial
infection. More consistent
condom use with regular partners was significantly associated with the absence of
sexually transmitted infection. These findings suggest that transmission between regular partners has been underestimated.