Table 2

Independent risk factors for rectal gonorrhoea and early syphilis among men who have sex with men, Amsterdam STI clinic, 1994–9, Netherlands

Rectal gonorrhoeaEarly syphilis
Risk factorsInfection rate No/n (%)Oradj(95% CI)p ValueInfection rate No/n (%)Oradj(95% CI)p Value
*p<0.01 †The interactions between time period and sexual contacts (p<0.001) for rectal gonorrhoea and between time period and nationality (p<0.001) for early syphilis were included in the multivariate model as new variables with four categories. ‡Missing values excluded.
Sexual contactsp<0.001
Bisexual34/1495 (2.3)Before HAART:homo14/1495 (0.3)1p=0.031
Exclusively homosexual516/9745 (5.3)Before HAART:bi0.83(0.50–1.39)74/9745 (0.8)3.05(1.11–8.40)
Time periodp<0.001
Before HAART149/3770 (4.0)Since HAART:homo1.38(0.27–0.79)*18/3770 (0.5)Before HAART:Western1
Since HAART401/7470 (5.4)Since HAART:bi0.47(1.12–1.71)*60/7470 (0.8)Before HAART:non-Western16.48(6.33–42.86)*
Nationality
Non-Western39/12071p=0.00955/10033 (0.5)After HAART:Western3.38(1.53–7.48)*
Western511/100331.60(1.13–2.26)23/1207 (1.9)After HAART:non-Western7.27(2.85–18.53)*
Age‡
<31228/3621 (6.3)1p<0.00133/3621 (0.9)
31–35123/2060 (6.0)0.81(0.64–1.03)14/2060 (0.7)
36–40125/2540 (4.9)0.70(0.55–0.89)*15/2540 (0.6)
>4074/3017 (2.5)0.37(0.28–0.49)*16/3017 (0.5)
Being a sex worker‡
yes26/970 (2.7)1p=0.01111/970 (1.1)
no524/10258 (5.1)1.75(1.14–2.70)67/10258 (0.7)
Being a client of sex workers‡
yes6/292 (2.1)2/292 (0.7)
no544/10940 (5.0)76/10940 (0.7)
Concurrent infectionsconcurrent rectal gonorrhoea
no333/10175 (3.3)1p<0.001No: 69/10690 (0.6)1p=0.011
Only genital gonorrhoea132/815 (16.2)5.02(4.03–6.26)*Yes:9/550 (1.6)2.50(1.23–5.06)
Only pharyngeal gonorrhoea56/138 (40.6)16.91(11.71–24.40)*
Both genital and pharyngeal29/112 (25.9)8.15(5.23–12.72)*
Concurrent syphilis infection
no541/11162 (4.8)1p=0.035
yes9/78 (11.5)2.31(1.06–5.03)