Table 5

Multivariate logistic regression analysis of variables associated with chlamydia infection—subanalysis by age*

VariableOR (95% CI)
*Variables in the model: sex, marital status, ethnic group, total number of partners, condom use with partners, history of gonorrhoea, history of foreign partner, number of same sex partners, alcohol, history of illicit drug use, occupational group, smoking, number of casual partners.
†Divorced, separated, living together, widowed.
Age under 25 (n=628)
Total number of partners
00.6 (0.05–7.4)
1 0.4 (0.3–0.6)
2 0.5 (0.3–0.8)
Over 21
Condom use with all partners
Never1
Always 0.3 (0.2–0.7)
Sometimes/often0.7 (0.4–1.1)
Smoking
None 8 (1–65)
1–5/day 0.6 (0.4–0.9)
Over 5/day1
Ethnic group
White1
Black Caribbean 2.3 (1.4–3.5)
Other1.2 (0.7–2.1)
Age 25 or over (n=743)
Total number of partners
00.001 (NS)
1 0.5 (0.3–0.8)
20.9 (0.6–1.4)
Over 21
Smoking
None1407 (NS)
1–5/day0.8 (0.6–1.1)
Over 5/day1
Ethnic group
White1
Black Caribbean 1.9 (1.3–2.8)
Other1.5 (0.9–2.7)
Marital status
Single 2.2 (1.2–4)
Married1
Other†0.8 (0.3–1.9)