Table 2

Characteristics and chlamydia positivity rates of participants who came for retest in one of the 10 participating sexually transmitted infection (STI) clinics in the Netherlands, 2012–2013

Factors (measured at T1)N response (%)n positive for chlamydiaPositivity rate % (95% CI)Univariate Cox regression PR (95% CI)Multivariate Cox regression PR (95% CI)*
Total2755620.4
Gender
 Male56 (20.4)1526.8 (14.8 to 38.3)1.0nt
 Female219 (79.6)4118.7 (13.5 to 23.9)0.7 (0.4 to 1.3)
Age (years)
 16–1981 (29.5)1923.5 (14.0 to 32.9)0.8 (0.5 to 1.4)nt
 20–23194 (70.5)3719.1 (13.5 to 24.6)1.0
Ethnicity
 Dutch246 (89.5)4819.5 (14.5 to 24.5)0.7 (0.3 to 1.5)nt
 Non-Dutch29 (10.5)827.6 (10.3 to 44.8)1.0
Notified by partner
 Yes10 (3.6)990.0 (67.4 to 112.6)5.1 (2.5 to 10.4)5.3 (2.4 to 11.5)
 No265 (96.4)4717.7 (13.1 to 22.4)1.0
STI-related symptoms†
 Yes41 (15.1)2253.7 (37.7 to 69.6)3.8 (2.2 to 6.4)3.2 (1.8 to 5.6)
 No231 (84.9)3314.3 (9.7 to 18.8)1.01.0
Residence†
 City157 (59.0)3824.2 (17.4 to 31.0)1.6 (0.9 to 2.7)1.6 (0.9 to 2.9)
 Rural109 (41.0)1715.6 (8.7 to 22.5)1.01.0
No. of partners <6 months
 0–2223 (81.1)3515.7 (10.9 to 20.5)1.01.0
 ≥352 (18.9)2140.4 (26.6 to 54.2)2.6 (1.5 to 4.4)1.5 (0.9 to 2.8)
Condom use during the last sexual contact†
 Yes61 (22.6)1931.1 (19.2 to 43.1)1.8 (1.0 to 3.2)1.7 (0.9 to 3.1)
 No209 (77.4)3617.2 (12.1 to 22.4)1.01.0
  • nt, not tested in multivariate model, since p>0.20 in univariate analysis.

  • In bold: significant (p<0.05); due to rounding to one decimal place, 1.0 is not always significant.

  • *Adjusted for notified by partner, STI symptoms, urbanisation, number of partners in <6 months and condom use during the last sex contact.

  • †Characteristic contains missings.

  • PR, prevalence ratio.