Table 2

Chlamydia positivity at retesting in CSI

UnivariateMultivariate (N=1964)
Number positive at retestNumber retested* Proportion positiveOR (95% CI)p ValueOR (95% CI)pLr
Socio-demographic data
Gender
 Male677269.2%1.08 (0.80 to 1.45)0.619
 Female17520308.6%1
 Total (100%)24227568.8%
Age group, year
 16–198457614.6%2.95 (2.05 to 4.26)<0.0012.99 (1.87 to 4.80)<0.001
 20–2410812658.5%1.61 (1.14 to 2.28)0.0071.59 (1.02 to 2.48)0.043
 25–29509155.5%1<0.0011<0.001
 Total24227568.8%
Education level
 Low1912515.2%2.35 (1.65 to 3.37)<0.0012.41 (1.34 to 4.35)0.004
 Middle9988911.1%3.37 (1.91 to 5.94)<0.0011.68 (1.15 to 2.46)0.008
 High489505.1%1<0.00110.004
 Total (71%)16619648.5%
Ethnicity
 Dutch9714726.6%1<0.00110.001
 Surinamese/Antillean7154313.1%2.13 (1.54 to 2.95)<0.0011.58 (1.05 to 2.36)0.028
 Turkish/Moroccan1813912.9%2.11 (1.23 to 3.61)0.0063.10 (1.66 to 5.80)<0.001
 Sub-Saharan Africa2915618.6%3.24 (2.06 to 5.09)<0.0012.21 (1.21 to 4.04)0.010
 Other274466.1%0.91 (0.59 to 1.42)0.6871.03 (0.61 to 1.75)0.910
 Total24227568.8%
Screening area
 Rotterdam139127810.9%2.31 (1.15 to 4.61)0.018
 Amsterdam9412997.2%1.47 (0.73 to 2.97)0.279
 South Limburg91795.0%10.001
 Total24227568.8%
SES
 High5816.2%10.371
 High average223256.8%1.10 (0.40 to 3.01)0.847
 Low average495628.7%1.45 (0.56 to 3.76)0.442
 Low15816769.4%1.58 (0.63 to 3.97)0.328
 Total (96%)23426448.9%
Community risk
 Low427205.8%1<0.001
 Medium11613938.3%1.47 (1.02 to 2.11)0.040
 High8464313.1%2.43 (1.65 to 3.57)<0.001
 Total24227568.8%
Screening round
 19611698.2%0.99 (0.57 to 1.40)0.971
 2898979.9%1.22 (0.86 to 1.73)0.257
 3576908.3%10.340
 Total24227568.8%
Behavioural data (self-reported data)§
 Index case treated for infection at T0
  Yes6611155.9%1
  No1412011.7%2.10 (1.14 to 3.86)0.017
  Total (45%)8012356.5%
 Current partner treated when indicated
  Yes406316.3%1
  No1616010.0%1.64 (0.89 to 3.01)0.110
  Total (29%)567917.1%
 History of STI
  No313947.9%1
  Yes3130810.1%1.31 (0.78 to 2.21)0.310
  Total (25%)627028.8%
 Age at first sex
  <16 years8772712.0%1<0.001
  16–18 years599955.9%0.46 (0.33 to 0.66)<0.001
  19 years and above202328.6%0.69 (0.42 to 1.16)0.161
  Total (71%)16619548.5%
 Number of lifetime partners
  153912.8%10.590
  2–5121517.9%0.59 (0.19 to 1.78)0.346
  6 or more232868.0%0.59 (0.21 to 1.67)0.323
  Total (17%)404768.4%
  • * Difference in numerator compared with table1 is due to ‘failed’ results. Only positive and negative Ct results were considered.

  • Variable included in model.

  • SES level could not be calculated for all participants, educational level is derived from a voluntary questionnaire. If denominator is lower than 100%, the percentage is stated.

  • § Due to small numbers for behavioural data, these variables were not included in multivariate analysis.

  • CSI, Chlamydia Screening Implementation Programme; SES, socio-economic status.