Table 2

Percentages, crude and adjusted ORs for demographic and behavioural risk factors associated with testing positive for chlamydia, by data source: men and women

Data sourceNatsal-2NCSP
Demographic and behavioural risk factors% (95% CI) testing positiveCrude OR (95% CI)Adjusted OR(95% CI)Denominator* % (95% CI) testing positiveCrude OR (95% CI)Adjusted OR (95% CI)Denominator
Men
 All3.0% (1.4% to 6.6%)270, 3429.8% (9.0% to 10.6%)5491
 Age group (y)p=0.986p=0.744p=0.118p=0.175
  18–193.1% (0.7% to 11.9%)1168, 799.1% (8.0% to 10.3%)112517
  20–243.0% (1.2% to 7.6%)0.98 (0.17 to 5.69)1.36 (0.21 to 8.79)202, 26310.4% (9.3% to 11.5%)1.15 (0.96 to 1.38)1.13 (0.95 to 1.35)2974
 Ethnic groupp=0.535p=0.056p=0.333p=0.123
  White3.0% (1.3% to 6.9%)11243, 3109.7% (8.9% to 10.5%)114943
  Black0.0%NANA11, 1212.3% (9.0% to 16.6%)1.31 (0.91 to 1.89)1.47 (1.02 to 2.13)285
  Other minority groups5.8% (0.8% to 32.9%)2.03 (0.22 to 19.0)9.13 (0.94 to 88.6)16, 209.1% (6.2% to 13.3%)0.94 (0.61 to 1.44)1.00 (0.65 to 1.55)263
 Condom use at last sexp=0.033p=0.070p<0.001p<0.001
  Yes0.5% (<0.01% to 3.5%)11125, 1517.5% (6.3% to 8.9%)111617
  No5.0% (2.2% to 11.3%)10.4 (1.21 to 89.3)10.3 (0.82 to 127.8)145, 19110.7% (9.8% to 11.8%)1.49 (1.20 to 1.84)1.53 (1.23 to 1.89)3874
 ≥2 sexual partners in last yearp<0.001p<0.001
  No0.0%NANA140, 1877.8% (6.8% to 8.9%)112491
  Yes6.7% (3.0% to 14.1%)130, 15511.4% (10.3% to 12.6%)1.53 (1.27 to 1.84)1.62 (1.34 to 1.96)3000
Women
 All2.8% (1.6% to 4.9%)357, 3379.0% (8.5% to 9.5%)11768
 Age group (y)p=0.967p=0.809p=0.001p=0.010
  18–192.9% (0.9% to 8.8%)1187, 8510.0% (9.2% to 10.9%)114773
  20–242.8% (1.5% to 5.3%)0.97 (0.25 to 3.74)1.18 (0.30 to 4.73)270, 2528.2% (7.6% to 8.9%)0.80 (0.71 to 0.91)0.84 (0.74 to 0.96)6995
 Ethnic groupp=0.147p=0.145p=0.011p=0.030
  White2.5% (1.3% to 4.5%)11323, 3099.1% (8.6% to 9.7%)1111129
  Black13.7% (2.6% to 48.5%)6.31 (0.95 to 41.8)5.85 (0.96 to 35.8)11, 73.0% (1.3% to 6.4%)0.30 (0.13 to 0.69)0.34 (0.15 to 0.76)203
  Other minority groups5.1% (1.1% to 20.6%)2.12 (0.38 to 11.7)2.01 (0.37 to 10.9)23, 217.8% (5.6% to 10.7%)0.84 (0.59 to 1.21)0.91 (0.64 to 1.31)436
 Condom use at last sexp=0.759p=0.034p=0.016p=0.004
  Yes2.5% (1.0% to 6.1%)11110, 978.0% (7.2% to 8.9%)113636
  No3.0% (1.5% to 5.8%)1.20 (0.37 to 3.86)1.31 (0.43 to 3.93)247, 2409.4% (8.8% to 10.0%)1.19 (1.03 to 1.37)1.23 (1.07 to 1.42)8132
 ≥2 sexual partners in last yearp=0.068p=0.079p<0.001p<0.001
  No1.9% (0.8% to 4.6%)11244, 2416.6% (6.0% to 7.2%)116070
  Yes5.3% (2.7% to 10.1%)2.92 (0.92 to 9.22)2.85 (0.88 to 9.22)113, 9611.5% (10.7% to 12.3%)1.83 (1.61 to 2.09)1.81 (1.58 to 2.06)5698
  • * Unweighted, weighted denominators. Percentages and ORs are based on weighted data for Natsal-2.

  • Denominator corresponds only to respondents with data available for all factors shown in table 2.

  • Adjusted for all other factors in table 2.

  • NA, not applicable; NCSP, National Chlamydia Screening Programme.