Table 2

Risk of incident STI diagnosis in the 18 months following survey completion; results from univariable and multivariable Cox regression models, by ethnic group

VariableModel 1: full study population (N=2940)Model 2: BC (N=519)Model 3: WBI (N=1052)
Outcome statisticsOutcome statisticsOutcome statistics
(STI diagnosis in follow-up period)(STI diagnosis in follow-up period)(STI diagnosis in follow-up period)
Diagnoses (n)Person-yearsIncidence rate (%)UnivariableMultivariableUnivariableMultivariableUnivariableMultivariable
HRP valueaHRSEP valueHRP valueaHRSEP valueHRP valueaHRSEP value
Demographic
Age (years)*
 25+ (max. 80)11925034.8
 15–2412116867.20.96<0.010.980.010.040.960.010.960.020.041.340.310.960.020.10
Gender
 Male9213726.7
 Female14828165.30.790.070.890.130.420.650.070.680.200.180.610.080.600.200.13
IMD
 Three least deprived quintiles4412743.5
 Two most deprived quintiles19628986.81.95<0.011.460.250.030.690.120.500.140.012.630.012.320.840.02
Ethnic group
 WBI4915003.2
 White other235514.21.310.291.400.360.18
 Black African294626.31.95<0.011.670.410.04
 BC7965112.13.74<0.012.600.50<0.01
 Black other64912.43.81<0.013.571.57<0.01
 Mixed/other385267.22.23<0.011.690.380.02
 Asian164173.81.200.531.340.390.32
Degree-level education
 No16020957.6
 Yes7920553.80.51<0.010.740.110.040.970.910.450.010.540.170.05
Currently employed
 No7611306.7
 Yes16430315.40.810.120.650.070.900.76
Behavioural and attitudinal
Contraception use in p12m (self or partner)
 Any barrier method14325615.6
 Permanent/LARC/hormonal (without barrier)406306.30.950.740.670.150.750.47
 Emergency/natural/no method only489095.31.140.480.560.091.500.30
Early sexual debut (<16 years of age)
 No11223964.7
 Yes12817937.11.52<0.011.130.160.401.340.201.730.06
Self-perceived risk
 Don't think I'm at risk of getting any STI13318937.0
 Think I'm at risk of STIs7216474.40.63<0.010.690.1430.690.28
Attitudes to concurrency
 Negative attitude18136005.0
 Positive attitude3835510.72.12<0.011.940.041.250.450.543.06<0.012.060.810.07
Number of partners in p12m
 15615593.6
 2–49517305.51.520.011.270.230.181.920.031.430.490.292.530.032.711.350.05
 5 or more8483610.12.77<0.011.970.40<0.013.23<0.011.780.750.174.21<0.012.461.320.09
Number of new partners in p12m
 None5112644.0
 16010795.61.370.101.530.161.500.42
 2–47212036.01.480.031.490.201.700.25
 5 or more495479.02.20<0.013.24<0.014.01<0.01
Partner concurrency in p12m
 No12428054.4
 Yes9511668.21.83<0.011.780.011.990.02
Age mixing with any of most recent three partners
 No13323465.7
 Yes8113416.01.060.660.610.071.730.062.370.780.01
Ethnic mixing with any of most recent three partners
 No8118004.5
 Yes13619237.11.56<0.011.200.451.540.16
Current partnership type
 Married/committed only8019524.1
 Casual only9713097.41.80<0.011.290.220.132.15<0.011.440.440.231.980.05
 Both1413210.62.550.011.650.500.101.880.251.140.650.812.690.19
 Don't have partner467516.11.490.031.300.250.171.100.810.650.290.331.980.08
Clinical
Time since last STI diagnosis
 Never11733593.5%
 At survey attendance9159015.44.34<0.014.04<0.013.54<0.01
 Within the 6 months before survey1614111.43.23<0.012.110.092.230.03
 Within the 7–12 months before survey169916.24.57<0.012.780.024.350.02
Type of STI diagnosed at survey and p12m
 None11733593.5
 CT only363889.32.64<0.012.160.021.790.23
 Any other STI (including or excluding CT)8744219.75.52<0.014.34<0.014.94<0.01
Number of STI episodes at survey and p12m
 None11733593.5
 At survey only6250612.33.47<0.012.680.44<0.013.05<0.012.650.80<0.012.340.031.650.650.21
 1 previous episode (±1 at survey)4829616.24.57<0.013.210.58<0.013.47<0.012.640.88<0.014.26<0.013.341.38<0.01
 ≥2 previous episodes (±1 at survey)132846.612.53<0.016.852.10<0.015.54<0.015.812.73<0.0128.00<0.0129.9423.92<0.01
  • Missing data full population: see table 1 footnote.

  • Missing data BC: degree-level education (5), current employment (1), contraception use (14), self-perceived risk (76), attitudes to concurrency (27), number of partners in p12m (11), number of new partners in p12m (14), partner concurrency in p12m (28), age mixing (66), ethnic mixing (62) and current partnership type (5).

  • Missing data WBI: IMD (7), degree-level education (6), current employment (4), contraception use (15), self-perceived risk (142), attitudes to concurrency (43), number of partners in p12m (10), number of new partners in p12m (15), partner concurrency in p12m (35), age mixing (104), ethnic mixing (95) and current partnership type (9).

  • Bold values indicate statistical significance.

  • *Age modelled as continuous.

  • †The time frame for clinical data was the survey attendance (±6 weeks) and the p12m.

  • aHR, adjusted HR; BC, black Caribbean; IMD, Index of Multiple Deprivation; LARC, long-acting reversible contraception; p12m, previous 12 months; SE, Standard error; WBI, white British/Irish.