ONLINE SUPPLEMENTARY MATERIAL

Transcription

1 Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual ONLINE SUPPLEMENTARY MATERIAL Supplementary Figure S1: Flow chart showing participants included in analyses of selfreported testing, self-reported diagnosis and prevalent infection detected in urine among 16 to 24 year-old Natsal-3 participants 16 to 24 year-old participants (n=3,869) Sexually-experienced (n=3,115: 1,740 women; 1,375 men) Urine sample provided (n=1,952) Valid chlamydia test result (n=1,832: 992 women, 840 men) Did not report any sexual partner by the time of the interview (n=754) Did not agree to provide a urine sample (n=1,163) Insufficient samples, mislabelled or missing consent (n=120) Chlamydia detected in urine (n=62 [37 women; 25 men]) Chlamydia not detected in urine (n=1,770) Key Participants included in analyses of self-reported testing and diagnoses Participants included in analyses of prevalent infection Supplementary material: Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual

2 Supplementary Table S1: Distribution of selected demographic and behavioural characteristics among a) individuals with a prevalent chlamydia infection, b) individuals reporting a recent chlamydia diagnosis and c) the sexually-experienced population (16-24 year old sexually-experienced women). (a) Prevalent infection detected in urine (n=37) (b) Diagnosed with chlamydia (n=54) (c) Sexually-experienced population (n=1,740) Percent 95% CI Percent 95% CI Percent 95% CI % ( ) 40.5% ( ) 35.6% ( ) % ( ) 59.5% ( ) 64.4% ( ) Country England 79.8% ( ) 92.1% ( ) 85.1% ( ) Scotland 9.5% ( ) 3.4% ( ) 9.5% ( ) Wales 10.8% ( ) 4.5% ( ) 5.4% ( ) IMD quintile of LSOA of residence a 2 least deprived quintiles 15.6% ( ) 30.9% ( ) 35.1% ( ) middle quintile 11.0% ( ) 12.5% ( ) 19.5% ( ) 2 most deprived quintiles 73.4% ( ) 56.7% ( ) 45.4% ( ) Age left school b % ( ) 74.9% ( ) 78.5% ( ) % ( ) 25.1% ( ) 21.5% ( ) Age at first heterosexual sex % ( ) 19.5% ( ) 33.6% ( ) % ( ) 27.0% ( ) 29.5% ( ) < % ( ) 53.5% ( ) 36.9% ( ) in the last year 0 or % ( ) 31.10% ( ) 65.3% ( ) % ( ) 21.70% ( ) 15.0% ( ) 3 to 4 6.4% ( ) 23.60% ( ) 11.6% ( ) % ( ) 23.60% ( ) 8.1% ( ) new in the last year % ( ) 21.9% ( ) 51.8% ( ) % ( ) 26.1% ( ) 27.6% ( ) % ( ) 51.9% ( ) 20.6% ( ) in the last year without a condom % ( ) 11.4% ( ) 21.8% ( ) % ( ) 43.0% ( ) 60.6% ( ) % ( ) 45.7% ( ) 17.5% ( ) over the lifetime 1 to % ( ) 16.1% ( ) 52.6% ( ) 5 to % ( ) 35.0% ( ) 26.3% ( ) % ( ) 48.9% ( ) 21.1% ( ) Condom used for most recent sex with most recent partner Yes 31.1% ( ) 21.9% ( ) 36.8% ( ) No 68.9% ( ) 78.1% ( ) 63.2% ( ) Concurrent partnerships in last year c No 65.0% ( ) 56.0% ( ) 76.2% ( ) Yes 22.6% ( ) 22.8% ( ) 11.3% ( ) Unknown 12.4% ( ) 21.2% ( ) 12.6% ( ) Frequency of binge drinking never / less than monthly 50.5% ( ) 41.2% ( ) 62.3% ( ) monthly 8.7% ( ) 26.4% ( ) 22.1% ( ) weekly or more often 40.7% ( ) 32.4% ( ) 15.6% ( ) Ever had any same sex experience/contact Yes 21.6% ( ) 28.1% ( ) 22.5% ( ) No 78.4% ( ) 71.9% ( ) 77.5% ( ) Bases (wt, unwt) 18, 37 28, , 1740 Supplementary material: Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual

3 Supplementary Table S2: Distribution of selected demographic and behavioural characteristics among a) individuals with a prevalent chlamydia infection, b) individuals reporting a recent chlamydia diagnosis and c) the sexually-experienced population reporting selected demographic and behavioural characteristics (16-24 year old sexually-experienced men). (a) Prevalent infection detected in urine (n=25) (b) Diagnosed with chlamydia (n=27) (c) Sexually-experienced population (n=1,375) Percent 95% CI Percent 95% CI Percent 95% CI % ( ) 35.6% ( ) 37.3% ( ) % ( ) 64.4% ( ) 62.7% ( ) Country England 71.8% ( ) 78.8% ( ) 85.7% ( ) Scotland 24.2% ( ) 19.2% ( ) 8.8% ( ) Wales 3.9% ( ) 2.0% ( ) 5.5% ( ) IMD quintile of LSOA of residence a 2 least deprived quintiles 22.0% ( ) 33.7% ( ) 36.9% ( ) middle quintile 12.9% ( ) 15.3% ( ) 18.2% ( ) 2 most deprived quintiles 65.1% ( ) 51.0% ( ) 44.9% ( ) Age left school b % ( ) 66.5% ( ) 75.4% ( ) % ( ) 33.5% ( ) 24.6% ( ) Age at first heterosexual sex % ( ) 12.3% ( ) 35.1% ( ) % ( ) 20.6% ( ) 26.1% ( ) < % ( ) 67.1% ( ) 38.8% ( ) in the last year 0 or % ( ) 25.2% ( ) 57.30% ( ) % ( ) 3.5% ( ) 18.70% ( ) 3 to % ( ) 4.4% ( ) 13.60% ( ) % ( ) 66.9% ( ) 10.40% ( ) new in the last year % ( ) 30.3% ( ) 42.1% ( ) % ( ) 23.3% ( ) 32.6% ( ) % ( ) 46.5% ( ) 25.3% ( ) in the last year without a condom 0 4.8% ( ) 8.2% ( ) 33.1% ( ) % ( ) 39.7% ( ) 47.5% ( ) % ( ) 52.1% ( ) 19.4% ( ) over the lifetime 1 to % ( ) 6.5% ( ) 52.70% ( ) 5 to % ( ) 16.7% ( ) 22.40% ( ) % ( ) 76.7% ( ) 24.90% ( ) Condom used for most recent sex with most recent partner Yes 15.5% ( ) 35.3% ( ) 51.7% ( ) No 84.5% ( ) 64.7% ( ) 48.3% ( ) Concurrent partnerships in last year c No 77.6% ( ) 74.5% ( ) 71.2% ( ) Yes 11.4% ( ) 22.0% ( ) 14.3% ( ) Unknown 11.0% ( ) 3.5% ( ) 14.5% ( ) Frequency of binge drinking never / less than monthly 25.1% ( ) 25.9% ( ) 52.6% ( ) monthly 26.7% ( ) 16.2% ( ) 20.2% ( ) weekly or more often 48.2% ( ) 57.9% ( ) 27.3% ( ) Ever had any same sex experience/contact Yes 6.8% ( ) 8.2% ( ) 8.0% ( ) No 93.2% ( ) 91.8% ( ) 92.0% ( ) Bases (wt, unwt) 14, 25 20, , 1375 N in column headings shows unweighted denominators. Total denominators by characteristic vary due to item-missingness. a IMD: Index of multiple deprivation of LSOA (lower super output area) of residence. IMD scores for England, Scotland and Wales were adjusted before being combined and assigned to quintiles, using the method described by Payne and Abel 39 ; b Excludes 16 year olds; c Among those with 1+ more in last year. Supplementary material: Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual

4 Supplementary Table S3: Percentage, unadjusted and adjusted odds ratios for prevalent chlamydia infection, self-reported diagnosis in the last year and self-reported testing by sociodemographic and behavioural factors (sexually-experienced year-old women) Prevalent infection detected in urine (n=992) Diagnosed with chlamydia (among those tested ) (n=940) Tested for chlamydia (n=1,736) Denominator (weighted, unweighted) a % (95% CI) OR (95% CI) p AOR b (95% CI) p % (95% CI) OR (95% CI) p AOR b (95% CI) p % (95% CI) OR (95% CI) p AOR b (95% CI) p Infection Diagnosis Tested % ( ) %( ) %( ) , , , %( ) 0.71 ( ) 0.71 ( ) 5.1%( ) 0.86( ) 0.80( ) 52.8%( ) 0.86( ) 0.82( ) 383, , , 1064 Country c England 2.9% ( ) %( ) < < , , , 1452 Scotland 3.1% ( ) 1.08 ( ) 1.34 ( ) 32.4%( ) 0.36( ) 0.29( ) 56, , 58 91, 178 Wales 5.3% ( ) 1.87 ( ) 1.88 ( ) 45.6%( ) 0.63( ) 0.53( ) 37, 72 24, 50 52, 106 IMD quintile of LSOA of residence d 2 least deprived 1.3% ( ) %( ) %( ) , , , 595 Middle quintile 1.8% ( ) 1.37 ( ) 1.40 ( ) 3.5%( ) 0.71( ) 1.06( ) 54.4%( ) 1.01( ) 1.03( ) 111, , , most deprived 4.9% ( ) 3.82 ( ) 4.23 ( ) 6.8%( ) 1.46( ) 1.70( ) 54.0%( ) 0.99( ) 0.97( ) 273, , , 817 Age left school e % ( ) %( ) %( ) , , , % ( ) 1.06 ( ) 6.2%( ) 1.21( ) 55.5%( ) 1.05( ) 120, , , 405 Age at first heterosexual sex % ( ) %( ) %( ) < , , , % ( ) 2.52 ( ) 2.20 ( ) 5.0%( ) 1.24( ) 0.80( ) 56.4%( ) 1.66( ) 1.39( ) 178, , , 503 <16 4.0% ( ) 2.65 ( ) 1.82 ( ) 6.9%( ) 1.76( ) 0.89( ) 63.9%( ) 2.27( ) 1.44( ) 213, , , or 1 2.5% ( ) %( ) %( ) < , , , % ( ) 1.62 ( ) 6.6%( ) 2.25( ) 65.2%( ) 2.15( ) 90, , , to 4 1.9% ( ) 0.75 ( ) 8.8%( ) 3.08( ) 69.7%( ) 2.63( ) 63, , , % ( ) 3.57 ( ) 11.6%( ) 4.19( ) 74.8%( ) 3.40( ) 49, 93 58, , 135 new 0 2.2% ( ) %( ) < %( ) < < , , , % ( ) 1.26 ( ) 1.17 ( ) 4.8%( ) 1.76( ) 1.89( ) 59.2%( ) 1.73( ) 1.69( ) 160, , , % ( ) 2.73 ( ) 1.65 ( ) 10.7%( ) 4.23( ) 3.09( ) 70.0%( ) 2.79( ) 1.46( ) 118, , , 359

5 without a condom 0 2.9% ( ) %( ) < %( ) < , , , % ( ) 0.76 ( ) 0.34 ( ) 3.8%( ) 0.90( ) 0.72( ) 54.7%( ) 2.11( ) 1.52( ) 368, , , % ( ) 2.25 ( ) 0.49 ( ) 10.3%( ) 2.60( ) 0.90( ) 74.2%( ) 5.04( ) 1.86( ) 108, , , 322 lifetime sexual partners 1 to 4 2.4% ( ) %( ) < %( ) < < , , , to 9 2.8% ( ) 1.15 ( ) 0.87 ( ) 6.2%( ) 3.07( ) 2.40( ) 63.8%( ) 2.29( ) 1.96( ) 150, , , % ( ) 2.29 ( ) 1.39 ( ) 9.9%( ) 5.12( ) 3.76( ) 69.6%( ) 2.97( ) 2.11( ) 121, , , 373 Condom used for most recent sex with most recent partner Yes 2.8% ( ) %( ) %( ) , , , 586 No 3.6% ( ) 1.28 ( ) 1.59 ( ) 6.3%( ) 1.90( ) 1.88( ) 58.0%( ) 1.30( ) 1.01( ) 352, , , 1027 Concurrent partnerships in last year f No 2.7% ( ) %( ) %( ) < , , , 1256 Yes 6.3% ( ) 2.40 ( ) 1.34 ( ) 8.1%( ) 1.95( ) 0.75( ) 74.6%( ) 2.81( ) 1.46( ) 66, , , 196 Unknown 3.1% ( ) 1.14 ( ) 1.13 ( ) 7.8%( ) 1.88( ) 1.46( ) 64.6%( ) 1.76( ) 1.53( ) 73, , , 226 Frequency of binge drinking never / <monthly 2.5% ( ) < %( ) %( ) , , , 1085 monthly 1.2% ( ) 0.49 ( ) 0.46 ( ) 6.6%( ) 1.85( ) 1.91( ) 52.4%( ) 1.01( ) 0.75( ) 130, , , 375 >weekly 7.9% ( ) 3.35 ( ) 2.51 ( ) 9.4%( ) 2.69( ) 2.06( ) 64.4%( ) 1.66( ) 1.16( ) 95, , , 274 Ever had any same sex experience/ contact No 3.1% ( ) %( ) %( ) < , , , 1352 Yes 3.2% ( ) 1.05 ( ) 0.74 ( ) 5.9%( ) 1.13( ) 0.71( ) 61.9%( ) 1.51( ) 1.21( ) 124, , , 384 a N in column headings shows unweighted denominators. Total denominators by characteristic and in multivariable models vary due to item-missingness.. b AOR: Adjusted odds ratios, adjusted for all variables shown. c Results for recent diagnosis are not reported due to small sample size in Scotland and Wales when limited to those tested. d IMD: Index of multiple deprivation of LSOA (lower super output area) of residence. IMD scores for England, Scotland and Wales were adjusted before being combined and assigned to quintiles, using the method described by Payne and Abel 24. e Excludes 16 year-olds. f Among those with >1 sexual partner in last year.

6 Supplementary Table S4: Percentage, unadjusted and adjusted odds ratios for prevalent chlamydia infection, self-reported diagnosis in the last year and self-reported testing by sociodemographic and behavioural factors (sexually-experienced year-old men) Prevalent infection detected in urine (n=840) Diagnosed with chlamydia (among those tested ) (n=471) Tested for chlamydia (n=1,375) Denominator (weighted, unweighted) a % (95% CI) OR (95% CI) p AOR b (95% CI) p % (95% CI) OR (95% CI) p AOR b (95% CI) p % (95% CI) OR (95% CI) p AOR b (95% CI) p Infection Diagnosis Tested % ( ) < %( ) %( ) < < , , , %( ) 10.6 ( ) 7.54 ( ) 6.7%( ) 1.46( ) 0.76( ) 31.1%( ) 0.67( ) 0.53( ) 391, , , 793 Country c England 1.9% ( ) %( ) < < , , , 1181 Scotland 5.7% ( ) 3.13 ( ) 3.16 ( ) 22.2%( ) 0.48( ) 0.33( ) 60, 72 20, 22 89, 111 Wales 1.7% ( ) 0.88 ( ) 1.20 ( ) 12.8%( ) 0.25( ) 0.19( ) 33, 49 7, 9 55, 83 IMD quintile of LSOA of residence d 2 least deprived 1.3% ( ) %( ) %( ) , , , 509 Middle quintile 1.6% ( ) 1.24 ( ) 1.01 ( ) 5.0%( ) 0.96( ) 0.68( ) 33.3%( ) 0.95( ) 1.04( ) 114, , , most deprived 3.4% ( ) 2.71 ( ) 3.75 ( ) 6.5%( ) 1.26( ) 1.06( ) 35.2%( ) 1.03( ) 1.13( ) 269, , , 603 Age left school e % ( ) %( ) %( ) , , , % ( ) 3.28 ( ) 7.2%( ) 1.38( ) 37.8%( ) 1.20( ) 143, , , 334 Age at first heterosexual sex % ( ) %( ) %( ) < , , , % ( ) 1.49 ( ) 1.14 ( ) 4.7%( ) 1.75( ) 1.14( ) 33.4%( ) 1.46( ) 1.13( ) 148, , , 351 <16 4.0% ( ) 4.18 ( ) 1.65 ( ) 7.8%( ) 2.99( ) 1.58( ) 45.3%( ) 2.40( ) 1.53( ) 238, , , or 1 1.5% ( ) %( ) < %( ) < , , , % ( ) 0.86 ( ) 0.9%( ) 0.27( ) 40.3%( ) 1.92( ) 123, , , to 4 3.1% ( ) 2.16 ( ) 1.5%( ) 0.44( ) 43.0%( ) 2.15( ) 70, , , % ( ) 5.47 ( ) 21.2%( ) 7.54( ) 60.9%( ) 4.42( ) 67, , , 146 new 0 1.8% ( ) %( ) %( ) < , , , % ( ) 0.42 ( ) 0.33 ( ) 4.0%( ) 0.71( ) 1.13( ) 36.7%( ) 1.64( ) 1.28( ) 203, , , % ( ) 2.87 ( ) 0.47 ( ) 8.0%( ) 1.48( ) 2.87( ) 46.3%( ) 2.45( ) 1.06( ) 152, , , 366

7 without a condom 0 0.3% ( ) < %( ) %( ) < , , , % ( ) 5.26 ( ) 1.23 ( ) 4.9%( ) 2.75( ) 0.78( ) 34.3%( ) 1.41( ) 1.12( ) 287, , , % ( ) 21.3 ( ) 4.95 ( ) 10.9%( ) 6.51( ) 0.46( ) 48.8%( ) 2.59( ) 1.37( ) 130, , , 281 lifetime sexual partners 1 to 4 0.4% ( ) < %( ) < < %( ) < < , , , to 9 1.2% ( ) 3.21 ( ) 1.78 ( ) 3.8%( ) 4.15( ) 4.87( ) 39.6%( ) 1.93( ) 1.50( ) 141, , , % ( ) 22.6 ( ) 8.69 ( ) 12.3%( ) 14.6( ) 19.80( ) 49.2%( ) 2.86( ) 2.23( ) 148, , , 342 Condom used for most recent sex with most recent partner Yes 0.7% ( ) < %( ) %( ) , , , 671 No 4.1% ( ) 6.03 ( ) 3.59 ( ) 7.4%( ) 1.79( ) 1.06( ) 38.0%( ) 1.22( ) 0.97( ) 283, , , 621 Concurrent partnerships in last year f No 2.6% ( ) %( ) %( ) < , , , 916 Yes 2.0% ( ) 0.75 ( ) 0.18 ( ) 6.5%( ) 0.96( ) 0.60( ) 49.7%( ) 2.02( ) 1.52( ) 82, , , 188 Unknown 1.7% ( ) 0.64 ( ) 0.60 ( ) 1.3%( ) 0.19( ) 0.06( ) 38.5%( ) 1.28( ) 1.18( ) 92, , , 193 Frequency of binge drinking never / <monthly 1.1% ( ) %( ) %( ) < , , , 715 monthly 3.0% ( ) 2.79 ( ) 1.47 ( ) 4.0%( ) 1.15( ) 0.60( ) 39.9%( ) 1.69( ) 1.48( ) 125, , , 289 >weekly 3.8% ( ) 3.58 ( ) 2.03 ( ) 9.8%( ) 2.98( ) 1.23( ) 43.2%( ) 1.94( ) 1.50( ) 177, , , 370 Ever had any same sex experience/ contact No 2.3% ( ) %( ) %( ) , , , 1260 Yes 2.0% ( ) 0.90 ( ) 0.31 ( ) 5.1%( ) 0.87( ) 0.79( ) 42.4%( ) 1.44( ) 2.08( ) 47, 78 31, 44 80, 115 a N in column headings shows unweighted denominators. Total denominators by characteristic and in multivariable models vary due to item-missingness.. b AOR: Adjusted odds ratios, adjusted for all variables shown. c Results for recent diagnosis are not reported due to small sample size in Scotland and Wales when limited to those tested. d IMD: Index of multiple deprivation of LSOA (lower super output area) of residence. IMD scores for England, Scotland and Wales were adjusted before being combined and assigned to quintiles, using the method described by Payne and Abel 24. e Excludes 16 year-olds. f Among those with >1 sexual partner in last year.