Coverage and uptake of systematic postal screening for genital Chlamydia trachomatis and prevalence of infection in the United Kingdom general population: cross sectional study
BMJ 2005; 330 doi: https://doi.org/10.1136/bmj.38413.663137.8F (Published 21 April 2005) Cite this as: BMJ 2005;330:940
Data supplement
Posted as supplied by authors.
Web table A: Chlamydia prevalence, uptake of screening, coverage, area deprivation and ethnic mix by practice
Practice number
N1
n2
Coverage, %3
Uptake, %4
Prevalence,
% (95% CI)5Deprivation score6
Ethnic mix, %7
1
345
38
83.4
16.4
0.0 (0.0, 0.9)8
63.6
68.3
2
60
13
79.5
28.1
0.0 (0.0, 4.9)8
42.7
25.5
3
746
130
73.2
23.3
1.7 (0.4, 7.1)
32.3
3.7
4
573
117
81.4
25.1
2.6 (0.8, 8.3)
36.0
4.5
5
381
53
69.7
19.9
3.1 (0.8, 11.8)
63.4
65.1
6
477
117
85.2
28.5
3.3 (1.2, 8.5)
15.2
1.2
7
752
237
63.1
52.0
3.4 (1.6, 6.9)
10.6
8.8
8
330
80
86.3
28.6
3.8 (1.2, 11.2)
36.4
9.7
9
338
116
86.2
39.8
3.8 (1.7, 8.3)
10.1
1.4
10
1308
249
49.6
41.3
4.1 (1.8, 9.0)
35.2
21.6
11
535
190
85.5
41.3
4.5 (2.2, 8.8)
7.7
1.7
12
1009
266
64.2
39.0
4.8 (2.8, 8.2)
28.1
10.6
13
226
45
76.9
25.5
4.9 (1.2, 17.9)
44.2
9.9
14
852
165
77.2
24.1
5.0 (2.3, 10.5)
38.1
7.3
15
402
129
84.8
37.4
5.2 (2.3, 11.4)
32.3
3.7
16
553
195
79.9
43.3
5.3 (2.8, 9.9)
27.3
3.8
17
209
56
83.3
32.2
5.5 (1.7, 15.8)
30.3
14.2
18
552
137
86.6
27.9
6.5 (3.4, 12.1)
38.8
5.8
19
1321
274
72.8
30.4
7.2 (4.2, 12.2)
15.6
2.0
20
689
188
78.2
33.1
7.6 (4.5, 12.6)
26.5
7.4
21
963
194
69.6
29.0
8.5 (5.3, 13.3)
59.1
67.7
22
718
197
83.4
34.0
8.5 (4.7, 14.7)
47.0
7.5
23
290
58
69.4
27.8
9.0 (3.7, 20.0)
40.0
40.8
24
265
70
83.6
31.5
9.9 (4.8, 19.5)
45.9
9.7
25
444
74
77.2
21.3
11.2 (5.1, 23.1)
38.4
35.6
26
340
76
80.6
27.0
12.3 (6.5, 22.1)
56.2
4.0
27
641
145
84.4
27.7
12.4 (7.2, 20.6)
30.6
5.5
Combined
15319
3609
75.6
31.5
5.9 (5.0, 7.0)
34.2
8.3
Legend:
1 – Total number of 16 to 24 year olds in each practice, including 4,074 patients confirmed non-resident at their registered address
2 – Number responding in each practice
3 – Proportion confirmed to have received a screening invitation, weighted to take sampling probability into account.
4 – Proportion of those receiving an invitation that returned a sample, weighted to take sampling probability into account,
5 – Prevalence estimates weighted to take sampling probability into account. Random effects meta-analysis of the log odds of prevalence was used to investigate heterogeneity of prevalence between practices (p=0.052). The I2 statistic suggested that 34% of variability was not due to random error.
6 – Index of Multiple Deprivations 2000 score. Average score for ward of residence of sampled 16-24 year patients in each practice, weighted for sampling probability.
7 – Proportion of practice population from non-white ethnic groups: 2001 Census. Average score for ward of residence of sampled 16-24 year patients in each practice, weighted for sampling probability.
8 – Exact 95% confidence interval. Does not account for sampling probability.
Web table B: Practice level factors associated with coverage and uptake of postal screening
Variable
Coverage, OR (95% CI)
Uptake, OR (95% CI)
Crude1
Adjusted2
P
Crude1
Adjusted2
P2
Deprivation score
Per 10 point increase
0.98 (0.88, 1.10)
1.13 (0.98, 1.29)
0.083
0.86 (0.80, 0.93)
0.88 (0.80, 0.96)
0.004
Proportion non-white
Per 10% increase
0.93 (0.87, 0.99)
0.87 (0.81, 0.94)
0.001
0.92 (0.87, 0.97)
0.98 (0.92, 1.05)
0.708
Legend:
Logistic regression models include 15,319 men and women aged 16 to 24 years in 27 general practices
1 – Adjusted for sampling probability using inverse probability weights and clustering by practice using robust standard errors.
2 – Additionally adjusted for variables in table plus age and sex. P value refers to adjusted model.
Web table C: Associations between prevalence and individual and practice level covariates. Men
Men
N1
Positive
Prevalence,2 % (95% CI)
Odds ratio (95% CI)
Crude2
Adjusted3
P4
All
1437
63
5.1 (4.0, 6.3)
Individual level factors
Age in years
16-19
679
22
3.5 (2.3, 5.2)
1 (reference)
1 (reference)
0.010
20-24
758
41
6.7 (5.0, 8.8)
2.0 (1.1, 3.5)
2.1 (1.2, 3.7)
Marital status
Single
1315
58
5.1 (4.0, 6.5)
1 (reference)
1 (reference)
0.706
Married
119
5
5.2 (2.2, 12.2)
1.0 (0.3, 2.9)
0.8 (0.3, 2.2)
Divorced
3
0
..
..
..
Ethnic group
White
1244
55
5.3 (4.1, 6.5)
1 (reference)
1 (reference)
0.322
Black
78
8
11.1 (5.9, 20.0)
2.0 (1.0, 4.6)
1.6 (0.6, 3.9)
Indian
70
0
..
..
..
..
Chinese
5
0
..
..
..
..
Other
40
0
..
..
..
..
Practice level factors
Deprivation score in practice population (per 10 point increase)
..
1.1 (1.0, 1.2)
1.1 (0.9, 1.4)
0.427
Proportion non-white in practice population (per 10% increase)
..
1.0 (0.9, 1.2)
1.1 (0.9, 1.3)
0.536
Uptake rate in practice (per 10% increase)
..
0.9 (0.7, 1.1)
0.9 (0.6, 1.2)
0.411
Legend:
1 – Logistic regression model restricted to 1437 men aged 16 to 24 years with complete data for all variables
2 – Adjusted for weighting and clustering using inverse probability weights and robust standard errors
3 – Adjusted for weighting, clustering and other variables in table
4 – Wald test for heterogeneity between categories: refers to adjusted model.
Web table D: Associations between prevalence and individual and practice level covariates. Women
Women
N1
Positive
Prevalence,2 % (95% CI)
Odds ratio (95% CI)
Crude2
Adjusted3
P4
All
2083
128
6.2 (5.2, 7.8)
Individual level factors
Age in years
16-19
881
54
6.0 (4.6, 8.4)
1 (reference)
1 (reference)
0.367
20-24
1202
74
6.2 (4.9, 8.4)
1.0 (0.7, 1.6)
1.2 (0.8, 2.0)
Marital status
Single
1646
116
7.0 (5.9, 9.2)
1 (reference)
1 (reference)
0.007
Married
426
12
2.6 (1.5, 4.8)
0.3 (0.2, 0.8)
0.3 (0.1, 0.7)
Divorced
11
0
..
..
..
Ethnic group
White
1778
104
5.9 (4.9, 7.7)
1 (reference)
1 (reference)
0.573
Black
164
18
9.5 (6.1, 21.0)
1.7 (0.7, 4.3)
2.0 (0.7, 5.1)
Indian
73
2
3.8 (1.0, 21.4)
0.6 (0.1, 4.0)
0.90 (0.1, 9.8)
Chinese
11
2
17.9 (4.5, 56.8)
3.5 (0.6, 22.0)
3.5 (0.5, 24.2)
Other
57
2
4.6 (1.2, 17.3)
0.8 (0.2, 3.4)
1.0 (0.2, 4.8)
Practice level factors
Deprivation score in practice population (per 10 point increase)
..
1.1 (0.9, 1.3)
1.2 (0.9, 1.5)
0.169
Proportion non-white in practice population (per 10% increase)
..
1.0 (0.8, 1.2)
0.8 (0.6, 1.1)
0.132
Uptake rate in practice (per 10% increase)
..
0.8 (0.6, 1.1)
0.8 (0.6, 1.1)
0.412
Legend:
1 – Logistic regression model restricted to 2083 women aged 16 to 24 years with complete data for all variables
2 – Adjusted for weighting and clustering using inverse probability weights and robust standard errors
3 – Adjusted for weighting, clustering and other variables in table
4 – Wald test for heterogeneity between categories: refers to adjusted model.
Posted as supplied by authors.
Participation in the Chlamydia Screening Studies project
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