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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: (Published 21 April 2005) Cite this as: BMJ 2005;330:940
  1. John Macleod, senior lecturer in primary care1 (j.a.macleod{at},
  2. Chris Salisbury, professor of primary health care2,
  3. Nicola Low, senior lecturer in epidemiology and public health3,
  4. Anne McCarthy, project manager3,
  5. Jonathan A C Sterne, reader in medical statistics and epidemiology3,
  6. Aisha Holloway, research fellow1,
  7. Rita Patel, research associate2,
  8. Emma Sanford, research associate3,
  9. Andrea Morcom, research fellow1,
  10. Paddy Horner, consultant in genitourinary medicine5,
  11. George Davey Smith, professor of clinical epidemiology3,
  12. Susan Skidmore, consultant clinical scientist6,
  13. Alan Herring, head, Genitourinary Infections Reference Laboratory7,
  14. Owen Caul, consultant virologist7,
  15. F D Richard Hobbs, professor of primary care and general practice1,
  16. Matthias Egger, professor of epidemiology and public health4
  1. 1 Department of Primary Care and General Practice, University of Birmingham, Birmingham B15 2TT
  2. 2 Department of Community Based Medicine, University of Bristol, Bristol BS6 6JL
  3. 3 Department of Social Medicine, University of Bristol, Bristol BS8 2PR
  4. 4 Department of Social and Preventive Medicine, University of Berne, Finkenhubelweg 11, Berne, CH-3012, Switzerland
  5. 5 Milne Centre, United Bristol Healthcare Trust, Bristol BS21 7LR
  6. 6 Public Health Laboratory Service, Birmingham B9 5SS
  7. 7 Public Health Laboratory Service, Bristol BS2 8EL
  1. Correspondence to J Macleod
  • Accepted 2 March 2005


Objective To measure the coverage and uptake of systematic postal screening for genital Chlamydia trachomatis and the prevalence of infection in the general population in the United Kingdom. To investigate factors associated with these measures.

Design Cross sectional survey of people randomly selected from general practice registers. Invitation to provide a specimen collected at home.

Setting England.

Participants 19 773 men and women aged 16-39 years invited to participate in screening.

Main outcome measures Coverage and uptake of screening; prevalence of chlamydia.

Results Coverage of chlamydia screening was 73% and was lower in areas with a higher proportion of non-white residents. Uptake in 16-24 year olds was 31.5% and was lower in men, younger adults, and practices in disadvantaged areas. Overall prevalence of chlamydia was 2.8% (95%confidence interval 2.2% to 3.4%) in men and 3.6% (3.1% to 4.9%) in women, but it was higher in people younger than 25 years (men 5.1%; 4.0% to 6.3%; women 6.2%; 5.2% to 7.8%). Prevalence was higher in the subgroup of younger women who were harder to engage in screening. The strongest determinant of chlamydial infection was having one or more new sexual partners in the past year.

Conclusions Postal chlamydia screening was feasible, but coverage was incomplete and uptake was modest. Lower coverage of postal screening in areas with more non-white residents along with poorer uptake in more deprived areas and among women at higher risk of infection could mean that screening leads to wider inequalities in sexual health.


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  • Contributors JM wrote the first draft of the paper, which was revised by JM and NL following comments from CS, JACS, AMcC, GDS, and ME. All authors commented on the final draft. ME, JM, CS, PH, OC, GDS, NL, and RH devised the ClaSS prevalence survey and helped obtain funding. JM, CS, NL, AMcC, JS, PH, ME, and the ClaSS study group undertook strategic management of ClaSS. AMcC was also responsible for day to day project management. AHo, RP, and AM recruited practices and undertook the survey under the supervision of JM and CS. SS and AHe supervised sample testing. JS devised the analysis strategy with JM, CS, and NL. ES undertook statistical analyses under the supervision of JS and NL. ME is lead investigator of the ClaSS study and is the guarantor.

  • Funding ClaSS is funded through the NHS R&D HTA programme. Participating individuals and institutions can be viewed at JM and NL are funded by NHS Career Scientist Awards.

  • Competing interests None declared.

  • Ethical approval South West Multicentre Research Ethics Committee and all relevant local research ethics committees.

  • Accepted 2 March 2005
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