title: Can we use postal surveys with anonymous testing to monitor chlamydia prevalence in young women in England? Pilot study incorporating randomised controlled trial of recruitment methods.
abstract: OBJECTIVE
  Chlamydia prevalence in the general population is a potential outcome measure for the evaluation of chlamydia control programmes. We carried out a pilot study to determine the feasibility of using a postal survey for population-based chlamydia prevalence monitoring.
  
  
  METHODS
  Postal invitations were sent to a random sample of 2000 17-year-old to 18-year-old women registered with a general practitioner in two pilot areas in England. Recipients were randomised to receive either a self-sampling kit (n=1000), a self-sampling kit and offer of £5 voucher on return of sample (n=500) or a self-sampling kit on request (n=500). Participants returned a questionnaire and self-taken vulvovaginal swab sample for unlinked anonymous Chlamydia trachomatis testing. Non-responders were sent a reminder letter 3 weeks after initial invitation. We calculated the participation rate (number of samples returned/number of invitations sent) and cost per sample returned (including cost of consumables and postage) in each group.
  
  
  RESULTS
  A total of 155/2000 (7.8%) samples were returned with consent for testing. Participation rates varied by invitation group: 7.8% in the group who were provided with a self-sampling kit, 14% in the group who were also offered a voucher and 1.0% in the group who were not sent a kit. The cost per sample received was lowest (£36) in the group who were offered both a kit and a voucher.
  
  
  CONCLUSIONS
  The piloted survey methodology achieved low participation rates. This approach is not suitable for population-based monitoring of chlamydia prevalence among young women in England.
  
  
  BACKGROUND
  (UKCRN ID 10913).
authors: Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK Research Department of Infection and Population Health, University College London, London, UK.
authors: Sarah C
authors: SC
authors: Woodhall
authors: Statistics Unit, Public Health England, London, UK.
authors: Tom
authors: T
authors: Nichols
authors: Microbiology Services, Public Health England, London, UK.
authors: Sarah
authors: S
authors: Alexander
authors: Microbiology Services, Public Health England, London, UK.
authors: Filomeno Coelho
authors: FC
authors: da Silva
authors: Research Department of Infection and Population Health, University College London, London, UK.
authors: Catherine H
authors: CH
authors: Mercer
authors: Microbiology Services, Public Health England, London, UK.
authors: Catherine
authors: C
authors: Ison
authors: Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
authors: O Noel
authors: ON
authors: Gill
authors: Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
authors: Kate
authors: K
authors: Soldan
mesh_terms: D000293:Adolescent; D035041:Anonymous Testing / Q000379:methods*; D002690:Chlamydia Infections / Q000453:epidemiology*; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D004739:England / Q000453:epidemiology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008403:Mass Screening; D010865:Pilot Projects; D011159:Population Surveillance; D011177:Postal Service; D015995:Prevalence; D013048:Specimen Handling; D011795:Surveys and Questionnaires
keywords: CHLAMYDIA TRACHOMATIS; EPIDEMIOLOGY (GENERAL); SURVEILLANCE