title: Assessing non-response to a mailed health survey including self-collection of biological material.
abstract: BACKGROUND
  Collection of biological material via mailed health surveys is an emerging trend. This study was conducted to assess non-response bias in a study of sexually transmitted infection utilizing self-collected, home-obtained specimens.
  
  
  METHODS
  Data from a nationwide administrative database on health care utilization together with data from a research study were used. The research study was an outreach screening programme including home-obtained, participant-collected, mail-delivered testing for Chlamydia trachomatis. A random sample of 1690 persons aged 18-35 years from the population registry was selected. Study materials (specimen collection kit, informed consent, questionnaire) were mailed in three waves.
  
  
  RESULTS
  The first mailing yielded a response rate of 18.5% (n = 259), the second 10.1% (n = 141) and the third 11.4% (n = 160). Women were more likely to respond than men, and responders were less likely to have had medical care in the past year and more likely to have had a prior sexually transmitted infection than non-responders. Chlamydia trachomatis infection rates tended to be higher in early responders. Late responders appeared more like non-responders in terms of demographic factors, health care utilization patterns and potential disease status.
  
  
  CONCLUSIONS
  Non-response in a health survey including biological material self-collection warrants research as it may differ from non-response in general health questionnaires.
authors.affiliation: Department of Public Health, University of Tartu, Tartu, Estonia. anneli.uuskula@ut.ee
authors.forename: Anneli
authors.initials: A
authors.lastname: Uusküla
authors.forename: Mart
authors.initials: M
authors.lastname: Kals
authors.forename: Louise-Anne
authors.initials: LA
authors.lastname: McNutt
mesh_terms: D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000175:diagnosis*; D002692:Chlamydia trachomatis; D004957:Estonia; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011177:Postal Service; D045808:Refusal to Participate / Q000706:statistics & numerical data*; D013048:Specimen Handling / Q000379:methods*; D055815:Young Adult
references.citation: JAMA. 2000 Jan 5;283(1):81-6
references.pmid: 10632284
references.citation: Sex Transm Dis. 2001 Feb;28(2):117-23
references.pmid: 11234786
references.citation: J Lab Clin Med. 1999 Aug;134(2):141-6
references.pmid: 10444027
references.citation: Sex Transm Infect. 2009 Feb;85(1):60-4
references.pmid: 18708480
references.citation: CMAJ. 2000 Sep 5;163(5):513-8
references.pmid: 11006761
references.citation: JAMA. 2002 Feb 13;287(6):726-33
references.pmid: 11851539
references.citation: Eur J Epidemiol. 1999 Mar;15(3):293-9
references.pmid: 10395061
references.citation: Sex Transm Infect. 2007 Jul;83(4):292-303
references.pmid: 17050567
references.citation: J Clin Epidemiol. 1997 Oct;50(10):1123-8
references.pmid: 9368520
references.citation: BMJ. 1996 Nov 9;313(7066):1186-9
references.pmid: 8916753
references.citation: J Acquir Immune Defic Syndr. 2007 Jun 1;45(2):224-30
references.pmid: 17417102
references.citation: Menopause. 2008 Jul-Aug;15(4 Pt 1):726-9
references.pmid: 18427354
references.citation: J Infect Dis. 2002 Jan 15;185(2):252-8
references.pmid: 11807700
references.citation: BMC Health Serv Res. 2004 Jul 06;4(1):16
references.pmid: 15238155
references.citation: BMJ. 2005 Apr 23;330(7497):940
references.pmid: 15809231
references.citation: Sex Transm Dis. 2005 Oct;32(10):625-9
references.pmid: 16205304
references.citation: Scand J Public Health. 2007;35(2):212-5
references.pmid: 17454926
references.citation: J Obstet Gynaecol Can. 2006 Dec;28(12):1083-1088
references.pmid: 17169231
references.citation: J Med Screen. 2004;11(1):16-22
references.pmid: 15006109
references.citation: Sex Transm Infect. 2005 Feb;81(1):17-23
references.pmid: 15681716
references.citation: Ann Epidemiol. 1999 Apr;9(3):188-95
references.pmid: 10192651
references.citation: Osteoporos Int. 1995;5(5):327-34
references.pmid: 8800782
references.citation: Am J Epidemiol. 1987 Feb;125(2):329-39
references.pmid: 3812439
references.citation: J Clin Epidemiol. 1997 Oct;50(10):1117-22
references.pmid: 9368519
references.citation: J Epidemiol Community Health. 1981 Dec;35(4):293-6
references.pmid: 6461711
references.citation: Int J Gynecol Cancer. 2007 May-Jun;17(3):615-22
references.pmid: 17504376
references.citation: J Clin Epidemiol. 1996 Mar;49(3):373-81
references.pmid: 8676188
references.citation: J Chronic Dis. 1979;32(1-2):51-63
references.pmid: 447779
references.citation: Am J Epidemiol. 1979 Apr;109(4):394-9
references.pmid: 443238
references.citation: Cochrane Database Syst Rev. 2007 Apr 18;(2):MR000008
references.pmid: 17443629
references.citation: Tidsskr Nor Laegeforen. 1999 Aug 30;119(20):2990-2
references.pmid: 10504845
references.citation: Epidemiology. 1993 Jul;4(4):375-9
references.pmid: 8347749
references.citation: Alcohol Alcohol. 2003 Mar-Apr;38(2):128-34
references.pmid: 12634259
references.citation: Am J Epidemiol. 1981 Jul;114(1):137-43
references.pmid: 7246521
references.citation: BMC Health Serv Res. 2010 Feb 10;10:38
references.pmid: 20146819
references.citation: Can J Public Health. 2007 Jan-Feb;98(1):37-40
references.pmid: 17278676