title: Factors associated with Chlamydia trachomatis testing in a high school based screening and previously in clinical practice: a cross-sectional study in Norway.
abstract: BACKGROUND
  High school based chlamydia screening has been shown to increase uptake and detect hidden infections among sexually active adolescents. Our study aimed to: i) examine the proportions of 15-20 year-olds tested in a high school based screening and previously in clinical practice, ii) determine chlamydia prevalence according to testing pattern, and iii) examine factors associated with testing in the two settings.
  
  
  METHODS
  A population based cross-sectional study was conducted in 5 high schools in Norway in 2009, using web-questionnaires and Chlamydia trachomatis PCR in first-void urine (800 girls/818 boys, mean age 17.2 years). Only sexually active participants at risk for chlamydia infections were included in the analyses. Crude and multivariable logistic regression models were applied with 'clinic based testing' and 'school based screening' as outcome variables.
  
  
  RESULTS
  56% of girls and 21% of boys reported previous clinic based testing. In the school based screening, 93% were tested with no gender difference. 42% of girls and 74% of boys were tested for the first time at school ('school-only test'). Both girls with clinic based testing and girls with school-only test had high chlamydia prevalence (7.3% vs 7.2%). Boys with clinic based testing had twice the prevalence of those with school-only test (6.2% vs 3.0%, p = 0.01). Half of infections were detected in participants with school-only test. One-fifth were repeat infections. In multivariable analysis of girls and boys combined, female gender, older age, early sexual debut, no condom use at first and last intercourse, steady relationship, and higher number of lifetime partners increased the odds of clinic based testing. The odds of school based screening increased with male gender, academic affiliation, later sexual debut, condom use at first intercourse, and current urogenital symptoms in multivariable analysis.
  
  
  CONCLUSIONS
  More than half the girls had been tested prior to the school based screening and had high prevalence independent of previous clinic based testing. School screening was mostly associated with factors unknown to increase chlamydia infection risk, while clinic based testing was associated with traditional risk factors. The unusually high and equal participation between genders and the detection of a large chlamydia reservoir confirms the value of school based screening suggesting this approach to be further explored in Norway.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Gravningen
authors.forename: Gunnar Skov
authors.initials: GS
authors.lastname: Simonsen
authors.forename: Anne-Sofie
authors.initials: AS
authors.lastname: Furberg
authors.forename: Tom
authors.initials: T
authors.lastname: Wilsgaard
mesh_terms: D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods; D009664:Norway / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D012572:School Health Services; D012725:Sexual Behavior; D011795:Surveys and Questionnaires; D055815:Young Adult
references.citation: BMC Infect Dis. 2012 Nov 22;12:319
references.pmid: 23174009
references.citation: Sex Transm Infect. 2011 Jun;87(4):306-11
references.pmid: 21429897
references.citation: J Infect Dis. 2010 Jan 1;201(1):42-51
references.pmid: 19929379
references.citation: Sex Transm Infect. 2003 Oct;79(5):408-11
references.pmid: 14573838
references.citation: Int J Epidemiol. 2014 Apr;43(2):536-44
references.pmid: 23382364
references.citation: Adolescence. 2008 Winter;43(172):927-31
references.pmid: 19149154
references.citation: Tidsskr Nor Laegeforen. 2007 Dec 13;127(24):3202-5
references.pmid: 18084360
references.citation: Tidsskr Nor Laegeforen. 2007 Aug 23;127(16):2077-9
references.pmid: 17717569
references.citation: Sex Transm Infect. 2009 Oct;85(6):455-8
references.pmid: 19574242
references.citation: BMC Public Health. 2010 Nov 24;10:725
references.pmid: 21106064
references.citation: Sex Transm Dis. 2008 Nov;35(11 Suppl):S28-33
references.pmid: 18418291
references.citation: Arch Pediatr Adolesc Med. 2003 Jun;157(6):523-9
references.pmid: 12796231
references.citation: J Fam Plann Reprod Health Care. 2009 Jan;35(1):21-6
references.pmid: 19126312
references.citation: Sex Transm Dis. 2006 Oct;33(10):614-20
references.pmid: 16614587
references.citation: Sex Transm Dis. 2003 Nov;30(11):850-3
references.pmid: 14603094
references.citation: Science. 1998 May 8;280(5365):867-73
references.pmid: 9572724
references.citation: AIDS Educ Prev. 1991 Fall;3(3):207-14
references.pmid: 1834142
references.citation: Sex Transm Infect. 2009 Jun;85(3):201-5
references.pmid: 19106148
references.citation: JAMA. 2004 May 12;291(18):2229-36
references.pmid: 15138245
references.citation: Psychol Bull. 2007 Sep;133(5):859-83
references.pmid: 17723033
references.citation: BMC Infect Dis. 2010 Nov 11;10:325
references.pmid: 21070646
references.citation: Sex Transm Infect. 2004 Oct;80(5):335-41
references.pmid: 15459399
references.citation: J Adolesc Health. 2011 Sep;49(3):252-7
references.pmid: 21856516
references.citation: BMC Public Health. 2004 Jun 09;4:21
references.pmid: 15189565
references.citation: Sex Transm Infect. 2013 Feb;89(1):20-4
references.pmid: 22773326
references.citation: Sex Transm Dis. 2012 Feb;39(2):97-103
references.pmid: 22249297