title: Circumcision and STD in the United States: cross sectional and cohort analyses.
abstract: BACKGROUND
  Male circumcision status has been shown to be associated with sexually transmitted disease (STD) acquisition in some, but not all, studies. Most studies have been cross sectional.
  
  
  OBJECTIVE
  We examined the association between circumcision status and the prevalence and incidence of gonorrhoea, chlamydia, and syphilis.
  
  
  METHODS
  We analysed cross sectional and cohort study data from a multicentre controlled trial in the United States. Between July 1993 and September 1996, 2021 men visiting public inner city STD clinics in the United States were examined by a clinician at enrolment and 1456 were examined at follow up visits 6 and 12 months later. At each visit, men had laboratory tests for gonorrhoea, chlamydia, and syphilis and were examined for circumcision status. We used multiple logistic regression to compare STD risk among circumcised and uncircumcised men adjusted for potentially confounding factors.
  
  
  RESULTS
  Uncircumcised men were significantly more likely than circumcised men to have gonorrhoea in the multivariate analyses, adjusted for age, race, and site, in both the cross sectional (odds ratio (OR), 1.3; 95% confidence interval (CI), 0.9 to 1.7) and in the cohort analysis (OR, 1.6; 95% CI, 1.0 to 2.6). There was no association between lack of circumcision and chlamydia in either the cross sectional (OR, 1.0; 95% CI 0.7-1.4) or the cohort analysis (OR, 0.9; 95% CI 0.5-1.5). The magnitude of association between lack of circumcision and syphilis was similar in the cross sectional (OR, 1.4; 95% CI 0.6 to 3.3) and cohort analysis (OR, 1.5; 95% CI 0.4 to 6.1).
  
  
  CONCLUSIONS
  Uncircumcised men in the United States may be at increased risk for gonorrhoea and syphilis, but chlamydia risk appears similar in circumcised and uncircumcised men. Our results suggest that risk estimates from cross sectional studies would be similar to cohort findings.
authors.affiliation: Kaiser Permanente Research Department, Nine Piedmont Center, 3495 Piedmont Road, NE, Atlanta, GA 30305-1736, USA. robert.diseker@kp.org
authors.forename: R A
authors.initials: RA
authors.lastname: Diseker
authors.forename: T A
authors.initials: TA
authors.lastname: Peterman
authors.forename: M L
authors.initials: ML
authors.lastname: Kamb
authors.forename: C
authors.initials: C
authors.lastname: Kent
authors.forename: J M
authors.initials: JM
authors.lastname: Zenilman
authors.forename: J M
authors.initials: JM
authors.lastname: Douglas
authors.forename: F
authors.initials: F
authors.lastname: Rhodes
authors.forename: M
authors.initials: M
authors.lastname: Iatesta
mesh_terms: D000328:Adult; D000368:Aged; D002690:Chlamydia Infections / Q000453:epidemiology*; D002944:Circumcision, Male / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D006069:Gonorrhea / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D012307:Risk Factors; D013587:Syphilis / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology