title: Circumcision and lifetime risk of urinary tract infection: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Urinary tract infection is common in infant males who are uncircumcised and can lead to renal parenchymal disease of the still growing pediatric kidney. Although the rate of urinary tract infection is highest in the first year of life, the cumulative incidence during the rest of the lifetime is under-recognized, but is expected to be nontrivial. Thus, any intervention that might prevent urinary tract infection would be expected to reduce suffering and medical costs.
  
  
  METHODS
  We conducted a meta-analysis of 22 studies examining the single risk factor of lack of circumcision, then determined the prevalence and relative risk of urinary tract infection in different age groups (0 to 1, 1 to 16 and older than 16 years). From these data we estimated the lifetime prevalence.
  
  
  RESULTS
  For age 0 to 1 year the relative risk was 9.91 (95% CI 7.49-13.1), for age 1 to 16 years RR was 6.56 (95% CI 3.26-13.2) and for older than 16 years it was 3.41-fold (95% CI 0.916-12.7) higher in uncircumcised males. We then calculated that 32.1% (95% CI 15.6-49.8) of uncircumcised males experience a urinary tract infection in their lifetime compared with 8.8% (95% CI 4.15-13.2) of circumcised males (RR 3.65, 95% CI 1.15-11.8). The number needed to treat was 4.29 (95% CI 2.20-27.2).
  
  
  CONCLUSIONS
  The single risk factor of lack of circumcision confers a 23.3% chance of urinary tract infection during the lifetime. This greatly exceeds the prevalence of circumcision complications (1.5%), which are mostly minor. The potential seriousness of urinary tract infection supports circumcision as a desirable preventive health intervention in infant males.
authors.affiliation: School of Medical Sciences and Bosch Institute, University of Sydney, New South Wales, Australia. brian.morris@sydney.edu.au
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Morris
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Wiswell
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001315:Australia; D002648:Child; D002675:Child, Preschool; D002944:Circumcision, Male / Q000009:adverse effects* / Q000379:methods; D016001:Confidence Intervals; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D055815:Young Adult