Question

• Does circumcision reduce the incidence of urinary tract infections?

Clinical Bottom Lines

1. Circumcision is associated with a lower incidence of symptomatic urinary tract infections (UTIs) in a population with low prevalence of circumcision, independent of age.
2. The odds ratio is 0.21 in favor of circumcision.
3. A number need to treat (circumcise) to prevent one UTI can be estimated to be 127.

Summary of Key Evidence

1. In a case-control study, 144 boys with UTI were compared to 742 control boys taken from the same ambulatory population.¹  All subjects were under five years old.
2. Among the controls, 47/742 (6.3%) were circumcised, compared to 2/144 (1.4%) of the cases.  This gives a protective odds ratio of 0.21 (95% CI: 0.06 - 0.76).
3. There was no evidence that age modified the protective effect of circumcision.
4. Taking anatomic abnormalities into account, the authors estimated that the percent of risk of UTIs attributable to circumcision status is 79.2%.

Additional Comments

• Age is known to be a protective factor in the occurrence of UTIs. Even when the patients in this study were stratified by age, the protective effect of circumcision remained.
• Other studies have looked at populations with a high prevalence of circumcision and in boys under 1 year old. Thus, it's nice to see that this study showed a benefit in this population.
• While the complication rate for circumcision is low (0.2 - 5%), it is not zero.
• Studies have suggested that the epithelium of the foreskin can foster the adherence of pathogenic bacteria. In this context, the prevention of UTIs by circumcising boys makes biologic sense.
• Individual, religious, and cultural preferences still play a major role in the decision to circumcise a male infant.
• The authors have been subsequently criticized for their collection methods (clean catch specimens) as this could have affected the culture results.

Citation

1. Craig JC, Knight JF, Sureshkumar P, Mantz E, Roy LP.  Effect of circumcision on incidence of urinary tract infection in preschool boys.  J Pediatr 1996; 128(1):23-7.

CAT Author: Allison Schwanda, MD

CAT Appraisers: John Frohna, MD

Date appraised: November 25, 1998