title: Male circumcision for the prevention of heterosexually acquired HIV infection: a meta-analysis of randomized trials involving 11,050 men.
abstract: OBJECTIVE
  Observational studies and a small collection of randomized controlled trials (RCTs) suggest that male circumcision may significantly reduce HIV transmission between sero-discordant contacts. The Joint United Nations Programme on HIV/AIDS (UNAIDS) and World Health Organization have recently announced recommendations to scale up male circumcision in countries with generalized epidemics and low levels of male circumcision. However, no meta-analysis has been conducted to determine the effectiveness of this intervention.
  
  
  METHODS
  We conducted a systematic review of medical literature, and included any RCTs assessing male circumcision to prevent heterosexually acquired HIV infection among males. We used the DerSimonian-Laird random effects method to pool study outcomes. We calculated the relative risk (RR), risk difference, number needed to treat (NNT) and I(2), all with 95% confidence intervals (CIs).
  
  
  RESULTS
  We identified three RCTs that met our inclusion criteria, involving a total of 11 050 men. The pooled RR was 0.44 (95% CI 0.33-0.60, P<0.0001, I(2)=0%, 95% CI 0-35%). The risk difference was 0.014 (95% CI 0.07-0.21), yielding a NNT of 72 (95% CI 50-143).
  
  
  CONCLUSIONS
  Male circumcision is an effective strategy for reducing new male HIV infections. Its impact on a population level will require consistently safe sexual practices to maintain the protective benefit.
authors.affiliation: St Paul's Hospital, British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada. emills@mail.cihhrs.org
authors.forename: E
authors.initials: E
authors.lastname: Mills
authors.forename: C
authors.initials: C
authors.lastname: Cooper
authors.forename: A
authors.initials: A
authors.lastname: Anema
authors.forename: G
authors.initials: G
authors.lastname: Guyatt
mesh_terms: D000293:Adolescent; D000328:Adult; D002944:Circumcision, Male; D015658:HIV Infections / Q000517:prevention & control* / Q000635:transmission; D015497:HIV-1; D006291:Health Policy; D006801:Humans; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012725:Sexual Behavior / Q000523:psychology*; D055815:Young Adult