Importance: Approximately 1.4 million male circumcisions (MCs) are performed annually in US medical settings. However, population-based estimates of MC-associated adverse events (AEs) are lacking.
Objectives: To estimate the incidence rate of MC-associated AEs and to assess whether AE rates differed by age at circumcision.
Design: We selected 41 possible MC AEs based on a literature review and on medical billing codes. We estimated a likely risk window for the incidence calculation for each MC AE based on pathogenesis. We used 2001 to 2010 data from SDI Health, a large administrative claims data set, to conduct a retrospective cohort study.
Setting and participants: SDI Health provided administrative claims data from inpatient and outpatient US medical settings.
Main outcomes and measures: For each AE, we calculated the incidence per million MCs. We compared the incidence risk ratio and the incidence rate difference for circumcised vs uncircumcised newborn males and for males circumcised at younger than 1 year, age 1 to 9 years, or 10 years or older. An AE was considered probably related to MC if the incidence risk ratio significantly exceeded 1 at P < .05 or occurred only in circumcised males.
Results: Records were available for 1,400,920 circumcised males, 93.3% as newborns. Of 41 possible MC AEs, 16 (39.0%) were probable. The incidence of total MC AEs was slightly less than 0.5%. Rates of potentially serious MC AEs ranged from 0.76 (95% CI, 0.10-5.43) per million MCs for stricture of male genital organs to 703.23 (95% CI, 659.22-750.18) per million MCs for repair of incomplete circumcision. Compared with boys circumcised at younger than 1 year, the incidences of probable AEs were approximately 20-fold and 10-fold greater for males circumcised at age 1 to 9 years and at 10 years or older, respectively.
Conclusions and relevance: Male circumcision had a low incidence of AEs overall, especially if the procedure was performed during the first year of life, but rose 10-fold to 20-fold when performed after infancy.