The incidence of inguinal hernia and associated risk factors of incarceration in pediatric inguinal hernia: a nation-wide longitudinal population-based study.

PURPOSE: This study uses a national database to evaluate the incidence of inguinal hernia and associated risk factors of incarcerated hernia in children from birth to 15 years of age.

METHODS: The study selected children born from 1997 to 2005 from a randomly selected cohort of 1,000,000 from an insured population of 23 million. We regarded children that were classified with code 550 and hernia surgery in accordance to the International Classification of Diseases, 9th Revision, as having inguinal hernia. We used the 2 chi-square test and logistic regression modeling for statistical analyses.

RESULTS: In total, 79,794 children (41,767 male and 38,027 female) were enrolled in the study. The cumulative incidence of inguinal hernia in males and females from birth to 15 years old were 6.62 and 0.74 %, respectively (p < 0.01). The peak incidence of inguinal hernia was at 0 years of age for males and 5 years of age for females. The ratio of unilateral vs. bilateral repair was 5.54:1. Females tend to have more bilateral inguinal hernia than males (25.4 vs. 12.9 %, p < 0.01). Incarcerated hernia occurred in 4.19 % children with inguinal hernia without significant gender discrepancy. Approximately 40 % of incarcerated hernia underwent hernia repair immediately after visiting the emergent department. In patients who presented with reducible hernia, we did not find significant correlation between waiting time to hernia repair and occurrence of incarceration.

CONCLUSIONS: The cumulative incidence of inguinal hernia from birth to 15 years of age was 6.62 and 0.74 % in males and females, respectively. Incarceration was not related to prematurity or the waiting time for surgery.