title: A longitudinal cohort study of incidence rates of inguinal hernia repair in 0- to 6-year-old children.
abstract: OBJECTIVE
  This study provides epidemiologic data on the incidence of inguinal hernia repair in preschool children using the Taiwan National Health Insurance Research Database. We believe that the data on hernia repair in said database provide a close approximation of the true incidence of inguinal hernia in young children.
  
  
  METHODS
  A cohort of 1,073,891 deidentified individuals was randomly selected from an insured population of 23 million. Subjects born during the period 1997-2004 were followed from birth to 6 years. The chi-square test and logistic regression modeling were used for statistical analyses.
  
  
  RESULTS
  A total of 92,308 individuals were born during the study period. Of these individuals, 3881 underwent hernia repairs. The cumulative incidence of hernia repair in children aged 0 to 6 years was 4.20%/7 years. The boy/girl ratio was 4.27:1 and the unilateral/bilateral ratio was 3.77:1. The incidence of hernia repair among boys was highest during the first year of life, but then decreased with age. In contrast, the incidence among girls remained stable during the first 6 years of life. Boys younger than 1 year had more bilateral repairs than boys in other age groups (p<0.0001) and girls had significantly more bilateral repairs than boys (p<0.0001). Subjects with a history of preterm birth also had a higher incidence of hernia repair than subjects who were born at full term (odds ratio=2.34, p<0.0001).
  
  
  CONCLUSIONS
  Yearly incidence of hernia repair was obtained from a nationwide database. Some of the observations have not been reported elsewhere.
authors.affiliation: Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Mei-Lien
authors.initials: ML
authors.lastname: Pan
authors.forename: Wei-Pin
authors.initials: WP
authors.lastname: Chang
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Lee
authors.forename: Hsin-Lin
authors.initials: HL
authors.lastname: Tsai
authors.forename: Chin-Su
authors.initials: CS
authors.lastname: Liu
authors.forename: Der-Ming
authors.initials: DM
authors.lastname: Liou
authors.forename: Yen-Jen
authors.initials: YJ
authors.lastname: Sung
authors.forename: Tai-Wai
authors.initials: TW
authors.lastname: Chin
mesh_terms: D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006552:Hernia, Inguinal / Q000453:epidemiology / Q000601:surgery*; D059685:Herniorrhaphy / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000453:epidemiology / Q000601:surgery; D019458:Insurance Coverage; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
keywords: Hernia repair; Hernioplasty; Incidence rate; Inguinal hernia; Preterm