title: Stratification of surgical site infection by operative factors and comparison of infection rates after hernia repair.
abstract: OBJECTIVE
  To investigate whether operative factors are associated with risk of surgical site infection (SSI) after hernia repair.
  
  
  METHODS
  Retrospective cohort study. Patients Commercially insured enrollees aged 6 months-64 years with International Classification of Diseases, Ninth Revision, Clinical Modification procedure or Current Procedural Terminology, fourth edition, codes for inguinal/femoral, umbilical, and incisional/ventral hernia repair procedures from January 1, 2004, through December 31, 2010.
  
  
  METHODS
  SSIs within 90 days after hernia repair were identified by diagnosis codes. The χ2 and Fisher exact tests were used to compare SSI incidence by operative factors.
  
  
  RESULTS
  A total of 119,973 hernia repair procedures were analyzed. The incidence of SSI differed significantly by anatomic site, with rates of 0.45% (352/77,666) for inguinal/femoral, 1.16% (288/24,917) for umbilical, and 4.11% (715/17,390) for incisional/ventral hernia repair. Within anatomic sites, the incidence of SSI was significantly higher for open versus laparoscopic inguinal/femoral (0.48% [295/61,142] vs 0.34% [57/16,524], P=.020) and incisional/ventral (4.20% [701/16,699] vs 2.03% [14/691], P=.005) hernia repairs. The rate of SSI was higher following procedures with bowel obstruction/necrosis than procedures without obstruction/necrosis for open inguinal/femoral (0.89% [48/5,422] vs 0.44% [247/55,720], P<.001) and umbilical (1.57% [131/8,355] vs 0.95% [157/16,562], P<.001), but not incisional/ventral hernia repair (4.01% [224/5,585] vs 4.16% [491/11,805], P=.645).
  
  
  CONCLUSIONS
  The incidence of SSI was highest after open procedures, incisional/ventral repairs, and hernia repairs with bowel obstruction/necrosis. Stratification of hernia repair SSI rates by some operative factors may facilitate accurate comparison of SSI rates between facilities.
authors.affiliation: 1Division of Infectious Diseases,Department of Medicine,Washington University School of Medicine,St. Louis,Missouri.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Olsen
authors.affiliation: 1Division of Infectious Diseases,Department of Medicine,Washington University School of Medicine,St. Louis,Missouri.
authors.forename: Katelin B
authors.initials: KB
authors.lastname: Nickel
authors.affiliation: 3HealthCore, Inc.,Wilmington,Delaware.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Wallace
authors.affiliation: 3HealthCore, Inc.,Wilmington,Delaware.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mines
authors.affiliation: 1Division of Infectious Diseases,Department of Medicine,Washington University School of Medicine,St. Louis,Missouri.
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Fraser
authors.affiliation: 1Division of Infectious Diseases,Department of Medicine,Washington University School of Medicine,St. Louis,Missouri.
authors.forename: David K
authors.initials: DK
authors.lastname: Warren
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D059685:Herniorrhaphy / Q000379:methods; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000209:etiology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult