title: Trends in the incidence of superficial versus deep-organ/space surgical site infection in a tertiary hospital.
abstract: BACKGROUND
  The frequency of surgical site infection (SSI) in western countries shows a variable tendency because of technical improvements on one hand and an aging and an increasingly fragile population on the other. Our hypothesis is that there is no time trend in the incidence of SSI. The objective of this article was to assess incidence trends of SSI, after adjusting for confounders and variables associated with SSI frequency.
  
  
  METHODS
  We studied trends of SSI over 13 y in our hospital in a cohort (26,810 patients), evaluating the factors associated with SSI (superficial or deep-organ/space), in a bivariate and multivariate analysis.
  
  
  RESULTS
  Global SSI was 4.8%, most of which was superficial (3.4%). We obtained two well-adjusted equations (area under receiver operating characteristic curves: 0.77 and 0.78, with nine variables). Main risk factors for SSI were duration of surgery (>60 min), infection on hospital admission, emergency and vascular surgery. After controlling for all risk factors, we found that superficial SSI showed a significant reduction (75) yearly, but deep-organ/space SSI rates remained stable over time.
  
  
  CONCLUSIONS
  We obtained a 7% yearly reduction in superficial SSI and no variation for deep-organ/space SSI after adjusting for eight risk and confounding factors.
authors.affiliation: Catedratico de Medicina Preventiva y Salud Publica, Universidad Autonoma Madrid, Madrid, Spain. Electronic address: rafael.herruzo@uam.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Herruzo
authors.forename: Jesus
authors.initials: J
authors.lastname: Diez-Sebastián
authors.forename: Eduardo
authors.initials: E
authors.lastname: Mora
authors.forename: Juan
authors.initials: J
authors.lastname: Garcia-Caballero
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D061646:Operative Time; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology*; D062606:Tertiary Care Centers / Q000639:trends*
keywords: Incidence; Surgical site infection; Tertiary hospital