title: Gender differences in case mix and outcome of critically ill patients.
abstract: BACKGROUND
  The potential for gender-related bias in the provision of medical treatments has gained increased interest in recent years. The aim of this retrospective, observational study was to evaluate the association between gender and clinical outcome in an Italian mixed medical-surgical ICU population.
  
  
  METHODS
  Data on 1978 patients admitted to the ICU during a 3-year period were analyzed. Demographics, diagnosis, and hospital stay details were recorded.
  
  
  RESULTS
  Male ICU admissions were predominant over female ones (64% vs 36%). Neither ICU survival rate (80% in group male, 79% in group female; P = 0.602) nor hospital survival rate (72% in group male, 72% in group female; P = 0.820) showed gender-related differences. A statistically significant difference was found in terms of mean (SD) age (57 [19] years in group male, 62 [18] years in group female; P < 0.001), ICU length of stay (7.0 [9.1] days in group male, 5.7 [7.7] days in group female; P < 0.001) and length of mechanical ventilation (6.3 [8.4] days in group male, 5.3 [7.5] days in group female; P = 0.001). Severity of illness, measured through the simplified acute physiology score II, was not statistically different between gender groups; nor was the incidence of infective complications. After stratifying for diagnostic subgroups a few gender differences were pointed out, but none of them affecting ICU and hospital survival rates. A Kaplan-Meier 30-day ICU survival analysis revealed no differences between the male and female groups of the study population.
  
  
  CONCLUSIONS
  According to our results, mortality among critically ill patients was not influenced by gender. Despite a higher frequency of men admitted, women were older than men. Moreover, men were treated for a longer period of time than women. Limitations of the study were the inability to establish causal relations and to account for variables with important effects on the reported associations. Moreover, the sample size was small if compared to similar multicenter studies.
authors.affiliation: I Servizio di Anestesia e Rianimazione, Azienda Ospedaliero - Universitaria di Parma, Parma, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Vezzani
authors.forename: Mario
authors.initials: M
authors.lastname: Mergoni
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Orlandi
authors.forename: Francesco
authors.initials: F
authors.lastname: Corradi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Volpi
authors.forename: Michele
authors.initials: M
authors.lastname: Zasa
mesh_terms: D000328:Adult; D000368:Aged; D016638:Critical Illness / Q000401:mortality*; D003953:Diagnosis-Related Groups; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D016896:Treatment Outcome