title: The battle of the sexes: women win out in gastrointestinal surgery.
abstract: BACKGROUND
  Women have been shown to have worse outcomes compared with men after cardiac surgery, but fare better after traumatic injury. No study considers the impact of gender on outcomes after major gastrointestinal surgery. We hypothesize that the physiologic insults of a major abdominal operation are similar to an injury model; therefore, women will have improved outcomes.
  
  
  METHODS
  We performed a retrospective review of the NIS database from 1998 to 2007. Patients undergoing major gastrointestinal surgery were identified by ICD-9 procedure codes: esophageal (42.4), gastric (43.5-43.9), small intestine (45.6), large intestine (45.7-45.8 and 17.3), rectal (48.4-48.6), hepatic (50.2-50.3), biliary (51.3 and 51.6), and pancreatic (52.5-52.7). Exclusion criteria included age over 60 y and under 18 y, multiple operations, and a sexual developmental disorder (25.52, 75.27, and 25.9). The primary outcome measure was in-hospital death.
  
  
  RESULTS
  A total of 307,124 patients were identified, of whom 50.3% were women. Overall, there were 6574 (2.14%) deaths; 2.45% of men and 1.84% of women died (P < 0.001). In multivariate analysis, women were 21.1% less likely to die than men (OR = 0.789, 95% CI = 0.74-0.84). When subset analysis was performed, women had improved mortality in the following types of surgery: gastric (OR = 0.751, 95% CI = 0.60-0.94), small intestine (OR = 0.704, 95% CI = 0.63-0.79), large intestine (OR = 0.845, 95% CI = 0.77--0.93), hepatic (OR = 0.562, 95% CI = 0.41-0.77), and pancreatic (OR = 0.658, 95% CI = 0.49-0.89, see Fig. 1).
  
  
  CONCLUSIONS
  Our study demonstrates that women may have improved outcomes after some types of major gastrointestinal surgery; however, the mechanism by which this occurs is unclear. Future studies are needed to further evaluate this interesting phenomenon.
authors.affiliation: Department of Surgery, University of California, San Diego, California 92103-8401, USA.
authors.forename: Carrie Y
authors.initials: CY
authors.lastname: Peterson
authors.forename: Hayley B
authors.initials: HB
authors.lastname: Osen
authors.forename: Hop S
authors.initials: HS
authors.lastname: Tran Cao
authors.forename: Peter T
authors.initials: PT
authors.lastname: Yu
authors.forename: David C
authors.initials: DC
authors.lastname: Chang
mesh_terms: D000328:Adult; D015897:Comorbidity; D013505:Digestive System Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012727:Sex Characteristics; D016896:Treatment Outcome