Background: High testosterone and low estradiol levels induce immunosuppression and adverse outcome after trauma in male animals. Gender-based outcome differences in human trauma have not been investigated. In order to test our hypothesis that female gender is associated with improved outcome after trauma, we conducted an inception cohort study at the R. Adams Cowley Shock Trauma Center, the adult trauma resource center for the state of Maryland.
Methods: All were blunt trauma patients (18,892) admitted from 1983 to 1995, stratified by Injury Severity Score (ISS) and age. Gender differences in mortality; nosocomial infection; and preinjury diabetes and cardiac, pulmonary, and liver diseases were determined.
Results: No significant differences in preinjury diseases were identified. Death and gender were independent variables in all groups except for patients who developed pneumonia. Male patients had a higher incidence of pneumonia in all groups except age 18 to 45, with an ISS < 15. The association between male gender and pneumonia was strongest in the age 46 to 65, ISS > 30 subgroup (p < 0.01). Among those with pneumonia, female patients were at 2.8 to 5.6 times higher risk for death than were male patients.
Conclusion: These data suggest that gender has no relation to mortality in blunt trauma patients who do not develop pneumonia. In contrast, male gender was significantly associated with an increased incidence of pneumonia after injury, and female patients with pneumonia were at significantly higher risk for mortality.