Does gender difference influence outcome?

Background: Recent laboratory studies have demonstrated that immune responses differ between male and female rodents, and some clinical studies have suggested gender differences regarding incidence and mortality from sepsis. The differences appear because of both deleterious testosterone and beneficial estrogen effects; clinical trials of testosterone blockage and/or estrogen administration for male subjects have been suggested. We evaluated the effect of gender on various outcomes in trauma patients. Methods: Trauma patients over a 52-month period were identified from the trauma registry. Early deaths were excluded. Outcomes included mortality, pneumonia (greater than or equal to 10(5) colony-forming units/mL in bronchoalveolar lavage effluent), acute respiratory distress syndrome, bacteremia, ventilator days, and intensive care unit and hospital length of stay. Patients were stratified by injury mechanism, gender, age (assuming women less than or equal to 40 were premenopausal and those > 50 were postmenopausal), and injury severity. Results: There were 18,133 patients identified, and 544 were excluded because of early death. There were 12,756 (73%) men and 4,833 (27%) women. There were no outcome differences after penetrating injury with respect to gender and age group. There was a survival advantage for women less than or equal to 40 in the Injury Severity Score 16 to 24 group, but these patients had statistically less severe injury. Overall, men tended to have more infectious complications, but women had lower survival in the face of infection. Logistic regression did not identify gender as an independent predictor of mortality. Conclusion: Although there was a survival advantage for women in subgroup analysis, there was no overall difference in mortality. Women with pneumonia, however, had a higher mortality than men. Further understanding of potential mechanisms is necessary before hormonal manipulation studies.