Does sex matter? Effects on venous thromboembolism risk in screened trauma patients.

BACKGROUND: Sex is associated with disparate risk of venous thromboembolism (VTE) in nontrauma patients, with increased risk seen during pregnancy and in women on hormone-containing medications. Sex effects on VTE after trauma are unclear. Some studies have demonstrated no effect whereas others have instead shown a higher incidence of VTE among men. We hypothesized that male sex would increase the risk of VTE across all age groups in trauma patients undergoing standardized duplex screening.

METHODS: All admissions to a Level I academic trauma center 2000 to 2014 were reviewed. We excluded patients for age <18 years, pregnancy, pre-admission anticoagulant use, and hospital length of stay (LOS) <72 hours. A strict venous duplex screening protocol was followed. Female patients were subcategorized into pre- and post-menopausal groups based on age (18-44 vs. ≥ 55 years). Bivariate analysis and logistic regression were used to identify variables correlating with VTE risk.

RESULTS: A total of 8,726 patients met inclusion criteria. The overall VTE rate was 5.3%. Bivariate analysis did not find a difference in VTE risk by sex (5.1% women vs. 5.4% men, p = 0.565), or between women and men within age-defined menopausal categories (pre-menopausal women 3.9% vs. men 4.7%, p = 0.293; post-menopausal women 5.9% vs. men 7.0%, p = 0.22). Logistic regression (see figure) did identify other risk factors for VTE including age ≥55 (adjusted odds ratio [AOR] 2.0), increasing ISS (AOR 1.5-2.1), penetrating mechanism of injury (AOR 2.2), lower extremity injury (AOR 1.7), need for mechanical ventilation (AOR 2.1), and increasing hospital length of stay (LOS 7-28 days, AOR 3.8; LOS > 28 days, AOR 9.1).

CONCLUSION: There was no difference in VTE rates based on patient sex, even after controlling for menopausal status. Aggressive VTE screening of over 8,700 patients did identify several other patient populations at increased risk of developing VTE. More intensive VTE prophylaxis may be appropriate in these patients.

LEVEL OF EVIDENCE: Epidemiologic study, level III; therapeutic study, level V.