Venous thromboembolism after spinal cord injury: Incidence, time course, and associated risk factors in 16,240 adults and children

Objective: To analyze the incidence of venous thromboembolism (VTE) after spinal cord injury (SCI). Design: Retrospective cohort analysis of all SCI cases (16,240) in California from 1991 through 2001. Setting: All public hospitals in California. Participants: Subjects (cases) coded as having complete or incomplete SCI. Interventions: Not applicable. Main Outcome Measure: Diagnosis of VTE or death within 91 days of the day of hospital admission. Results: For all cases, the 91-day cumulative incidence of VTE was 5.4%. In a multivariate model, significant predictors of VTE included male sex (odds ratio [OR]=1.4; 95% confidence interval [CI], 1.2-1.7), African-American race (OR=1.6; 95% CI, 1.3-1.9), complete paraplegia versus tetraplegia (OR=1.8; 95% CI, 1.4-2.3), and presence of 3 or more comorbid conditions versus none (OR=1.6; 95% CI, 1.3-2.1). Age less than 14 years was predictive of not developing VTE (OR=0.2; 95% CI, 0.1-0.7). The incidence of VTE did not change significantly over the 11-year time period (P=.07), and VTE was not a significant predictor of death in the first 91 days after hospitalization. Conclusions: The incidence of VTE in SCI patients in California did not change between 1991 and 2001. We identified specific risk factors for VTE. Further studies are needed to determine if prompt initiation of medical prophylaxis in high risk subjects reduces the incidence of symptomatic VTE.