A patient-level multivariate logistic regression analysis was performed to explore potential predictors of major bleeding (Table 6). The variables (univariate p<0.10) predicting patients with and without major bleeding were massive versus submassive PE, immobility within 30 days of PE, presence of co-morbid conditions, multiple venous access attempts, use of an adjunctive IVC filter, and baseline serum creatinine level. Only massive PE (adjusted odds ratio 3.6, 95% confidence interval 1.01–12.9; p=0.049) and multiple venous access attempts (adjusted odds ratio 10.09, 95% confidence interval 1.98–51.46; p=0.005) were independently associated with increased risk of major bleeding.