Predictive model for deep venous thrombosis caused by closed lower limb fracture after thromboprophylactic treatment.

Currently, there are still no convincing clinical models predicting closed lower extremity fracture-associated deep vein thrombosis in patients treated through thromboprophylactic methods. We aimed at using two retrospective cohorts to develop and externally verify a clinical prediction model for deep vein thrombosis in patients treated with anticoagulants after suffering closed lower extremity fractures.We evaluated the patients' pre- and post-operatively, to accurately determine the predictive power of the biomarkers and clinical risk factors. Two retrospective cohorts were used for the development and external verification of a pre-operative clinical prediction model (development: n = 2,253; verification: n = 833) and post-operative clinical prediction model (development: n = 1,422; verification: n = 449), respectively.The C-indices were used to show the predicted incidence of objective thrombosis at the pre- and post-operative stage, which were then compared with the observed incidence of thrombosis in both cohorts. Biomarkers and clinical indicators were included in pre- and post-operative nomograms, which were adequately calibrated in both cohorts. The cross-validated C-indices of the pre- and post-operative clinical prediction models in the verification cohort were 0.706 (95% Cl, 0.67-0.74) and 0.875 (95% Cl, 0.84-0.91), respectively.We present our findings of novel pre- and post-operative nomograms for the prediction of deep venous thrombosis in patients who received thromboprophylaxis after suffering closed lower extremity fractures.