A validated risk model to predict 90-day VTE events in post-surgical patients.

Pannucci CJ, Laird S, Dimick JB, Campbell DA, Henke PK.

Abstract

ABSTRACT BACKGROUND Venous thromboembolism (VTE) is the proximate cause of 100,000 deaths in the United States each year. Peri-operative VTE risk among surgical patients varies by 20-fold. This highlights the importance of risk stratification to identify high-risk patients, in whom chemoprophylaxis can decrease VTE risk, and low-risk patients, for whom the risk-benefit relationship of prophylaxis may be unfavorable. MATERIALS AND METHODS We used data from a statewide surgical quality collaborative for surgical procedures performed between 2010 and 2012. Regression-based techniques identified predictors of 90-day VTE while adjusting for procedural complexity and comorbid conditions. A weighted risk index was created and was subsequently validated in a separate, independent data set. RESULTS Data were available for 10,344 patients, who were randomly allocated to derivation or validation cohorts. 90-day VTE rate was 1.4%. 66.2% of derivation cohort and 65.5% of validation cohorts received chemoprophylaxis. Seven risk factors were incorporated into a weighted risk index: personal history of VTE, current cancer, sepsis/septic shock/SIRS, age ≥60 years, BMI ≥40 kg/m2, male gender, and family history of VTE. Prediction for 90-day VTE was similar in the derivation and validation cohorts (AUROC 0.72 and 0.70, respectively). An 18-fold variation in 90-day VTE rate was identified. CONCLUSIONS A weighted risk index quantifies 90-day VTE risk among surgical patients, and identifies an 18-fold variation in VTE risk among the overall surgical population. CLINICAL TRIALS REGISTRATION Not applicable.