A nomogram predicting the risk of venous thromboembolism in patients following urologic surgeries

Abstract

There are inconsistent results pertaining to risk factors for venous thromboembolism (VTE) in patients following urologic surgeries. We attempted to establish a visualization model to shed further light upon this topic. Consequently, a total of 436 patients who were tested for VTE following urologic surgeries were retrospectively enrolled. Least absolute shrinkage and selection operator method (LASSO) method was utilized to determine risk factors for VTE and a subsequent nomogram was constructed. The concordance index (C-index) and calibration curve were utilized to evaluate the nomogram. The results suggested that age, history of smoking, D-dimer levels on the first postoperative day, transfusion volume and body mass index (BMI) were identified as significant risk factors for VTE. The C-index of the nomogram composed of the five variables was 0.747 (95% CI 0.700-0.793) and the calibration plot demonstrated good performance. Therefore, the present nomogram could predict the risk of VTE following urologic surgeries.

Keywords: Cohort study; LASSO analysis; Nomogram; Urologic surgeries; Venous thromboembolism.

Fig. 1

Nomogram for predicting VTE in patients after urologic surgeries. BMI body mass index.

Fig. 2

The calibration plot for risk of VTE in the study cohort.

Fig. 3

Decision curve analysis of the nomogram for predicting VTE risk in patients after urologic surgeries. The black line represents the hypothesis that all patients do not have VTE. The gray line represents the hypothesis that all patients have VTE. The red line represents the nomogram. The y-axis represents net benefit, and the x-axis represents threshold probability. This diagnostic nomogram shows a notable positive net benefit, indicating that it has a good clinical utility in predicting the risk of VTE.