Abstract: Objective To identify the independent risk factors for lower extremity distal deep vein thrombosis (DDVT) in the elderly inpatients and to establish a nomogram prediction model. Methods The clinical data of 621 elderly inpatients from Department of Geriatrics, Ruijin Hospital were collected, and LASSO and multivariate logistic regression analysis were used to identify the independent risk factors for DDVT. In this way, a nomogram prediction model was established. Receiver operating characteristic curve analysis was used to calculate the area under the curve, and calibration and decision curves were plotted to assess the predictive performance of the model. Results A total of 621 elderly inpatients were enrolled, and 172 (27.70%) cases presented with lower extremity DDVT. Eleven predictors were identified as independent risk factors for lower extremity DDVT in elderly inpatients by multivariate logistic regression analysis, including gender(male), surgery within three months, acute cerebral stroke, active malignant tumor, long-term use of corticosteroids, acute infection in four weeks, immobility in 72 hours, heart failure, D-dimer≥0.55 mg/L, fibrin degradation products(FDP)≥5.0 mg/L, CA125>24 U/L. C index was 0.930(95%CI: 0.909－0.951), which showed good discrimination. The calibration curve and decision analysis curve indicated good predictive performance and clinical benefit. Conclusions The established prediction model has a high accuracy in predicting the risk of lower extremity DDVT in the elderly inpatients, providing an effective tool for clinicians to identify high-risk patients and implement early intervention.

Key words: elderly inpatient, distal deep vein thrombosis, predictive model