Data_Sheet_1_Prognostic Nomogram for Predicting Lower Extremity Deep Venous Thrombosis in Neurointensive Care Unit Patients: A Prospective Observational Study.DOCX

BackgroundDeep venous thrombosis (DVT) of the lower extremities is one of the common complications for neurointensive care unit patients, which leads to increased morbidity and mortality. The purpose of our study was to explore risk factors and develop a prognostic nomogram for lower extremity DVT in neurointensive care unit patients.
MethodsWe prospectively collected and analyzed the clinical data of 420 neurointensive care unit patients who received treatment in our institution between January 2018 and September 2019. Stepwise logistic regression was used to select predictors. R software was used to develop the prognostic nomogram. The performance of the nomogram was validated using a validation cohort of patients with data collected between October 2019 and March 2020.
ResultsAmong 420 patients, 153 (36.4%) had lower extremity DVT and five (1.2%) had both DVT and pulmonary embolism (PE) in our study. Logistic regression analysis indicated that age [odds ratio (OR): 1.050; 95% confidence interval (CI): 1.029–1.071; P < 0.001], Glasgow Coma Scale (GCS) score (OR: 0.889; 95% CI: 0.825–0.959; P = 0.002), D-dimer level (OR: 1.040; 95% CI: 1.008–1.074; P = 0.014), muscle strength (OR: 2.424; 95% CI: 1.346–4.366; P = 0.003), and infection (OR: 1.778; 95% CI: 1.034–3.055; P = 0.037) were independent predictors for lower extremity DVT. These predictors were selected to be included in the nomogram model. The area under the curve values in the primary cohort and validation cohort were 0.817 (95% CI: 0.776–0.858) and 0.778 (95% CI: 0.688–0.868), respectively, and respective Brier scores were 0.167 and 0.183.
ConclusionAge, GCS score, D-dimer level, muscle strength, and infection are independent predictors for lower extremity DVT. The nomogram is a reliable and convenient model to predict the development of lower extremity DVT in neurointensive care unit patients.

背景：下肢深静脉血栓（Deep Venous Thrombosis, DVT）是神经重症监护病房患者常见并发症之一，可升高患者的发病率与死亡率。本研究旨在探讨神经重症监护病房患者下肢DVT的危险因素，并构建其预后列线图（nomogram）。
方法：本研究前瞻性收集并分析了2018年1月至2019年9月于本机构接受治疗的420例神经重症监护病房患者的临床资料。采用逐步Logistic回归筛选预测因子，使用R软件构建预后列线图。以2019年10月至2020年3月收集的患者队列作为验证队列，对该列线图的预测性能进行验证。
结果：本研究纳入的420例患者中，153例（36.4%）发生下肢DVT，5例（1.2%）同时合并DVT与肺栓塞（Pulmonary Embolism, PE）。Logistic回归分析显示，年龄[优势比（odds ratio, OR）=1.050；95%置信区间（confidence interval, CI）：1.029~1.071；P<0.001]、格拉斯哥昏迷量表（Glasgow Coma Scale, GCS）评分（OR=0.889；95%CI：0.825~0.959；P=0.002）、D-二聚体水平（OR=1.040；95%CI：1.008~1.074；P=0.014）、肌力（OR=2.424；95%CI：1.346~4.366；P=0.003）及感染（OR=1.778；95%CI：1.034~3.055；P=0.037）为下肢DVT的独立预测因子。上述预测因子被纳入列线图模型。训练队列与验证队列的受试者工作特征曲线下面积（AUC）分别为0.817（95%CI：0.776~0.858）与0.778（95%CI：0.688~0.868），对应的布里尔分数（Brier score）分别为0.167与0.183。
结论：年龄、GCS评分、D-二聚体水平、肌力及感染为下肢DVT的独立预测因子。该列线图是一款可靠且便捷的模型，可用于预测神经重症监护病房患者下肢DVT的发生风险。