ObjectiveTo compare the predictive value of six thrombotic risk assessment scales, including Autar, Wells, Padua, Caprini, Khorana, and COMPASS-CAT, for the deep venous thrombosis (DVT) of lower extremity in patients with gastrointestinal tumors. MethodsThe patients with gastrointestinal tumors who received surgical treatment in the General Surgery Department of Lanzhou University Second Hospital from March 2023 to October 2023 were collected. The risk of DVT on day 3 after surgery for the patient with gastrointestinal tumors was prospectively evaluated using the Autar, Wells, Padua, Caprini, Khorana, and COMPASS-CAT assessment scales. And the DVT was detected by ultrasound examination. The pionts of six thrombotic risk assessment scales were compared between the patient with DVT and without DVT based on the ultrasound examination results. The predictive value of the six thrombotic risk assessment scales for the lower extremity DVT in the patients with gastrointestinal tumors was evaluated by the area under receiver operating characteristic curve (AUC). ResultsA total of 108 patients who met the criteria, including 71 males and 37 females, were enrolled, age ranged from 18 to 85 years old, (58.3±11.2) years old. Fourty-two cases (38.9%) of DVT occurred. The age of patients with DVT was older than that of patients without DVT (P<0.05), but there were no statistical differences in the gender, body mass index, tumor location, comorbidities, and so on (P>0.05). The points of Autar, Padua, and Caprini in the patients with DVT were higher than those in the patients without DVT (P<0.05), while there were no statistical differences in the points of Wells, Khorana, and COMPASS-CAT between the two (P>0.05). The AUC for differentiating the occurrence of DVT in the patients with gastrointestinal tumors using the Autar, Wells, Padua, Caprini, Khorana, and COMPASS-CAT assessment scales were 0.907, 0.548, 0.636, 0.627, 0.589, and 0.535, respectively; The sensitivities were 97.6%, 14.3%, 52.4%, 83.3%, 47.6%, and 21.4%; The specificities were 2.4%, 85.7%, 47.6%, 16.7%, 52.4%, and 78.6%, respectively. ConclusionAccording to the abilities of Autar, Wells, Padua, Caprini, Khorana, and COMPASS-CAT to distinguish the occurrence of DVT in patients with gastrointestinal tumors after surgery, only the Autar evaluation scale is found to be more effective, while the other five evaluation scales are generally able to distinguish the occurrence of DVT.