Abstract: Objective To investigate the risk factors of nausea and vomiting during postoperative chemotherapy in patients with gastric cancer and to construct a corresponding risk prediction model.Methods This study collected gastric cancer patients from the first affiliated hospital of Hunan university of traditional Chinese medicine from February 2020 to February 2021 as a modeling set to explore the risk factors of nausea and vomiting during chemotherapy in gastric cancer patients after surgery,and constructed a corresponding risk prediction models.The data were collected from March 2021 to February 2022(Year 1),March 2022 to February 2023(Year 2),and March 2023 to February 2024(Year 3) as a validation set,which was used to validate the risk prediction model constructed by the modeling set.The incidence of vomiting during chemotherapy was detected in the modeling set.The univariate and multivariate Logistic regression to analyze the risk factors of nausea and vomiting during chemotherapy in gastric cancer patients after surgery,and constructing a corresponding risk prediction model.The accuracy of the corresponding risk prediction model was validated using receiver operating characteristic curve(ROC) with a validation set from March 2021 to February 2024.Results  A total of 112 patients were included in the modeling set,of which 75 patients(66.96%) did not have nausea and vomiting during postoperative chemotherapy and were included in the control group,while 37 patients(33.04%) developed nausea and vomiting during postoperative chemotherapy and were included in the observation group.The univariate analysis showed that age,gender,history of alcohol consumption,history of motion sickness,frequency of chemotherapy,history of chemotherapy-related nausea and vomiting,history of vomiting during pregnancy,Pittsburgh sleep quality index(PSQI) and psychological expectation of post chemotherapy nausea and vomiting were related to the occurrence of nausea and vomiting during postoperative chemotherapy(P＜0.05).Logistic regression analysis showed that age,gender,history of motion sickness,chemotherapy frequency,history of vomiting during pregnancy,PSQI,and psychological expectation of postoperative nausea and vomiting in gastric cancer patients were risk factors for nausea and vomiting during postoperative chemotherapy(P＜0.05).A risk prediction model based on Logistic regression to identify statistically significant factors.Internal validation of the model was conducted by the Bootstrap method,with an area under curve(AUC) of 0.71(95% CI:0.71-1.00) for the first year validation set,0.69(95% CI:0.58-0.96) for the second year validation set,and 0.66(95% CI:0.54-0.95) for the third year validation set.Conclusion The Age,gender,history of motion sickness,frequency of chemotherapy,history of vomiting during pregnancy,PSQI and psychological expectation of postoperative nausea and vomiting during chemotherapy are risk factors for nausea and vomiting during postoperative chemotherapy.The risk prediction model for nausea and vomiting during chemotherapy in gastric cancer patients constructed based on the above factors has good predictive performance and can provide reference for clinical treatment of gastric cancer patients.

Key words: gastric cancer, chemotherapy, nausea, vomiting, risk prediction model