Risk Factors Analysis for Clinical Important Postoperative Nausea and Vomiting in Patients Undergoing Laparoscopic Gastrointestinal Surgery Based on LASSO and Stepwise Regression

Drawing from prior studies, we conducted a sample size calculation for a predictive model using the website https://mvansmeden.shinyapps.io/BeyondEPV/. By setting the number of candidate predictors to 9, the events fraction to 0.14, and the criterion value for rMPSE to 0.04, we determined that a minimum total sample size of 900 is required, with a minimally expected event per variable of 13.9. All patients were classified into either the CI-PONV group or the non-CI-PONV group. All 56 perioperative clinical features, encompassing baseline characteristics, preoperative conditions, and intraoperative information, were considered as potential predictive factors. In the quest to uncover potential predictive factors associated with CI-PONV, we employed the least absolute shrinkage and selection operator (LASSO) to sift through clinically significant variables. Subsequently, we utilized stepwise regression based on the Akaike Information Criterion (AIC) to further refine the selection of the ultimate predictors.