Patient characteristics
A total of 4867 patients presenting to the emergency department of Zhongshan Hospital from July 2018 to October 2022 met the inclusion criteria and were included in the study. Among them, 519 could not be confirmed of PE status by CTPA, 1102 had high missing proportions of important predictors, 6 were pregnant and these patients were thus excluded from the study. Among 3240 patients included in the analysis, 2555 were randomly assigned to the derivation set and the remaining 685 patients were allocated to the validation set (Fig. Study workflow. The workflow of excluding patients passing the exclusion criteriaPatient characteristics in the derivation and validation setData are n (%), median (IQR), or mean (SD). Patients were randomly divided into the derivation and validation set using a stratified randomization scheme. P values were obtained using student t test for normally distributed variables, Wilcoxon rank sum test for skewed distributed variables and Chi-square (or Fisher’s exact) test for categorical variables