Statistical analysis
OHE
REGRESSION
The statistical analysis was performed by SPSS 26.0 (SPSS Inc, Chicago, USA) and R 4.0.3 (Institute of Statistics and Mathematics). The univariate or multivariate analysis was conducted at a test level of 0.01 or 0.05, respectively. Means of continuous variables were calculated and compared using Mann–Whitney U tests or Student's t tests. Statistically significant indicators in the univariate analysis were included in the multivariate analysis. The variables associated with OHE were assessed using logistic regression analyses. The nomogram prediction model was evaluated by establishing consistency index and evaluating calibration curve. We compared the predictive value of this new nomogram model with other predictive OHE scores. In order to determine the accuracy of this nomogram, a calibration chart with 1000 bootstrap samples was applied. DCA was used to measure clinical utility of this nomogram by calculating net benefit at different threshold probabilities.