Construction and validation of the nomogram
REGRESSION
The primary outcome of the study is the presence of NPOBC on postoperative day 3. The risk factors for the presence of NPOBC on postoperative day 3 were identified using univariate logistic regression, and varibles with P < 0.05 were included in the multivariate logistic analysis. A total score was calculated by analyzing the scores corresponding to each predictor variable in the nomogram, and a probability of NPOBC was calculated. Different methods were used to evaluate and validate the poformance of the prediction model. The calibration curve were drawn to reveal the reliability of the prediction model [