Construction and validation of the nomogram
COPD
REGRESSION, COPD, TUBERCULOSIS
Participants were randomly divided into two sets. The training set had 1,491 individuals, while the validation set had 995 individuals. The difference in the characteristics between the two populations was not statistically significant (Univariable and multivariable logistic regression analysis in training set.BMI, body-mass index; OR, odd ratio; CI, confidence interval.Stepwise logistic regression model.Bold values denote significant Nomogram for COPD reserving altitude, age, sex, history of tuberculosis, coal as fuel, and smoking status as predictors.The ROC curve, calibration curve, and DCA were used to assess the efficiency of the nomogram. In the training set, the AUC was 0.722 (0.690–0.754); the predicted probabilities were almost identical to the actual probabilities; when the threshold probability ranged from 0.08 to 0.45, the clinical benefit was positive (The assessment of the nomogram. 