Fig. 3

The nomogram for predicting hyponatremia in AECOPD patients. Nomogram was used to visualize and validate the binary logistics regression model. A Nomogram. The total point of a specific patient is the sum of individual variable points. The predicted probability of hyponatremia is on the Hyponatremia-scale, which is corresponding to Total points-scale. B Calibration curves. Ideal line: the nomogram reference line; Apparent line: the actual probability of each patient in our study; Bias-corrected line is adjusted by bootstrap with 1000 resamples. The length of the vertical lines at the top of the plot represents the numbers of patients. C ROC curve. D DCA curve. None line: the assumption that all patients had no hyponatremia. All line: the assumption that all patients had hyponatremia. Red line: the nomogram