Fig. 6From: Nomogram to identify severe coronavirus disease 2019 (COVID-19) based on initial clinical and CT characteristics: a multi-center studyThe ROC and calibration curves of the nomogram in the training cohort (a, c) and validation cohort (b, d), respectively. The y-axis of calibration curves represents the actual probability, the x-axis represents the predicted probability and the diagonal dashed line indicates the ideal prediction by a perfect modelBack to article page