Fig. 2

Nomogram model and calibration curve. (1) KL-6 and RSG were used to develop a nomogram model by SMOTE strategy to predict 28-day mortality in COVID-19 patients. For example (indicated by a solid red circle and arrow), the KL-6 and RSG results of an admitted patient were 810U/ml and grade 3, respectively. The points for his/her KL-6 and RSG were approximately 26 and 81 respectively. Hence, the total point for this patient was 107, which indicated a probability of 0.568 for the development of death events during 28 days after admission. (2) Calibration curve of the nomogram in the smote group and validation group, in terms of agreement between the predicted risk and actual observed outcomes. KL6, Krebs von den Lungen-6; RSG, radiological severity grade