Fig. 2

Risk factors for critical illness in COVID-19. Receiver-Operator Curve plots of individual risk factor models (a) and combined risk factor models (b) for predicting critical illness in SARS-CoV-2 infection. LASSO model was built based on age, dyspnea, SOFA score, and white blood cell count, risk factors selected by LASSO logistic regression. c LASSO coefficient profiles of the 14 risk factors of critical illness in SARS-CoV-2 infection. d Mean − Squared Error (MSE) plot of the LASSO model with different lambda. The best combination of risk factors was selected by LASSO logistic regression analyses, with four risk factors (labeled in (c)) selected by the lambda at which the minimal MSE was achieved