F2 and COVID-19: The AUC values of age, neutrophil count, lymphocyte count, prothrombin time, d-dimer and PCT for predicting the in-hospital mortality of COVID-19 patients were 0.808 (95% CI 0.715–0.901), 0.809 (95% CI 0.710–0.907), 0.811 (95% CI 0.724–0.898), 0.745 (95% CI 0.643–0.847), 0.872 (95% CI 0.804–0.940), 0.881 (95% CI 0.809–0.953 (Fig. 1), respectively.