Objectives: To evaluate hematological features and metabolic characteristics
and determine the contributing factors to the treatment outcome of COVID-19 patients. Methods: We conducted a cross-sectional descriptive study on 225 severe and critical COVID-19 patients treated at this COVID-19 Resuscitation Center from September 2021 to November 2021. Results: There was an association between age and mortality caused by COVID-19, the age group over 60 has a 2.0 times higher risk of death than the group aged 60 and under. The hematological indices of leukocytes and platelets had statistically significant differences between the mortality group and the group of hospital discharge. The number of white blood cells in the mortality group was higher than the hospital discharge group, 17.5 (13.4 - 25.3) thousand/mm3 compared with 9.4 (6.4 - 13.6 thousand/mm3, p <
0.001). The rate of neutrophils in the mortality group was higher than in the discharge group, but the rate of lymphocytes was lower. The NLR index had a significant difference between the mortality group and the discharge group, 37.5 (20.1 - 52.8) compared with 11.8 (4.4 - 22.6), NLR could well mortality - predictdue to COVID-19 with AUC = 0.78. Using the 22.25 cut - off, the NLR had a sensitivity/specificity in predicting COVID-19 mortality of 74.2% and 74.5%, respectively. There was a statistically significant difference in platelet counts in the mortality and discharge groups, 166 (106 - 289) million/mm3 versus 236 (183 - 338) mm3.