Neutrophil-to-lymphocyte ratio as a potential biomarker for disease severity in COVID-19 patients

• Controlling age and sex, NLR>6.5 increases the chance of disease severity by 4 times. • NLR>6.5 increases the chance of death about 1.8 times after age and sex adjustments. • The average value of WBC among severe patients was higher than non-severe.