ALB and COVID-19: Subgroup analysis showed that patients with influenza presented high CRP, PCT, D-dimer, ESR, and fibrinogen content, but low lymphocyte count, lymphocyte percentage, RBC, Hgb, Hct, TP, and Alb than patients with COVID-19 (mild or moderate groups) (p < 0.05), which was consistent with a previous study (31).