ALB and COVID-19: A total of 63 potential predictors from 217 elderly COVID-19 patients in the training cohort were enrolled in LASSO regression, and seven candidate predictors were selected, including age, OH time, lactic dehydrogenase (LDH), d-dimer, total bile acid (TBA), ALB and lymphocyte-to-monocyte ratio (LMR) (Figure 2A and 2B).