ALB and chronic kidney disease: Thus, among the 10 variables from the age-adjusted univariable analysis included in the model, the multivariable logistic regression analysis with conditional step-wise backward method retained 7 variables: respiratory rate >20 breaths per minute, albumin ≤ 2.5 g/dL, D-dimer ≥4 mcg/mL, PaO2/FiO2 ratio ≤ 300, CKD-EPI ≤ 60 ml/min, WBC ≥10 × 103, troponin ≥14 pg/mL.