In univariate analysis, vital signs such as body temperature, heart rate, systolic blood pressure, respiratory rate and PaO2/FiO2 ≤ 250, laboratory findings such as Alb, BUN, Cr and CRP value, multilobar pneumonia, bacteremia and treatment with mechanical ventilation and vasopressor drugs were significant predictive factors for ICU admission on the day of hospitalization. Here, CRP is linked to bacterial infectious disease with sepsis.