ALB and chronic obstructive pulmonary disease: Increasing age, presence of COPD and malignancy as comorbidities, hypothermia, tachypnea, PaO2/FiO2 ratio ≤250 mmHg, low Alb level, high BUN level and mechanical ventilatory support predict a worse prognosis; AZM combination therapy should be considered for CAP, excluding HCAP.