RESULTS: A chart review revealed that 108 cases of non-ventilator-associated nosocomial pneumonia were admitted to the medical ICU during a 2-year period. Sputum samples were obtained in 39.8% of patients before antibiotic initiation and were not obtained in 13.9% of patients within 3-day of antibiotics treatment. Good quality sputum samples were obtained in 18.5% of patients. Sputum cultures were positive in 39.8% of patients. In multivariate analysis, both the timing (0-72 hours) and quality of sputum sample were associated with positive culture results (timing: OR 0.92, 95% CI = 0.85-0.96; p < 0.05) (quality: OR 15.74, 95% CI = 3.68-119.43; p < 0.05) and de-escalation rate (timing: OR 0.94, 95% CI = 0.89-0.98; p < 0.05) (quality: OR 6.09, 95% CI = 2.00-21.41; p < 0.05). They were not associated with the duration of antibiotics treatment, hospital-free days (HFDs), ICU-free days (IFDs), ventilator-free days (VFDs), pneumonia recurrence, ICU or hospital re-admission, or mortality.