Background: The 2007 Infectious Disease Society of America (IDSA) / American Thoracic Society (ATS) guidelines defined severe community-acquired pneumonia (CAP) and recommended intensive care unit (ICU) admission when patients fulfilled 3 out of 9 minor criteria. These criteria have not been validated.
Methods: We reviewed all patients admitted to our hospital from 2004-2007 for CAP retrospectively. We excluded patients who fulfilled any IDSA/ATS major criteria for severe CAP at the emergency department, i.e. the need for mechanical ventilation or vasopressors. We compared the predictive characteristics of the IDSA/ATS minor criteria with those of the Pneumonia Severity Index (PSI) and the CURB-65 score for hospital mortality and ICU admission.
Results: 1242 patients were studied (mean age 65.7 years, hospital mortality 14.7%). The areas under the receiver operating characteristic curves for the IDSA/ATS minor criteria were 0.88 (95% confidence interval [CI] 0.86-0.91) and 0.85 (95% CI 0.81-0.88) for predicting hospital mortality and ICU admission respectively. These were greater than the corresponding areas for the PSI and the CURB-65 score (p<0.05). The sensitivity, specificity, positive and negative predictive values of the minor criteria were respectively 81.4%, 82.9%, 45.2% and 96.3% for hospital mortality, and 58.3%, 90.6%, 52.9% and 92.3% for ICU admission. The minor criteria were more specific than the PSI and more sensitive than the CURB-65 score for both outcomes.
Conclusion: Our findings support the use of the IDSA/ATS minor criteria to predict hospital mortality and guide ICU admission in inpatients with CAP who do not require emergent mechanical ventilation or vasopressors.