Validation and clinical implications of the IDSA/ATS minor criteria for severe community-acquired pneumonia

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 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.