Mortality among severe community-acquired pneumonia patients depends on combinations of 2007 IDSA/ATS minor criteria

• Different combinations of 2007 IDSA/ATS minor criteria for severe community-acquired pneumonia were associated to diverse severities and different mortalities.
• The combination of PaO2/FiO2 ≤ 250 mm Hg, confusion and uremia predicted more severity and higher mortality compared with other combinations.

ObjectivesThe individual 2007 Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) minor criteria for severe community-acquired pneumonia (CAP) are of unequal weight in predicting mortality. It is not clear whether the combinations of predictive findings might imply diverse severities or different mortalities.MethodsA prospective two centre cohort study was performed of 385 severe CAP patients fulfilling three or more IDSA/ATS minor criteria amongst 1430 patients.ResultsHospital mortality rose sharply from 5.7%, 9.9%, and 16.5%, respectively, for patients with none of three predictive findings most strongly associated to mortality (PaO2/FiO2 ≤ 250 mm Hg, confusion and uraemia), one of those, and two of those to 38.6% for patients with all those (p < 0.001). The number of three predictive findings present had a significantly increased odds ratio for mortality of 2.796 (p < 0.001), and had the degree of positive association with sequential organ failure assessment scores at 72 hours, incurring significantly longer hospital stay and higher costs.ConclusionsDifferent combinations of 2007 IDSA/ATS minor criteria for severe CAP were associated to diverse severities and different mortalities. The combination of PaO2/FiO2 ≤ 250 mm Hg, confusion and uraemia predicted more severity and higher mortality compared with others.