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

Abstract

Objectives: The 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.

Methods: A prospective two centre cohort study was performed of 385 severe CAP patients fulfilling three or more IDSA/ATS minor criteria amongst 1430 patients.

Results: Hospital 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 ≤ 250mm 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 72hours, incurring significantly longer hospital stay and higher costs.

Conclusions: Different combinations of 2007 IDSA/ATS minor criteria for severe CAP were associated to diverse severities and different mortalities. The combination of PaO2/FiO2 ≤ 250mm Hg, confusion and uraemia predicted more severity and higher mortality compared with others.

Keywords: Combination; Minor criteria; Mortality; Severe community-acquired pneumonia.