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 ≤ 250 mm Hg, confusion and uraemia), one of those, and two of those to 38.6% for patients with all those (p
