Pneumonia is a major cause of morbidity and mortality around the world [1]. The setting in which pneumonia is acquired, i.e., in the community or in the hospital, heavily influences diagnostic and therapeutic choices [1]. Community-acquired pneumonia (CAP) is the leading cause of infectious death in Europe and the United States [2, 3]. Several studies have reported an increase in hospital admissions for CAP in recent years [4–7], which is not fully explained by an aging population, rising prevalence of coexisting conditions, or coding changes [5, 6].
