Elderly Medicare patients are hospitalized with community-acquired pneumonia at a rate of 18.3 per 1000, compared to 4 per 1000 in younger populations.
Kaplan V, Angus D, Griffin M, Clermont G, et al. Hospitalized Community-Acquired Pneumonia in the Elderly. Am J Respir Crit Care Med. 2002; 165(6): 766-22. http://www.atsjournals.org/doi/full/10.1164/ajrccm.165.6.2103038#.UnKS6kbD_IU