Risk of HAIs from hospitalization increases with age
Hospitalized elderly patients are 2 – 5 times more likely to develop a healthcare-associated infection than younger patients.
Haley, Robert W., Hooton, Thomas W., David H. Culver, Richie C. Stanley, T. Grace Emori, C. David Hardison, Dana Quade, Richard H. Shachtman, Dennis R. Schaberg, Babu V. Shah, and Gary D. Schatz. Nosocomial Infections in U.S. Hospitals, 1975-1976. Am J Med. 1981; 70(4): 947-59. http://www.amjmed.com/article/0002-9343%2881%2990561-1/abstract