Prospective survey of the incidence, risk factors and outcome of hospital-acquired infections in the elderly.

Four hundred and thirty-six patient admissions to either an acute assessment or a rehabilitation ward for the care of the elderly were studied. A total of 113 episodes fitting the definition of a hospital-acquired infection (HAI) occurred in 81 (18.5%) of admissions. The global infection rate was 10.8 per 1000 patient bed days and did not differ between the wards. The chest and urinary tract were the commonest sites of infection, and 26 patients appeared to be infected at more than one site. The majority of first infections occurred within 14 days of admission. Median length of stay for patients with one or more infective episodes was significantly longer than for those who did not develop an HAI. The presence of an HAI, multiple-site infections and chest infections were significantly associated with fatal outcome. HAI occurs commonly in elderly patients and is associated with prolonged hospital stay and increased mortality.