A survey of nosocomial infections and their influence on hospital mortality rates.

Nosocomial infections play an important role in contributing to hospital mortality. In order to obtain a large sample a survey was conducted between 1978 and 1989 of more than 66,000 patients in German acute care hospitals. The data were used to assess the influence of nosocomial infections on mortality rates. Hospital infections were more frequent in female patients, but mortality with or without nosocomial infection was higher in male patients. Nosocomial infections increased hospital mortality threefold when raw numbers were used. Controlling for age and sex, the existence of at least one nosocomial infection (diagnosed at the second or a later day of hospital stay) increased hospital mortality by a factor of two. The influence of nosocomial infections was shown to be small for some diseases, such as malignancy, but was greater for others such as metabolic and immunological diseases or trauma. In the case of trauma, nosocomial infections increased hospital mortality rates by a factor of three even after controlling for age.