A practical application of Rhame and Sudderth's formula on nosocomial infection surveillance.

We have conducted an epidemiological analysis of the utility of Rhame and Sudderth's formula--establishing a relationship between prevalence, incidence and duration of nosocomial infection--as an effective model in the surveillance of such infection. We carried out a follow-up study in a surgical service of our hospital on a sample of 799 patients admitted between January 1 and June 17, 1983 (24 weeks). We confirmed the condition of steady-state and were able to conclude that the Rhame and Sudderth model can have great utility when cross-sectional studies are performed with an adequate interval. We also concluded that the application of this model is not influenced by the size of the ward or zone of survey.