INFLUENCE OF NOSOCOMIAL INFECTION ON MORTALITY-RATE IN AN INTENSIVE-CARE UNIT

Objective: To assess the impact of nosocomial infection on the mortali ty rate in an intensive care unit (ICU). Design: Prospective cohort st udy. Setting: The ICU of the University of Granada Hospital in Spain. Patients: All patients (n = 279) admitted for greater than or equal to 48 hrs at the ICU between December 1986 and April 1988. Measurements: Nosocomial infections were diagnosed according to Study on the Effica cy of Nosocomial Infection Control (SENIC) and Centers for Disease Con trol criteria. Patient severity on admission (using Acute Physiology a nd chronic Health Evaluation (APACHE II) and Therapeutic Intensity Sco ring Systems were also used. Results: Mortality risk was 2.48 times hi gher in patients with a nosocomial infection than in noninfected patie nts. Relative risk of mortality in nosocomially infected patients was higher in young and less severely ill patients, in those patients with respiratory diseases, and in those patients with longer ICU stays. Lo gistic stepwise regression analysis, adjusting for several confounding factors (affected organ system, APACHE II score, and therapeutic inte nsity), showed that the risk of death in nosocomially infected patient s was 2.1 times greater (95% confidence interval = 1.0 to 4.41) than i n patients without such infection. Conclusions: Nosocomial infection i ncreases the risk of death. The effect is stronger in younger and less severely ill patients.