[The estimation of the cost of nosocomial infection in an intensive care unit].
Nosocomial infection (NI) represents an increase of hospital morbidity and mortality. The data available concerning the hospital expenses due to the prolongation of hospital stay associated to NI are fundamentally derived from American studies. The aim of this study was to evaluate the direct cost of nosocomial infection in an intensive medicine unit (IMU). A study of cases and paired controls was carried out with a cohort study made up of 88 cases and 88 controls paired by age and severity (APACHE II grading). Previously identified confusion factors were controlled in the analysis. The mean stay in the IMU for infected patients was 17.2 days and for non infected patients 6.8 days. When these stays were adjusted by the variables associated with both NI and in the IMU this became 14.2 days for infected patients and 9.9 days for uninfected patients. The prolongation of stay in the IMU due to NI was 4.3 days. The extra cost for the hospital due to infection acquired by a patient's during stay in the IMU was estimated as 239,441 pesetas. The methodology used was considered as valid for estimating the prolongation of stay in intensive medicine units attributed to nosocomial infection. The high economic expense which nosocomial infection represents emphasizes the justification for measures of control of this entity.