Risk factors for nosocomial bacteremia in a large Spanish teaching hospital: a case-control study.

OBJECTIVE

Identify independent risk factors associated with the development of nosocomial bacteremia.

DESIGN

Exploratory, unmatched, case-control study.

SETTING

A 970-bed Spanish university hospital.

PATIENTS: All non-neutropenic adult patients with nosocomial bacteremia admitted during a 12-month period were eligible as cases. All adult non-neutropenic patients without nosocomial bacteremia were eligible as controls.

RESULTS

The incidence of bacteremia in the study population was 6.9/1000 admissions/year. One hundred eighty cases and 180 controls were analyzed. Multivariate analysis (stepwise logistic regression techniques) identified seven risk factors independently associated with nosocomial bacteremia: age above 65 years; prior admission (within six months) to the hospital; underlying diseases that were ultimately or rapidly fatal; indwelling urethral catheter in place for more than three days; intravenous central lines or peripheral venous lines (if in place for more than four days); "high-risk surgery" (i.e., lower abdominal, cardiac or thoracic); and admission to an intensive care unit.

CONCLUSIONS

Although five variables are not modifiable, the remaining two relate to the use and duration of devices. Our data give strong support for the value of testing strict guidelines for limiting vascular catheters and evaluating the need for prolonged urethral catheterization. If effective infection control measures are identified, we could target hospital-wide surveillance to patients whose risk factors are amenable to intervention.