Risk Factors for Bacteremia in Patients With Urinary Catheter-Associated Bacteriuria

Catheter-associated bacteriuria is complicated by secondary bacteremia in 0.4% to 4.0% of cases. The directly attributable mortality rate is 12.7%.

To identify risk factors for bacteremia associated with catheter-associated bacteriuria.

Data were acquired from a large electronic clinical and administrative database of consecutive adult inpatient admissions to 2 acute care hospitals during a 7-year period. Data on patients with catheter-associated bacteriuria and bacteremia were compared with data on control patients with catheter-associated bacteriuria and no bacteremia, matched for date of admission plus or minus 30 days. Urine and blood cultures positive for the same pathogen within 7 days were used to define catheter-associated bacteriuria and bacteremia. Multivariable conditional logistic regression was used to determine independent risk factors for bacteremia.

The sample consisted of 158 cases and 474 controls. Independent predictors of bacteremia were male sex (odds ratio, 2.76), treatment with immunosuppressants (odds ratio, 1.68), urinary tract procedure (odds ratio, 2.70), and catheter that remained in place after bacteriuria developed (odds ratio, 2.75). Patients with enterococcal bacteriuria were half as likely to become bacteremic as were patients with other urinary pathogens (odds ratio, 0.46). Odds of secondary bacteremia increased 2% per additional day of hospital stay (95% CI, 1.01-1.04) and decreased 1% with each additional year of age (95% CI, 0.97-0.99).

The results add new information about increased risk for bacteremia among patients with catheters remaining in place after catheter-associated bacteriuria and confirm evidence for previously identified risk factors.