Risk factors for nosocomial urinary tract-related bacteremia: A case-control study

Background: Risk factors for bacteremia in patients with hospital-acquired bacteriuria are largely unknown. Given the morbidity and costs associated with nosocomial bacteremia, determining risk factors could enhance the safety of hospitalized patients. Methods: We conducted a case-control study within the Veterans Affairs Puget Sound Health Care System. A patient hospitalized between 1984 and 1999 from whom a urine culture and a blood culture grew the same organism >= 48 hours after admission was considered a case. Control patients were those with significant bacteriuria detected 48 hours after admission who did not have a positive blood culture. We used logistic regression to determine independent risk factors for bacteremia. Results: There were 95 cases and 142 controls. Independent, statistically significant predictors of bacteremia included immunosuppressant therapy within 14 days of bacteriuria (odds ratio [OR], 8.13); history of malignancy (OR, 1.94); male sex (OR, 1.88); cigarette use in the past 5 years (OR, 1.26); number of hospital days before bacteriuria (OR, 1.03); and antibiotic use within 3 days of bacteriuria (OR, 0.76). corticosteroid use within 7 days of bacteriuria predicted bacteremia in patients < 70 years old (OR, 14.24). Similarly, patients < 70 years old were more likely to develop bacteremia if they had diabetes mellitus (OR, 6.19). Conclusion: Delineating risk factors for nosocomial urinary tract-related bacteremia can help target appropriate preventive practices at the highest risk patients.