Risk Factors for Ineffective Therapy in Patients With Bloodstream Infection

Abstract

Background Infections occurring among outpatients having recent contact with the health care system have been termed health care–associated infections. The objective of this study was to analyze the impact of health care–associated status on effectiveness of initial therapy in hospitalized patients with bloodstream infections. Methods Prospective cohort study of adults with bloodstream infections at 3 North Carolina hospitals. Bloodstream infection was defined as health care–associated if it occurred within the first 48 hours after hospitalization and if patients had 1 of the following characteristics: had received home health services, outpatient intravenous therapy, or outpatient renal dialysis in the 30 days prior to hospital admission; had been hospitalized within 90 days prior to admission; or lived in a long-term care facility. Results Of 466 bloodstream infections, 132 (28%) were community-acquired, 178 (38%) were health care–associated, and 156 (33%) were nosocomial. Multivariable logistic regression using community-acquired status as a reference identified health care–associated status (odds ratio, 3.1; 95% confidence interval, 1.6-6.1) and nosocomial status (odds ratio, 4.3; 95% confidence interval, 2.2-8.3) as independent predictors of ineffective initial antibiotic therapy. Among health care–associated characteristics, hospitalization in the 90 days prior to admission was independently associated with ineffective initial therapy (odds ratio, 2.4; 95% confidence interval, 1.4-4.2). Conclusions Among patients treated in the hospital for bloodstream infection, health care–associated status was an independent predictor of ineffective initial antibiotic therapy. Hospitalization within 90 days prior to hospital admission was the component of health care–associated status most strongly associated with ineffective initial therapy.