Antimicrobial therapy escalation and hospital mortality among patients with health-care-associated pneumonia: a single-center experience

Abstract

Background: Patients with health-care-associated pneumonia (HCAP) are frequently infected with a resistant pathogen and receive inappropriate empiric antibiotics (ie, pathogens resistant to administered treatment). Initial inappropriate treatment has been shown to increase hospital mortality. It is not known whether escalation in response to culture results mitigates this risk.

Methods: We identified patients admitted with a culture-positive pneumonia between January 2003 and December 2005. HCAP patients met one or more of the following criteria indicating ongoing contact with the health-care system: recent hospitalization (< or = 12 months), admission from a nursing home, immunosuppression, or long-term dialysis. We compared survivors to nonsurvivors among those patients with HCAP still hospitalized beyond 48 h.

Results: Of 431 HCAP patients, 396 patients (92%) were alive and still hospitalized beyond 48 h. The crude mortality rate was 21.5%. Compared to survivors, nonsurvivors were significantly more likely to be treated with inappropriate empiric antibiotics (37.6% vs 24.1%, p = 0.013). Although mortality was higher among patients receiving inappropriate than appropriate therapy (30.0% vs 18.3%, p = 0.013), this difference was more pronounced among nonbacteremic patients (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.26 to 4.75) than bacteremic patients (OR, 1.25; 95% CI, 0.41 to 3.57). In a logistic regression, inappropriate empiric antibiotic treatment among nonbacteremic patients was independently associated with mortality (OR, 2.88; 95% CI, 1.46 to 5.67); treatment escalation did not attenuate the risk of death.

Conclusion: Among HCAP patients alive and hospitalized beyond 48 h, hospital mortality was high and, in the absence of bacteremia, greater with initial inappropriate antibiotic treatment. Despite subsequent escalation, initial inappropriate antibiotic choice nearly tripled the risk of hospital death.