Guideline-concordant antibiotic therapy and clinical outcomes in healthcare-associated pneumonia

Background: The 2005 ATS/IDSA guidelines defined healthcare-associated pneumonia (HCAP) as a novel category of pneumonia in patients with significant healthcare exposure in whom the risk of drug resistant bacteria may be higher. In this study, we compare clinical outcomes in patients with HCAP who were treated with guideline-concordant antibiotic regimens with those who were not. Methods: Medical records of 100 patients meeting HCAP criteria admitted to an academic tertiary care hospital between January 2009 and January 2011 were retrospectively reviewed. Cases were divided into guideline-concordant and guideline-discordant groups based on antibiotic therapy. Demographic, microbiological and clinical outcome data were compared for both groups. Results: Patients in this cohort had multiple co-morbidities, severe pneumonia (mean PSI score 124.1), and significant mortality (22%). 21 of the 100 cases (21.0%) were culture positive, of which 11 (53.8%) represented drug-resistant pathogens. No statistically significant differences for any of the four clinical outcome measures were detected between the guideline-concordant therapy group and guideline-discordant group. In multivariate regression analysis controlling for possible confounders, similar results were observed, with the exception that length of stay was significantly longer (3.99 days, p < 0.001) in the discordant group. Three or more HCAP criteria (OR 10.89) and wound care (OR 6.32) were characteristics found to be associated with increased risk for drug-resistant pathogens. Conclusion: In our cohort, the HCAP model identified a population with significant co-morbidities and increased risk for drug-resistant pathogens, severe pneumonia, and increased mortality. However, clinical outcomes were not significantly improved with guideline-concordant antibiotic therapy.