Clinical characteristics of health care-associated pneumonia in a Korean teaching hospital

Background: Health care-associated pneumonia (HCAP) has been proposed as a new category of respiratory infection. ATS/IDSA guidelines state that all patients with HCAP should receive empirical therapy directed at multidrug-resistant pathogens. However, recent data from other countries have reported a different picture of HCAP. Methods: We conducted a retrospective observational study of patients with HCAP and CAP who were hospitalized through the emergency department in January-December 2008 at Samsung Medical Center, Seoul, Korea, and compared clinical characteristics, severity, distribution of pathogen, and outcomes. Results: In total, 345 patients hospitalized with pneumonia were eligible, 182 (52.8%) with HCAP and 163 (47.2%) with CAP. Patients with HCAP had greater comorbidity and higher Pneumonia Severity Index (PSI) score (P < 0.001). Although Streptococcus pneumoniae was the most frequently isolated pathogen in HCAP and CAP patients, the occurrence of potentially drug-resistant pathogens (29.3% vs. 13.0%; P = 0.044) and inappropriate initial antimicrobial treatment (24.6% vs. 8.7%; P = 0.032) were significantly higher in HCAP patients. Patients with HCAP had a longer duration of hospital stay (13 [8-18] vs. 8 [6-12] days; P < 0.001), and higher in-hospital mortality (19.2% vs. 7.4%; P = 0.001). In a multiple logistic regression analysis, however, in-hospital mortality was independently associated with higher PSI class (OR 2.82, 95% CI 1.19-6.70) and ICU admission (OR 15.37, 95% CI 3.58-66.05). Conclusions: Severity of illness, rather than type of pneumonia, was the main predicting factor for in-hospital mortality among patients with pneumonia hospitalized through the emergency department.