Clinical characteristics of nursing home-acquired pneumonia in elderly patients admitted to a Korean teaching hospital

Background/Aims: Nursing home-acquired pneumonia (NHAP) is included under healthcare-associated pneumonia. However, the optimal treatment strategy for NHAP has been controversial in several studies. We evaluated the clinical features of NHAP compared to community-acquired pneumonia (CAP) in elderly patients admitted with pneumonia. Methods: This was a retrospective study in elderly patients aged ${\geq}65years$ with NHAP or CAP who were hospitalized at Jeju National University Hospital between January 2012 and April 2013. Results: A total of 209 patients were enrolled, and 58 (27.7%) had NHAP. The patients with NHAP were older, had more frequent central nervous system disorders, and showed worse clinical parameters. Potential drug-resistant pathogens were more frequently detected in the NHAP group (22.4% vs. 9.9%, p = 0.018), and the incidences of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus were 8.6% and 10.3%, respectively. In-hospital mortality occurred in 13 patients (22.4%) with NHAP and 17 patients (11.2%) with CAP (p = 0.039). In multivariate analyses, only higher pneumonia severity index (PSI) score was associated with increased mortality (p < 0.001), and the PSI score was higher in the NHAP group than that in the CAP group. Conclusions: Elderly patients admitted with NHAP showed more severe pneumonia at onset, higher rates of potentially drug-resistant pathogens, and worse clinical outcomes than those with CAP. However, higher in-hospital mortality in those with NHAP seemed to be related to the PSI score reflecting host factors and severity of pneumonia rather than the type of pneumonia or the presence of drug-resistant pathogens.