Antimicrobial Resistance and Clinical Outcomes in Nursing Home-Acquired Pneumonia, Compared to Community-Acquired Pneumonia

PURPOSE Patients with nursing home-acquired pneumonia (NHAP) should be treated as hospital-acquired pneumonia (HAP) according to guidelines published in 2005. However, controversy still exists on whether the high mortality of NHAP results from multidrug resistant pathogens or underlying disease. We aimed to outline differences and factors contributing to mortality between NHAP and community-acquired pneumonia (CAP) patients. MATERIALS AND METHODS We retrospectively evaluated patients aged 65 years or older with either CAP or NHAP from 2008 to 2014. Patients with healthcare-associated pneumonia other than NHAP or HAP were excluded. RESULTS Among 317 patients, 212 patients had CAP and 105 had NHAP. Patients with NHAP had higher mortality, more frequently used a ventilator, and had disease of higher severity than CAP. The incidences of aspiration, tube feeding, and poor functional status were higher in NHAP. Twenty three out of 54 NHAP patients and three out of 62 CAP patients had multidrug resistant pathogens (p<0.001). Eleven patients with NHAP died at discharge, compared to 7 patients with CAP (p=0.009). However, there was no association between mortality rate and presence of multidrug-resistant pathogens. The number of involved lobes on chest X-ray [odds ratio (OR)=1.708; 95% confidence interval (CI), 1.120 to 2.605] and use of mechanical ventilation (OR=9.537; 95% CI, 1.635 to 55.632) were significantly associated with in-hospital mortality. CONCLUSION Patients with NHAP had higher mortality than patients with CAP. The excess mortality among patients with NHAP and CAP was related to disease severity but not to the presence of multidrug resistant pathogens.