A prospective comparison of nursing home acquired pneumonia with community acquired pneumonia.

Nursing home acquired pneumonia (NHAP) is thought to be clinically distinct from community acquired pneumonia (CAP). This observation, based on studies conducted mainly in North America, may not be relevant in countries with a different healthcare system. The authors describe an 18-month prospective cohort study of 437 patients admitted to hospital with CAP, 40 (9%) of whom came from nursing homes. Detailed microbiological tests were performed in a subset of patients over 12 months. Patients with NHAP were less likely to have a productive cough (odds ratio (OR) 0.4, p=0.02) or pleuritic pain (OR 0.1, p=0.03), but they were more likely to be confused (OR 2.6, p<0.001). They had poorer functional status (p<0.001) and more severe disease (p=0.03). Mortality was higher compared to CAP (53% versus 13%), but this was mainly explained by prior functional status (OR 0.5, after adjustment for functional status). Pathogens were identified in 68% of 22 NHAP and 80% of 44 matched CAP patients. Streptococcus pneumoniae was the most common (55% NHAP, 43% CAP). Atypical pathogens, enteric Gram negative bacilli and Staphylococcus aureus were uncommon. In conclusion, differences in functional status accounted for the increased mortality in nursing home acquired pneumonia compared to community acquired pneumonia. The pathogens implicated were similar. No grounds for a difference in choice of empirical antibiotics were apparent.