Studies of Respiratory Tract Infection in Nursing Home Residents: What Are We Learning?

The burden of respiratory infection in nursing home residents is substantial. As a result, there has been increasing interest in the epidemiology of nursing home pneumonia during the past decade because of its high morbidity and mortality. In addition, there have been an increasing number of studies describing respiratory outbreaks in nursing homes. In this issue, there appear three studies of respiratory infection in nursing home residents: two addressing pneumonia and one describing large outbreaks of respiratory illness in two nursing homes. As more studies of respiratory infection in older people are published, it is important to determine the effect, if any, of the findings of these studies on the care of this frail population. The study by Shariatzadeh et al. focuses on aspiration pneumonia in adult patients admitted to six hospitals in Edmonton, Alberta, Canada. The authors’ objectives were to define the prevalence of aspiration pneumonia in the study population and to compare the features of community-acquired aspiration pneumonia (CAAP) with those of ‘‘continuing care facility’’ aspiration pneumonia (CCF-AP). CCFs were defined as facilities providing independent living, assisted living, medical services, long-term care, and skilled nursing all in one location. The authors do not clearly state the rationale for conducting this study. In addition, the difference in the factors predisposing to aspiration pneumonia between elderly people in the community and those in CCFs has been well described in the literature, as reviewed by Marik. This study also has several design limitations. The main limitation is that the definition of aspiration used in this study is broad and would include those with aspiration pneumonia and aspiration pneumonitis. The authors used the broad definition, because, even after chart review, there was not sufficient information to allow them to distinguish between aspiration pneumonia and aspiration pneumonitis, but this distinction has some importance. In a recently published study of nursing home residents admitted to the hospital with suspected pneumonia, aspiration pneumonitis occurred more commonly than pneumonia based on clinical criteria. Thus, the group defined as having CFF-AP in the study by Shariatzadeh et al. likely had a substantial number of people with aspiration pneumonitis, which has a different outcome from aspiration pneumonia. Of more interest are two findings that the authors do not emphasize. First, a substantial proportion of cases of CAAP and nonaspiration community-acquired pneumonia were classified as being at low risk for mortality (Classes I-III) using the classification of Fine et al. It would have been useful to know the mortality by individual risk class, because it has been suggested that patients in risk Classes I through III have low mortality and probably do not need to be hospitalized. Second, there was no significant difference in mortality between those with CAAP and those with CCF-AP, despite the fact that patients with CCF-AP were more debilitated, had a significantly higher mean pneumonia severity score, and were significantly less likely to be admitted to an intensive care unit. The lack of difference in mortality may be related to the inclusion of those with pneumonitis, who have a better short-term prognosis, in the CCF-AP group. Overall, there appears to be little new information in the study by Shariatzadeh et al. that would affect patient care. In the second study of nursing home pneumonia, investigators retrospectively evaluated the management of nursing home residents with advanced dementia and suspected pneumonia during the last 6 months of life with the specific intention of identifying factors associated with what they defined as aggressiveness of antibiotic therapy. Antibiotic therapy was ranked from the least to the most aggressive based on the following categories: no antibiotic, oral antibiotic only, intramuscular antibiotic, and any intravenous antibiotic. The authors evaluated ‘‘suspected’’ pneumonia, because chest radiographs were taken in only 45% of 229 episodes. Of the 102 episodes in which a chest radiograph was taken, only 56% had a documented infiltrate. Thus, the clinical diagnosis of pneumonia may have been incorrect in more than half of the episodes, but because 90% of those with suspected pneumonia received some type of antibiotic therapy, merely taking a chest radiograph to confirm the clinical diagnosis may have avoided antibiotic therapy in a substantial number of episodes. The clinically relevant findings of Chen et al. can be summarized as follows. First, suspected pneumonia was most common in the last 30 days of life (about 53% of the total episodes during the study period), and approximately 54% of the study population received parenteral antibiotics, and 14% were hospitalized. Second, lack of a do-nothospitalize order was the strongest predictor of aggressive antibiotic therapy even if residents were not hospitalized. Third, before the development of the terminal stage of dementia, physicians and nursing facility staff had documented discussions with surrogates regarding end-of-life care for 85% of the study population, and 45% of the residents had DOI: 10.1111/j.1532-5415.2005. 00611.x