Nonspecific presentation of pneumonia in hospitalized older people: age effect or dementia?

Older adults, when presenting with pneumonia, are often thought to present with nonspecific symptoms instead of more suggestive symptom(s). However, studies designed to determine whether age is associated with nonspecific presentations have yielded contradictory results. Many studies have not distinguished between the effects of preexisting cognitive impairment that results from dementia and the effects of age. The aim of this study is to determine whether there are significant differences in the presentation of pneumonia in demented versus nondemented patients across two age groups. We hypothesized that the nonspecific presentation of pneumonia in older people is due to dementia rather than to chronological age.

We compared retrospectively nonspecific (weakness, decreased appetite, urinary incontinence, falls, and delirium) and specific (cough, sputum production, dyspnea, and chest pain) symptoms of pneumonia in 148 hospitalized adult subjects from two urban, general medical teaching hospitals.

When the subjects with dementia were included in the analysis, two (falls and delirium) of the five nonspecific symptoms were associated with older age and one other symptom (weakness) showed a trend toward statistical significance. However, when we excluded the demented subjects, nonspecific presenting symptoms were similar in old and young adults with the exception of an increased frequency of delirium on presentation. Similarly, when demented subjects were excluded, we found a stronger association of younger age with the classic specific symptoms than were seen when the demented subjects were included.

We conclude that age differences in the presentation of pneumonia are largely due to the presence of dementia.