Background:  Hospitalizations and mortality due to pneumonia increase steadily with age. The purpose of this study is to describe the frequency, costs, and risk factors for hospitalization for pneumonia among older adults with particular attention to the effect of functional disability.
Methods: The Longitudinal Study of Aging (LSOA) is the follow-up to the Supplement on Aging, which was appended to the 1984 National Health Interview Survey. Participants included a nationally representative sample of 7,527 community-dwelling adults aged 70 and older in 1984 who were followed prospectively for 8 years. The LSOA data are linked to the National Death Index and to yearly abstracts from the Medicare Automated Data Retrieval System (1984-1991).
Results: From 1984 to 1991, 617 subjects (8.2%) had at least one hospitalization for pneumonia, 4,333 (57.5%) had at least one hospitalization for any reason, and 2,867 (38.1%) of the LSOA subjects died. The yearly frequency of hospitalization for pneumonia increased over time from 0.6% in 1984 to 2.4% in 1991. The median length of stay was 8 days, and the median hospital charge was $5,100. Over 8 years, median discounted charges for a pneumonia hospitalization increased 75% while length of stay remained relatively constant. Patients hospitalized for pneumonia had greater comorbidity, total hospital resource use, and mortality, but over 80% survived their first hospitalization for pneumonia. Hospitalization for pneumonia was associated with age, male gender, malnutrition, history of hip fracture, prior hospitalizations, and lower body limitations.
Conclusions:  Hospitalization for pneumonia was frequent and accounted for 6% of the Medicare expenditures over 8 years among this cohort of older adults. Hospitalization for pneumonia occurred most often among subjects with prior evidence of failing health, but most subjects survived the first hospitalization for pneumonia. Even controlling for comorbidity, prior hospitalizations, and functional impairment, hospitalization for pneumonia was independently associated with age.