Hospitalization for pneumonia in the Cardiovascular Health Study: incidence, mortality, and influence on longer-term survival.

OBJECTIVES: To estimate the rate of hospitalization for pneumonia in community-dwelling older adults and to assess its risk factors and contribution to mortality.
DESIGN: Prospective observational study.
SETTING: The Cardiovascular Health Study (CHS) in four U.S. communities. PARTICIPANTS: Five thousand eight hundred eighty-eight men and women aged 65 and older who were followed for a median 10.7 years. MEASUREMENTS: Participants were interviewed about medical history and demographics; evaluated for lung, physical, and cognitive function; and followed for hospitalizations, cardiovascular disease, and death.
RESULTS: Nearly 10% of the cohort was hospitalized for pneumonia, for a rate of 11.1 per 1,000 person-years (95% confidence interval (CI)=10.2-12.0). Risk factors included older age, male sex, current and past smoking, poor physical and lung function, and history of cardiovascular disease and chronic obstructive pulmonary disease. Ten percent of participants died during their incident pneumonia hospitalization, and death rates were high in those who survived to discharge. Compared with participants who had not been hospitalized for pneumonia, the relative risk of total mortality was 4.9 (95% CI=4.1-6.0) during the first year after hospitalization and 2.6 (95% CI=2.2-3.1) thereafter, adjusted for age, sex, and race. The respective relative risks were 3.9 (95% CI=3.1-4.8) and 2.0 (95% CI=1.6-2.4) after further adjustment for baseline history of cardiovascular disease; diabetes mellitus; smoking; and measures of lung, physical, and cognitive function.
CONCLUSION: In older people, hospitalization for pneumonia is common and is associated with an elevated risk of death, as shown in this population-based, prospective cohort.