Influence of comorbid conditions on long-term mortality after pneumonia in older people

Abstract

Objectives: To test the hypothesis that increased long-term mortality after hospitalization for community-acquired pneumonia (CAP) is independent of comorbid conditions.

Design: Prospective observational cohort study in metropolitan areas.

Setting: Memphis, Tennessee, and Pittsburgh, Pennsylvania.

Participants: Three thousand seventy-five subjects aged 70 to 79 over 5.2 years.

Measurements: Unadjusted and adjusted mortality from an initial hospitalization for CAP were compared with mortality from different causes of hospitalization, including cancer, fracture, congestive heart failure (CHF), cerebrovascular accident (CVA), and other causes. Demographics, smoking, nutritional markers, functional status, inflammatory markers, and chronic health conditions were adjusted for.

Results: Of the 106 subjects hospitalized for CAP, 22 (20.8%) and 38 (35.8%) died at 1 and 5 years. Subjects hospitalized with CAP had higher mortality than nonhospitalized subjects (adjusted odds ratio (OR)=7.8, 95% confidence interval (CI)=4.2-14.4). One- and 5-year mortality after CAP hospitalization were higher than mortality from other causes requiring hospitalization and remained unchanged in multivariable analysis (adjusted OR=3.5, 95% CI=1.5-8.1; adjusted OR=5.6, 95% CI=2.8-11.2, respectively). One- and 5-year mortality after hospitalization for CAP were similar to or higher than mortality after an initial hospitalization for CHF, CVA, or fracture. Rehospitalization was common in subjects hospitalized for CAP and may explain greater long-term mortality.

Conclusion: In this high-functioning cohort of older persons, an initial hospitalization for CAP was associated with greater long-term mortality, independent of prehospitalization comorbid conditions. Hospitalization for CAP has as serious a prognosis as hospitalization for CHF, stroke, or major fracture.