Characteristics and outcomes of older adults with community-acquired pneumococcal bacteremia

Abstract

Objectives: To describe baseline characteristics and clinical outcomes of older adults with pneumococcal bacteremia, compare the frequency of serious outcomes according to pneumococcal vaccination status, and assess factors associated with mortality.

Design: Population-based case-series.

Setting: Group Health Cooperative, a health maintenance organization in Washington State.

Participants: Community-dwelling adults aged 65 and older with a first episode of pneumococcal bacteremia between 1988 and 2002.

Measurements: Demographic characteristics, underlying medical conditions, vaccination status, and clinical outcomes, including death, hospitalization, length of hospital stay, and postdischarge care, were assessed using chart review.

Results: The mean age of the 200 elderly patients with pneumococcal bacteremia was 78; 61% were female. Forty percent had had chart-documented pneumococcal vaccination before the onset of bacteremia. The spectrum of clinical severity and consequences was broad. Ten percent were treated as outpatients. Of the 90% who were hospitalized, 16% were admitted to the intensive care unit. All-cause mortality at 30 days was 11%. Of survivors, 23% were discharged with home services, and another 20% were discharged to a nursing home. After controlling for age, sex, and pneumococcal vaccination status, predictors of death included coronary artery disease (odds ratio (OR)=4.6, 95% confidence interval (CI)=1.4-14.5) and immunocompromising conditions (OR=5.0, 95% CI=1.6-15.7). Outcomes were similar in patients who did and did not receive pneumococcal vaccination.

Conclusion: In this elderly group, pneumococcal bacteremia was associated with substantial morbidity, mortality, and loss of independence. Coronary artery disease and immunocompromising conditions were independent predictors of death.