Mortality and mortality-related factors after hospitalization for acute exacerbation of COPD

Acute exacerbations form a major component of the socioeconomic burden of COPD. As yet, little information is available about the long-term outcome of patients who have been hospitalized with acute exacerbations, although high mortality rates have been reported.

The aim of this study was to investigate prospectively the outcome for all patients admitted to the hospital with acute exacerbations of COPD during hospital admission and after 1-year of follow-up. Furthermore, patient characteristics related to increased mortality rate were analyzed.

We investigated prospectively the 1-year mortality rate and potential determinants of mortality for all patients admitted to the hospital with an acute exacerbation between January 1 and December 31, 1999.

A total of 171 patients were included in the study. The mortality rate during hospital stay was 8%, increasing to 23% after 1 year of follow-up. Despite a comparable in-hospital mortality rate (6%), the 1-year mortality rate was significantly higher for patients admitted to the ICU for respiratory failure (35%). The multivariate Cox proportional hazards model was used to determine independent predictors of survival. Variables included in the regression model were age, sex, FEV(1), PaO(2), PaCO(2), body mass index, long-term use of oral corticosteroids, comorbidity index, and hospital readmissions. The maintenance use of oral glucocorticosteroids (relative risk [RR], 5.07; 95% confidence interval [CI], 2.03 to 12.64), PaCO(2) (RR, 1.17; 95% CI, 1.01 to 1.38), and age (RR, 1.07; 95% CI, 1.01 to 1.12) were independently related to mortality.

We conclude that the prognosis for patients who have been admitted to the hospital for acute exacerbation of COPD is poor. Long-term use of oral corticosteroids, higher PaCO(2), and older age could be identified as risk factors associated with higher mortality.