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

Background: 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. Study objective: 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. Design: 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. Results: 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, FEV1, PaO2, PaCO2, 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), PaCO2 (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. Conclusion: 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 PaCO2, and older age could be identified as risk factors associated with higher mortality.