Predictors of 1-Year Mortality at Hospital Admission for Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background: Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are related to high mortality, especially in hospitalized patients. Predictors for severe outcomes are still not sufficiently defined. Objectives: To assess the mortality rate and identify potential determinants of mortality in a cohort of patients hospitalized for AE-COPD. Methods: A retrospective, observational cohort study including all consecutive patients admitted between January 1, 2009, and April 1, 2010, for AE-COPD. Potential predictors were assessed at initial presentation at the emergency room. The primary outcome was mortality during 1-year follow-up. Univariate and multivariate time-to-event analyses using Cox proportional hazard models were employed for statistical analysis. Results: A total of 260 patients were enrolled in this study. Mean age was 70.5 +/- 10.8 years, 50.0% were male and 63.4% had severe COPD. The in-hospital mortality rate was 5.8% and the 1-year mortality rate was 27.7%. Independent risk factors for mortality were age [hazard ratio (HR) = 1.04; 95% confidence interval (CI) = 1.01-1.07], male sex (HR = 2.00; 95% CI = 1.15-3.48), prior hospitalization for AE-COPD in the last 2 years (HR = 2.56; 95% CI = 1.52-4.30), prior recorded congestive heart failure (HR = 1.75; 95% CI = 1.03-2.97), PaCO2 >= 6.0 kPa (HR = 2.90; 95% CI = 1.65-5.09) and urea >= 8.0 mmol/l (HR = 2.38; 95% CI = 1.42-3.99) at admission. Conclusions: Age, male sex, prior hospitalization for AE-COPD in the last 2 years, prior recorded congestive heart failure, hypercapnia and elevated levels of urea at hospital admission are independent predictors of mortality within the first year after admission. Copyright (C) 2012 S. Karger AG, Basel