Prognostic factors associated with poor outcomes among multiethnic patients with acute exacerbation of chronic obstructive pulmonary disease

Background: Acute exacerbation is the most common cause of hospitalization for patients with chronic obstructive pulmonary disease (COPD). Objectives: To investigate prognostic factors associated with poor outcomes after acute exacerbation of COPD. Methods: A retrospective study of patients with a diagnosis of acute exacerbation of COPD (AECOPD) admitted to hospital in Penang over 5-year periods between January 2007 and December 2011 were conducted. We analyzed survival data using a Kaplan-Meier curves, and Cox regression was used to identify prognostic factors for mortality and readmission. Results: The study included 259 patients with a median age of 70 years (interquartile range = 59.7-76.7 years), and men comprised 92.7% of the cohort. Mortality after 1, 3, and 5 years was 26.3%, 49.8%, and 59.5% respectively. Older age (hazard ratio (HR), 2.53; 95% confidence interval (CI), 1.29-4.92) and long-term oxygen therapy (LTOT) at discharge (HR, 2.78; 95% CI, 1.54-5.02) were identified as independent prognostic factors associated with a higher risk of mortality after discharge. The risk of hospital readmission was 34% for 1 year, 43.2% for 3 years, and 48.6% for 5 years. Older age (HR, 1.78; 95% CI, 1.12-2.85), LTOT at discharge (HR, 3.63; 95% CI, 1.89-6.95), frequency of admissions in the previous year (HR, 2.92; 95% CI, 1.47-5.80), and being ventilated (HR, 0.19; 95% CI, 0.08-0.47) were identified as prognostic factors associated with readmission. Conclusions: Patients surviving AECOPD were prone to poor outcomes. Older patients and those discharged with LTOT were at higher risk of mortality and readmission at any time.