OBJECTIVES: Hospital readmission has been an important issue in patients with chronic obstructive pulmonary disease (COPD), as it reflects exacerbation of the disease and quality of medical care, and incurs high medical expenditures. This study aimed to examine pattern and economic burden of readmission, and identify factors associated with risk of readmission in patients hospitalized for COPD in Taiwan. METHODS: The National Health Insurance claims database of a representative sample (two million subjects) of Taiwanese population in 2005 was adopted for this study. Adult individuals who were discharged from acute hospitals for COPD in 2005 were selected and their readmission pattern one-year after discharge were examined. Cox proportional hazards regression models were adopted to identify factors associated with risk of readmission. RESULTS: The majority of the subjects was male and aged older than 65 years old. The 30-day, 3-month and one-year all-cause readmission rates were 28%, 46%, and 69%, respectively. The 30-day, 3-month and one-year COPD-specific readmission rates were 10%, 17%, and 31%, respectively. Approximately one-fourth of the subjects were readmitted more than twice during the follow-up. COPD, pneumonia, and respiratory failure/insufficiency/arrest were the top three most frequent causes for readmission during 30 days, 3 months, or one year after discharge. In the one-yar follow-up, hospital readmission accounted for 73% of total healthcare expenditures. Gender, previous hospitalization history, comorbidities, and length of stay and hospital accreditation level of the index hospitalization were associated with risk of all-cause readmission. Gender, previous hospitalization history, and length of stay and hospital accreditation level of the index hospitalization were associated with risk of COPD-specific readmission. CONCLUSIONS: This study identified patterns and causes of short-term and long-term readmission, and factors associated with risk of readmission in patients hospitalized for COPD. The information is of importance for planning interventions to reduce hospital readmission rate.