Managed care patients (aged >40 years) who were FSC naive in the 12 months pre-index period. The index-date was the date of discharge of the index COPD-related hospitalization/ED visit. Eligible patients were required to newly initiate or switch to drug therapy with FSC or IPR/TIO during the identification period (01/01/2004 to 01/31/2008) to treat COPD. Patients who switched to another maintenance medication or had an exacerbation in the treatment assessment period (30-days post-index date) were excluded from the study. Follow-up period was 12 months post treatment assessment period.