All population i.e. at least 40 years: Each initial maintenance treatment (IMT) cohort (FSC 250/50mcg dose only, IP, and TIO) includes patients aged 40 years and older with at least 9 months of continuous enrollment (6 months pre-index and at least three months post-index) with a primary or secondary diagnosis of COPD [International Classification of Disease, 9th revision, Clinical Modification (ICD-9-CM) codes 491.xx, 492.xx or 496.xx]. Patients are observed such that everyone provides minimum 6 months of pre index baseline data and minimum 3 months post index (risk analysis) and minimum 12 months post index for cost analysis. Patients must receive either a 30-day supply of FSC or IP or TIO as the initial IMT medication, indicating "intent to treat." Patients may not also have a prescription filled for the other IMT medication within 60 days of the index date, or for the combination therapy budesonide/ formoterol (BFC), an inhaled corticosteroid (ICS) or a long acting beta agonist (LABA). Six months of observation (continuous enrollment) prior to the index date is assessed to confirm that the patient meets the inclusion and exclusion criteria as well as to identify baseline characteristics and covariates. Cost analysis was done using a 12 months fixed follow up period. Outcome measures are assessed during the post-index period