Patient records for commercially-insured patients with chronic obstructive pulmonary disease (COPD) aged 40 and older. For the risk-analysis population, patients were required to have at least 12 months of continuous enrollment prior to the index date and at least 3 months of continuous enrollment after the index date. A subgroup analysis was conducted for costs that included patients in the total population who also had at least 12 months of continuous coverage following the index date (the cost-analysis population).