This was a retrospective observational study of COPD patients in the United States treated with LABA/LAMA or LABA/ICS combination. Insurance claims from January 1, 2004, through December 31, 2014, were used as the data source. Patients were required to have greater than one prescription filled for the combination medications, and they were followed from 30 days after drug initiation. Individuals were censored if they discontinued a study medication, initiated medication from the opposite cohort (LAMA or ICS), lost enrollment eligibility, or at the study period end. Exacerbation rates were compared using Poisson regression.