Inclusion Criteria:  ≥40 years of age as of the year of the index date  At least one pharmacy claim for Stiolto Respimat or Trelegy Ellipta.  For Stiolto Respimat users, the first pharmacy claim of Fixed Dose Combination (FDC) of Tiotropium + Olodaterol (5/5 micrograms (mcg)) will be defined as the index date. For Trelegy Ellipta users, the first pharmacy claim of FDC of Fluticasone Furoate + Umeclidinium + Vilanterol (100/62.5/25 mcg), will be defined as the index date. Two medical claims (at least one claim on index date or before in the baseline period) with an International Statistical Classification of Diseases and Related Health Problems (ICD)-9/10 diagnosis code(s) for chronic obstructive pulmonary disease (COPD) in any position during the study period (baseline ± post index date). At least one year of continuous medical and pharmacy health plan eligibility prior to the index date is required (to allow a baseline period for the covariates and characterizing the study population).  Exclusion Criteria:  To increase the likelihood of a true diagnosis of COPD, we will exclude all patients with two medical claims of asthma, cystic fibrosis, lung cancer, or interstitial lung disease in any position on separate dates of service during the study period. To restrict the cohort to first line maintenance therapy of Stiolto Respimat or first line maintenance therapy of Trelegy Ellipta we will exclude: patients on long-acting muscarinic antagonists (LAMA) monotherapy; long-acting beta2 agonists (LABA) monotherapy; inhaled corticosteroids (ICS) monotherapy; free or FDC of: ICS+LABA, LAMA+LABA, ICS+LABA+LAMA therapy within six months prior to index date. Pharmacy claims for multiple index medications on the index date. Pharmacy claims for non-index COPD maintenance medications on the index date.