Introduction: This retrospective, observational cohort study utilized an integrated dataset from an electronic health records system and a claims database to describe demographic and clinical characteristics, healthcare resource utilization (HCRU), and treatment patterns in COPD patients initiating long-acting muscarinic antagonist (LAMA)/long-acting β 2 -agonist (LABA) fixed-dose combination (FDC) treatment in the USA. Methods: Patients were aged ≥40 years and had a COPD diagnosis (Practice Fusion system) and ≥1 prescription of LAMA/LABA FDC therapy, with an index date (first prescription) 1 May 2014-31 December 2017. For the HCRU analysis, patients had ≥2 claims from the Symphony Health database within 12 months before index. All analyses of outcomes relating to demographic and clinical characteristics, HCRU, and treatment patterns were descriptive. Results: Patients initiating LAMA/LABA FDCs (n=8224) had a mean age of 67.9 years, 52.8% were female, and mean BMI was 29.2 kg/m 2 . The most common comorbidities were cardiovascular disease (74.3%), hypertension (64.0%), and hyperlipidemia (45.6%). In the 12 months prior to index, 53.1% of patients had used inhaled therapy: 23.4% short-acting therapy only, 16.7% short-acting and maintenance therapy, and 13.1% maintenance therapy only. Amongst users of inhaled therapies, the pMDI was the most frequently used device (64.3%, n=2812/4370). Of 7050 patients included in the HCRU analysis, 79.8% had COPDrelated costs; mean cost/patient was $4174. Mean COPD-related costs per patient for moderate and severe exacerbations were $910 and $23,208, respectively. Per-patient costs included $23,032 for inpatient visits, $2358 for emergency visits, $4432 for outpatient visits, and $1989 for pharmacy claims. Conclusion: This observational study is the first to describe the real-world demographic and clinical characteristics and HCRU of patients initiating LAMA/LABA FDC treatment in the USA. Patients were generally elderly and overweight, with comorbidities of CVD, hypertension, and hyperlipidemia. Inpatient visits were the largest contributor to COPD-related costs per patient in the year prior to initiation of LAMA/LABA FDCs.