ObjectiveManagement of chronic obstructive pulmonary disease (COPD) with inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) improves lung function and health status and reduces COPD exacerbation risk versus monotherapy. This study described treatment use, healthcare resource utilisation (HCRU), healthcare costs and outcomes following initiation of single-device ICS/LABA as initial maintenance therapy (IMT).DesignRetrospective cohort study.SettingPrimary care, England.Data sourcesLinked data from the Clinical Practice Research Datalink Aurum and Hospital Episode Statistics datasets.ParticipantsPatients with COPD and ≥1 single-device ICS/LABA prescription between July 2015 and December 2018 were included.Primary and secondary outcome measuresTreatment pathways, COPD-related HCRU and healthcare costs, COPD exacerbations, time to triple therapy, medication adherence (proportion of days covered ≥80%) and indexed treatment time to discontinuation. Data for patients without prior maintenance therapy history (IMT users) and non-triple users were assessed over a 12-month follow-up period.ResultsOf 13 451 new ICS/LABA users, 5162 were IMT users (budesonide/formoterol, n=1056; beclomethasone dipropionate/formoterol, n=2427; other ICS/LABA, n=1679), for whom at 3 and 12 months post-index, 45.6% and 39.4% were still receiving any ICS/LABA. At >6 to ≤12 months, the proportion of IMT users with ≥1 outpatient visit (10.1%) and proportion with ≥1 inpatient stay (12.6%) had increased from those at 3 months (9.0% and 7.4%, respectively). Inpatient stays contributed most to total COPD-related healthcare costs. For non-triple IMT users, at 3 and 12 months post-index, 4.5% and 13.7% had ≥1 moderate-to-severe COPD exacerbation. Time to triple therapy initiation and time to discontinuation of index medication ranged from 45.9 to 50.2 months and 2.3 to 2.8 months between treatments. Adherence was low across all time points (21.5–27.6%). Results were similar across indexed therapies.ConclusionsIn the year following treatment initiation, ICS/LABA adherence was poor and many patients discontinued or switched therapies, suggesting that more consideration and optimisation of treatment is required in England for patients initiating single-device ICS/LABA therapy.