(B-113) Changes in Initial Maintenance Inhaler Regimens for Canadian Patients with Chronic Obstructive Pulmonary Disease from 2018-2023: A Multi-Province Analysis

Background: Patients with chronic obstructive pulmonary disease (COPD) often experience acute episodes of more severe symptoms (i.e., exacerbations). When used daily, three types of inhalers have been shown to reduce the risk of exacerbations: long-acting beta agonists (LABA), long-acting muscarinic agonists (LAMA), and inhaled corticosteroids (ICS). How choice of initial therapy varies across Canada and how that variation has changed with recent guideline updates is unknown.

Objectives: Describe trends in initial therapy regimens (out of six regimens including LABA, LAMA, LABA/ICS, LABA/LAMA, LAMA/ICS, and LABA/LAMA/ICS) in patients with COPD from 2018 to 2023 across six Canadian provinces (Alberta, AB; British Columbia, BC; Manitoba, MB; Nova Scotia, NS; Ontario, ON; and Saskatchewan, SK).

Methods: We identified patients over the age of 40 in provincial drug claims whose first prescription for a LABA, LAMA, or ICS therapy occurred between 2018 and 2023 with at least 2 years of look-back and a COPD diagnosis in the 2 years prior to dispensing (i.e., the index date). We defined the regimen a patient initially received based on which ingredients were in the inhalers dispensed within 14 days of the index date. Patients in ON were aged 67+ years at study entry and those in NS were accrued as of 2019 due to data availability. We identified the annual percentage of patients initiating each regimen by province and overall.

Results: A total of 112,411 patients were included in the cohort (AB: 27,429; BC: 28,691; MB: 6,661; NS: 7,088; ON: 35,346; SK: 7,196). The four most common initial regimens were LAMA (46% of patients), LABA/ICS (31%), LABA/LAMA (12%), and LABA/LAMA/ICS (9%). Temporal trends in the top four initial treatment regimens varied by province. For example, the percentage of patients initiating with LABA/ICS declined by 2023 in some provinces, especially those where it was a common choice in 2018 or 2019 (BC: 47% to 30%; MB: 52% to 36%; NS: 47% to 27%; SK: 18% to 11%); the percentage did not change over time in the other two provinces (AB: 27% to 27%; ON: 26% to 26%). Meanwhile, the percentage of patients initiating with LAMA regimens increased in several provinces (BC: 28% to 50%; NS: 37% to 53%; SK: 57% to 65%), held steady in others (AB: 54% to 52%; MB: 29% to 27%), and dropped in one (ON: 45% to 36%).

Conclusions: While the choice of first-line pharmacotherapy regimen for patients with COPD changed substantially from 2018 to 2023 in Canada, the nature and extent of the changes varied by province. This suggests that, together with practice guidelines and research, local factors, such as public drug plan coverage may influence choice of initial therapies in COPD.