Medication use of Canadians with chronic obstructive pulmonary disease: a cohort study

ObjectivesThe objectives of this study were to describe medication use, treatment patterns and adherence, as well as acute exacerbations of chronic obstructive pulmonary disease (AECOPD) among adults living with COPD.MethodsA retrospective observational study using administrative data (linked by unique person-level personal health numbers) between 1 April 2007 and 31 March 2018 from Alberta, Canada was performed. Individuals aged ≥35 years who had been living with COPD ≥1 year on 1 April 2017 (index date) were identified. COPD-related medication use was determined on the index date (baseline), and medication use, treatment patterns, adherence and AECOPD were measured during the 1-year postindex observation period; descriptive statistics were applied.ResultsAmong the total cohort (n=192 814), 59% were not using a COPD-related medication at baseline; among those using medication, the most common (>10%) classes were short acting bronchodilators only (29%), dual inhaled corticosteroids/long acting beta2 agonists (ICS/LABA, 27%), combined ICSs/LABA/long acting muscarinic antagonist (ICS/LABA/LAMA, 21%) and LAMA monotherapy (12%). During the observation period, those with baseline COPD medication use had low adherence (42% were adherent (medication possession ratio ≥0.80) to their baseline medication class) and AECOPD were common (13%–40%); 66% of those with ≥1 dispensation for an additional medication class had a step-up in therapy that was concordant with guideline recommendations.ConclusionsIn this population-based study, the majority of individuals identified as living with COPD were not taking any COPD-related medication, while in those who were taking medication, adherence was low, deficits in alignment to guideline-recommended therapy were observed and many had AECOPD. Strategies for earlier identification of undertreatment, consideration of guideline-based knowledge transfer strategies and mechanisms to improve long-term medication adherence may improve outcomes.