Trends in prescriptions and costs of inhaled medications in chronic obstructive pulmonary disease: a 19-year population-based study from Canada.

Background: The patterns of medication use in chronic obstructive pulmonary disease (COPD) may change over time due to the availability of new medications, updates in guideline-based recommendations, and changes in patient and care provider preferences. Objectives: To document population-level trends of filled prescriptions and costs for major classes of inhaled COPD therapies. Method: We used administrative health databases of the province of British Columbia, Canada, from 1997 to 2015, to create a retrospective cohort of COPD patients. We documented the percentage of patients receiving major inhaled COPD-related medications, including short-acting beta-2 adrenoreceptor agonists (SABA), long-acting beta-2 adrenoreceptor agonists (LABA), inhaled corticosteroids (ICS), short-acting muscarinic receptor antagonists (SAMA), and long-acting muscarinic receptor antagonists (LAMA). We quantified the average, and relative annual change in, dispensed quantities and costs (in 2015 Canadian dollars [$]) of medications. Combination therapy was assessed as the proportion of time covered by two or more long-acting medications of different classes. Results: A total of 176,338 patients were included in the final cohort (mean age at entry 68.7, 48.5% female). In 2015, the most common medication was ICS (45.7% of the patients), followed by LABA (36.5%). LAMA was the least used medication (18.9%). The number of filled prescriptions per patient per year for LAMA (+7.8% per year) and LABA (+4.9%) increased, while they decreased for SAMA (-6.3%) and SABA (-3.8%), and remained relatively constant for ICS. The average annual per-patient costs of inhaled medications were $570.8 in 2015, which was double the costs from 1997. Single-inhaler ICS/LABA had the highest rate of increase (11.6% per year), and comprised 53.7% of the total costs of inhalers in 2015. In 2015, 28.5% of the patient time was on combination therapies, with 7.1% on triple ICS/LABA/LAMA therapy. Conclusion: Utilization of inhaled therapies for COPD has changed significantly over time. The low utilization of LAMA and high utilization of combination therapies (particularly those containing ICS) do not seem to be aligned with COPD treatment guidelines.