The Financial Burden of Prescribed Medications in COPD.

Background: Medication costs are an important component of chronic disease burden. Among individuals with COPD, medication costs have increased consistently over time. Research Question: What excess medication costs are observed among individuals with COPD compared with those without COPD, and what share of these costs is financed privately through out-of-pocket or private insurance? Study Design and Methods: Using administrative health databases from British Columbia, Canada (2001-2020), we created a retrospective cohort of patients with physician-diagnosed COPD matched to individuals without COPD on demographic and socioeconomic characteristics. We estimated excess direct medication costs as the adjusted difference in all-cause medication costs between individuals with and without COPD, using generalized linear models. Primary outcomes included total excess medication costs, privately financed excess medication costs, defined as prescription medication costs minus PharmaCare contributions, and inhaler costs among patients with COPD. Trends were assessed using the average annual percentage change. Costs were reported in 2020 Canadian dollars. Results: The final sample consisted of 207,502 individuals with COPD and 403,941 individuals without COPD (mean baseline age, 68.9 and 68.4 years; 52.4% and 51.3% male, respectively). Average overall excess medication costs were $1,336 (95% CI, 1,321-1,352) per patient-year (PY), of which 40% ($528/PY; 95% CI, $521-$535) were privately financed, and increased more rapidly than PharmaCare-financed spending (average annual percentage change, 8.3% vs 3.8%). Patients with COPD bore one-half of the inhaler costs ($179/PY of $352/PY). Interpretation: Our results show that individuals with COPD have higher all-cause medication costs and a growing private cost burden compared with those without COPD.