Jamie Falk, Natalia Dik, Shawn Bugden

The aim of this study was to evaluate the first initiation, sequence of addition, and appropriate prescribing of COPD medications in Manitoba, Canada. A population-based cohort study of COPD medication use was conducted using administrative health care data (1997-2012). Those aged ≥35 years with COPD based on three or more COPD-related outpatient visits over a rolling 24-month window or at least one COPD-related hospitalization were included. The first medication(s) dispensed on or after the date of COPD diagnosis were determined based on pharmacy claims. The next medication(s) in sequence were determined to be additions or switches to the previous regimen. Evaluation of guideline-based appropriateness to receive inhaled corticosteroids (ICS) was based on exacerbation history and past medication use. Of 13,369 patients dispensed COPD medications after diagnosis, 66.0% were dispensed short-acting bronchodilators as first medications. Although long-acting bronchodilators alone were uncommonly used as first or subsequent medications, ICS were dispensed as first medications in 28.2% of patients. Over the study period, use of short-acting bronchodilators as first medications declined from 70.6% to 59.4% (P<0.0001), whereas the use of ICS as a first medication increased from 23.5% to 34.4% (P<0.0001). Dispensation of an ICS plus a long-acting β-agonist increased dramatically from 1.2% to 27.3% (P<0.0001). By the end of the study period, the majority of patients (53.3%) were being initiated on two or more medications. Of 5,823 patients dispensed an ICS, 52.4% met Canadian guideline criteria for initiating an ICS, whereas 0.3% met Global Initiative for Chronic Obstructive Lung Disease guideline criteria. The use of first-line medications has declined over time, replaced primarily by combination inhalers prescribed early without prior trials of appropriate next step medications. This, along with an increasingly predominant use of multiple first medications, indicates a significant degree of medication burden in this already complex patient population.