Evaluating Inhaled Medication Barriers in Relation to Exacerbations of COPD

Abstract

Background: Inhaled medications improve symptom burden, spirometry values, and reduce frequency and severity of exacerbations in COPD. However, there continues to be critical inhaler errors caused by inadequate inspiratory flows, poor dexterity, and technique to name a few. Furthermore, access and affordability remain an issue for many patients which can cause interruption of scheduled doses or overall self-discontinuance. We aim to evaluate inhaled medication barriers and its relation to exacerbation history in new to COPD clinic patients.

Methods: A retrospective analysis of documentation was performed on 258 new patients seen in the UC Davis Comprehensive COPD Clinic between April 2019 and February 2023. We evaluated peak inspiratory flow (PIF), inhaler technique, and medication affordability as well as symptomology that was assessed and documented by the RT COPD Case Manager at the time of the clinic visit. This review was declared exempt by the UC Davis IRB (#2060632-1). Statistical analysis was performed with Chi-square and student t-test when appropriate.

Results: Of the 258 chart reviews, 156 patients had experienced at least one exacerbation requiring prednisone use in the previous 12-months while 102 patients had not. Fifty-four percent (n = 85) in the exacerbation cohort demonstrated an optimal PIF of 60 L/min with 59% (n = 60) in the non-exacerbated cohort, P = .49. Of the optimal PIF patients, 35% (n = 55) of exacerbators had good inhaler technique compared to 39% (n = 40) with non-exacerbator group, P = .52. Only 24% (n = 37) of the exacerbators with optimal PIF and technique could afford their medications and take them regularly compared to 35% (n = 36) in the non-exacerbation cohort, P = .44. The mean COPD Assessment Test scores in the exacerbation cohort was 22.1 vs. 18 in the non-exacerbation group, P = .34.

Conclusions: There were statistically significant differences between patients who had exacerbations 12-months prior to their clinic visit compared to patients without an exacerbation in that timeframe. This difference occurred in three key factors to medication delivery and adherence: PIF, technique, and affordability. The barriers to benefiting from inhaled medication also showed a statistically significant increase in symptoms in the exacerbation cohort. Thoughtful examination of inhaled regimen selection, continued evaluation of barriers during varying touchpoints, and affordability aspects are necessary to improve symptom and exacerbation outcomes in COPD.