Inhaler Technique Comparison Between Dry Powder Inhaler and Metered Dose Inhaler Among Adults with Obstructive Airway Disease in a Tertiary Government Hospital Outpatient Setting

Abstract

Background: In the management of obstructive airway diseases, inhaled medication remains a cornerstone of therapy. Aside from medication type, the manner of delivery through various devices is important. Evaluating current practice provides a measure of performance and allows identification of areas for improvement. The study evaluated inhaler techniques of patients on dry powder inhalers (DPI) versus metered dose inhalers (MDI) at the outpatient setting. The prevalence of specific inhaler technique errors was assessed along with associated factors.

Methodology: This study was conducted with a cross-sectional design, involving patients with use of DPI and/or MDI for the past six months. Inhaler technique was evaluated and a short instruction on proper technique was provided with repeat evaluation immediately after.

Results: A total of 124 participants were assessed, resulting in 76 DPI and 52 MDI technique observations. Overall, a higher prevalence of any error was observed for DPI at 88.2% versus MDI at 86.5%. Immediately post-instruction, repeat assessment showed significant improvement, with reduction of any error to 57.9% (DPI) and 50% (MDI) (p <0.001 for both). The most common DPI errors were failure to perform full exhalation prior (77.6%) and lack of sufficient breath holding after (44.7%). The most common MDI errors were failure to perform full exhalation prior (71.2%) and improper inhalation (53.8%). For MDI users, only advanced age had an association with having any error (OR 1.10, CI 1.03-1.17).

Conclusion: Inhaler technique errors remain high in the outpatient setting regardless of device, with older participants at risk of having errors with MDI, but not with DPI. Although technique review and instruction show promise in reducing errors, the durability of these skills is known to decay. Appropriate patient and device selection, along with regular technique assessment and reinforcement by healthcare professionals, remains the recommended practice to maximize the benefit of inhalers.