Usability of inhaler devices: a parameter currently misused

Area of Science:

• Respiratory Medicine
• Drug Delivery Systems
• Biomedical Engineering

Background:

• Inhalation is a preferred route for respiratory drug delivery, with significant advancements in pocket inhaler technology.
• Despite technological progress, the effectiveness of inhaled therapies remains a challenge due to patient errors and device variability.
• Selecting the optimal inhaler is critical for effective patient outcomes in real-world clinical practice.

Purpose of the Study:

• To highlight the critical role of usability in assessing and comparing pocket inhaler performance.
• To underscore that patient errors and variable inhalation capabilities necessitate a comprehensive usability evaluation.
• To propose usability as a key metric for optimizing current inhalation treatments and guiding future device development.

Main Methods:

• Analysis of critical errors encountered by patients using various inhaler devices.
• Evaluation of patient's ability to inhale effectively across different inhaler classes.
• Discussion of factors contributing to inhaler usability, including patient beliefs, behavior, device engineering, and cost.

Main Results:

• Patients make critical errors with all inhaler types, and inhalation effectiveness varies significantly between devices.
• Usability discrepancies exist even within the same class of inhalers, irrespective of patient awareness.
• Usability is a complex, multidimensional parameter influenced by patient-related, device-related, and economic factors.

Conclusions:

• Usability is the definitive parameter for objectively assessing, comparing, and ranking pocket inhaler performance.
• Addressing usability challenges is essential for optimizing the appropriateness of inhalation therapy.
• Usability assessment should guide the development of innovative and more effective future inhaler devices.