Patient Characteristics to Consider When Selecting an Inhaler for the Treatment of Chronic Obstructive Pulmonary Disease and Available Assessment Methods: A Narrative Review.

Inhaler misuse is common among patients with chronic obstructive pulmonary disease and associated with poor disease control. Many patient characteristics are reported to impact inhaler use, but there are no studies in the literature on the best way to evaluate them. This narrative review aims to identify patient characteristics that influence the correct use of an inhaler and describe the tools available for their assessment. First, we searched four different databases to identify reviews describing patient characteristics reported to impact inhaler use. In a second step, ways to characterize these aspects were searched using the same databases. Fifteen patient characteristics impacting on the use of inhalers were identified. Peak inspiratory flow, dexterity, and cognitive impairment were the most studied characteristics and appeared to have the highest impact on the correct use of inhalers. Notably, peak inspiratory flow can be reliably assessed in clinical practice using the In-Check Dial®. Triggering coordination, breath retention, collaboration/consciousness, and muscle strength in the fingers were important characteristics, but insufficient data exist to recommend the use of a specific tool for their assessment in daily practice. Other identified characteristics have a more uncertain impact. A demonstration of inhalation technique by the patient, combined with the measurement of peak inspiratory flow using the In-Check Dial®, appears to be an effective strategy to assess the characteristics with the highest impact on the correct use of an inhaler. In the future, "smart" inhalers could also play a decisive role in this area.