Inhaler devices in asthma and COPD--an assessment of inhaler technique and patient preferences.

Background: Incorrect use of inhaler devices remains an obstacle for respiratory diseases management. We aimed to evaluate the frequency of inhaler technique errors; to determine the devices perceived as the easiest and favourite to use; to study the association of device type, demographics and patient preferences with inhaler technique (IT).

Methods: Cross-sectional assessment of 301 adults, with asthma (194) or chronic pulmonary obstructive disease, undergoing treatment with Aerolizer®, Autohaler®, Breezehaler®, Diskus®, Handihaler®, MDI without spacer, Miat-haler®, Novolizer®, Respimat® and/or Turbohaler®. Patients completed self-assessment questionnaires and face-to-face interview, with demonstration of inhaler technique. The rate of wrong steps (number of wrong steps ÷ number of total steps; RWS) was the primary outcome. Adjusted odds ratio (aOR) (95% confidence intervals [CI]) for presenting ≥1 IT errors were computed.

Results: From the 464 inhaler technique performances, the median RWS was 18%. Turbohaler® (21%) and Diskus® (19%) were chosen as easiest and Novolizer® (18%), Diskus® (18%), Turbohaler® (17%) as favourite for daily use. Females (aOR 2.68 [95% CI 1.55-4.65]; vs. males], patients with >64 yr (aOR 2.73 [95% CI 1.15-6.48]; vs <45 yr) and patients using Aerolizer® or Handihaler® (aOR 3.24 [95% CI 1.13-9.32] and aOR 3.71 [95% CI 1.38-10.2], respectively) were more likely to perform IT errors; otherwise, no association was found, including with using the favourite device (aOR 1.43 [95% CI 0.84-2.42]).

Conclusion: The frequency of inhaler technique errors was high and no device was clearly preferred over the others. Using the preferred inhaler device was not associated with less errors.