Limitation of the effectiveness of inhalation training in patients with asthma and COPD

Knowledge of factors impacting the effectiveness of training of correct inhalation technique could increase the effectiveness of inhalation technique.

The aim of the study was to assess the effectiveness of inhalation technique training and to identify factors impacting the effectiveness of training.

This single centre, interventional, non-randomized study involved 180 adult patients with asthma or COPD. Inhalation technique was evaluated using a checklist of common errors and peak inspiratory flow (PIF). Patients who made any mistakes during inhalation were trained. We searched for factors which may have impacted the effectiveness of inhalation training.

A total of 115 asthma and 65 COPD patients were analyzed. In 140 patients using either metered-dose inhalers (MDI) or soft mist inhalers (SMI; SMI users were grouped with MDI users for analysis), only 9 patients (6.4 %) used inhalers correctly, for dry-powder inhalers (DPI) only 31 (28.2 %). The training of inhalation technique was successful in 112/131 MDI users (85.5 %) and 67/79 DPI users (84.8 %). Among MDI users, patients who achieved short term improvement in inhalation technique were more likely to have asthma (68.8 % vs. 42.1 %, p = 0.047), be non-smokers (33 % vs 5.3 %, p = 0.039) and younger (64 vs. 66 years, p = 0.028) vs. patients without improvement; respectively among DPI users: cognitive disorders were less often found (0 % vs. 16.7 %, p = 0.018), patients more often read drug leaflets (80.6 % vs 50 %, p = 0.022) and had good self-esteem of inhalation skills (97 % vs. 75 %, p = 0.025).

Training in inhalation leads to short term improvement of inhalation technique for most trainees. As different factors are important for efficacy of training in inhalation skills for MDI and DPI, an individual approach for training is important.