Usage and usability of one dry powder inhaler compared to other inhalers at therapy start: an open, non-interventional observational study in Poland and Germany.

Introduction: Inhalation is the preferred route of drug administration for patients with asthma or COPD. It is generally predicted that there is a high error rate in inhaler usage, especially at the therapy start. The primary objective of this study was the validation of a questionnaire that can be used for assessing a successful inhalation technique, patient satisfaction as well as the compliance in daily practice.The secondary objective was to examine the "real-life" usage of one inhalation device in comparison with other devices at the start of the therapy.

Material and methods: This open, multi centre and non-interventional study was designed to examine usage and usability of dry powder inhaler Easyhaler® (EH) (Orion Pharma, Finland) and other inhalers assessed by the physicians as well as by the patients. Inclusion criteria for patients were a physician-diagnosis of COPD or asthma or children with asthmatic disease, therapy start with an inhalation device and no or only few experiences with inhaler usage (inhaler usage for not more than 3 months). Each physician enrolled an equal number of patients in each group.

Results: 263 adult/adolescent patients with asthma and 115 with COPD as well as 164 children with asthmatic disease were enrolled. 49.4% of the adult/adolescent patients with asthma used an EH and 50.6% other inhalers. In the case of COPD, 47.8% were treated with an EH and 52.2% used other inhalation devices. Finally, 50.6% of the children with asthmatic disease used an EH and 49.4% were treated with other inhalers. Inhaler usage, patient satisfaction, compliance and patients assessments of usability were better when the patients used an EH. Inconvenient features were mainly documented for other inhalers. The analysis of Cronbachs alpha clearly showed the consistency of the received data from all patients. In addition, there was a large association between the assessment of the inhaler usage and the general assessment of the used inhaler in all patient groups.

Conclusion: The results of this study show that investigators found EH easy to teach, the patients found it easy to use and their satisfaction with the device was high in comparison to other inhalation devices. Thus EH can be matched to many patients already at the therapy start. In addition, the high consistency of the received data and large association of the assessment of the inhaler usage and the general assessment of the inhaler indicate that the used questionnaires were appropriate tools to examine usage and usability of inhaler devices in adult patients and children.