Influence of two different inhalation devices on therapy compliance in asthmatic patients.

OBJECTIVE To examine the influence of inhalation device (Autohaler versus metered dose inhaler) and patients' subjective opinion towards the different devices, as well as daily frequency and duration of treatment on medication compliance. DESIGN Prospective study measuring compliance in the same patients of the Autohaler twice daily with the metered dose inhaler twice daily, as well the Autohaler twice daily with the Autohaler four times daily. SETTING Primary health care. SUBJECTS 34 subjects with asthma. MAIN OUTCOME MEASURES Patients preference and compliance. RESULTS Patients preferred the Autohaler. The percentage of patients with a negative opinion towards the metered dose inhaler was 38% compared with 12% towards the Autohaler. The median values of the compliance rate of the Autohaler with twice and four times daily frequency were 90.8% (25-75th percentile 61.6-98.0%) and 78.5% (25-75th percentile 49.0%-91.2%), respectively (p < 0.001). The duration of treatment period had a significant negative influence on compliance when four times daily dosage frequency was prescribed (p = 0.05). CONCLUSION In conclusion, the devices (metered dose inhaler and Autohaler) and the patients' opinion about the devices did not significantly contribute to the compliance rates. Compliance towards the medication treatment, however, is negatively influenced by a high daily frequency.