Objective: Incorrect inhaler usage is frequent, particularly in elderly asthmatic patients. This study aimed at comparing inhaler technique errors and their determinants, as well inhaler technique self-perception versus real performance, between elderly and non-elderly asthmatics. Methods: Cross-sectional assessment of 92 elderly and 100 non-elderly asthmatics followed at specialty clinics. A standardized questionnaire was applied and inhaler technique demonstration was requested. Errors were assessed using checklists based on manufacturers' instructions and inhaler technique was graded as correct, acceptable or incorrect. Chi-Square Test and Fischer's Exact Test were used for comparative analysis of nominal variables. A p value equal to or less than 0.05 was considered statistically significant. Results: Inhaler technique was correct in a minority of elderly and young patients, without significant differences between study groups. Only 11.1% of the elderly who classified their inhaler as easy and 12.7% who stated their technique was correct had no errors. Previous regular inhaler training was associated with better actual performance in young but not in elderly patients. Conclusion: Our study showed that in spite of regular follow up at specialized outpatient clinics, inhaler devices are associated with a high frequency of errors in elderly and non-elderly asthmatics. In addition, most patients tend to overestimate their technique as correct. Finally, previous, frequent training was associated with a significantly higher percentage of patients showing correct or acceptable technique but only in non-elderly asthmatics, which suggests that elderly asthmatics may need specifically tailored inhaler education programs.
Keywords: Asthma knowledge; determinants; inhaler technique; inhalers; self-perception.