Differences in Adherence Barriers to Inhaled Medicines between Japanese Patients with Chronic Obstructive Pulmonary Disease and Asthma Evaluated using the "Adherence Starts with Knowledge 20" (ASK-20) Questionnaire.

Objective This multicenter, cross-sectional, non-interventional trial aimed to investigate adherence barriers to inhaled medicines when compared with oral medicines in Japanese patients with chronic obstructive pulmonary disease (COPD) and asthma. Methods The self-reporting "Adherence Starts with Knowledge 20" (ASK-20) questionnaire was administered for adherence barriers of inhaled and oral medicines to outpatients with regular clinic attendance. Results Patients with COPD and asthma reported different adherence barriers to inhaled medicines. Independent adherence barriers [odds ratio (95% confidence interval)] to inhaled medicines relative to those for oral medicines among patients with COPD and asthma were those related to item Q8 [ "I know if I am reaching my health goals"; 2.49 (1.39-4.47); p=0.0022] and item Q2 [ "I run out of my medicine because I do not get refills on time"; 2.69 (1.26-5.75); p=0.0127], respectively. Among patients with poor adherence to only inhaled medicines, those with COPD and asthma recognized item Q3 [ "consuming alcohol and taking medicines"; 6.63 (1.27-34.7); p<0.05] and item Q1 [ "forget to take medicines only sometimes"; 4.29 (1.83-10.0); p<0.05], respectively, were recognized as independent adherence barriers to inhaled medicines. The total ASK-20 scores and total barrier counts in patients with poor adherence to inhaled medicines were significantly higher than in those without poor adherence among patients with asthma (p=0.0057) but not those with COPD (p>0.05). Conclusion These results will aid in personalizing education on adherence to inhaled medicines among patients with COPD and asthma.