Internationally, adult asthma medication adherence rates are low. Studies characterizing variations in barriers by country are lacking.
Conduct a scoping review to characterize international variations in barriers to asthma medication adherence among adults.
Searched MEDLINE, EMBASE, WOS, and CINAHL from inception to February 2017. Selected English-language studies employing qualitative methods (e.g., focus groups, interviews) to assess adult patient and/or caregiver-reported barriers to asthma medication adherence. Two investigators independently identified, extracted data, and collected study characteristics, methodologic approach, and barriers. Mapped barriers using Theoretical Domains Framework and categorized findings according to participant’s country of residence, countries’ gross national income and presence of universal health care (World Health Organization definitions).
Among 2,942 unique abstracts, we reviewed 809 full-texts. Among these, we identified N=47 studies, conducted in 12 countries, meeting eligibility. Studies included a total of n=2,614 subjects, predominately female (67%), and mean age 19.1 to 70 years. Most commonly reported barriers were beliefs about consequences (e.g., medications not needed for asthma control, N=29, 61.7%) and knowledge (e.g., not knowing when to take medication, N=27, 57.4%); least common was goals (e.g., asthma not a priority, N=1, 2.1%). In N=27 studies conducted in countries classified as high income (HIC) with universal health care (UHC), the most reported barrier was participants’ beliefs about consequences (N=17, 63.3%). However, environmental context and resources (N=12, 66.7%) were more common in HIC without UHC.
International adherence barriers are diverse and may vary with a country’s sociopolitical context. Future adherence interventions should account for trends.

Copyright © 2020. Published by Elsevier Inc.