BACKGROUND
Mobile health applications show vast potential in supporting patients and health care systems with the globally increasing prevalence and economic costs of non-communicable diseases. However, despite the availability of evidence-based mHealth apps, a substantial proportion of users does not adhere to them as intended and may consequently not receive treatment. Therefore, understanding factors that act as barriers or facilitators to adherence is a fundamental concern to prevent intervention dropouts and increase the effectiveness of digital health interventions.
OBJECTIVE
This review aims to identify intervention- and patient-related factors influencing the continued use of mHealth applications targeting non-communicable diseases (NCDs). We further derive quantified adherence scores for different health domains, which may help stakeholders plan, develop, and evaluate mHealth apps.
METHODS
A comprehensive systematic literature search (January 2007- December 2020) was conducted in MEDLINE, Embase, Web of Science, Scopus, and ACM Digital Library. Data on intended use, actual use, and factors influencing adherence were extracted. Intervention-related and patient-related factors with a positive or negative influence on adherence are presented separately for the health domains NCD-Self-Management, Mental Health, Substance Use, Nutrition, Physical Activity, Weight Loss, Multicomponent Lifestyle Interventions, Mindfulness, and other NCDs. Quantified adherence measures, calculated as the ratio between estimated intended and actual use, were derived for each study and compared with qualitative findings.
RESULTS
The literature search yielded 2862 potentially relevant articles, of which 99 were included as part of the inclusion criteria. Four intervention-related factors indicated positive effects on adherence across all health domains: (1) personalization or tailoring the content of the mHealth app to the individual needs of the user, (2) reminders in the form of individualized push notifications, (3) a user-friendly and technically stable app design, and (4) personal support complementary to the digital intervention. Social and gamification features were also identified as drivers of app adherence across several health domains. A wide variety of patient-related factors like user characteristics or user recruitment channels further affects adherence. Derived adherence scores of included mHealth apps averaged 56.0%.
CONCLUSIONS
This study contributes to the scarce scientific evidence on factors positively or negatively influencing adherence to mHealth apps and is the first to compare adherence relative to the intended use of various health domains quantitatively. As underlying studies mostly have a pilot character with short study durations, research on factors influencing adherence to mHealth apps is still limited. To facilitate future research on mHealth app adherence, researchers should clearly outline and justify the app's intended use, report objective data on actual use relative to the intended use, and ideally, provide long-term usage and retention data.