Factors associated with adherence or nonadherence to insulin therapy among adults with type 2 diabetes mellitus: A scoping review

One of the greatest barriers to the treatment of T2DM is nonadherence which particularly applies to insulin therapy. There is a need for a comprehensive overview of all factors associated with nonadherence to insulin therapy. The aim of this study was to identify factors associated with adherence or nonadherence to insulin therapy among adults with T2DM. A scoping review was conducted in accordance with the PRISMA 2020 statement. A systematic search was performed in PubMed, Cinahl, and Web of Science (January 2013 to March 2023). A final sample of 48 studies was included in the scoping review. The synthesis revealed 30 factors associated with adherence or nonadherence. The factors were grouped into 6 themes: demographics, attitude and perceptions, management of diabetes, impact on daily living, disease and medication, and healthcare system. The most prominent factors identified were age, cost of healthcare, personal beliefs towards insulin therapy, social stigma, patient education, complexity of diabetes treatment, impact of insulin therapy on daily life, and fear of side effects. The results indicate a need for further research to determine threshold values for the factors associated with adherence or nonadherence. •Nonadherence is a critical barrier for insulin therapy.•Numerous factors are associated with nonadherence.•Threshold values for the factors are lacking.•The priority of contradicting factors needs to be established.