Does Health Literacy Have an Impact on Adherence to Diabetes Mellitus Treatment?

(1) Background: Health literacy is the intersection of general literacy, health, and healthcare, but it can also incorporate elements of other types of literacies to varying degrees. The notion of literacy surfaced from the fear that individuals would require more than general literacy skills to manage the complexities of health and health system issues. There is a substantial overlap between general literacy and health literacy. Diabetes patients frequently misinterpret medication instructions, resulting in non-adherence and poor health outcomes. (2) Aim: This study sought to review the literature on the impacts of health literacy on adherence and compliance to diabetes mellitus treatment. (3) Methods: A Narrative Literature Review method was used to identify, analyze, assess, and interpret the available information on health literacy regarding prescribed medication instructions. The following databases and search engines were used to locate the literature: electronic databases, search engines, and hand searches. Fifty-three (53) quantitative and qualitative studies and two books were reviewed. (4) Result: The review pointed out the following: the importance of health literacy, the implications of health illiteracy versus medication non-adherence, factors influencing health literacy versus medication adherence, and the interventions to improve medication non-adherence. (5) Conclusion: Relatively few studies have been conducted on how people living with diabetes should carry out their treatment. Therefore, more research on how people living with diabetes carry out their treatment daily is required. (6) Contributions: This study has identified that health literacy plays a role in adherence to treatment and contributes to improved health outcomes.