A holistic conceptual framework model to describe medication adherence in and guide interventions in diabetes mellitus.

BACKGROUND: Nonadherence to medications in patients with diabetes, which results in poor treatment outcomes and increased healthcare costs, is commonly reported globally. Factors associated with medication adherence have also been widely studied. However, a clear and comprehensive, disease-specific conceptual framework model that captures all possible factors has not been established.

OBJECTIVE: This study aimed to develop a conceptual framework that addresses the complex network of barriers to medication adherence in patients with diabetes.

METHODS: Fourteen databases and grey literature sources were systematically searched for systematic reviews reporting barriers to medication adherence in patients with diabetes. A thematic approach was used to categorize all identified barriers from the reviews and to create a matrix representing the complex network and relations of the different barriers.

RESULTS: Eighteen systematic reviews were identified and used for the development of the conceptual framework. Overall, six major themes emerged: patient-, medication-, disease-, provider-, system-, and societal-related factors. Each of these themes was further classified into different sub-categories. It was noted that most interactions were identified to be within the patient-related factors, which not only interact with other themes but also within the same theme. Patient's demographics as well as cultural beliefs were the most notable factors in terms of interactions with other categories and themes.

CONCLUSIONS: The intricate network and interaction of factors identified between different themes and within individual themes indicate the complexity of the problem of adherence. This framework will potentially enhance the understanding of the complex relation between different barriers for medication adherence in diabetes and will facilitate design of more effective interventions. Future interventions for enhancing medication adherence should look at the overall factors and target multiple themes of barriers to improve patient outcomes.