Factors associated with medication adherence to oral hypoglycaemic agents in different ethnic groups suffering from type 2 diabetes: a systematic literature review and suggestions for further research.

ABSTRACT

AIMS: To synthesize knowledge regarding the different factors that may influence adherence to oral hypoglycaemic agents in different ethnic groups through a systematic review of the literature. METHODS: Thirteen databases were searched and 1201 articles were screened by two authors independently from each other. Different quantitative study designs were included if the study population included at least one ethnic group other than White people, medication adherence was a dependent variable and a clear description was given of the method used to measure medication adherence. RESULTS: Demographic, disease-related and treatment-related, socio-economic and cultural factors were associated with medication adherence in the populations that were studied. However, to synthesize results, the number of studies was too small and the included studies differed too much with respect to their study designs and the ethnic groups that were studied. We discuss several methodological challenges with respect to measuring medication adherence, measuring ethnicity and study designs that need to be resolved to make future studies comparable. We propose methodological improvements for future research. CONCLUSION: Although medication adherence is an essential part of the diabetic regimen, little is known about the association between ethnicity and medication adherence and the underlying factors that could explain this association. More research is needed in which important methodological challenges will have to be faced.