Association between diabetes patients' knowledge about medications and their blood glucose control

Background: Diabetes mellitus is a common chronic disorder frequently resulting in hyperglycemia and numerous long-term complications. Research has shown that improved glycemic control reduces the rate and number of diabetes-related complications. Evidence suggests that patients who are more knowledgeable about diabetes self-care may be more likely to achieve better glycemic control. Objective: The purpose of this study is to determine the relationship between patients' knowledge about their diabetes medications and their blood glucose control. Methods: Patients receiving oral pharmacologic treatment for type 2 diabetes mellitus were asked to answer a short questionnaire assessing their knowledge about their medications. Patients were part of an ambulatory care practice in Baltimore, Maryland, that provides primary care medical services to an inner-city, predominantly African American population. A medication knowledge score (number of correct responses to 8 components) was tabulated and correlated to the most recent glycosylated hemoglobin (A1c) (drawn within the previous 90 days). Multivariate models were constructed, with A1c as the outcome and patients' medication knowledge as the independent variable. Potential confounders included in the models were age, sex, education level, number of diabetes medications, and insurance status. Results: Fifty patients were screened for the study; 44 agreed to participate and met inclusion criteria. Patients' diabetes medication knowledge scores ranged between 1 and 7, with a median score of 5. Older patients (65 years and older) and male patients scored lower than their counterparts. There was a strong inverse association between knowledge score and A1c (r = -0.61; P < .001). Glycosylated hemoglobin was one-half unit lower with each one-unit increase in knowledge score among men; among women A1c was 1.6 units lower for each one-unit increase in knowledge score. Conclusion: Patients with greater understanding and knowledge of their diabetes medications demonstrated better glycemic control. This cross-sectional association of medication knowledge and A1c was more pronounced in women than in men. (c) 2008 Elsevier Inc. All rights reserved.