Assessing and Predicting Medication Adherence and Diabetes Control Among African American Adults with Uncontrolled Diabetes

Background/Objectives: Uncontrolled diabetes and associated comorbidities disproportionately affect African American (AA) adults. Medication adherence is key to diabetes control yet is often suboptimal, particularly among AA adults. This study examined associations between patient characteristics and adherence among AA adults with uncontrolled diabetes and compared two medication adherence instruments for predicting diabetes control. Methods: This cross-sectional analysis used baseline data from the Management of Diabetes in Everyday Life (MODEL) study, a clinical trial to improve diabetes self-care among AA adults with uncontrolled diabetes. Internal consistency of the 12-item Adherence to Medication Refills and Medications Scale for diabetes medications (ARMS-D) was evaluated by comparing its Cronbach α to the standardized Cronbach α calculated from MODEL data. Associations with variables were examined using correlations, t-tests, or ANOVA, as appropriate. Stepwise multiple regression identified predictors of diabetes control assessed by hemoglobin A1c (HbA1c). Results: Among 665 participants (mean age = 54 years, HbA1c = 10.24%; 67% female; 73% high health literacy), 75% reported perfect adherence on the Summary of Diabetes Self-Care Activities Medications Subscale (SDSCA-MS) versus 7.3% on ARMS-D. ARMS-D showed strong internal consistency (α = 0.81). Lower adherence by ARMS-D was associated with younger age, higher social complexity, and depression (all p ≤ 0.001). ARMS-D score, age, depression, and insulin, dipeptidyl peptidase 4 inhibitor, and sodium-glucose co-transporter 2 inhibitor use predicted baseline HbA1c. Conclusions: This study demonstrates that younger age, depression, and high social complexity are associated with lower medication adherence measured using the ARMS-D. Adherence gaps identified by ARMS-D may validly predict diabetes control and help guide interventions to improve diabetes care in AA adults with uncontrolled diabetes.