The Association Between Cost-Related Non-Adherence Behaviors and Diabetes Outcomes

Background: We examined the impact of various comorbid conditions on diabetes and condition-specific cost-related nonadherence (CRN), and HbA1c in adults with diabetes. Methods: This was a cross-sectional analysis of participants with diabetes and poor glycemic control in an ongoing trial (n = 600). We computed prevalence of condition-specific CRN, prevalence of specific types of diabetes-related CRN by comorbid condition, prevalence of specific types of condition-specific CRN within each comorbidity, and the association between condition-specific and diabetes-related CRN and HbA1c for each comorbid condition. Results: Fifty-eight percent (n = 350) of participants reported diabetes-related CRN. Diabetes-related CRN rates were highest in those with liver problems (63%), anemia (61%), respiratory diseases (60%), and hyperlipidemia (60%). Condition-specific CRN rates were high in those with respiratory diseases (44%), back pain (41%), and depression (40%). Participants with cancer and kidney diseases reported the lowest rates of diabetes-related and condition-specific CRN. Delaying getting diabetes prescriptions filled was the most commonly reported form of diabetes-related CRN across all comorbid conditions and was the highest in those with liver problems (47%), anemia (46%), and respiratory diseases (45%). In adjusted models, those with back pain (beta-coefficient, 0.45; 95%CI 0.02-0.88; P=.04) and hyperlipidemia (beta-coefficient, 0.50; 95%CI 0.11-0.88; P=.01) who reported both diabetes-related and condition-specific CRN had higher HbA1c. Conclusions: CRN in patients with diabetes is higher than in other comorbid conditions and is associated with poor diabetes control. These findings may be driven by higher out-of-pocket costs for medications to manage diabetes, lack of symptoms associated with poor diabetes control, or other factors, with implications for both clinicians and health insurance programs.