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

We examined the impact of various comorbid conditions on diabetes and condition-specific cost-related nonadherence (CRN), and HbA1c in adults with diabetes.

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.

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.

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.