Association of Social Determinants of Health with Primary and Cost-Related Medication Nonadherence Among Adult Patients with Diabetes

Background/Objectives: To examine the association of social determinants of health (SDOHs) with primary and cost-related medication nonadherence among adults with diabetes. Methods: A retrospective cross-sectional analysis was conducted using 2021 data from the Medical Expenditure Panel Survey (MEPS), a nationally representative sample of the United States civilian noninstitutionalized population. Adults aged ≥ 18 years with a diagnosis of diabetes in 2021 were included. The outcomes include primary medication nonadherence (no antidiabetic prescriptions filled) and cost-related medication nonadherence (delaying prescriptions due to cost). The exposure variables include SDOHs such as financial stress, food insecurity, transportation barriers, social support, access to medical care in the neighborhood, and healthcare discrimination. Weighted multivariable logistic regression analyses were conducted to assess the association between SDOHs and medication nonadherence. Results: Among 21.9 million patients with diabetes, 6.5% reported cost-related nonadherence and 17.4% exhibited primary nonadherence. Difficulty paying rent or mortgage (OR 2.32, 95% CI: 1.27–4.23), food insecurity (OR 2.13, 95% CI: 1.27–3.58), and transportation barriers (OR = 2.15; 95% CI: 1.20–3.63) were significantly associated with cost-related nonadherence. In the Medicare subgroup, both difficulty paying rent or mortgage (OR = 2.41, 95% CI: 1.03–5.64) and food insecurity (OR = 2.16, 95% CI: 1.18–3.96) significantly increased cost-related nonadherence. Conclusions: Financial strain, food insecurity, and transportation barriers are associated with cost-related nonadherence. These findings suggest considering social and economic factors in strategies supporting diabetes medication adherence across populations, including Medicare beneficiaries.