Differences in GLP-1 RA medication adherence across place-based variables in patients with diabetes living in Wisconsin.

BACKGROUND

Glucagon-like peptide-1 receptor agonist (GLP-1 RA) medications are efficacious in improving health outcomes in patients with type 2 diabetes mellitus (T2DM). As demand and costs have increased, questions have arisen around socioeconomic and geographic differences in adherence.

OBJECTIVE

To understand these differences, pharmacy claims data were used to examine medication fills across urban and rural areas and Census tract-level income and racial make-up.

METHODS

Data obtained from the Wisconsin Health Information Organization database included adults (aged ≥18 years) diagnosed with T2DM, with a prescription fill for a GLP-1 RA medication between January 1, 2020, and September 30, 2022. Adherence was defined as proportion of prescription days covered of 80% or greater for 1 year from first fill. Unadjusted and adjusted logistic regression was performed. Adherence was compared across urban and rural residence and Census tract-level median household income quintiles and race (majority Black residents vs nonmajority, majority Hispanic residents vs nonmajority, and majority White residents vs nonmajority). Adjusted models included age, sex, insurance provider, and number of comorbidities.

RESULTS

Patients (N = 7,265) were 56.3% female with a mean age of 55.3 (SD = 12.1) years. Place-based variables showed 38.2% lived in rural areas, 5.8% lived in areas with majority Black population, 2.0% with majority Hispanic population, and 87.9% with majority White population. Overall, 40.1% of patients were adherent 1 year following first prescription fill. Adjusted models showed that patients in tracts with the lowest incomes had lower odds of adherence compared with those living in the highest income tracts (odds ratio [OR] = 0.76; 95% CI = 0.59-0.98). Patients in areas with majority Black residents had lower odds of adherence (OR = 0.67; 95% CI = 0.52-0.85) than areas with less than a majority of Black residents, whereas patients living in areas with majority White residents had higher odds of adherence (OR = 1.31; 95% CI = 1.11-1.56) than areas with less than a majority of White residents.

CONCLUSIONS

This analysis highlights geographic differences in medication adherence in patients with T2DM. Patients living in high-income areas and areas with higher percentages of White residents had higher odds of adherence to GLP-1 RA medications. As demand for GLP-1 RA medications grow, future work that identifies reasons for disparities in adherence and potential strategies to improve adherence is critical.