Social determinants of health and newer glucose-lowering drugs adoption among US Medicare beneficiaries with type 2 diabetes.

BACKGROUND

Two classes of newer glucose-lowering drugs (GLDs), sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, improve cardiovascular and renal outcomes among patients with type 2 diabetes (T2D). However, racial and ethnic minority groups carry higher cardiovascular risks but have lower access to newer GLDs. Contextual-level social determinants of health (SDOH) may be the underlying factor associated with newer GLD adoption.

OBJECTIVE

To identify the association between contextual-level SDOH and real-world adoption of newer GLDs among Medicare beneficiaries and to examine the nonstationarity in the associations.

METHODS

Data were from 15% random samples of January 2017 to December 2018 nationwide Medicare beneficiaries. We identified patients with T2D who did not use newer GLDs in the year before the index date-January 1, 2018-and followed the cohort for 1 year to record their status of initiating a newer GLD. We used a geographically weighted multivariable Poisson regression model to determine to what extent the SDOH-newer GLD initiation association (β coefficient) varied geographically.

RESULTS

We identified 795,469 eligible Medicare beneficiaries with T2D during the study period from our dataset. Of the study cohort, mean age was 73.1 (SD = 10.5) years, 424,312 (53.3%) were female, 562,994 (70.8%) were non-Hispanic White, 96,891 (12.2%) were non-Hispanic Black, 84,744 (10.6%) were Hispanic, and 29,645 (3.7%) were Asian/Pacific Islander. Newer GLD initiation was negatively associated with the percentage of the population reporting non-Hispanic Black race, Hispanic ethnicity, and unemployment, as revealed by nonspatial regression analyses. The county-level median household income was also associated with higher newer GLD initiation. The spatial analysis presented distinct distributions of local parameter estimates for each contextual-level SDOH.

CONCLUSIONS

We identified key contextual-level SDOH associated with real-world adoption of newer GLDs and explored their geographic variation through spatially explicit, data-driven analytical approaches. Identifying areas of strong association between SDOH and newer GLD initiation is crucial for policymakers to allocate resources and develop interventions that address structural inequities.