Glucose-lowering treatment after type 2 diabetes diagnosis differed by race/ethnicity

Initiation of type 2 diabetes medication soon after diagnosis varies significantly by race and ethnicity, according to a recent study.

Researchers used data from a large integrated health care delivery system in California to conduct a cohort study examining racial/ethnic differences in diabetes medication initiation in the year after diagnosis. They estimated the association between race/ethnicity and medication initiation in the entire cohort and within subpopulations defined by HbA1c, body mass index, age at diagnosis, comorbidity, and neighborhood deprivation index (a census tract-level socioeconomic indicator). Eligible patients were categorized into 12 race/ethnicity groups using self-reported data, and early medication initiation was defined as the first dispensing of a diabetes medication (metformin, sulfonylureas, dipeptidyl peptidase-4 inhibitors, thiazolidinediones, meglitinides, alpha-glucosidase inhibitors, sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, or insulin) in the year after diagnosis. The results were published Aug. 4 by the Journal of General Internal Medicine.

A total of 77,199 patients received a new diagnosis of diabetes from 2005 to 2016, and of these, 47% started a diabetes medication within 12 months of diagnosis. Prevalence of medication initiation ranged from 32% in Chinese patients to 58% in patients of other/unknown races and ethnicities. Medication initiation was less likely in Chinese patients (relative risk [RR], 0.78 [95% CI, 0.72 to 0.84]) and Japanese patients (RR, 0.82 [95% CI, 0.75 to 0.90]) versus White patients, but more likely among Hispanic/Latinx (RR, 1.27 [95% CI, 1.24 to 1.30]), African American (RR, 1.14 [95% CI, 1.11 to 1.17]), other Asian (RR, 1.13 [95% CI, 1.08 to 1.18]), South Asian (RR, 1.10 [95% CI, 1.04 to 1.17]), other/unknown (RR, 1.31 [95% CI, 1.24 to 1.39]), American Indian or Alaska Native (RR, 1.11 [95% CI, 1.04 to 1.18]), and Native Hawaiian/Pacific Islander (RR, 1.28 [95% CI, 1.19 to 1.37]) patients. Racial/ethnic differences in prescribing were mitigated overall by higher HbA1c levels at diagnosis, although African American patients with an HbA1c level of 7.5% to 8.9% at diagnosis were less likely to receive medication (RR, 0.95 [95% CI, 0.91 to 0.99]) and American Indian or Alaska Native patients with an HbA1c level of 9% or more at diagnosis were more likely to receive medication (RR, 1.05 [95% CI, 1.04 to 1.05]).

Limitations of the study include the potential lack of generalizability and the grouping of all diabetes medications, among other factors, the authors noted. They pointed out that the overall rates of medication initiation seen in their study were lower than expected based on current treatment guidelines for type 2 diabetes and the known benefits of early drug treatment, especially with metformin. Medication initiation in the year after diagnosis of type 2 diabetes appears to differ significantly by race/ethnicity, they concluded.

“Future research on the post-diagnosis period should identify situations where treatment differences are more likely to occur (e.g., greater clinical uncertainty) and distinguish treatment differences that reflect individualized type 2 diabetes care (e.g., informed by patients' differing needs, risks, and treatment preferences) from those that stem from the need for clinician education (e.g., recent updates to treatment guidelines), provider bias (implicit or explicit), or barriers to patient-provider shared decision-making (e.g., limited health literacy, language discordant providers, lack of provider cultural humility),” the authors wrote. “Such research can contribute to ensuring that glucose-lowering medications are appropriately and equitably offered to all newly diagnosed patients.”