Study Finds Racial, Gender Disparities in SGLT2 Inhibitor Use

— Drugs prescribed less often to Black, Asian, female, and lower-income type 2 diabetes patients

MedicalToday
A close up of a Black woman’s hands using a glucose meter

Women, Black and Asian people, and those with lower incomes were less likely to receive sodium-glucose cotransporter 2 (SGLT2) inhibitors for their type 2 diabetes, according to a large retrospective study of claims data.

Furthermore, in more than 900,000 U.S. adults with type 2 diabetes, use of SGLT2 inhibitors increased from 3.8% in 2015 to 11.9% in 2019, but remained relatively low, reported researchers led by Lauren Eberly, MD, of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.

Use of this drug class in 2019 was notably lower than average among patients with heart failure with reduced ejection fraction (HFrEF; 7.6%), atherosclerotic cardiovascular disease (ASCVD; 9.8%), and chronic kidney disease (CKD; 7.5%), they noted in .

In multivariable analyses, Black patients were significantly less likely to receive an SGLT2 inhibitor (OR 0.83, 95% CI 0.81-0.85), as were Asian patients (OR 0.94, 95% CI 0.90-0.98), and women (OR 0.84, 95% CI 0.82-0.85).

Patients with a median household income of $100,000 or more, however, were more likely to receive an SGLT2 inhibitor (OR 1.08, 95% CI 1.05-1.10), as were those with incomes of $50,000 or more (OR 1.05, 95% CI 1.03-1.07) compared with those with a median household income less than $50,000.

"To our knowledge, this is the first study to investigate whether there is inequitable access to SGLT2 inhibitor treatment among commercially insured patients with type 2 diabetes in the United States," Eberly's group wrote.

"Despite a well-demonstrated benefit of the SGLT2 inhibitor class of medications and a higher burden of adverse sequelae of type 2 diabetes among Black patients, Black race was independently associated with a lower rate of SGLT2 inhibitor use," they noted. "Although this finding may reflect differences in specialist consultation and decreased access to providers familiar with the clinical benefits of SLGT2 inhibitor treatment, we found that lower rates of SGLT2 inhibitor prescription persisted even after adjustment for visits to cardiology and endocrinology specialists. This result suggests that racism and bias in care delivery may contribute to the findings of this study as well."

Barriers to care have also been documented among women and certain Asian-American subgroups in the U.S., Eberly and colleagues said. Previous research has shown that guideline-directed therapies are adopted more slowly and are under-used among female patients.

"Poorer provider communication may also contribute to gender inequality," they wrote. "Furthermore, for Asian patients who have access to care, provider interactions are more frequently characterized by lower rates of patient-centered care and input regarding treatment decisions, which may explain these results."

The higher cost of SGLT2 inhibitors likely explains the differences in their use by income, the researchers noted. Median retail price for a 30-day supply is approximately $300. Older, more traditionally used therapies such as sulfonylureas can be obtained as part of the $4 generic drug program at some pharmacies, they added.

The lower use of SGLT2 inhibitors among patients with HFrEF, ASCVD, and CKD is less than ideal because of the demonstrated cardioprotective and kidney-protective effects of this class of drugs, Eberly and team said. "Although SGLT2 inhibitor use was not incorporated into American Diabetes Association guidelines until 2019, these results highlight the need for strategies, such as decision pathways, for new guidelines in order to lessen inequities by reducing subjectivity in making the decision to initiate therapy," they wrote.

On a better note, the study found that having a visit with an endocrinologist in the past 12 months was one of the strongest factors positively associated with SGLT2 inhibitor use (OR 2.06, 95% CI 1.99-2.12, P<0.001).

"The demonstrated clinical benefit, dating from 2015, may not yet be common knowledge among many nonspecialist providers who treat patients with diabetes. Strategies to increase the comfort of all providers with prescribing SGLT2 inhibitor therapy will be essential to address inequitable use and ensure improved cardiovascular and kidney outcomes for all patients with type 2 diabetes," the researchers wrote.

Eberly and colleagues analyzed data from the Optum Clinformatics Data Mart database, a large administrative private-payer claims database of inpatient, outpatient, and pharmacy claims for more than 17 million patients with commercial health insurance and Medicare Advantage health plans from all 50 states. Data from Oct. 1, 2015 to June 30, 2019 for 934,737 commercially insured adults with type 2 diabetes were included. Their mean age was 65, half were women, and 57.6% were white.

Limitations to the study included a lack of information on clinical decision-making details, clinical context, physician and patient preferences, and each patient's treatment plan, said the study authors. In addition, although the Optum database included information on patients from all 50 states, the greatest concentration of coverage was in the South and Midwest, which could limit the generalizability of the study's findings, they added. Another factor was that, although all patients had commercial insurance, variations among individual policies (such as copays and drug tiers) could have influenced the study's results.

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    Jeff Minerd is a freelance medical and science writer based in Rochester, NY.

Disclosures

No funding sources were reported for this study.

The authors reported no relevant conflicts of interest.

Primary Source

JAMA Network Open

Eberly LA, et al "Association of race/ethnicity, gender, and socioeconomic status with sodium-glucose cotransporter 2 inhibitor use among patients with diabetes in the US" JAMA Netw Open 2021; DOI: 10.1001/jamanetworkopen.2021.6139.