Study Finds Disparities in SGLT-2 Prescriptions for T2D

Patients who are Black or female, as well as those of lower socioeconomic status, are less likely to be prescribed sodium-glucose cotransporter-2 (SGLT-2) inhibitors for type 2 diabetes, pointing to the need for more equitable care, according to a new study.

Overall, although SGLT-2 usage has risen sharply, rates remained lower for patients with type 2 diabetes who had cardiovascular or kidney disease as well—diseases more commonly found in Black and lower-income individuals, according to the study, published in JAMA Network Open.

“Inequitable use of novel pharmacologic agents such as SGLT2 inhibitor agents, a medication class with well-documented cardioprotective and kidney-protective benefit, may contribute to the well-documented racial disparities in cardiovascular and kidney outcomes; barriers to accessing therapy with clinical benefit may contribute to the widening of disparities in cardiovascular outcomes in the US,” wrote the authors of the study, led by University of Pennsylvania researchers.

Between 2015 and 2019, the percentage of patients overall treated with an SGLT-2 inhibitor rose from 3.8% to 11.9%. However, analyses showed that Black patients were considerably less likely to receive the medication (adjusted odds ratio [AOR], 0.83; 95% CI, 0.81-0.85), as were Asian patients (AOR, 0.94; 95% CI, 0.90-0.98). The odds of women receiving the drug were similar to those of Black patients (AOR, 0.84; 95% CI, 0.82-0.85). Furthermore, higher median household income (≥$100,000: AOR, 1.08 [95% CI, 1.05-1.10]; $50,000-$99,999: AOR, 1.05 [95% CI, 1.03-1.07] vs <$50,000) was associated with a higher rate of use.

The rates of prescribing from 2015 to 2019 also rose less than the overall rate for those with heart failure with reduced ejection fraction (HFrEF; 1.9% to 7.6%), when the muscle of the left ventricle pumps 40% or less of the amount of blood the body needs; atherosclerotic cardiovascular disease (ASCVD; 3.0% to 9.8%), and chronic kidney disease (CKD; 2.1% to 7.5%). The lower usage is despite guidelines from the American Diabetes Association and a statement from the American College of Cardiology that patients with diabetes should use SGLT-2 inhibitors regardless of glycemic control if they have or are at risk of cardiovascular disease, heart failure, or CKD.

The study reviewed 934,737 patients with type 2 diabetes in a database of commercially insured patients. It found that 81,007 (8.7%) were treated with an SGLT-2 inhibitor from 2015 to 2019.

The researchers said they undertook the study because of literature showing pervasive inequities by race, gender, and socioeconomic status. Black individuals have a disproportionately higher burden of cardiovascular and advanced kidney disease, with cardiovascular rates of mortality highest among Black patients in the US. The results supported the need for interventions to reduce disparity.

“Barriers to adoption of novel therapeutic agents include decreased access to quality diabetes care and to specialists familiar with the benefits of SGLT2 inhibitor use, structural racism, provider bias that certain groups of patients may be less likely to be adherent to treatment with an expensive agent, and prescription abandonment owing to economic barriers,” the researchers wrote.

Black race was independently associated with a lower rate of SGLT-2 inhibitor use, and in subgroup analyses of patients with ASCVD and CKD, the findings showed. The researchers said the findings may reflect differences in specialist consultation and decreased access to providers familiar with the treatment; however, the lower rates of SGLT-2 inhibitor usage persisted even when adjusting 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,” the researchers wrote.

Inequities were not present in SGLT-2 inhibitor prescription among Latino patients, but the findings did reflect that Asian patients tend to face barriers in accessing care, and that their interactions with providers are more frequently characterized by lower rates of patient-centered care and input regarding treatment decisions, according to the researchers.

Even women with HFrEF, ASCVD, and CKD were less likely to be prescribed SGLT-2 inhibitors. The authors wrote the findings were consistent with those of other studies showing that guideline-directed therapies are initially adopted more slowly and underused among female patients. They also said that poorer provider communication may be a factor.

The authors noted the medications (median retail price of $300 for a 30-day supply; $1097-$1211 annually) are unaffordable to many with lower income, calling for minimizing the cost burden and for providers to be aware of possible bias.

A visit to an endocrinologist in the last 12 months was strongly associated with SGLT-2 inhibitor use, the authors wrote, indicating that the drug might not yet be common knowledge among nonspecialists.

Reference

Eberly LA, Yang L, Eneanya ND, 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;4(4):e216139. doi:10.1001/jamanetworkopen.2021.6139