HbA1c Criteria Excludes More Black Than White Participants with Diabetic Macular Edema

Credit: Duke University School of Medicine

HbA1c criteria of 10.0 or less excluded a significantly higher number of Black participants with diabetic macular edema than White participants, according to a new study.¹

Clinical trials often underrepresent minority groups. Julia A. Haller, MD, spoke to HCPLive at the 127th Annual American Academy of Ophthalmology (AAO) conference in San Francisco, California about healthcare disparities in terms of both diabetic macular edema and retinal vein occlusion.²

Another study, presented by Durga S. Borkar, MD, MMCi from the Duke Eye Center at Duke University School of Medicine, also addressed the underrepresentation of minority groups in clinical group, this time focused on hbA1c criteria. The investigators examined how many patients of different races with diabetic macular edema clinical trials were excluded from the study due to the HbA1c criteria, thus exploring the impact of HbA1c thresholds.¹

The investigators used the Optum database to find participants with a new diabetic macular edema diagnosis from January 1, 2002 – June 30, 2022. The team excluded participants if they had < 2 years of “continuous enrollment before the index date” (n = 215,457), previous anti-VEGF treatment or focal laser (n = 54,348), previous diseases that could be confused with diabetic macular edema (such as retinal vein occlusion) (n = 41,260), and no documented race (n =741). In total, this excluded 350,314 individuals. After exclusion, only 12,783 individuals participated in the study.

Of eligible participants, 6864 were White, 2327 were Black, 2904 were Hispanic, and 688 were Asian. The breakdown of HbA1c < 10% for each race was 87.8% White (n = 6024) (P < .001), 81.9% Black (n = 1906) (P <.001), 82.4% Hispanic (n = 2393) (P <.001, and 90.4% Asian (n = 622) (P = .04).

“The impact of restrictive inclusion and exclusion criteria related to disease control is likely understated in this study since only patients with insurance were studied,” the investigators wrote. “Careful evaluation of inclusion and exclusion criteria and their potential differential impact on eligibility of minority populations may be one method to improve diversity in clinical trial populations.”

References

1. ^{Borkar, Durga. Understanding the Impact of HbA1c Thresholds on DME Clinical Trial Eligibility by Race. Presented at the 2023 American Academy of Ophthalmology Annual Meeting, November 3 – 6, 2023.}
2. ^{Derman, C. Julia A. Haller, MD: Disparities in Diabetic Macular Edema, Retinal Vein Occlusion Treatment. 2023. HCPLive. Published November 4, 2023. Accessed November 6, 2023. https://www.hcplive.com/view/julia-a-haller-md-disparities-in-diabetic-macular-edema-retinal-vein-occlusion.}