Continuous Glucose Monitoring and Hemoglobin A1c in Young Marginalized Patients

Equitable access to continuous glucose monitoring (CGM) can help alleviate the hemoglobin A_1c disparities found between patients with type 1 diabetes mellitus (T1DM) who are vs are not Hispanic and who are publicly vs privately insured, according to research published in JAMA Network Open.

Researchers aimed to analyze hemoglobin A_1c (HbA_1c) trajectories stratified by ethnicity and insurance in an effort to evaluate the effect social and payer-related restrictions on health outcomes.

The researchers enrolled participants into a clinical research pilot program, termed Teamwork, Targets, Technology and Tight Control (4T), which initiated CGM using the Dexcom G6 system (Dexcom) within 1 month of diagnosis. Patients aged younger than 18 years with T1DM were enrolled between July 25, 2018, and June 15, 2020. Participants also received weekly insulin dose change recommendations by certified diabetes care and education specialists, sent via MyChart electronic medical system.

Participant race was self reported, and insurance type (public vs private) was determined by electronic medical record.

The primary outcome was change in HbA_1c from 4 months to 12 months postdiagnosis. Secondary outcomes included participants who met target HbA_1c levels of less than 7.5% or 7.0%, according to the American Diabetes Association guidelines and data analysis, respectively.

A historical cohort of 272 patients was compared to the Pilot-4T cohort. The median age of the historical cohort was 9.7 years, mean HbA_1c at diagnosis was 10.7%, and there was 56.2% CGM use within 30 days or less of diagnosis.

A total of 135 patients (52.6% boys and 47.4% girls) were evaluated in the Pilot-4T cohort study. Of these patients, 77.0% had private insurance and 23.0% had public insurance. Self reported ethnicity included 21.5% Hispanic patients and 68.1% non-Hispanic patients. Average HbA_1c at diagnosis was 12.2%, with a median CGM initiation of 7 days (range 5-11 days).

Overall, compared with the historical cohort, Pilot-4T participants had improvements in HbA_1c, regardless of ethnicity or insurance.

For Hispanic patients, HbA_1c was lower at 6, 9, and 12 months in the Pilot-4T cohort compared with the historical cohort (estimated differences, -0.26% [95% CI, -1.05% to 0.43%], -0.60% [95% CI, -1.46% to 0.21%], and -0.15% [95% CI, -1.48% to 0.80%], respectively).

Patients with public insurance in the Pilot-4T cohort followed similar trends at 6, 9, and 12 months (estimated difference, -0.52% [95% CI, -1.22% to 0.15%], -0.38% [95% CI, -1.26% to 0.33%], and -0.57% [95% CI, -2.08% to 0.74%]). Patients with private insurance also had similar results at 6, 9, and 12 months (estimated difference, -0.34% [95% CI, -0.67% to 0.03%], -0.57% [95% CI, -0.85% to -0.26%], and -0.43% [95% CI, -0.85% to 0.01%]).

Lower HbA_1c at diagnosis and higher HbA_1c at 6, 9, and 12 months postdiagnosis were observed for Hispanic patients compared with non-Hispanic patients (estimated difference, 0.28% [95% CI, -0.46% to 0.86%], 0.63% [95% CI, 0.02% to 1.20%], and 1.39% [95% CI, 0.37% to 1.96%]) and for patients that had public vs private insurance (estimated difference, 0.39% [95% CI, -0.23% to 0.99%], 0.95% [95% CI, 0.28% to 1.45%], and 1.16% [95% CI, -0.09% to 2.13%]).

A greater proportion of patients in the Pilot-4T cohort achieved a HbA_1c target of less than 7.0% at 12 months postdiagnosis more frequently (Hispanic vs non-Hispanic ethnicity: 47.0% vs 54.0%; public vs private insurance: 47.0% vs 57.0%) compared with historical subgroups (Hispanic vs non-Hispanic ethnicity: 24.0% vs 30.0%; public vs private insurance: 19.0% vs 30.0%).

Limitations of the study include the sample size and lack of individuals who identify as non-Hispanic Black, which limits generalizability.

“The findings of this cohort study suggest that universal access to CGM at diabetes diagnosis was associated with an improvement in HbA_1c for all participants independent of ethnicity and insurance status but not with elimination of disparities in our Pilot-4T cohort,” the study authors wrote. “Payers, clinicians, and technology developers should strive to address these gaps in diabetes technology access and to better identify and address drivers of disparities in HbA_1c outcomes.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.