T2D Management Among a Community Clinic Patient Sample After California's May 2022 Medicaid Expansion

In May 2022, California expanded its Medicaid program ('Medi-Cal') to all low-income adults over 50 years, regardless of immigration status. We compare haemoglobin A1c (HbA1c) and body mass index (BMI) among undocumented patients with Type 2 diabetes mellitus (T2D) in a primary care setting before and after the expansion.

The study focused on encounters from undocumented and documented patients from two community clinics in Los Angeles County between May 1, 2021 to June 29, 2023 (n = 14 028). The primary outcomes were HbA1c and BMI. We included documented patients to compare to secular T2D trends. We used generalized linear mixed models to estimate the changes in HbA1c and BMI pre/post May 2022 and whether there were differential changes by immigration status. We also stratified by treatment status, as Medi-Cal offered undocumented patients access to newer classes of T2D therapeutics.

Patients' mean age was 61.1 years, 65.1% were female and 80.9% were Latino. Both undocumented and documented patients saw significant declines after the policy. HbA1c declined across all encounters by 0.22 points (95% CI = -0.27, -0.18) and BMI declined by 0.15 points (95% CI = -0.21, -0.10); there were no significant differences by immigration status. Patients on the new medications experienced bigger drops in HbA1c and BMI compared to those who were not on the new medications after the policy was enacted. Again, this did not vary by immigration status.

T2D management improved among both undocumented and documented patients after Medi-Cal expansion. These improvements may reflect access to new classes of T2D medication for all patients.