Medication Engagement, Determinants of Health, and A1C Levels Among Adults With Type 2 Diabetes Within a Tribal Health System

Purpose: The purpose of this study was to examine the association between determinants of health, medication engagement, and A1C levels in adults with type 2 diabetes (T2DM) receiving Tribal health and pharmacy services.

Methods: A retrospective analysis of 2020-2021 electronic health record data was conducted and included adult patients with T2DM using Choctaw Nation Health Services Authority prescribed ≥1 noninsulin glucose-lowering medication in 2020, had ≥1 A1C value in 2020 and 2021, and had a valid zip code in 2021. Patients receiving both insulin and other noninsulin glucose-lowering medication were included. The proportion of days covered (PDC) was used to calculate medication engagement. Statistical analyses included bivariate analysis and linear regression.

Results: There were 3787 patients included in the analyses; 62.5% were considered engaged (PDC ≥ 0.8). The mean 2020 A1C level was 8.0 (64 mmol/mol) ± 1.8; 33% had an A1C of <7%, 42% had an A1C of 7% to 9%, and 25% had an A1C >9%. The mean A1C in 2021 was 7.9 (63 mmol/mol) ± 1.7; 34% had an A1C of <7%, 44% had an A1C of 7% to 9%, and 22% had an A1C >9%. Older age was weakly correlated with higher engagement; higher engagement was associated with lower A1C levels while adjusting for covariates.

Conclusions: Medication engagement was associated with lower A1C levels, and older age was weakly associated with higher engagement to noninsulin glucose-lowering medications, consistent with previous literature. No determinants of health were significantly associated with A1C levels while adjusting for covariates.