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

Abstract

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.