1277-P: Medication Adherence Associated with Better Cardiometabolic Control among American Indians with Type 2 Diabetes

Introduction: Increased medication adherence is expected to be associated with better health outcomes, but the extent to which medication adherence contributes to disparities in cardio-metabolic control (CMC) among American Indians is unknown. Our study purpose was to examine relationships between medication adherence and CMC in American Indians with type 2 diabetes (T2D) who live on Tribal lands with medication at no cost to them.

Methods: From Tribal electronic health record data, we obtained a cross-sectional cohort of 2,938 adults with T2D who were on all three classes of medication (anti-hypertensive, oral glucose- and lipid-lowering) in 2018. Using logistic regression models, we examined the associations between CMC and medication adherence, measured by the proportion of days covered (PDC, range 0-1).

Results: The sample mean ±SD age was 59.6±11.5 years; the majority were male (52%), married (52%), and lived in a rural setting (87%). Medication adherence for patients with a PDC of at least 80% was similar across all drug classes ranging from 63%-68% with an overall PDC of 64%. The mean for each CMC indicator was 135.6±13.2(systolic blood pressure, [SBP]), 7.8±1.6 (HbA1c), and 90.1±31.9(LDL). Higher overall PDC was associated with lower SBP (β=-12.5, p<.001), lower HbA1c levels (β=-1.8, p<.001), and lower LDL levels (β=-45.6; p<.001).

Conclusions: Our sample had higher medication adherence rates, using PDC at an 80% or higher threshold, compared to the typically estimated 40%-50% rates found in settings where medications were not provided at no cost to patients. Even with higher medication adherence rates the sample had above target CMC indicators for SBP (>130) and HbA1c (>7.0).