The Association Between HbA1c and 1-Year Diabetes-Related Medical Costs: A Retrospective Claims Database Analysis

The American Diabetes Association (ADA) has identified a target hemoglobin A1c (HbA1c) < 7% as appropriate for most adults with type 2 diabetes (T2D). This research examines US diabetes-related healthcare costs for adults with T2D for individuals with glycemic control (HbA1c < 7%) compared to poor glycemic control (HbA1c ≥ 7%).

The Optum Clinformatics^® Data Mart database from 2016 to 2020 was used to identify a cohort of adults with T2D who had a recorded HbA1c test (with first such date identified as the index date) and continuous insurance from 1 year prior through 1 year post index date. Patients with glycemic control were propensity matched to patients with poor glycemic control. Generalized linear models and two-part models examined diabetes-related outpatient, drug, acute care, and total costs over the 1-year post-period.

There were 34,538 propensity matched individuals included in the study. Results indicate that glycemic control (HbA1c < 7%), compared to poor glycemic control (HbA1c ≥ 7%) ,was associated with statistically significantly lower annual diabetes-related acute ($5671 ± $4216 vs $6138 ± $4211), outpatient ($6051 ± $4216 vs $7259 ± $7771), drug ($3739 ± $4581 vs $4288 ± $4788), and total costs care ($13,704 ± $10,635 vs $16,460 ± $10,885) (all P < 0.0001). Sensitivity analyses also examined results based upon alternative HbA1c thresholds which were chosen on the basis of expert guidelines and prior clinical trial thresholds (< 6%, ≤ 6.5%, < 8%, and ≤ 9%). In all cases, being below threshold was associated with statistically significantly lower diabetes-related total costs and component costs. Results also illustrate that, in general, higher HbA1c thresholds are associated with higher diabetes-related costs.

Glycemic control was found to be associated with significantly lower annual diabetes-related component and total costs. Results suggest economic benefits associated with having HbA1c at or below target.