Impact of Reducing Glycated Hemoglobin on Healthcare Costs Among a Population with Uncontrolled Diabetes.

Introduction: Glycated hemoglobin (A1C) is considered a "gold standard" measure of glycemic control in patients with diabetes and is correlated with a lower risk of diabetes complications and cost savings. This retrospective claims-analysis assessed the impact of A1C reduction on healthcare costs in patients with uncontrolled Type 1 and Type 2 diabetes.

Methods: Using a large repository of US health plan administrative data linked to A1C values, patients with a diabetes diagnosis and at least two A1C values between 1 January 2009 and 31 December 2014 were selected to identify changes in A1C and associated changes in healthcare expenditure. We used all medical and pharmacy claims to calculate direct healthcare costs from 1 year prior to the index A1C to 2 years after the index A1C. A propensity score method was used to match patients with decreased A1C to patients whose A1C did not decrease, based on potentially confounding variables. Then, a generalized linear model regression was used to estimate the difference-in-difference (DD) effect on costs between the two groups.

Results: Of the 3,197 patients who had a first A1C ≥ 9%, 2,273 patients (71%) had a decrease in A1C (Decreasers) and 924 patients (27%) had an increase in A1C (Non-decreasers). After matching, we compared 912 Decreasers to 912 Non-decreasers. Patients in the former group had average annual healthcare costs that were 24% lower during the first year of follow-up and 17% lower during the second year of follow-up, compared to patients whose A1C did not decrease. This reflected a savings of US$2503 and US$1690, respectively. For both time periods, the outpatient category was the largest contributor to cost savings.

Discussion: In our analysis, A1C reduction among patients with T1DM and T2DM was associated with slower growth in healthcare costs within 1-2 years. These findings suggest that programs aimed at reducing A1C over a short timeframe may lead to substantial savings and may be worth pursuing by health plans and other payers.