title: Association Between Sustained Glycated Hemoglobin Control and Healthcare Costs.
abstract: OBJECTIVE
  To examine the relationship between sustained glycemic control and health care costs among patients with diabetes with an initial hemoglobin A1c≥9%.
  
  
  METHODS
  We conducted a retrospective analysis of administrative data from patients with diabetes and initial poor HbA1c control enrolled in a large health plan in Hawai'i (n=1304). We used propensity scores to identify a comparable cohort based on age, gender, type of coverage, diabetes duration, number of medications, location of residence, comorbidity conditions, and morbidity level. We examined the relationship between reduced A1c values and costs in the same year as well as the impact of achieving sustained A1c control (at < 7%)for three years on changes in health care costs using generalized linear models.
  
  
  RESULTS
  In cross-sectional comparisons, the average annual direct medical costs for patients withHbA1c less than 7% was $14,821 compared to $12,108 for the matched sample of patients with A1c greater than or equal to 7%, for a difference of $2,713 95%CI[$285, $5,140]. In contrast, when we examined the change in cost from 2006 to 2009 for patients who had sustained levels of A1c at <7% for all three years, we found that total cost care for patients with sustained control decreased by $2,207 compared to a $3,006 increase for patients without sustained control, for a difference of -$5,214, 95%CI[-$10,163, -$264].
  
  
  CONCLUSIONS
  Our study suggests that while reducing hemoglobin A1c levels to target goals may not immediately result in cost reductions, sustained A1c control were associated with lower costs in a three-year time frame.
authors.affiliation: College of Pharmacy, University of Hawai'i at Hilo.
authors.forename: Dt
authors.initials: D
authors.lastname: Juarez
authors.affiliation: College of Pharmacy, University of Hawai'i at Hilo.
authors.forename: R
authors.initials: R
authors.lastname: Goo
authors.affiliation: College of Pharmacy, University of Hawai'i at Hilo.
authors.forename: S
authors.initials: S
authors.lastname: Tokumaru
authors.affiliation: Department of Public Health Sciences, John A. Burns School of Medicine, Honolulu, Hawai'i.
authors.forename: T
authors.initials: T
authors.lastname: Sentell
authors.affiliation: Department of Biostatistics & Data Management Core, John A. Burns School of Medicine, Honolulu, Hawai'i.
authors.forename: Jw
authors.initials: J
authors.lastname: Davis
authors.affiliation: Native Hawaiian Health, John A. Burns School of Medicine, Honolulu, Hawai'i.
authors.forename: Mm
authors.initials: M
authors.lastname: Mau
keywords: diabetes mellitus; glycemic control; health care costs; quality of care