Oral antidiabetic medication adherence and glycemic control in managed care

Am J Manag Care. 2008 Feb;14(2):71-5.


Objective: To evaluate adherence to oral diabetes medications (ODMs) in patients with type 2 diabetes and the impact of ODM adherence on glycemic control.

Study design: Retrospective observational study.

Methods: Medical and pharmacy claims from a managed care plan in Oregon were used to identify adults with diabetes who newly initiated ODM therapy (n = 2741); a subset of this cohort linked to electronic health records was used to evaluate the relationship between adherence and glycemic control (n = 249). Glycemic control was assessed based on most recent glycosylated hemoglobin (A1C) measurement within the study period.

Results: Mean cohort age was 54 years; 46% initiated therapy with metformin, 39% with a sulfonylurea, and 12% with a thiazolidinedione. Mean adherence overall was 81%, and 65% of subjects had good adherence (>80%). Increasing age and comorbidity burden were associated with higher medication adherence. In the patient subset with A1C measurements, mean baseline A1C was 8%. An inverse relationship existed between ODM adherence and A1C; controlling for baseline A1C and therapy regimen, each 10% increase in ODM adherence was associated with a 0.1% A1C decrease (P = .0004).

Conclusion: Although most patients were adherent to ODM therapy, adherent patients were more likely to achieve glycemic control than nonadherent patients. Greater efforts are needed to facilitate diabetes self-management behaviors to improve patient outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Blood Glucose
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Female
  • Glycated Hemoglobin A
  • Humans
  • Hyperglycemia / drug therapy
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / therapeutic use*
  • Insurance Claim Review
  • Male
  • Metformin / therapeutic use
  • Middle Aged
  • Oregon
  • Patient Compliance*
  • Retrospective Studies
  • Sulfonylurea Compounds / therapeutic use
  • Thiazolidinediones / therapeutic use


  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Sulfonylurea Compounds
  • Thiazolidinediones
  • Metformin
  • 2,4-thiazolidinedione