Medication Adherence in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

Area of Science:

• Endocrinology
• Pharmacology
• Clinical Research

Background:

• Previous reports on differential adherence to diabetes medications showed inconsistencies.
• The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) aimed to clarify these differences.

Purpose of the Study:

• To examine medication adherence in type 2 diabetes patients.
• To evaluate differences in adherence among treatment groups (insulin glargine, glimepiride, liraglutide, sitagliptin).
• To assess the association between adherence and glycemic outcomes.

Main Methods:

• A substudy of 1,739 participants in the GRADE trial was conducted.
• Participants had type 2 diabetes, duration <10 years, HbA1c 6.8%-8.5%, and were on metformin alone.
• Adherence was measured semiannually for 3 years using a validated three-item scale (0-100).

Main Results:

• Overall mean adherence was high (88.7 ± 10.01) and decreased slightly over 3 years.
• Small, statistically significant differences in adherence emerged at 3 years, favoring glimepiride and sitagliptin over liraglutide.
• A 10-point decrease in adherence was linked to increased risk of reaching glycemic targets (HbA1c ≥7.0% or >7.5%).

Conclusions:

• Medication adherence in the GRADE study was consistently high.
• Observed treatment group differences in adherence were minimal and of uncertain clinical significance.
• Lower adherence was a robust predictor of poorer glycemic control, emphasizing the need for ongoing adherence assessment.