Polypharmacy and medication adherence in patients with type 2 diabetes

Area of Science:

• Endocrinology
• Pharmacology
• Public Health

Background:

• Type 2 diabetes management often requires multiple medications.
• Medication adherence is crucial for achieving therapeutic goals.
• Predictors of adherence in community-based diabetes populations require further investigation.

Purpose of the Study:

• To assess medication adherence in a community cohort of patients with type 2 diabetes.
• To identify predictors of suboptimal adherence, particularly concerning the number of prescribed medications.
• To test the hypothesis that adherence decreases with an increasing number of prescribed medicines.

Main Methods:

• A pharmacist-administered questionnaire assessed medication use in 128 randomly selected patients with type 2 diabetes.
• Survey data were linked to electronic medical records for clinical data.
• Self-reported adherence, barriers, attitudes, HbA1c, cholesterol, and blood pressure were evaluated.

Main Results:

• Patients took an average of 4.1 diabetes-related medicines, with high self-reported adherence (6.7/7 days).
• The number of prescribed medicines did not correlate with adherence.
• Adherence was lower for medications perceived as not improving health (6.1 vs. 6.9 days, P < 0.001).
• Side effects were common and often unreported; lack of perceived benefit predicted lower adherence.

Conclusions:

• High medication adherence rates were reported by patients with diabetes, irrespective of the number of prescribed medicines.
• For patients on multiple medications, suboptimal adherence typically involved non-adherence to a single agent.
• Unreported side effects and diminished confidence in medication benefits are key predictors of suboptimal adherence.
• Physicians should be encouraged to prescribe multiple agents for optimal disease control.