Adherence to study drug in a stroke prevention trial"?>

Area of Science:

• Clinical Trials
• Neurology
• Pharmacology

Background:

• Recent advancements in international consensus have improved standards for reporting and analyzing medical therapy adherence.
• Applying these standards to stroke clinical trials can identify critical points for intervention to maintain patient adherence.

Purpose of the Study:

• To analyze adherence to study medication in patients participating in the Insulin Resistance Intervention after Stroke (IRIS) trial.
• To identify specific phases of non-adherence (initiation, implementation, persistence) and factors influencing them within a stroke prevention trial.

Main Methods:

• Utilized the European Society for Patient Adherence, COMpliance, and Persistence (ESPACOMP) Medication Adherence Reporting Guideline (EMERGE) taxonomy.
• Classified adherence into initiation, implementation (drug holidays ≥14 days), and persistence (premature/permanent discontinuation) based on self-report.
• Employed coaching algorithms to address non-adherence during the IRIS randomized, placebo-controlled trial of pioglitazone.

Main Results:

• Less than 1% of participants failed to initiate study drug.
• 20% on pioglitazone and 17% on placebo took drug holidays; 36% and 30% discontinued prematurely, respectively.
• The risk of discontinuation was highest in the first year post-randomization, influenced by pioglitazone's adverse effects, with rates becoming similar between groups in subsequent years.

Conclusions:

• Stroke trial participants face the highest risk of premature drug discontinuation early in the trial.
• Reasons for discontinuation evolve throughout the trial, with early discontinuations often linked to adverse effects.
• Significant site-to-site variation in discontinuation rates suggests that implementing best practices from high-performing sites can enhance adherence.