Medication adherence before an increase in antihypertensive therapy: a cohort study using pharmacy claims data

Area of Science:

• Cardiovascular Medicine
• Pharmacology
• Health Services Research

Background:

• Optimal blood pressure control remains a challenge, with less than one-third of hypertensive patients achieving target levels.
• Poor medication adherence is a significant factor contributing to uncontrolled hypertension.
• Understanding adherence patterns is crucial for effective hypertension management.

Purpose of the Study:

• To investigate the hypothesis that patients requiring an intensified antihypertensive regimen exhibit poorer medication adherence compared to those maintained on a stable regimen.
• To analyze the relationship between medication adherence and the need for escalating antihypertensive therapy.

Main Methods:

• A prospective cohort and nested case-control study utilizing health plan enrollment and pharmacy claims data.
• Cumulative medication adherence (CMA) was calculated based on medication availability.
• Interval medication adherence (IMA) assessed adherence in the period preceding regimen intensification.

Main Results:

• The study included 5089 patients, with 18.4% experiencing a regimen increase over a median of 23 months.
• Patients with a regimen increase demonstrated a 12.0% higher CMA (P < 0.001) compared to stable patients.
• No significant difference in IMA was observed before regimen intensification between the increase and control groups (98.3% vs 101.0%).

Conclusions:

• Contrary to the hypothesis, patients requiring intensified antihypertensive therapy showed similar or slightly better medication adherence.
• Poor medication adherence was not found to be a predictor of antihypertensive regimen intensification in this cohort.
• These findings challenge the assumption that non-adherence is the primary driver for escalating hypertension treatment.