Adherence to statins in primary prevention: yearly adherence changes and outcomes

Area of Science:

• Cardiology
• Pharmacology
• Public Health

Background:

• Real-world statin adherence is suboptimal.
• Changes in adherence over time and their link to cardiovascular (CV) outcomes require further investigation.

Purpose of the Study:

• To analyze yearly adherence changes in primary prevention statin users.
• To determine the association between adherence shifts and subsequent CV event risk.

Main Methods:

• Utilized a 10% random sample from a large health plan claims database (1997-2008).
• Assessed adherence using proportion of days covered (PDC) in yearly segments.
• Employed Cox-proportional hazards models to evaluate CV event risk linked to adherence transitions.

Main Results:

• Among patients starting with PDC ≥ 0.80, adherence often decreased over subsequent years.
• Transitioning to PDC < 0.20 in year 2 showed a 2.26-fold increase in CV event hazard.
• Low adherence (PDC < 0.80) in year 3 was associated with a 271% rise in CV hazard compared to high adherence.

Conclusions:

• Statin adherence tends to decrease over time.
• Reduced adherence (PDC < 80%) is linked to a higher risk of cardiovascular events.
• Findings support targeted interventions to improve patient adherence.