Measuring medication adherence.

Area of Science:

• Health Services Research
• Pharmaceutical Outcomes
• Healthcare Management

Background:

• Poor medication adherence significantly increases illness severity, mortality, and healthcare expenses.
• A lack of standardized, practical measurement tools for medication adherence hinders effective health management.
• The Care Continuum Alliance (CCA) convened a clinical workgroup to address this measurement gap.

Purpose of the Study:

• To develop and standardize a methodology for measuring medication adherence rates.
• To establish a practical and comprehensive approach to assessing adherence in diverse populations.
• To validate the developed methodology through real-world testing and data analysis.

Main Methods:

• A clinical workgroup reviewed literature, incorporated expertise, and reached consensus on measurement techniques.
• The medication possession ratio (MPR) was selected as the standardized metric for measuring medication adherence.
• Accordant Health Services tested the MPR methodology using 2007 data from health plan and employer group populations.

Main Results:

• Condition-specific MPRs for health plan populations ranged from 78.9% to 83.6%.
• Condition-specific MPRs for employer group populations ranged from 75.4% to 76.5%.
• Results demonstrated the feasibility and reliability of the MPR methodology within the 95% confidence interval.

Conclusions:

• A standardized MPR methodology provides a practical tool for measuring medication adherence.
• This standardized approach can support improved health management and potentially reduce healthcare costs.
• The developed guidelines were approved for inclusion in the CCA's Outcomes Guidelines Report.