Medication Adherence Claims Analysis Case Study

Client question

A client needed to measure medication adherence across a population for core chronic medication classes. The goal was to create reliable, claims-based adherence measures that could support quality strategy, care management, provider performance review, and market-level benchmarking.

FastHSR built the analysis using Medicare claims and Part D data for a calendar year, creating a consistent measurement period for enrollment, denominator logic, prescription fills, days supply, and adherence outcomes.

Data sources

The analysis combined Medicare claims, Part D prescription drug event data, and enrollment data. Claims helped identify clinical context and eligible populations, while Part D data captured prescription fills, service dates, days supply, drug classes, and refill patterns needed to calculate adherence.

• Medicare claims for clinical context, diagnoses, utilization, and beneficiary history.
• Part D prescription data for fills, days supply, therapeutic class logic, and refill timing.
• Enrollment data for coverage periods and calendar-year eligibility.
• Measure logic implemented across a defined calendar-year measurement window.

Medication adherence measure families

FastHSR programmed adherence measures for three major medication families commonly used in quality and Star Ratings strategy.

• MAD Diabetes: adherence for diabetes medications.
• MAH Hypertension: adherence for hypertension medications.
• MAC Cholesterol: adherence for cholesterol medications.

Calendar-year measurement

The project used a calendar year as the measurement period. A fixed calendar year gave the client a clean analytic frame for member eligibility, denominator construction, prescription fills, days supply accumulation, gap logic, and adherence classification.

Calendar-year measurement also made outputs easier to compare across plans, providers, markets, and population segments because each result used the same time window.

How claims data measures adherence

Medication adherence is not measured by asking whether a patient took a pill every day. At population scale, claims and Part D data are used to estimate whether beneficiaries had enough medication on hand during the measurement period.

• Identify eligible beneficiaries for each medication class.
• Use Part D fills and days supply to build medication possession timelines.
• Account for refill timing and overlapping fills.
• Calculate whether each beneficiary met the adherence threshold for the calendar year.
• Aggregate adherence rates by plan, provider, geography, market, or other analytic segment.

Why population-level analysis matters

Claims data is especially powerful for adherence because it covers large numbers of beneficiaries over time. That scale allows the analysis to identify adherence variation across markets, providers, medication classes, and patient populations while reducing noise from small sample sizes.

Population-level adherence measures can reveal where outreach, pharmacy coordination, formulary strategy, care management, or provider engagement may have the greatest impact.

Deliverables

• Calendar-year medication adherence analytic file.
• Denominator and numerator logic for diabetes, hypertension, and cholesterol adherence.
• Beneficiary-level adherence flags for each eligible medication class.
• Population-level adherence rates by requested analytic segments.
• Documentation of measure logic, eligibility rules, data sources, and calculation methods.

Use cases

• Population health and chronic disease management.
• Medicare Advantage Star Ratings improvement strategy.
• Provider performance evaluation and care-gap targeting.
• Pharmacy, PBM, and formulary strategy.
• Market-level adherence benchmarking.
• Patient segmentation for adherence outreach and intervention design.

Frequently asked questions

Why are Medicare claims and Part D data useful for medication adherence measurement?

Medicare claims and Part D data capture prescription fills, days supply, eligibility, enrollment, diagnoses, and outcomes across large populations, making them well suited for population-level adherence measurement.

Which medication adherence measure families did FastHSR analyze?

FastHSR analyzed adherence for diabetes medications, hypertension medications, and cholesterol medications, often described as MAD diabetes, MAH hypertension, and MAC cholesterol adherence.

Why use a calendar year for medication adherence analysis?

A calendar-year frame creates a clear measurement period for eligibility, fills, days supply, denominator construction, numerator logic, and comparison across plans, providers, markets, or populations.

What can medication adherence claims analytics support?

Medication adherence analytics can support population health strategy, Star Ratings improvement, provider performance evaluation, pharmacy and PBM strategy, care management targeting, and market-level quality benchmarking.

For medication adherence claims analysis, Medicare Part D analytics, quality measurement, or population health benchmarking, please email us.

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