1. What is Proportion of Days Covered (PDC)?

Definition: PDC is a medication adherence measure that calculates the percentage of days a patient has medication available over a specific time period.

Purpose: It helps healthcare providers assess medication adherence for Medicare patients, particularly for chronic conditions.

2. How Does the PDC Calculator Work?

The calculator uses the formula:

Where:

• \( PDC \) — Proportion of days covered (percentage)
• \( DC \) — Days covered (days medication was available)
• \( T \) — Total days in measurement period (days)

Explanation: The days covered is divided by total days to get a ratio, then multiplied by 100 to convert to percentage.

3. Importance of PDC Calculation

Details: PDC is a key metric in Medicare Star Ratings and quality measures. Higher PDC indicates better medication adherence, which leads to improved health outcomes.

4. Using the Calculator

Tips: Enter the days covered (DC) and total days in measurement period (T, default 30 days). DC must be ≤ T and both must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is considered a good PDC score?
A: Generally, PDC ≥ 80% is considered good adherence for most medications.

Q2: How is DC (days covered) determined?
A: DC is calculated based on prescription fill dates and days supply, accounting for overlapping fills.

Q3: What time periods are typically used?
A: Common periods are 30, 90, or 365 days depending on the measurement purpose.

Q4: How does PDC differ from MPR?
A: PDC accounts for overlapping fills (more conservative), while MPR (Medication Possession Ratio) simply sums days supply.

Q5: Why is PDC important for Medicare?
A: Medicare uses PDC to assess quality of care in Part D plans and for Star Ratings calculations.