1. What is Medication Possession Ratio?

The Medication Possession Ratio (MPR) is a measure of medication adherence that calculates the proportion of days in a treatment period that a patient has possession of their medication. It is commonly used in healthcare to assess patient compliance with prescribed therapies.

2. How Does the Calculator Work?

The calculator uses the MPR equation:

Where:

• \( \text{Days Supply} \) — Total days of medication supplied during the period
• \( \text{Days in Period} \) — Total days in the observation period

Explanation: The equation provides a decimal value between 0 and 1 (often expressed as a percentage) representing the fraction of time the patient had medication available.

3. Importance of MPR Calculation

Details: MPR is crucial for evaluating medication adherence, which directly impacts treatment effectiveness. Higher MPR values indicate better adherence, while lower values may signal the need for intervention.

4. Using the Calculator

Tips: Enter the total days supply (sum of all medication days supplied during the period) and the total days in the observation period. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good MPR value?
A: Typically, MPR ≥0.8 (80%) is considered good adherence, though this may vary by medication and condition.

Q2: How does MPR differ from PDC?
A: While both measure adherence, PDC (Proportion of Days Covered) accounts for overlapping fills and is generally considered more accurate.

Q3: What time period should be used for calculation?
A: Common periods are 30, 90, or 365 days, depending on the medication and purpose of assessment.

Q4: Are there limitations to MPR?
A: MPR can overestimate adherence if patients don't actually take their medication, and doesn't account for early refills or stockpiling.

Q5: Should MPR be used alone to assess adherence?
A: MPR is best used with other measures like patient self-reports or clinical outcomes for a complete picture of adherence.