Adherence Metrics
| Metric | Formula | Adherent Threshold | Best For |
|---|---|---|---|
| MPR (Medication Possession Ratio) | Days of medication supplied / days in period | >80% | Chronic medications with fixed dosing |
| PDC (Proportion of Days Covered) | Days covered by medication / days in period | >80% | Medications with variable dosing |
| Refill gap | Days between refills vs. expected | <7 days gap | Identifying non-adherence episodes |
Adherence by Condition
Adherence analytics should be conducted for chronic disease medications — diabetes, hypertension, cardiovascular disease, and mental health. These conditions have the highest clinical and financial impact of non-adherence. Identify members with PDC <80% for each condition and target them for adherence outreach.
Adherence and Total Cost
IQ Insight
Medication non-adherence costs the US healthcare system $300 billion annually in preventable hospitalizations and ER visits. For employer plans, improving adherence for chronic disease medications reduces medical costs by 2–5x the cost of the additional medications. Adherence analytics that identifies non-adherent members and triggers proactive outreach is one of the highest-ROI pharmacy management investments.