What SUPD measures
Statin Use in Persons with Diabetes (SUPD) is a Medicare Part D quality measure. It is the percentage of Part D members 40 to 75 years old with diabetes who filled at least one statin medication during the measurement year. The measure is stewarded by the Pharmacy Quality Alliance (PQA) and used by the Centers for Medicare and Medicaid Services (CMS) in the Part D Star Ratings. Higher is better.
SUPD is an appropriate-treatment measure. It checks whether an at-risk patient got a statin at all, not how consistently they took it over the year. That distinction is what separates it from the adherence measures, and it changes how a plan closes the gap.
How SUPD is calculated
SUPD is a ratio of two pharmacy-claims counts. The denominator is every Part D member 40 to 75 with diabetes. The numerator is the members in that group who filled at least one statin during the same year. Divide the numerator by the denominator and you have the plan's SUPD rate.
A member lands in the denominator after at least two fills of a diabetes medication on different dates of service during the measurement year. That two-fill rule is how PQA identifies an established diabetic from pharmacy data rather than a one-time prescription. A member then counts in the numerator after a single statin fill at any point that same year. One statin fill is enough, which is why SUPD is a treatment measure and not an adherence measure.
SUPD vs the adherence (PDC) measures
SUPD and the adherence measures look at the same drugs from different angles. SUPD asks whether a statin was dispensed at least once. The adherence measures, scored by proportion of days covered (PDC), ask whether the member had medication on hand at least 80% of the days they were on therapy. A member can pass one and fail the other, so both matter.
The weighting is also different. SUPD is a process measure weighted 1x. The three triple-weighted Part D adherence measures, diabetes medications, statins, and hypertension medications, are weighted 3x because CMS treats sustained adherence as the higher-value outcome. A plan that fills a statin once but lets the member lapse passes SUPD and still fails the statin adherence measure. Working only one of the two leaves Star points on the table.
Why SUPD is a Star measure
SUPD exists because statins are underused in a population that benefits from them. Major guidelines, including the American Diabetes Association, recommend statin therapy for most adults 40 to 75 with diabetes to lower cardiovascular risk. CMS turned that guideline into a Star measure to push plans to find the diabetic members who are not on a statin and get them treated.
The clinical logic is direct. Diabetes raises cardiovascular risk, statins lower it, and the evidence is strong enough that guidelines treat statin therapy as standard for this age band. A diabetic patient 40 to 75 with no statin fill is a flagged gap in both the chart and the Star score.
How plans close SUPD gaps
Closing an SUPD gap takes two steps: identify diabetic members 40 to 75 with no statin fill, then get a prescriber to write the statin and the patient to fill it. Pharmacy claims surface the gap. The work is the outreach that follows.
That outreach is where SUPD stalls. A coordinator has to reach the prescriber for the new prescription, reach the patient so they actually pick it up, and confirm the fill landed at the pharmacy. Each gap is several calls across three parties, and a list of a few thousand open gaps is more than a small team can chase one by one before the measurement year closes. The gap is easy to see and slow to close, and the slow part is the phone work, not the analytics.
How Pelica handles SUPD
Most platforms show you the SUPD gap list. Pelica closes it. The Pharmacy & Part D copilot works from one live member record, finds the diabetic members 40 to 75 with no statin on file, and its voice AI makes the calls to the patient, the pharmacy, and the prescriber, then follows up until the fill happens. A coordinator steps in only when a case needs a human.
That is the same copilot holding 96 to 98% medication adherence on the triple-weighted measures, so the statin gap and the statin adherence gap get worked together instead of in two separate queues. At HealthCare Partners, the largest IPA in the country, teams cover two to three times more members on one record without adding headcount, with 175,000+ patients managed live. The work that used to sit in a backlog gets done.
Related terms
SUPD sits inside Part D pharmacy quality alongside the adherence measures. See PDC for the proportion-of-days-covered method behind adherence scoring, triple-weighted measures for why the adherence measures count 3x and SUPD counts 1x, and medication adherence for how adherence is defined and why it drives Stars.