(106) Real time use of a CFTR modulator tracking report can identify problems with adherence

Background: Cystic Fibrosis transmembrane conductor regulator modulators have revolutionized CF care. However, given the extreme cost of modulators, measures to track adherence and outcomes are needed. Published adherence rates range from about 60 – 90%. Kaiser Permanente Northwest (KPNW) adult and pediatric CF centers developed a modulator tracking report to track adherence. Providers get monthly feedback so we can intervene quickly if problems are identified.

Methods: For all patients on modulator therapies, we track dispense date, date medication on hand will last until, coverage gap, medication possession ratio (MPR), proportion of days covered (PDC), and additional supply of medication on hand. Modulators are always dispensed at our center as a 28-day supply. MPR was calculated as the days dispensed divided by the number of days since the last refill. If a prescription was filled early the MPR would be greater than 100%, and less than 100% if the prescription was filled late. PDC was calculated as sum of days’ supply in a period “covered” divided by the number of days in the same period. A maximum PDC is 100%. Additional supply of medication on hand was calculated based on dispense date and day’s supply. Patients with either poor adherence or excessive supply of medication on hand were flagged. The report is distributed to the CF team monthly with a summary highlighting the patients with potential concerns. A provider then reaches out to these patients to discuss their medication use.

Results: KPNW adult and pediatric CF centers care for a total of 84 patients (56 adults and 25 children). As of March 2022, the majority were taking modulator therapy (n=56, 66%). Almost all (95%) were taking elexacaftor/tezacaftor/ivacaftor (ETI). Average adherence of the entire population has been very good. In the 2021 measurement year, median MPR was 101.4% (IQR = 93.1 – 108.9%) and median PDC was 98.9% (IQR 93.2 – 100%). However, there were outliers with a minimum MPR of 48.4% and maximum of 122%. Some patients accumulated an excess of medication. Examples include two patients who had accumulated 79 and 116 excess days’ supply respectively over an approximately 2-year period. This represented more than $160,000 of excess medication dispensed between these patients alone.

Conclusions: Our KPNW modulator tracking report provides monthly feedback directly to providers and has helped identify both poor adherence and stockpiling. We have found this report to be timelier and provide more actionable data than vendor supplied reports. This has led directly to timely discussions with patients to identify and correct barriers to adherence as well as address reasons for stockpiling. We identified patients who reported taking their medication, but we were able to see refills were delayed. One patient repeatedly reported taking medication regularly despite refill history suggesting otherwise. A sweat test performed was very elevated. After this test, the patient admitted not taking the medication. Another patient had an extreme excess supply. A conversation revealed the patient was worried about potential supply chain issues, so they were ordering a few days early each month. One limitation of our tracking system is that it relies on providers to review each patient’s monthly report. In the future we hope to have a pharmacy team monitor the report regularly. This will hopefully allow us to identify potential concerns earlier.

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