Abstract 366: Pharmacy Quality Alliance Measure: Adherence to Non-Warfarin Oral Anticoagulant Medication
Authors: Crivera Concetta , Nelson Winnie W , Bookhart Brahim , Martin Silas , Germain Guillaume , Laliberté François , Schein Jeffrey , Lefebvre Patrick 
Published: July 2021

Background:
The Pharmacy Quality Alliance (PQA) has endorsed adherence to non-warfarin anticoagulant agents as a new performance measure, but it has not yet been adopted by the Medicare Part D Star Ratings program. Medication adherence and other pharmacy measures are currently weighted at nearly half of a plan’s Star rating. Two, 3, 4 and 5 Star ratings are based on achievement of adherence threshold levels (e.g. 74%, 79%, 82%, and 85% for oral diabetes medications). Inclusion of the adherence to non-warfarin anticoagulant measure in the Star Ratings program would increase a plan’s incentives to improve patient adherence.

Objective:
To assess the adherence to medication of patients who used the target-specific oral anticoagulants (TSOAC) rivaroxaban, dabigatran, or apixaban in 2013 based on the PQA’s adherence to non-warfarin anticoagulant agent measure.

Methods:
Healthcare claims from the Humana database during the year of 2013 were analyzed. Adult patients with ≥2 dispensings of TSOAC agents in 2013, at least 180 days apart between two TSOAC dispensings in 2013 (a criterion to include chronic users), and with at least 60 days of supply were identified. Patients were observed from the first rivaroxaban, dabigatran, or apixaban dispensing in 2013 up to end of insurance coverage or 12/31/2013. Patients who filled prescriptions for warfarin or other injectable anticoagulants during the follow-up were excluded. The PQA measure was calculated as the percentage of patients who had a proportion of days covered (PDC) ≥80% during the follow-up. PQA measures were evaluated for a) the index TSOAC agent and b) allowing switches to other TSOAC agents (i.e., a patient still counted as using therapy after a switch). Comparisons of PQA measures were made between the rivaroxaban group and each of the other two groups using chi-squared tests.

Results:
A total of 9,948 TSOAC users (rivaroxaban: n=4,194, dabigatran: n=5,489, apixaban: n=265) were identified; mean age was between 75-77 years; 49.7%, 45.7%, and 43.4% were female, respectively. The mean follow-up period was 308, 329, and 247 days for rivaroxaban, dabigatran, and apixaban users, respectively. For rivaroxaban users, the proportion of patients with a PDC ≥0.8 (PQA measure) calculated using the index TSOAC agent at 75.4% was significantly higher compared to dabigatran users (67.6%; P<.001) and trending higher compared to apixaban users (70.6%; P=0.076). When allowing switches to other TSOAC agents in the PQA measure, rivaroxaban users had a significantly higher PQA measure at 76.9% compared to both dabigatran (72.9%; P<.001) and apixaban (71.3%; P=0.037) users.

Conclusion:
Based on the PQA’s adherence to non-warfarin anticoagulant agent measure, rivaroxaban users were found to have a higher adherence compared to dabigatran and apixaban users. Healthcare providers should consider the impact of anticoagulation selection on achieving quality metrics.