PB0510 - Primary Care Clinician Perceptions and use of Reduced-Dose Direct Oral Anticoagulants for Extended Phase Venous Thromboembolism Treatment

Background: We formerly reported that practice differs among Thrombosis Experts when prescribing the two direct oral anticoagulants (DOACs), apixaban and rivaroxaban, for extended-phase treatment of venous thromboembolism (VTE).

Aims: Here we report primary care clinician practice and characteristics surrounding dose-reduction of DOACs for extended-phase VTE treatment.

Methods: We conducted a 16-question REDCap survey between 04/13/2022 and 01/13/2023 targeting members of the American College of Physicians and US Veteran Administration anticoagulation management services, and online via Twitter™. We performed univariate logistic regression to explore factors associated with dose-reduction. Considering dosing behaviors, we used k-means clustering while maintaining sufficient cluster size. We assessed for clustering of clinicians by characteristics around dose reduction decision-making. Descriptive statistics were used to describe the clusters.

Results: Among the 231 respondents 49.4% were internal medicine/primary care/hospitalists, and 23.9% were primary care pharmacists (Table). 59.3% of respondents dose-reduce DOACs, and the likelihood of dose-reduction raised with number of patients treated. Pharmacists had a higher odds (OR=5.5) and hospitalists had a lower odds (OR=0.9) of electing dose-reduction. We identified 5 clusters that showed distinct patterns of behavior regarding dose-reduction (Figure).
• Cluster 1: Usually/sometimes dose-reduces, always re-escalates dosing for most indications, equally prescribes and equally reduces each DOAC;
• Cluster 2: Never dose-reduces, would always re-escalate dosing, prefers apixaban, and would equally dose-reduce each DOAC;
• Cluster 3: Never dose-reduces, would not temporarily re-escalate, and prefers apixaban;
• Cluster 4: Sometimes/rarely dose-reduces, does not temporarily re-escalate dosing, prefers apixaban, and dose-reduces each DOAC equally;
• Cluster 5: Usually dose-reduces, prefers apixaban, and dose-reduces each DOAC equally.

Conclusion(s): A majority of primary care clinicians dose-reduce DOACs. The likelihood of a clinician to dose-reduce increases with volume of patients treated. Clinician prescribing patterns clustered around frequency of dose-reduction, DOAC preference, and re-escalation during high-risk periods.