Values and Preferences Towards Antithrombotic Therapy in Patients with Myeloproliferative Neoplasms: A Qualitative Study

Background: Philadelphia chromosome-negative (Ph-) myeloproliferative neoplasms (MPNs), including polycythemia vera (PV) and essential thrombocythemia (ET), confer a high risk for thrombotic events. The primary and secondary prevention of thrombotic events is managed with antithrombotic therapy, which is complicated by a high frequency of bleeding in Ph- MPN patients. When making shared decisions about antithrombotic therapy, physicians and patients must weigh thrombotic and bleeding risks and their consequences. However, little is known about the preferences and perceptions of patients with MPNs regarding antithrombotic therapy. The objectives of this study were therefore to identify: 1) patient-important factors and 2) barriers and facilitators to the use of antithrombotic therapy as thromboprophylaxis among patients with MPNs.

Methods: In this qualitative study, semi-structured focus groups (FGs) were conducted with people diagnosed with PV and ET recruited via email from Canadian MPN Patient Support Groups. Focus groups were stratified based on previous history of a bleed requiring medical attention, previous history of thrombosis, or no history of bleeding or thrombosis. Open-ended questions and probes were used to guide FG discussions and FGs concluded with a polling exercise in which participants selected the most important facilitators and barriers to antithrombotic medication use. Data were analyzed using thematic analysis and the techniques of the Framework Method (Gale et al., 2013). Two team members independently reviewed and coded FG audio transcripts using NVivo to develop a coding framework. Coding comparison queries were run to assess agreement, discussion was used to resolve discrepancies, and the coding framework was iteratively refined. Data were reviewed by two members of the study team and preliminary themes were identified, guided by the research objectives.

Results: We present preliminary results of our analysis. Four FGs were conducted with a total of 18 participants (range 3-6 participants). The average age of participants was 59 years, 13 (72%) were female and 10 (56%) had ET. Participants were taking aspirin (16/18, 89%), warfarin (1/18, 5%), and apixaban (1/18, 5%). Three participants (17%) had a prior thrombotic event, (ischemic stroke, myocardial infarction, and splanchnic vein thrombosis), and 3 (17%) had a prior bleeding event (epistaxis, gastrointestinal [GI] bleeding).

The most important factors identified for taking antithrombotic therapy were preventing thrombotic events (94%) and a physician's recommendation (83%). Many participants perceived there was no choice when it came to the decision to use antithrombotic therapy; rather it was a physician-prescribed, necessary treatment to prevent thrombosis. Perceived downsides to antithrombotic therapy included the higher risk of bleeding, prolonged bleeding, and bruising, with specific concern about the visibility of bruises. Several participants also voiced concerns about the impact of long-term aspirin use on GI health and the potential for ulcer formation. A few participants reported lowering their dose of aspirin, as per physician recommendations or by self-adjusting the dose based on concerns about GI bleed risk. However, some participants did not perceive any downsides to using antithrombotic therapy or considered that the benefits outweighed the risks, while others were less certain. Additional analyses are underway.

Conclusion: Patients with MPNs accept antithrombotic therapy use, motivated by trust in their physician's recommendations and the desire to prevent a stroke or myocardial infarction. While these values and preferences align with PV and ET treatment guidelines, it is important to recognize the influence that physician recommendations have on patients' perceptions towards antithrombotic therapy in the shared decision-making process.

Hillis:Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; Janssen: Consultancy; Pfizer: Consultancy; Paladin: Consultancy; Sierra Oncology: Research Funding; Novartis: Research Funding; AstraZeneca: Research Funding; Lundeck: Research Funding. Siegal:Roche: Honoraria, Other: paid to research institute; Leo Pharma: Honoraria, Other: paid to research institute; BMS-Pfizer: Honoraria, Other: paid to research institute; Servier: Honoraria, Other: paid to research institute.