PB0032 - Patient self-management for managing warfarin in patients with non-valvular atrial fibrillation in the US: A threshold analysis of cost-effectiveness analysis

Background: Patient self-management (PSM) is a warfarin management strategy where patients adjust their warfarin dose independently of direct clinician oversight. Evidence-based guidelines recommend PSM over other monitoring strategies, including anticoagulation management services (AMS) due to fewer thrombosis events without increasing bleeding risk and lower cost.

Aims: This study estimated the threshold of relative efficacy, safety, and cost where AMS would be the preferred strategy compared to PSM in patients with non-valvular atrial fibrillation (NVAF) in the US from a societal perspective.

Methods: A Markov model was utilized to estimate costs and outcomes over a patient’s lifetime. The model simulated a cohort of 70-year-old patients with NVAF over their lifetime. Stakeholder engagement was performed to discuss and adjust the analysis plan. Transition probabilities were derived from patient-level data from the University of Utah health system electronic medical records. Comparative efficacy and safety among the interventions were obtained from a network meta-analysis. Costs and utility data were acquired from data sources in the US. All costs were adjusted to 2022 US dollars. A discount rate of 3% was applied for future costs and outcomes.

Results: The base-case simulation demonstrated that PSM is dominant (i.e., lower cost, more effective) compared to AMS. From a cost-effectiveness perspective, AMS would be the preferred option if (1) the relative risk of developing stroke with PSM was 1.83 times higher (from 0.53 to 0.97) or (2) the relative risk of developing major bleeding with PSM was 201 times higher (from 0.95 to 191), or (3) stroke-related costs were 64.82% lower.

Conclusion(s): PSM is a dominant strategy for managing warfarin in patients with NVAF, compared with AMS. Cost neutralization would require a dramatic worsening of outcomes with PSM or a significant reduction of stroke-related costs. PSM should be considered in the US health settings.