An Economic Model Exploring the Impact of Formulary Restrictions on the Incidence and Cost of Clinical Events in Patients with Non-Valvular Atrial Fibrillation Receiving Direct Oral Anticoagulants in the United States
Author(s)
Rupesh Subash, BSc, MSc1, Elisabeth Vodicka, MHA, PhD2, Serina Deeba, MPH2, Vasileios Vasilopoulos, MSc3, Carissa Dickerson, PhD3, Ewa Stawowczyk, PhD3;
1Pfizer Ltd., Walton Oaks, Surrey, United Kingdom, 2Pfizer Inc., New York, NY, USA, 3Health Economics and Outcomes Research Ltd., Cardiff, United Kingdom
1Pfizer Ltd., Walton Oaks, Surrey, United Kingdom, 2Pfizer Inc., New York, NY, USA, 3Health Economics and Outcomes Research Ltd., Cardiff, United Kingdom
Presentation Documents
OBJECTIVES: Direct-acting oral anticoagulants (DOACs) are recommended to reduce stroke risk in patients with non-valvular atrial fibrillation (NVAF). Some health plans regulate prescriptions using prior authorization (PA; approval for a treatment prior to prescribing) or step therapy (ST; patients must fail cheaper alternatives first). While these protocols aim to control healthcare spending and unnecessary drug prescription, restrictions can delay treatment access, impair adherence and encourage patients to use less effective/safe therapies, resulting in adverse clinical outcomes. This study compared the incidence and cost of clinical events in patients with NVAF with restricted versus unrestricted access to DOACs in the United States.
METHODS: A decision analytic model was developed to assess the incidence and cost of stroke, major bleed (MB), transient ischemic attack (TIA) and all-cause mortality (ACM) in patients with NVAF with restricted (i.e., all DOACs require PA or ST) versus unrestricted (i.e., immediate access to DOACs) access over one-year. A hypothetical cohort of 1,000,000 Medicare Fee-For-Service plan members from the general population was used; epidemiology inputs and market share estimates were used to determine the treatment eligible population. Clinical inputs were derived from a published cohort study assessing formulary restrictions on DOACs. Cost inputs were sourced from literature and online databases and inflated to 2024 US dollars.
RESULTS: Of 1,000,000 Medicare members, 67,984 patients with prevalent NVAF received DOAC treatment. Over one-year, the restricted access cohort accrued an additional 613 clinical events (57 strokes, 61 MBs, 43 TIAs, 452 ACM) versus the unrestricted access cohort, resulting in annual incremental costs of $8,008,860 ($9.82 per NVAF patient/month; $0.67 per member/month).
CONCLUSIONS: Compared with unrestricted access, any (PA or ST) restrictions in patients with NVAF resulted in more clinical events and higher clinical event-related costs for US Medicare payers. Removing PA and ST restrictions on DOAC prescriptions may reduce event-related costs and improve patient outcomes.
METHODS: A decision analytic model was developed to assess the incidence and cost of stroke, major bleed (MB), transient ischemic attack (TIA) and all-cause mortality (ACM) in patients with NVAF with restricted (i.e., all DOACs require PA or ST) versus unrestricted (i.e., immediate access to DOACs) access over one-year. A hypothetical cohort of 1,000,000 Medicare Fee-For-Service plan members from the general population was used; epidemiology inputs and market share estimates were used to determine the treatment eligible population. Clinical inputs were derived from a published cohort study assessing formulary restrictions on DOACs. Cost inputs were sourced from literature and online databases and inflated to 2024 US dollars.
RESULTS: Of 1,000,000 Medicare members, 67,984 patients with prevalent NVAF received DOAC treatment. Over one-year, the restricted access cohort accrued an additional 613 clinical events (57 strokes, 61 MBs, 43 TIAs, 452 ACM) versus the unrestricted access cohort, resulting in annual incremental costs of $8,008,860 ($9.82 per NVAF patient/month; $0.67 per member/month).
CONCLUSIONS: Compared with unrestricted access, any (PA or ST) restrictions in patients with NVAF resulted in more clinical events and higher clinical event-related costs for US Medicare payers. Removing PA and ST restrictions on DOAC prescriptions may reduce event-related costs and improve patient outcomes.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
EE88
Topic
Economic Evaluation
Disease
SDC: Cardiovascular Disorders (including MI, Stroke, Circulatory)