Evolution of Medicare Formulary Coverage Changes for Antithrombotic Therapies After Guideline Updates
Bibliographic record
Abstract
C ◼ Medicare Part D ◼ venous thrombembolism In January 2019, the American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) guideline for atrial fibrillation (AF) was updated, recommending direct-acting oral anticoagulants (DOACs) over warfarin for patients with nonvalvular AF and no contraindication to DOACs. 1 The previous ACC/AHA/HRS guideline for AF and the most recent American College of Chest Physicians (CHEST) guideline for venous thromboembolism have also recommended an increased role for DOACs: the 2014 ACC/AHA/HRS AF guideline recommended either warfarin or DOACs as first-line antithrombotic therapy, 2 and in 2016, the CHEST venous thromboembolism guideline recommended DOACs over warfarin in noncancer patients. 3ormulary coverage and utilization management strategies can be used to promote guideline recommended medication use, but the impact of these guideline updates on DOAC formulary coverage is unknown.We characterized Medicare formulary changes after publication of the 2014 ACC/AHA/HRS and 2016 CHEST guidelines by using the Medicare Prescription Drug Plan Formulary Files, which include all available Medicare Advantage and stand-alone Part D plans, to compare coverage in the second quarters of 2013 (preguidelines), 2015 (post-ACC/AHA/HRS AF guideline), and 2017 (post-CHEST venous thromboembolism guideline) for DOACs (ie, apixaban, dabigatran, edoxaban, and rivaroxaban) at maintenance dosing for patients without impaired renal function, and for warfarin at a commonly prescribed dose (5 mg).We first determined formulary coverage and, among formularies providing coverage, determined formulary restrictiveness based on use of three utilization management strategies: cost-sharing tier-level 3 or higher, prior authorization requirement, and step therapy requirement.Formularies were categorized as unrestrictive if no approaches were used, restrictive if any approach was used, and no coverage.Chi-square or Fisher exact tests were used, as appropriate, to examine differences in formulary restrictiveness for each drug over the study period.Statistical tests were 2-sided, with P <0 .05indicating statistical significance.Institutional review board approval was not required for this study given that it was confined to analysis of data containing no patient information.For the second quarters of 2013, 2015, and 2017, there were 314, 389, and 378 Medicare Prescription Drug Plan formularies, respectively.All but 1 provided unrestrictive coverage of warfarin in all 3 time periods (Figure).Among DOACs, in 2013, 38 (12%) and 118 (38%) of formularies provided unrestrictive and restrictive coverage of apixaban, 64 (20%) and 245 (78%) of dabigatran, and 79 (25%) and 196 (62%) of rivaroxaban, whereas by 2017, 89 (24%) and 271 (70%) provided unrestrictive and restrictive coverage of apixaban, 92 (24%) and 276 (73%) of dabigatran, 115 (30%) and 261 (69%) of rivaroxaban, and 6 (2%) and 63 (17%) of edoxaban (P < 0.001).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.068 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.005 | 0.009 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".