There’s good news and bad news. The good news is Medicare drug plans are increasing coverage of newer, better drugs to prevent blood clots in people at risk. The bad news is that coverage comes with significant strings attached, including higher patient copayments that could prevent access to the newer, better drugs.

Two charts say it all. In a new study in Circulation, Elias Dayoub and colleagues report on time trends in formulary coverage of warfarin and newer, more effective drugs that became the preferred option in professional guidelines published in 2014 and 2016. Overall coverage of the newer drugs (Apixaban, Dabigatran, and Rivaroxaban) increased between 2013 (pre-guidelines) and 2017, although most of that coverage came with some restrictions.

Bar chart showing coverage of apixaban, dabigatran, rivaroxaban, and warfarin

And the nature of these restrictions is concerning. Specifically,  the newer drugs were often put in “tiers” that require significant patient cost sharing. For tier-level 3 drugs, 77% of plans require copays (median $40) while the remaining plans require a coinsurance of 20%. For tier-level 4 drugs, nearly all plans require 40% coinsurance. Thus, a patient transitioning from warfarin to a newer drug could see out-of-pocket costs increase from $1 to $40 or up to 40% coinsurance if the anticoagulant is tier-level 3 or higher. At current prices of $320-$400 per month for the newer drugs, coinsurance at these levels will be unaffordable for many patients.

Coverage of formulary plans for apixaban, dabigatran, rivaroxaban, and warfarin over 2013, 2015, and 2017

Many patients with atrial fibrillation are at risk for blood clots and must take an anticoagulant long-term. The newer drugs require less blood monitoring, and have fewer drug and food interactions. But the price of these newer drugs is straining Medicare drug budgets and likely motivating increased restrictions on coverage. Dayoub and colleagues note that Medicare annual spending on oral anticoagulants increased 6-fold from 2012 to 2016 (from $750 million to $4.7 billion), despite only a 1.4-fold increase in the number of beneficiaries taking these medications.

Until the price of these newer drugs decrease, affordability and access issues will be a barrier to achieving the superior clinical outcomes that professional guidelines specify. The authors point out two ways that prices can decrease, one far more passive than the other. One is to wait until 2022, when the patents on these newer drugs begin to expire, opening up the potential for cheaper generic competition. Another way is to lift restrictions on the federal government’s ability to negotiate drug prices on behalf of Medicare beneficiaries, similar to what the Veterans Health Administration does for veterans. In the mean time, some Medicare patients will face out-of-pocket costs that will limit their access to newer, better anticoagulants despite increased formulary coverage.


The study, “Evolution of Medicare Formulary Coverage Changes for Antithrombotic Therapies After Guideline Updates,” was published online in Circulation on September 30, 2019.  Elias Dayoub, MD, MPP, is a VA scholar in the National Clinician Scholars Program at Penn, and an LDI Associate Fellow.  Other authors incluse Joseph S. Ross, MD, MHS; Nilay D. Shah, PhD; and Sanket S. Dhruva, MD, MHS.