Financial Impact of Direct-Acting Oral Anticoagulants in Medicaid: Budgetary Assessment Based on Number Needed to Treat

Background Faced with rising healthcare costs, state Medicaid programs need short-term, easily calculated budgetary estimates for new drugs, accounting for medical cost offsets due to clinical advantages. Objective To estimate the budgetary impact of direct-acting oral anticoagulants (DOACs) compared with warfarin, an older, lower-cost vitamin K antagonist, on 12-month Medicaid expenditures for nonvalvular atrial fibrillation (NVAF) using number needed to treat (NNT). Method Medicaid utilization files, 2009 through second quarter 2015, were used to estimate OAC cost accounting for generic/brand statutory minimum (13/23%) and assumed maximum (13/50%) manufacturer rebates. NNTs were calculated from clinical trial reports to estimate avoided medical events for a hypothetical population of 500,000 enrollees (approximate NVAF prevalence × Medicaid enrollment) under two DOAC market share scenarios: 2015 actual and 50% increase. Medical service costs were based on published sources. Costs were inflation-adjusted (2015 US$). Results From 2009–2015, OAC reimbursement per claim increased by 173 and 279% under maximum and minimum rebate scenarios, respectively, while DOAC market share increased from 0 to 21%. Compared with a warfarin-only counterfactual, counts of ischemic strokes, intracranial hemorrhages, and systemic embolisms declined by 36, 280, and 111, respectively; counts of gastrointestinal hemorrhages increased by 794. Avoided events and reduced monitoring, respectively, offset 3–5% and 15–24% of increased drug cost. Net of offsets, DOAC-related cost increases were US$258–US$464 per patient per year (PPPY) in 2015 and US$309–US$579 PPPY after market share increase. Conclusions Avoided medical events offset a small portion of DOAC-related drug cost increase. NNT-based calculations provide a transparent source of budgetary-impact information for new medications.