MODELING VALUE-BASED PAYMENT ADJUSTMENTS FOR TIMELY ACUTE STROKE CARE: COST-EFFECTIVENESS ANALYSIS MODELING MEETS PAY-FOR-PERFORMANCE

Purpose: Healthcare payers in the U.S. are increasingly tying provider payments to quality or value using pay-for-performance (P4P) policies. Cost-effectiveness analysis (CEA) quantifies value in healthcare but is not currently used to design P4P policies. We used a stroke simulation model to demonstrate how value-based acute ischemic stroke (AIS) payment adjustments (P4P incentives) could be determined using CEA.

Methods: We used a previously-published AIS simulation model to calculate the difference in population-level net monetary benefit (NMB, willingness-to-pay of $100,000/quality-adjusted life year [QALY]) accrued under current Medicare policy (stroke payment not adjusted for performance) compared to various hypothetical P4P scenarios. Performance measurement was based on time-to-thrombolytic treatment with tissue-type plasminogen activator (tPA). tPA within 0-3 hours of stroke onset leads to superior acute outcomes quantified by the modified Rankin Scale (mRS). In the model, time-to-tPA influenced acute mRS outcomes; discounted lifetime QALYs and stroke-related costs (payer perspective) were projected based on mRS outcomes. Time-to-tPA was modeled by adding time from: 1) stroke onset to hospital arrival; to 2) hospital arrival to tPA (“door-to-needle”). In P4P scenarios, we modeled door-to-needle time reductions of 0-30 minutes (range based on the national Get With The Guidelines initiative average 10 minute reduction) and tPA payment (unadjusted payment=$6,270) increases of 0-50% for timely (cost-effective) treatment.

Results: Without performance-based payment (i.e, current payment), tPA versus no tPA had incremental cost-effectiveness ratios of: $14,300/QALY in the 0-3 hour treatment window; $27,100/QALY in the 3-4.5 hour window; and was dominated in the 4.5-6 hour window. Compared to current payment, equivalent population-level NMB was achieved in P4P scenarios with 10 minute door-to-needle time reductions (6,392 more AIS cases/year in the 0-3 hour window) incentivized by increasing tPA payment by as much as: 10.5% for 0-4.5 hours; 12% for 0-3 hours and 6% for 3-4.5 hours; or 13.75% for 0-3 hours only. Population-level NMB differences between current and P4P payment scenarios depended on the sizes of performance improvements and payment incentives (Figure).    

Conclusions: Determining the optimal size of financial incentives used in P4P is an important challenge facing policy developers who seek to improve the value of healthcare delivered in the U.S. Value-based AIS payment adjustments can be set using CEA and a NMB framework that could be generalized to other quality measures across health conditions.