Abstract WP77: Cost-effectiveness Analysis Of Increasing Dual Antiplatelet Therapy Treatment After High-risk Transient Ischemic Attack Or Minor Ischemic Stroke

Abstract

Background: Use of guideline recommended dual antiplatelet therapy (DAPT) after high-risk TIA or minor ischemic stroke is suboptimal. We performed a cost-effectiveness analysis of current DAPT treatment patterns and modeled optimal parameters for future healthcare delivery quality improvement (QI) interventions designed to increase DAPT use. Methods: We constructed two decision tree models. Our first model compared DAPT (90 days of aspirin and clopidogrel) to aspirin alone at current national treatment rates (45% of eligible patients receive DAPT). Our second model compared current DAPT treatment patterns to a theoretical QI intervention that increases DAPT use at an initial cost of $20,000 per institution, in keeping with costs of published stroke QI interventions, with variable annual maintenance costs. Healthcare costs and outcomes (stroke, MI, major bleed, death) were modeled using 90-day and lifetime horizons. We calculated incremental cost-effectiveness ratios (ICER) and considered an ICER<$100,000 per quality-adjusted life year (QALY) to be cost-effective. Sensitivity analyses varying key inputs, including QI costs, were performed using Monte Carlo simulations. Results: Compared to aspirin alone, DAPT use was not cost-effective at 90 days (ICER $173,003/QALY) but was cost saving ($3,030) and more effective (0.31 more QALYs) over a lifetime at current treatment rates. Increasing the use of DAPT by 20% with a QI intervention was not cost-effective at 90 days (ICER $474,467/QALY) but was cost-effective over a lifetime (ICER $29,217/QALY). Increasing DAPT use with a QI intervention was the preferred strategy in 89% of Monte Carlo runs (lifetime horizon). QI interventions to increase DAPT use were cost-effective over a range of annual costs (Figure). Conclusion: In a modeling study, current rates of DAPT use after TIA/minor stroke are cost-effective over a lifetime, but a QI intervention to increase DAPT use is preferred in nearly all simulations.