Cost-Effectiveness of Endovascular Thrombectomy in Large Vessel Occlusion Stroke for the Very Elderly

Abstract

BACKGROUND AND OBJECTIVES: Endovascular thrombectomy (EVT) is associated with considerable clinical benefits for patients after large vessel occlusion (LVO) stroke. However, EVT remains underused in Australia, particularly among the very elderly (aged ≥80 years). The aim of this study was to evaluate the cost-effectiveness and clinical effectiveness of EVT vs standard medical management among very elderly patients using real-world, observational data. METHODS: A modeled cost-effectiveness study was conducted from the Australian health care perspective. Data from a retrospective cohort of patients aged 80 years or older treated with EVT at 4 comprehensive stroke centers across Australia and New Zealand, as well as data from the International Stroke Perfusion Imaging Registry, were used to inform our economic analyses. The distribution of 90-day modified Rankin Scale (mRS) outcomes after propensity score matching was used to inform a decision-analytic Markov model. Costs and utility data for calculating quality-adjusted life years (QALYs) were drawn from published sources. The primary outcome of this analysis was the incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained for EVT compared with medical management. Uncertainty was evaluated with deterministic and probabilistic sensitivity analyses. RESULTS: A total of 548 patients (mean age 85.1 years and 296 women [54%]) were included to inform the propensity score matching analysis. After propensity score matching, the proportion of patients with favorable (mRS score ≤2) outcomes was higher for EVT vs standard care (37% vs 18%). Based on the modeled cost-effectiveness analysis comprising a hypothetical sample of 10,000 patients, EVT was estimated to prevent 471 deaths over a period of 15 years. On a per-patient basis, EVT was associated with a gain of 0.95 years of life and 0.97 QALYs at a net cost of AU$3,399. That is, from a health care perspective, EVT is cost-effective for very elderly patients with LVO stroke (ICER: $3,508 per QALY). Sensitivity analyses supported the robustness of the model, with 100% of simulated ICERs falling below the commonly accepted Australian willingness-to-pay threshold of AU$50,000 per QALY. DISCUSSION: EVT is cost-effective and associated with considerable clinical benefits relative to standard medical management for very elderly patients with LVO stroke. Our findings support the provision of EVT to the very elderly.