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

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.

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.

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.

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.