Cost-effectiveness of low-dose compared to standard-dose alteplase for acute ischemic stroke in China : a within-trial economic evaluation of the ENCHANTED Study

Introduction: The Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED) showed that a low-dose alteplase was safe but not clearly non-inferior to standard-dose alteplase in acute ischemic stroke (AIS). Given the significant cost of this medicine, we undertook a cost-effectiveness analysis to determine the probability that low-dose is cost-effective relative to standard-dose alteplase in China. Methods: For ENCHANTED participants in China with available health cost data, cost-effectiveness and cost-utility analyses were undertaken in which death or disability (modified Rankin scale scores 2-6) at 90 days and quality-adjusted life-years (QALYs) were used as outcome measures, respectively. There was adherence to standard guidelines for health economic evaluations alongside non-inferiority trials and according to a health-care payer's perspective. The equivalence margin for cost and effectiveness was set at USD 691 and -0.025 QALYs, respectively, for the base-case analysis. Probabilistic sensitivity analyses were used to evaluate the probability of low-dose alteplase being non-inferior. Results: While the mean cost of alteplase was lower in the low-dose group (USD 1,569 vs. USD 2,154 in the standard-dose group), the total cost was USD 56 (95% confidence interval [CI]: -1,000-1,113) higher compared to the standard-dose group due to higher hospitalization costs in the low-dose group. There were 462 (95% CI: 415-509) and 410 (95% CI: 363-457) patients with death or disability per 1,000 patients in the low-dose and standard-dose groups, respectively. The low-dose group had marginally lower (0.008, 95% CI: -0.016-0.001) QALYs compared to their standard-dose counterparts. The low-dose group was found to have an 88% probability of being non-inferior based on cost-effectiveness versus the standard-dose group. Conclusions: This health economic evaluation alongside the ENCHANTED indicates that the use of low-dose alteplase does not save overall healthcare costs nor lead to a gain in QALYs in the management of Chinese patients with AIS compared to the use of standard dose. There is little justification on economic grounds to shift from standard-of-care thrombolysis in AIS.