Cost-effectiveness of multimodal CT for evaluating acute stroke

Abstract

Multimodal CT, including noncontrast CT (NCCT), CT with contrast, CT angiography (CTA), and perfusion CT (CTP), is increasingly used in acute stroke patients to identify candidates for endovascular therapy. Our goal is to explore the cost-effectiveness of multimodal CT as a diagnostic test. A Markov model compared multimodal CT to NCCT in a hypothetical cohort of nonhemorrhagic stroke patients presenting within 3 hours of symptom onset who were potential IV tPA candidates. Patients who failed to improve after IV tPA or in whom IV tPA was contraindicated were candidates for endovascular therapy. Direct costs (2008 USD), outcomes, and probabilities were obtained from the literature. For the 3-month time horizon, multimodal CT had lower costs (-$1,716), had greater quality-adjusted life-years (QALYs, 0.004), and was the cost-effective choice 100% of the time for a willingness-to-pay of $100,000/QALY (probabilistic sensitivity analysis). The number needed to screen with multimodal CT to avoid 1 diagnostic angiogram was 2. Over a lifetime, multimodal CT had lower costs (-$2,058), had greater QALYs (0.008), and was cost-effective, with a 90.1% likelihood, for a willingness-to-pay of $100,000/QALY. Multimodal CT appears to be a cost-saving screening tool over the short term. However, additional data regarding clinical outcomes following multimodal CT-guided intra-arterial treatment are needed before the long-term cost-effectiveness can be suitably addressed. This analysis can be incorporated into future discussions of multimodal CT as a diagnostic test for unselected patients, within and beyond the 3-hour IV tPA time window.