Cost-effectiveness of CT perfusion for the detection of large vessel occlusion acute ischemic stroke followed by endovascular treatment: A model-based health economic evaluation study
Authors: van Voorst Henk , Hoving Jan W. , Koopman Miou S. , Daems Jasper D. , Peerlings Daan , Buskens Erik , Lingsma Hester F. , Beenen Ludo F.M. , de Jong Hugo W.A.M. , Berkhemer Olvert A. , van Zwam Wim H. , Roos Yvo B.W.E.M. , van Walderveen Marianne A.A. , van den Wijngaard Ido , Dippel Diederik W.J. , Yoo Albert J. , Campbell Bruce C.V. , Kunz Wolfgang G. , Emmer Bart J. , Majoie Charles B.L.M. ,   CONTRAST consortium,   MR CLEAN Registry Investigators
Published: March 2023

Background

CT perfusion (CTP) has been suggested to increase the rate of large vessel occlusion (LVO) detection in patients suspected of acute ischemic stroke (AIS) if used in addition to a standard diagnostic imaging regime of CT angiography (CTA) and non-contrast CT (NCCT). The aim of this study was to estimate the costs and health effects of additional CTP for endovascular treatment (EVT)-eligible occlusion detection using model-based analyses.

Methods

In this Dutch, nationwide retrospective cohort study with model-based health economic evaluation, data from 701 EVT-treated patients with available CTP results were included (January 2018–March 2022; trialregister.nl:NL7974). We compared a cohort undergoing NCCT, CTA, and CTP (NCCT+CTA+CTP) with a generated counterfactual where NCCT and CTA (NCCT+CTA) was used for LVO detection. The NCCT+CTA strategy was simulated using diagnostic accuracy values and EVT effects from the literature. A Markov model was used to simulate 10-year follow-up. We adopted a healthcare payer perspective for costs in euros and health gains in quality-adjusted life years (QALYs). The primary outcome was the net monetary benefit (NMB) at a willingness to pay of € 80,000, secondary outcomes were the difference between LVO detection strategies in QALYs (Δ QALY) and costs (Δ Costs).

Results

We included 701 patients (median age:72 IQR:[62-81]) years). Per LVO patient, CTP-based occlusion detection resulted in cost savings (Δ Costs median:€ -2671 IQR:[€ -4721;€ -731]), a health gain (Δ QALY median:0.073 IQR:[0.044;0.104]), and a positive NMB (median:€ 8436 IQR:[5565;11876]) per LVO patient.

Conclusion

Adding CTP to NCCT and CTA for EVT-eligible LVO detection resulted in cost savings and health gains.

Clinical relevance statement

In recent clinical trials, CTP-based patient selection for endovascular treatment resulted in worse patient outcomes after ischemic stroke. We found that an alternative use of CTP, CTP-based screening for endovascular treatable occlusions is cost-effective.

Key points

Using CTP to detect an endovascular treatment-eligible occlusions resulted in a health gain and cost savings when considering 10-years of follow-up.

Depending on the screening costs related to the number of patients needed to image (NNI) with CTP, cost savings could be considerable (Δ Costs NNI=4.3 median:€ -3857 IQR:[€ -5907;€ - 1916]; NNI=8.3 median:€ -2671 IQR:[€ - 4721;€ -731])

Variations in sensitivity difference due to the use of CTP affect the health gain (Δ QALYs sensitivity difference=baseline median:0.073 IQR:[0.044;0.104]; sensitivity difference=(baseline-4%) median:0.052 IQR:[0.031;0.075]).