Cost-effectiveness of multimodal CT for evaluating acute stroke

Current stroke care requires rapid and accurate diagnostic tools. Noncontrast CT (NCCT) is commonly used to rule out hemorrhage in acute stroke patients. However, NCCT lacks the ability to identify ischemic tissue viability or large vessel occlusions. Multimodal CT combines NCCT with contrast-enhanced imaging, angiography, and perfusion scans to provide more detailed diagnostic information. Prior research has shown that NCCT alone is insufficient for guiding endovascular therapy decisions. This gap motivated a closer look at whether additional imaging modalities improve diagnostic accuracy while remaining cost-effective. No prior work had resolved the economic impact of using multimodal CT in unselected stroke patients. The literature suggests that diagnostic accuracy influences treatment eligibility and outcomes. However, the financial implications of broader imaging use remain unclear. This study aimed to address that uncertainty by comparing multimodal CT to standard NCCT in terms of cost and effectiveness.

The study aimed to evaluate whether multimodal CT is a cost-effective diagnostic strategy for acute stroke patients. The specific problem addressed is the lack of clarity about the economic impact of using additional imaging modalities beyond NCCT. The motivation stems from the growing use of multimodal CT in clinical practice and the need to understand its financial implications. The researchers wanted to determine if the added diagnostic information justifies the increased costs. The study focused on patients presenting within 3 hours of stroke onset who might be eligible for IV tPA or endovascular therapy. The goal was to compare multimodal CT with NCCT in terms of cost, quality-adjusted life-years (QALYs), and likelihood of being cost-effective. The researchers also sought to estimate how often multimodal CT could avoid unnecessary diagnostic angiograms. The study’s findings could inform clinical guidelines and healthcare policy decisions regarding stroke diagnostics.

The researchers used a Markov model to simulate outcomes for a hypothetical cohort of nonhemorrhagic stroke patients. The model compared multimodal CT with NCCT as diagnostic tests. The study population included patients presenting within 3 hours of symptom onset who were potential candidates for IV tPA. Probabilistic sensitivity analysis was used to assess the robustness of findings. The model incorporated probabilities of treatment success, costs, and outcomes derived from published literature. The time horizon was set to 3 months and extended to a lifetime for long-term analysis. Direct costs were calculated in 2008 USD, including imaging, treatment, and follow-up expenses. The model evaluated cost-effectiveness using a willingness-to-pay threshold of $100,000 per QALY. The number needed to screen to avoid one diagnostic angiogram was also calculated. The model structure allowed for comparison of both short- and long-term outcomes.

Multimodal CT was found to be less costly than NCCT in the 3-month analysis, with a net saving of $1,716. It also generated more quality-adjusted life-years (QALYs) by 0.004. The model showed that multimodal CT was the cost-effective option 100% of the time at a $100,000/QALY threshold. Over a lifetime horizon, multimodal CT remained cost-saving with a $2,058 reduction in costs. The QALY gain increased to 0.008 in the long-term analysis. The likelihood of multimodal CT being cost-effective dropped to 90.1% in the lifetime model. The number needed to screen with multimodal CT to avoid one diagnostic angiogram was 2. These findings suggest that multimodal CT is a cost-saving strategy in the short term. However, the long-term cost-effectiveness remains uncertain due to limited clinical outcome data.

The authors concluded that multimodal CT is a cost-saving diagnostic tool in the short term for acute stroke patients. Their findings suggest that the added imaging modalities reduce costs and improve outcomes compared to NCCT alone. The researchers emphasized that multimodal CT is 100% cost-effective at a $100,000/QALY threshold in the 3-month analysis. Over a lifetime, multimodal CT remained cost-saving but with a slightly lower likelihood of cost-effectiveness at 90.1%. The study proposed that multimodal CT could be a valuable screening tool within and beyond the 3-hour IV tPA window. The authors acknowledged that long-term outcomes following multimodal CT-guided treatment remain uncertain. They suggested that additional clinical data are needed to fully assess the long-term cost-effectiveness of multimodal CT. The findings support the use of multimodal CT as a diagnostic strategy in unselected stroke patients.