Cost-effectiveness of CT perfusion, low-field MRI, and delayed high-field MRI in emergency department patients with dizziness concerning for stroke
摘要
Stroke diagnoses may be missed or delayed in patients presenting to the emergency department (ED) with acute dizziness or vertigo. Even in patients who do not receive acute stroke treatment, accurate diagnosis is still essential to improve outcomes to ensure appropriate risk stratification and initiation of secondary prevention strategies. High-field MRI is the most sensitive imaging modality, but is not immediately available at many EDs.
ObjectiveTo investigate the cost-effectiveness of alternate neuroimaging approaches in the evaluation of patients presenting to the emergency department (ED) with dizziness when high-field MRI is not available.
MethodsA Markov decision-analytic model was constructed from a healthcare system perspective for evaluation of a patient presenting to the ED with acute vestibular syndrome (AVS) – the dizziness subtype most concerning for stroke. Six diagnostic strategies were compared: non-contrast head CT, head and neck CTA (added to non-contrast CT), whole brain perfusion CT (CTP) added to CT and CTA, low-field portable MRI, admission to observation for high-field MRI, and inter-facility transport to high-field MR. Differing long-term costs and outcomes related to stroke detection and secondary prevention were compared. Cost-effectiveness was calculated in terms of lifetime expenditures in 2024 U.S. dollars for each quality-adjusted life year (QALY); deterministic and probabilistic sensitivity analyses were performed.
ResultsObservation for high-field MRI resulted in the highest QALYs and was the most cost-effective strategy. Transport to high-field MRI had an incremental cost of $5402, but negative marginal utility (-0.0047 QALYs) compared to observation. CTP (added to CTA and CT) had the next-highest health benefit, although was dominated by extension, at an incremental cost of $1022 for an additional 0.02 QALYs, compared to low-field MRI. CTA and non-contrast CT alone had the lowest utility. In the deterministic sensitivity analyses, observation for high-field MRI remained the most cost-effective strategy across a wide range of model parameters. Relative benefit was largely driven by differences in imaging sensitivity. Probabilistic sensitivity analyses yielded similar results to the base-case analysis.
ConclusionObservation for high-field MRI in patients presenting to the ED with AVS-type dizziness can is more cost-effective and improves long-term outcomes compared to CT and CTA. When high-field MRI is not available via observation or transport, both CTP and low-field MRI are reasonable alternatives.
Clinical ImpactWhen high-field MRI is not immediately available, short delays in imaging associated with observation or transport do not alter the preference for MRI-based evaluation. CTP and low-field MRI are preferred to CTA or CT alone.