Cost-effectiveness targets for multi-detector row CT angiography in the work-up of patients with intermittent claudication

PURPOSE: To determine the costs, sensitivity for detection of significant stenoses, and proportion of equivocal multi-detector row computed tomographic (CT) angiography results in the work-up of patients with intermittent claudication that would make this imaging examination cost-effective compared with gadoliniumenhanced magnetic resonance (MR) angiography. MATERIALS AND METHODS: A decision model was used to compare the societal cost-effectiveness of a new imaging modality with that of gadolinium-enhanced MR angiography. Main outcome measures were quality-adjusted life years (QALYs) and lifetime costs. By using threshold analysis of a given willingness to pay per QALY, target values for costs, sensitivity for detection of significant stenoses, and proportion of cases requiring additional work-up with intraarterial digital subtraction angiography owing to equivocal results of the new modality were determined. The base case evaluated was that of 60-year-old men with severe intermittent claudication and assumed an incremental cost-effectiveness threshold of $100,000 per QALY. RESULTS: If treatment were limited to angioplasty, a new imaging modality would be cost-effective if the costs were $300 and the sensitivity was 85%, even if up to 35% of patients needed additional work-up. When both angioplasty and bypass surgery were considered as treatment options, a new imaging modality was cost-effective if the costs were $300, the sensitivity was higher than 94%, and 20% of patients required additional work-up. CONCLUSION: Multi-detector row CT angiography, as compared with currently used imaging modalities such as MR angiography, has the potential to be cost-effective in the evaluation of patients with intermittent claudication.