Cost-effectiveness of identifying aortoiliac and femoropopliteal arterial disease with angiography or duplex scanning

ObjectivesCost-effectiveness analysis of three diagnostic imaging strategies for the assessment of aortoiliac and femoropopliteal arteries in patients with peripheral arterial occlusive disease. The strategies were: angiography as the reference strategy, duplex scanning (DS) plus supplementary angiography (S1) and DS plus confirmative angiography (S2).Design, materials and methodsA decision model was built with sensitivity and specificity data from literature, supplemented with prospective hospital cost data in Euro (€). The probability of correctly identifying the status of a lesion was taken as the primary outcome. We compared strategies by assessing the extra costs per additional correctly identified case.ResultsAssuming no false positive or false negative results, angiography is the most effective strategy if the prevalence of significant obstructive lesions in the aortoiliac and femoropopliteal tract exceeds 70%, or if the sensitivity of duplex scanning is lower than 83%. In case of lower prevalence, strategy S1 becomes equally or even more effective than angiography. At a prevalence of 75%, performing angiography costs €8443 per extra correctly identified case compared with strategy S1.ConclusionsIn most situations angiography is more effective than diagnostic strategy S1. However, if society is unwilling to pay more than €8443 for knowing a patient's disease status, diagnostic strategy S1 is a cost-effective alternative to angiography, especially at lower prevalence values.