New Diagnostic Criterion of Ankle Brachial Index for Peripheral Arterial Disease

ABSTRACT

BACKGROUND: The ankle brachial index (ABI) is a simple, inexpensive diagnostic test for peripheral arterial disease (PAD). However the diagnostic criterion of 0.9 has shown variable accuracy for identification of stenosis. We investigated more specific and sensitive diagnostic criterion of ABI for the diagnosis of PAD. METHODS: Among 5,379 patients who performed ABI test, 398 patients with abnormal ABI results or PAD symptoms underwent computed tomography angiography to confirm PAD. Each ABI results were compared with its sensitivity, specificity, positive and negative predictive values. ROC analysis and cross-tabulation analysis were performed to yield proper ABI criterion. RESULTS: ABI of 0.9 showed very high level of sensitivity (92.2%) and very low specificity(59.3%). ABI of 0.84 showed high level of specificity (81.4%), sensitivity (82.2%) and diagnostic correspondent rate (0.607). CONCLUSION: The ABI of 0.84 could be more accurate and useful diagnostic Criterion for identifying PAD.