The perfusion index is a useful screening tool for peripheral artery disease.

The number of people with peripheral artery disease (PAD) has been increasing globally; therefore, it is important to explore more options to screen patients who are at a risk of developing PAD. The perfusion index (PI) represents the degree of circulation through the peripheral tissues and is measured noninvasively. We investigated the correlation between the PI and ankle-brachial index (ABI) to explore whether the PI could be used a screening tool for PAD. This cross-sectional study included 390 patients. We measured the ABI and PI for all patients. The median ABI value was 1.06 (0.92-1.13); the PI was 1.7% (0.9-3.5). The PI was higher in men than in women (P < 0.0001). The PI was positively correlated with the estimated glomerular filtration rate and ABI in both men and women. The sensitivity and specificity of the PI to predict PAD (ABI ≤0.9) were 90.0% and 80.3%, respectively, and the cutoff PI value was 1.5% in men. The sensitivity and specificity of the PI to predict PAD were 82.1% and 79.2%, respectively, and the cutoff PI value was 1.1% in women. PI could be a reliable screening tool for diagnosing PAD because it does not restrict the patient's mobility, can be completed in a short time period, and is associated with reduced costs.