Clinical examination and non-invasive screening tests in the diagnosis of peripheral artery disease in people with diabetes-related foot ulceration

Aim: Peripheral artery disease is common in people with diabetes-related foot ulceration and is a risk factor for amputation. The best method for the detection or exclusion of peripheral artery disease is unknown. This study investigated the utility of clinical examination and non-invasive bedside tests in screening for peripheral artery disease in diabetes-related foot ulceration. Methods: Some 60 people presenting with new-onset ulceration participated. Accuracy of pulses, ankle pressure, toe pressure, toe–brachial index (TBI), ankle–brachial pressure index (ABPI), pole test at ankle, transcutaneous oxygen pressure and distal tibial waveform on ultrasound were examined. The gold standard diagnostic test used was > 50% stenosis in any artery or monophasic flow distal to calcification in any ipsilateral vessel on duplex ultrasound. Results: The negative and positive likelihood ratios of pedal pulse assessment (0.75, 1.38) and the other clinical assessment tools were poor. The negative and positive likelihood ratios of ABPI (0.53, 1.69), transcutaneous oxygen pressure (1.10, 0.81) and ankle pressure (0.67, 2.25) were unsatisfactory. The lowest negative likelihood ratios were for tibial waveform assessment (0.15) and TBI (0.24). The highest positive likelihood ratios were for toe pressure (17.55) and pole test at the ankle (10.29) but the negative likelihood ratios were poor at 0.56 and 0.74. Conclusions: Pulse assessment and ABPI have limited utility in the detection of peripheral artery disease in people with diabetes foot ulceration. TBI and distal tibial waveforms are useful for selecting those needing diagnostic testing.