[Concordance between 3 methods of measurement the ankle-brachial index to diagnose peripheral artery disease]

Background and objectives: To determine the concordance of the ankle-brachial index (ABI) determined by automatic measurements (sphygmomanometer Omron and the triple cuff device) using doppler as the gold-standard, computing as well as sensitivity and specificity.

Patients and methods: ARTPER population cohort subjects, classified as peripheral arterial disease (PAD) if ABI<0.9, calcified if ABI≥1.4 and healthy otherwise. To asses concordance we used kappa index using the 3 categories and the intraclass correlation coefficient (ICC) for ABI continuous values.

Results: Eighty-eight participants, 52% women, 57-87 years. It was possible to calculate the ABI using doppler for 100%, 97% using Omron and 95% using triple. ABI means (standard deviation) were: doppler 1.089 (0.236), Omron 1.082 (0.110), triple 1.146 (0.134), with poor agreement (ICC doppler/Omron=0.27, doppler/triple=0.13, and triple/Omron=0.39). Categorizing ABI as PAD-healthy-calcified 13.6% (doppler), 6.8% (Omron) and 3.4% (triple) were PAD and 9.1% (doppler), 1.1% (Omron) and 9.1% (triple) were calcified. Kappa indexes were weak (doppler/Omron=0.22, doppler/triple=0.01, triple/Omron=0.17). Both triple and Omron were highly specific (97%) but had very low sensitivity (8 and 33%, respectively) compared to doppler.

Conclusions: Concordance of ABI automatic measurements as Omron and triple with doppler was poor, and they do not seem suitable for screening for PAD in primary care consultations.