School of Health Sciences, University of Newcastle, Ourimbah, Australia.
Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, Australia.
J Foot Ankle Res. 2020 May 12;13(1):21. doi: 10.1186/s13047-020-00389-w.
The ankle-brachial index (ABI) is widely used for determining the presence and severity of peripheral arterial disease (PAD), and current guidelines suggest it should be used to monitor possible progression in affected individuals. It is therefore important that the technique demonstrates adequate reliability for repeated measurements. Existing studies suggest that the ABI is reliable in the general population however, there is a lack of evidence for the reliability of the ABI in people with diabetes. The aim of this study was to investigate the intra-tester reliability of the ABI in people with and without diabetes.
Eighty-five participants (40 with and 45 without diabetes) underwent ankle and brachial systolic blood pressure measurements by a single clinician during two testing sessions. Intraclass correlation coefficients (ICC), their 95% limits of agreement, standard error of measurement and minimal detectable change were determined.
Intra-tester reliability of the ABI was found to be good (ICC: 0.80), however sub-group analysis of participants with and without diabetes found that ABI was slightly less reliable in people with diabetes (ICC: 0.78) than in those without (ICC: 0.82). The relatively large limits of agreement (- 0.16 to 0.16), standard error of measurement (0.03 overall, 0.04 for the diabetes group), and minimal detectable change (0.08 overall, 0.11 for the diabetes group) suggest that a large change in ABI is required for it to demonstrate a true change rather than the result of measurement variability. The minimal detectable change for the ABI was 0.08 overall, and 0.11 for the diabetes group.
The ABI demonstrated good reliability in all groups analysed. However, the wide limits of agreement and considerable standard error of measurement obtained support the use of multiple methods of vascular assessment for ongoing monitoring of lower limb vascular status.
踝臂指数（ABI）广泛用于确定周围动脉疾病（PAD）的存在和严重程度，目前的指南建议使用它来监测受影响个体的可能进展。因此，该技术对于重复测量具有足够的可靠性非常重要。现有研究表明，ABI 在普通人群中是可靠的，然而，在糖尿病患者中，ABI 的可靠性缺乏证据。本研究旨在调查ABI 在有或没有糖尿病的人群中的测试者内可靠性。
85 名参与者（40 名有糖尿病，45 名无糖尿病）由一名临床医生在两次测试期间测量踝部和肱动脉收缩压。确定了组内相关系数（ICC）、其 95%置信区间、测量误差标准和最小可检测变化。
ABI 的测试者内可靠性被发现是良好的（ICC：0.80），然而对有糖尿病和无糖尿病的参与者进行亚组分析发现，ABI 在有糖尿病的患者中（ICC：0.78）比无糖尿病的患者（ICC：0.82）稍微不太可靠。相对较大的一致性界限（-0.16 至 0.16）、测量误差标准（总体为 0.03，糖尿病组为 0.04）和最小可检测变化（总体为 0.08，糖尿病组为 0.11）表明，ABI 发生较大变化才能证明是真正的变化，而不是测量变异性的结果。ABI 的最小可检测变化总体为 0.08，糖尿病组为 0.11。
ABI 在所有分析的组中都表现出良好的可靠性。然而，获得的较大一致性界限和相当大的测量误差标准支持使用多种血管评估方法来持续监测下肢血管状况。
