Background 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. Methods 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. Results 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. Conclusions 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.

中文翻译：

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糖尿病患者和非糖尿病患者的踝肱指数：测试者内可靠性

背景 踝臂指数 (ABI) 广泛用于确定外周动脉疾病 (PAD) 的存在和严重程度，目前的指南建议应使用它来监测受影响个体的可能进展。因此，该技术证明重复测量具有足够的可靠性是很重要的。现有研究表明 ABI 在一般人群中是可靠的，但是缺乏证据表明 ABI 在糖尿病患者中的可靠性。本研究的目的是调查 ABI 在糖尿病患者和非糖尿病患者中的内部测试可靠性。方法 85 名参与者（40 名患有糖尿病和 45 名未患糖尿病）在两次测试期间由一名临床医生测量踝关节和肱动脉收缩压。确定了组内相关系数 (ICC)、它们的 95% 一致限、测量标准误差和最小可检测变化。结果发现 ABI 的测试者内可靠性良好（ICC：0.80），但是对患有和未患有糖尿病的参与者进行的亚组分析发现，ABI 在糖尿病患者中的可靠性（ICC：0.78）略低于非糖尿病患者（ICC：0.82）。相对较大的一致性限（- 0.16 至 0.16）、测量标准误差（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 的较大变化是需要它来证明真实的变化而不是测量变异的结果。ABI 的最小可检测变化总体为 0.08，糖尿病组为 0.11。结论 ABI 在所有分析的组中都表现出良好的可靠性。然而，所获得的测量的广泛一致性和相当大的标准误差支持使用多种血管评估方法来持续监测下肢血管状态。