Diagnostic Accuracy of Ankle-Brachial Index in Patients With Peripheral Arterial Disease: A Meta-analysis

Peripheral artery disease (PAD), characterized by the narrowing of peripheral arteries, often manifests as exertional leg pain. The ankle-brachial index (ABI) is a noninvasive, first-line diagnostic tool for PAD, but its reported diagnostic accuracy varies across studies. This meta-analysis evaluates the overall diagnostic performance of ABI (≤0.90) in detecting PAD among patients with intermittent claudication. A systematic review and meta-analysis were conducted using PubMed, Embase, and Cochrane Central databases. Studies included assessed ABI ≤0.90 for diagnosing PAD, defined as ≥50% arterial stenosis confirmed by a reference standard such as duplex ultrasound, magnetic resonance angiography, or conventional arteriography. Pooled sensitivity, specificity, diagnostic odds ratio, positive predictive value, and the area under the receiver operating characteristic curve were calculated. Fifteen studies comprising 3460 participants met the inclusion criteria. The pooled diagnostic odds ratio was 18.24 [95% confidence interval (CI), 10.85-30.65], indicating strong diagnostic capability. The area under the summary receiver operating characteristic curve was 0.8579 (standard error = 0.0241), and the Q* index was 0.7887 (standard error = 0.0231). Pooled sensitivity and specificity were 0.65 (95% CI, 0.63-0.67) and 0.89 (95% CI, 0.87-0.90), respectively. The positive and negative likelihood ratios were 6.11 and 0.36, with a positive predictive value of 84.7%. ABI demonstrates good diagnostic accuracy and high specificity in detecting PAD among symptomatic patients. It remains a valuable initial diagnostic tool, though further research is needed to optimize its application across patient subgroups.