Sensitivity and Specificity of the Toe-Brachial Index for Detecting Peripheral Arterial Disease: Initial Findings

J Ultrasound Med. 2015 Oct;34(10):1737-43. doi: 10.7863/ultra.15.14.09071. Epub 2015 Aug 25.

Abstract

Objectives: The toe-brachial index (TBI) is an alternative to the ankle-brachial index (ABI) in screening for peripheral arterial disease (PAD); however, there is limited evidence comparing their diagnostic accuracy. This study compared the diagnostic accuracy of the ABI and TBI in a population at risk of PAD.

Methods: The sensitivity and specificity of the ABI and TBI were determined by color duplex sonography. Receiver operating characteristic (ROC) analysis was performed.

Results: A total of 119 participants were recruited (75 male and 44 female). The sensitivity for PAD was highest for the TBI (71%; ABI, 45%), and the specificity was highest for the ABI (93%; TBI, 78%). Receiver operating characteristic analysis indicated that the TBI (ROC area, 0.77; P = .0001) had greater clinical efficacy for diagnosis of PAD than the ABI (ROC area, 0.65; P = .005).

Conclusions: In specific populations, the TBI may have greater clinical efficacy than the ABI for diagnosis of PAD.

Keywords: ankle-brachial index; peripheral arterial disease; sensitivity; specificity; toe-brachial index; vascular ultrasound.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Algorithms*
  • Ankle Brachial Index / methods*
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Male
  • Middle Aged
  • Observer Variation
  • Peripheral Arterial Disease / diagnosis*
  • Pilot Projects
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Severity of Illness Index*
  • Ultrasonography, Doppler, Color / methods*