title: Can we measure the ankle-brachial index using only a stethoscope? A pilot study.
abstract: BACKGROUND
  Ankle-brachial index (ABI) is an excellent method for the diagnosis of peripheral arterial disease (PAD) when it is performed with Doppler. However, this device is not always available for primary care physicians. The ABI measured with stethoscope is an easy alternative approach, but have not been proved to be useful.
  
  
  OBJECTIVE
  To assess the accuracy of the ABI measured using a stethoscope comparatively to that of the current eligible method for the diagnosis of PAD, the Doppler ABI, and describe the characteristics of this new approach.
  
  
  METHODS
  We conducted a diagnostic study of ABI measured with a stethoscope and a Doppler probe and compared the results. Eighty-eight patients were accessed by both methods.
  
  
  RESULTS
  Mean stethoscope ABI, 1.01 +/- 0.15, and mean Doppler ABI, 1.03 +/- 0.20, (P = 0.047) displayed a good correlation. Measurements of stethoscope ABI diagnostic accuracy in recognizing a Doppler ABI are described. The comparison of this data with the current gold standard method results gave a sensitivity of 71.4% [95% confidence interval (CI), 41.9-91.6] and specificity of 91.0% (95% CI, 81.5-96.6), with predictive positive value of 62.5% (95% CI, 38.6-81.5) and negative predictive value of 93.8% (95% CI, 85.2-97.6). The study accuracy was 87.7%. The area under the ROC curve was 0.895 (95% CI, 0.804-0.986, P < 0.0001).
  
  
  CONCLUSIONS
  According to our study, the stethoscope ABI is a useful method to detect PAD and it may be suitable for its screening in the primary care setting.
authors.affiliation: Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. gabriel_carmo@yahoo.com.br
authors.forename: G A L
authors.initials: GA
authors.lastname: Carmo
authors.forename: A
authors.initials: A
authors.lastname: Mandil
authors.forename: B R
authors.initials: BR
authors.lastname: Nascimento
authors.forename: B D
authors.initials: BD
authors.lastname: Arantes
authors.forename: J C
authors.initials: JC
authors.lastname: Bittencourt
authors.forename: E B
authors.initials: EB
authors.lastname: Falqueto
authors.forename: A L
authors.initials: AL
authors.lastname: Ribeiro
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D005260:Female; D006801:Humans; D008297:Male; D016491:Peripheral Vascular Diseases / Q000175:diagnosis; D010865:Pilot Projects; D019023:Stethoscopes; D018608:Ultrasonography, Doppler