title: Relative value of the Ankle-Brachial Index of intermittent claudication.
abstract: BACKGROUND
  The Ankle-Brachial Index (ABI) makes it possible to identify patients with peripheral artery disease (PAD). Intermittent claudication (IC) is the first major symptom of PAD, although many patients with an ABI ≤ 0.9 do not exhibit IC, and the range of ABI among those who do have IC is very variable. This study evaluates the correlation between ABI and the perception (symptomatology) of claudicant patients.
  
  
  METHODS
  An observational, cross-sectional and multicentre, study of 920 patients with IC. Clinical history, ABI, Walking Impairment Questionnaire (WIQ) and European Quality of Life Questionnaire (EQ-5D) were recorded. Associations were analysed using Spearman's correlation coefficient.
  
  
  RESULTS
  The mean ABI of the series was 0.63 (SD = 0.19). The mean WIQ-distance was 34.07 (SD = 26.77), values being smaller for lower ABI values (r = 0.343, p < 0.001). The mean EQ-5D score of the series was 0.58 (SD = 0.21), also showing lower values as the ABI decreased (r = 0.278, p < 0.001). The correlations of WIQ and EQ-5D with ABI were statistically significant in both cases, but always less than 0.400 (between 0.278 and 0.343).
  
  
  CONCLUSIONS
  The correlations of ABI with the questionnaires of walking capacity and quality of life are weak. For this reason, although in clinical practice the ABI of CI patients is commonly measured, decisions should not be taken during the development of IC exclusively on the basis of the ABI.
authors.affiliation: Hospital Universitario de Salamanca and IBSAL, Salamanca, Spain.
authors.forename: F S
authors.initials: FS
authors.lastname: Lozano
authors.forename: J R
authors.initials: JR
authors.lastname: March
authors.forename: J R
authors.initials: JR
authors.lastname: González-Porras
authors.forename: E
authors.initials: E
authors.lastname: Carrasco
authors.forename: J M
authors.initials: JM
authors.lastname: Lobos
authors.forename: E
authors.initials: E
authors.lastname: Ros
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055109:Ankle Brachial Index / Q000401:mortality / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000401:mortality; D011788:Quality of Life; D013030:Spain; D011795:Surveys and Questionnaires