title: Prevalence and risk factors of PAD among patients with elevated ABI.
abstract: OBJECTIVE
  To assess the prevalence and clinical significance of elevated ankle-brachial index (ABI) in patients referred to vascular consultation.
  
  
  METHODS
  Retrospective clinical study.
  
  
  METHODS
  In 1,762 patients referred with a suspicion of peripheral arterial disease (PAD), ABI and toe brachial index (TBI) were measured by photoplethysmography. ABI>/=1.3 was considered falsely elevated and TBI<0.60 was the diagnostic criterion for PAD.
  
  
  RESULTS
  The prevalence of elevated ABI was 8.4% and that of PAD among these patients 62.2%. PAD was significantly more prevalent among subjects with severe symptoms (rest pain, ulcers or gangrene) than in those with intermittent claudication (83.8% and 45.3%, respectively, p<0.001). The risk of PAD diagnosis was ten-fold (OR 10.31, 95% CI 2.07-51.30) among those with chronic renal failure, five-fold among patients with a history of smoking (OR 5.63, 95% CI 1.22-26.00) and over three-fold (OR 3.44, 95% CI 1.46-8.12) among those with coronary heart disease. The specificities of elevated ABI threshold levels (1.3, 1.4 and 1.5) in identifying PAD were 86%, 94% and 96%, respectively, the sensitivities being 44%, 38% and 36%, respectively.
  
  
  CONCLUSIONS
  The prevalence of elevated ABI in patients referred to vascular consultation is 8.4% and that of PAD among these 62.2%. PAD is significantly more probable among those with chronic renal failure, a history of smoking and coronary heart disease. Furthermore, the specificity of elevated ABI (>/=1.3) in recognizing PAD is good, whereas the sensitivity is only satisfactory.
authors.affiliation: Department of Surgery, Division of Vascular Surgery, Tampere University Hospital, Tampere, Finland. velipekka.suominen@pshp.fi
authors.forename: V
authors.initials: V
authors.lastname: Suominen
authors.forename: T
authors.initials: T
authors.lastname: Rantanen
authors.forename: M
authors.initials: M
authors.lastname: Venermo
authors.forename: J
authors.initials: J
authors.lastname: Saarinen
authors.forename: J
authors.initials: J
authors.lastname: Salenius
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle / Q000098:blood supply*; D001794:Blood Pressure; D001916:Brachial Artery / Q000503:physiopathology*; D003327:Coronary Disease / Q000150:complications / Q000503:physiopathology; D005121:Extremities / Q000098:blood supply; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007511:Ischemia / Q000150:complications / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010044:Outpatient Clinics, Hospital; D016491:Peripheral Vascular Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology*; D017156:Photoplethysmography; D011237:Predictive Value of Tests; D015995:Prevalence; D012017:Referral and Consultation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012907:Smoking / Q000009:adverse effects