title: Baseline functional performance predicts the rate of mobility loss in persons with peripheral arterial disease.
abstract: OBJECTIVE
  We compared rates of mobility loss among persons with versus without peripheral arterial disease (PAD). Associations between baseline functional performance and mobility loss in persons with and without PAD were studied.
  
  
  BACKGROUND
  Persons with PAD have poorer functional performance than persons without PAD. The prognostic value of poorer performance in persons with PAD is unknown.
  
  
  METHODS
  Participants were 398 persons with and 240 without PAD who were free of mobility impairment at baseline. Participants were followed for a median of 50 months. Baseline measures included the 6-min walk and the Short Physical Performance Battery score. Mobility status, assessed annually, was defined as the self-reported loss of the ability to walk one-quarter mile or walk up and down one flight of stairs without assistance.
  
  
  RESULTS
  Adjusting for age and gender, we found that PAD participants had a greater rate of mobility loss than persons without PAD (hazard ratio [HR] 1.63; 95% confidence interval [CI] 1.03 to 2.56). This difference was not statistically significant after additional adjustment for baseline performance. Among PAD participants, risk of mobility loss in the lowest versus the 2 highest quartiles of baseline performance were as follows: HR 9.65 (95% CI 3.35 to 27.77, p < 0.001) for the 6-min walk and HR 12.84 (95% CI 4.64 to 35.55, p < 0.001) for the Short Physical Performance Battery when adjusting for confounders.
  
  
  CONCLUSIONS
  Persons with PAD experience greater mobility loss than persons without PAD. This association was explained by poorer baseline functional performance among participants with PAD. Poorer lower extremity performance predicts increased mobility loss in persons with and without PAD.
authors.affiliation: Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA. mdm608@northwestern.edu
authors.forename: Mary M
authors.initials: MM
authors.lastname: McDermott
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Lu
authors.initials: L
authors.lastname: Tian
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.forename: Yihua
authors.initials: Y
authors.lastname: Liao
authors.forename: Michael H
authors.initials: MH
authors.lastname: Criqui
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D016491:Peripheral Vascular Diseases / Q000503:physiopathology*; D011446:Prospective Studies; D016138:Walking