title: Validity of a modified shuttle test in adult cystic fibrosis.
abstract: BACKGROUND
  The purpose of this study was to provide some evidence of the validity of a modified shuttle test (MST) by comparing performance on the MST with peak oxygen consumption (VO2peak) measured during a treadmill test in a group of adult patients with cystic fibrosis.
  
  
  METHODS
  Twenty patients with stable cystic fibrosis performed a ramped maximal treadmill test (STEEP protocol) and the MST using a randomised balanced design.
  
  
  RESULTS
  The relationship between the distance achieved on the MST and VO2peak was strong (r = 0.95, p<0.01) with 90% of the variance in VO2peak explained by the variance in MST distance. The relationship was represented by the regression equation (with 95% confidence intervals) VO2peak = 6.83 (2.85 to 10.80) + 0.028 (0.019 to 0.024) x MST distance.
  
  
  CONCLUSIONS
  This study provides evidence of the construct validity of the MST as an objective measure of exercise capacity in adults with cystic fibrosis.
authors.affiliation: Sport and Exercise Sciences, University of Ulster at Jordanstown, Co. Antrim BT37 0QB, UK.
authors.forename: J
authors.initials: J
authors.lastname: Bradley
authors.forename: J
authors.initials: J
authors.lastname: Howard
authors.forename: E
authors.initials: E
authors.lastname: Wallace
authors.forename: S
authors.initials: S
authors.lastname: Elborn
mesh_terms: D000328:Adult; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000378:metabolism*; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011379:Prognosis; D012129:Respiratory Function Tests; D016138:Walking