title: Shuttle walking test as predictor of survival in chronic obstructive pulmonary disease patients enrolled in a rehabilitation program.
abstract: BACKGROUND
  The Incremental Shuttle Walking Test (ISWT) is used to assess exercise capacity in chronic obstructive pulmonary disease (COPD) and is employed as an outcome measure for pulmonary rehabilitation. We studied the value of this test in predicting survival in COPD patients enrolled in a rehabilitation program.
  
  
  METHODS
  A total of 416 patients performed an ISWT before entering a 7-week outpatient pulmonary rehabilitation program. Their survival was observed over a mean period of 4.5 years (range = 1.2-7.2 years).
  
  
  RESULTS
  During the observation period, 169 (40.6%) patients died. Univariate analyses showed that the ISWT as well as age, gender, present and previous tobacco smoking, forced expiratory volume in 1 second, body mass index, oxygen saturation at rest, long-term oxygen therapy, Medical Research Council dyspnea score, and treatment with oral corticosteroids were significantly associated with survival. Multivariate analysis, including relevant confounders, revealed that low ISWT was independently associated with poor survival (P = .001). The association was not linear and the risk of dying increased markedly when ISWT was lower than 170 m (RR = 2.84, 95% CI: 2.05-3.93).
  
  
  CONCLUSIONS
  This study shows that the ISWT is a strong and independent predictor of survival in patients with COPD enrolled in a rehabilitation program.
authors.affiliation: Department of Cardiology and Respiratory Medicine, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark. ringbaek@dadlnet.dk
authors.forename: Thomas
authors.initials: T
authors.lastname: Ringbaek
authors.forename: Gerd
authors.initials: G
authors.lastname: Martinez
authors.forename: Eva
authors.initials: E
authors.lastname: Brøndum
authors.forename: Jane
authors.initials: J
authors.lastname: Thøgersen
authors.forename: Mike
authors.initials: M
authors.lastname: Morgan
authors.forename: Peter
authors.initials: P
authors.lastname: Lange
mesh_terms: D000368:Aged; D015992:Body Mass Index; D016001:Confidence Intervals; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010045:Outpatients; D010101:Oxygen Consumption; D011379:Prognosis; D015397:Program Evaluation; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality* / Q000534:rehabilitation; D012306:Risk; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D006113:United Kingdom; D016138:Walking / Q000502:physiology*