title: Outcome measures report different aspects of patient function three months following critical care.
abstract: BACKGROUND
  Previous investigation of the relationship between physical performance and patient self-report physical function (PF) measures in intensive care unit (ICU) survivors have not been performed.
  
  
  OBJECTIVE
  To (1) analyze the extent to which other activity-based measures of physical performance may serve as proxies for the 6-min walk test (6 MWT); (2) determine the extent to which the Short Form (SF) 36 domain of PF and physical component summary (PCS) score, reflect components of physical performance and (3) examine the relationship between demographic and ICU variables and the 6 MWT.
  
  
  METHODS
  Cross-sectional data from two clinical trials.
  
  
  METHODS
  Two acute care hospitals (Melbourne, Australia and Denver, USA).
  
  
  METHODS
  A total of 177 survivors of ICU.
  
  
  METHODS
  Were evaluated at 3 months. Performance-based measures were: 6 MWT, timed up and go test (TUG), the five times sit to stand test (5 × STS), the Berg balance scale (BBS) and two self-report measures: the SF-36 PF domain and the PCS score.
  
  
  RESULTS
  6 MWT showed excellent correlation with the TUG (rho = -0.79) and BBS (rho = 0.80); and good correlation with 5 × STS (rho = -0.69) and SF-36 PF scores (rho = 0.69). 6 MWT explained 54 and 33% of variance in SF-36 PF and PCS scores respectively. No variables were clinically important in predicting 6 MWT.
  
  
  CONCLUSIONS
  The 6 MWT and TUG may both be acceptable measures of PF performance 3 months after ICU. Performance-based tests measure different constructs than self-report measures and choice of outcome variables should be aligned with study aims to ensure the most appropriate measure is used.
authors.affiliation: Department of Physiotherapy, The University of Melbourne, Melbourne, Australia, l.denehy@unimelb.edu.au.
authors.forename: Linda
authors.initials: L
authors.lastname: Denehy
authors.forename: Amy
authors.initials: A
authors.lastname: Nordon-Craft
authors.forename: Lara
authors.initials: L
authors.lastname: Edbrooke
authors.forename: Daniel
authors.initials: D
authors.lastname: Malone
authors.forename: Sue
authors.initials: S
authors.lastname: Berney
authors.forename: Margaret
authors.initials: M
authors.lastname: Schenkman
authors.forename: Marc
authors.initials: M
authors.lastname: Moss
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia; D003120:Colorado; D003422:Critical Care / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D057566:Self Report; D012959:Socioeconomic Factors; D017741:Survivors / Q000706:statistics & numerical data*; D013997:Time Factors