title: The five-repetition sit-to-stand test as a functional outcome measure in COPD.
abstract: BACKGROUND
  Moving from sitting to standing is a common activity of daily living. The five-repetition sit-to-stand test (5STS) is a test of lower limb function that measures the fastest time taken to stand five times from a chair with arms folded. The 5STS has been validated in healthy community-dwelling adults, but data in chronic obstructive pulmonary disease (COPD) populations are lacking.
  
  
  OBJECTIVE
  To determine the reliability, validity and responsiveness of the 5STS in patients with COPD.
  
  
  METHODS
  Test-retest and interobserver reliability of the 5STS was measured in 50 patients with COPD. To address construct validity we collected data on the 5STS, exercise capacity (incremental shuttle walk (ISW)), lower limb strength (quadriceps maximum voluntary contraction (QMVC)), health status (St George's Respiratory Questionnaire (SGRQ)) and composite mortality indices (Age Dyspnoea Obstruction index (ADO), BODE index (iBODE)). Responsiveness was determined by measuring 5STS before and after outpatient pulmonary rehabilitation (PR) in 239 patients. Minimum clinically important difference (MCID) was estimated using anchor-based methods.
  
  
  RESULTS
  Test-retest and interobserver intraclass correlation coefficients were 0.97 and 0.99, respectively. 5STS time correlated significantly with ISW, QMVC, SGRQ, ADO and iBODE (r=-0.59, -0.38, 0.35, 0.42 and 0.46, respectively; all p<0.001). Median (25th, 75th centiles) 5STS time decreased with PR (Pre: 14.1 (11.5, 21.3) vs Post: 12.4 (10.2, 16.3) s; p<0.001). Using different anchors, a conservative estimate for the MCID was 1.7 s.
  
  
  CONCLUSIONS
  The 5STS is reliable, valid and responsive in patients with COPD with an estimated MCID of 1.7 s. It is a practical functional outcome measure suitable for use in most healthcare settings.
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, , Harefield, UK.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Jones
authors.forename: Samantha S C
authors.initials: SS
authors.lastname: Kon
authors.forename: Jane L
authors.initials: JL
authors.lastname: Canavan
authors.forename: Mehul S
authors.initials: MS
authors.lastname: Patel
authors.forename: Amy L
authors.initials: AL
authors.lastname: Clark
authors.forename: Claire M
authors.initials: CM
authors.lastname: Nolan
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.forename: William D-C
authors.initials: WD
authors.lastname: Man
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D015588:Observer Variation; D011187:Posture / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000534:rehabilitation; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology*
keywords: COPD Pathology; Exercise; Pulmonary Rehabilitation