title: Assessment of the Minimum Clinically Important Difference in the Timed Up and Go Test After Surgery for Lumbar Degenerative Disc Disease.
abstract: The Timed Up and Go Test (TUG Test) has previously been described as a reliable tool to evaluate objective functional impairment in patients with degenerative disc disease.
  
  
  
  The aim of this study was to assess the minimum clinically important difference (MCID) of the TUG Test.
  
  
  
  The TUG Test (measured in seconds) was correlated with validated patient-reported outcome measures (PROs) of pain intensity (Visual Analog Scale for back and leg pain), functional impairment (Oswestry Disability Index, Roland Morris Disability Index), and health-related quality of life measures (Short Form-12 and EuroQol 5D). Three established methods were used to establish anchor-based MCID values using responders of the following PROs (Visual Analog Scale back and leg pain, Oswestry Disability Index, Roland Morris Disability Index, EuroQol 5D index, and Short Form-12 Physical Component Summary) as anchors: (1) average change, (2) minimum detectable change, and (3) change difference approach.
  
  
  
  One hundred patients with a mean ± SD age of 56.2 ± 16.1 years, 57 (57%) male, 45 patients undergoing microdiscectomy, 35 undergoing lumbar decompression, and 20 undergoing fusion surgery were studied. The 3 MCID computation methods revealed a range of MCID values according to the PRO used from 0.9 s (Oswestry Disability Index based on the change difference approach) to 6.0 s (EuroQol 5D index based on the minimum detectable change approach), with a mean MCID of 3.4 s for all measured PROs.
  
  
  
  The MCID for the TUG Test time is highly variable depending on the computation technique used. The average TUG Test MCID was 3.4 s using all 3 methods and all anchors.
authors.affiliation: Department of Neurosurgery and Fac-ulty of Medicine, University Hospital Geneva, Geneva, Switzerland.
authors.forename: Oliver P
authors.initials: OP
authors.lastname: Gautschi
authors.affiliation: Department of Neurosurgery and Fac-ulty of Medicine, University Hospital Geneva, Geneva, Switzerland.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Stienen
authors.affiliation: Department of Neurosurgery and Fac-ulty of Medicine, University Hospital Geneva, Geneva, Switzerland.
authors.forename: Marco V
authors.initials: MV
authors.lastname: Corniola
authors.affiliation: Depart-ment of Neurosurgery, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
authors.forename: Holger
authors.initials: H
authors.lastname: Joswig
authors.affiliation: Department of Neurosurgery and Fac-ulty of Medicine, University Hospital Geneva, Geneva, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Schaller
authors.affiliation: Depart-ment of Neurosurgery, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hildebrandt
authors.affiliation: School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Nicolas R
authors.initials: NR
authors.lastname: Smoll
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D004185:Disability Evaluation; D006233:Persons with Disabilities; D017586:Diskectomy; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011788:Quality of Life; D016896:Treatment Outcome; D064232:Visual Analog Scale
keywords: Degenerative disc disease; Low back pain; Lumbar spine surgery; MCID; Objective outcome measurement; Postoperative outcome; Timed Up and Go Test