title: The development and validation of a novel outcome measure to quantify mobility in the dysvascular lower extremity amputee: the amputee single item mobility measure.
abstract: OBJECTIVE
  This study describes the development and psychometric evaluation of a novel patient-reported single-item mobility measure.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Four Veteran's Administration Medical Centers.
  
  
  METHODS
  Individuals undergoing their first major unilateral lower extremity amputation; 198 met inclusion criteria; of these, 113 (57%) enrolled.
  
  
  METHODS
  None.
  
  
  METHODS
  The Amputee Single Item Mobility Measure, a single item measure with scores ranging from 0 to 6, was developed by an expert panel, and concurrently administered with the Locomotor Capabilities Index-5 (LCI-5) and other outcome measures at six weeks, four months, and 12 months post-amputation. Criterion and construct validity, responsiveness, and floor/ceiling effects were evaluated. Responsiveness was assessed using the standardized response mean.
  
  
  RESULTS
  The overall mean 12-month Amputee Single Item Mobility Measure score was 3.39 ±1.4. Scores for transmetatarsal, transtibial, and transfemoral amputees were 4.2 (±1.3), 3.2 (±1.5), and 2.9 (±1.1), respectively. Amputee Single Item Mobility Measure scores demonstrated "large" and statistically significant correlations with the LCI-5 scores at six weeks (r = 0.72), four months (r = 0.81), and 12 months (r = 0.86). At four months and 12 months, the correlation between Amputee Single Item Mobility Measure scores and hours of prosthetic use were r = 0.69 and r = 0.66, respectively, and between Amputee Single Item Mobility Measure scores and Trinity Amputation and Prosthesis Experience Scales functional restriction scores were r = 0.45 and r = 0.67, respectively. Amputee Single Item Mobility Measure scores increased significantly from six weeks to 12 months post-amputation. Minimal floor/ceiling effects were demonstrated.
  
  
  CONCLUSIONS
  In the unilateral dysvascular amputee, the Amputee Single Item Mobility Measure has strong criterion and construct validity, excellent responsiveness, and does not exhibit floor/ceiling effects.
authors: Spectrum Research, Inc., Tacoma, WA, USA dan@specri.com.
authors: Daniel C
authors: DC
authors: Norvell
authors: VA Puget Sound Health Care System, Seattle, WA, USA Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
authors: Rhonda M
authors: RM
authors: Williams
authors: VA Puget Sound Health Care System, Seattle, WA, USA Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
authors: Aaron P
authors: AP
authors: Turner
authors: VA Puget Sound Health Care System, Seattle, WA, USA Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
authors: Joseph M
authors: JM
authors: Czerniecki
mesh_terms: D000368:Aged; D000671:Amputation, Surgical; D001186:Artificial Limbs; D015331:Cohort Studies; D003925:Diabetic Angiopathies / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D017063:Outcome Assessment, Health Care; D016491:Peripheral Vascular Diseases / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D011594:Psychometrics; D015203:Reproducibility of Results; D057566:Self Report
keywords: Amputation; diabetes; mobility; patient-reported outcome; peripheral arterial disease; validity