title: Construct Validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M) in Adults With Lower Limb Amputation.
abstract: To assess construct validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M), a self-report mobility measure for people with lower limb amputation (LLA).
  
  
  
  Cross-sectional study.
  
  
  
  Private prosthetic clinics (n=37).
  
  
  
  Current lower limb prosthesis users (N=199; mean age ± SD, 55.4±14.3y; 71.4% men) were assessed before receiving a replacement prosthesis, prosthetic socket, and/or prosthetic knee.
  
  
  
  Not applicable.
  
  
  
  Convergent construct validity was examined using correlations between participants' PLUS-M T-scores and measures of physical function, mobility, and balance, including the Amputee Mobility Predictor (AMP), timed Up and Go (TUG), Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Prosthesis Evaluation Questionnaire-Mobility Subscale (PEQ-MS), and Activities-specific Balance Confidence (ABC) Scale. Known-groups construct validity was evaluated by comparing differences in PLUS-M T-scores among participants grouped by Medicare Functional Classification Level (MFCL).
  
  
  
  PLUS-M T-scores demonstrated a moderate positive relationship with AMP scores (ρ=.54, P<.001) and a moderate negative relationship with TUG times (ρ=-.56, P<.001). The PLUS-M also showed a strong positive relationship with PEQ-MS scores (ρ=.78, P<.001), ABC Scale scores (ρ=.81, P<.001), and PROMIS-PF T-scores (ρ=.81, P<.001). Significant differences (P<.05) in PLUS-M T-scores were found among groups of people classified by different MFCLs.
  
  
  
  Study results support the validity of the PLUS-M as a self-report measure of prosthetic mobility. Correlations between PLUS-M and measures of physical function, mobility, and balance indicate convergent construct validity. Similarly, significant differences in PLUS-M T-scores across MFCL groups provide evidence of known-groups construct validity. In summary, evidence indicates that PLUS-M has good construct validity among people with LLA.
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA. Electronic address: bhafner@uw.edu.
authors: Brian J
authors: BJ
authors: Hafner
authors: Research Department, Miami Veterans Affairs Healthcare System, Miami, FL; Department of Physical Therapy, University of Miami Miller School of Medicine, Coral Gables, FL.
authors: Ignacio A
authors: IA
authors: Gaunaurd
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA.
authors: Sara J
authors: SJ
authors: Morgan
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA.
authors: Dagmar
authors: D
authors: Amtmann
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA.
authors: Rana
authors: R
authors: Salem
authors: Research Department, Miami Veterans Affairs Healthcare System, Miami, FL; Department of Physical Therapy, University of Miami Miller School of Medicine, Coral Gables, FL.
authors: Robert S
authors: RS
authors: Gailey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000534:rehabilitation*; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D026741:Physical Therapy Modalities / Q000592:standards*; D004856:Postural Balance; D015203:Reproducibility of Results; D016138:Walking; D055815:Young Adult
keywords: Amputation; Artificial limbs; Motor activity; Movement; Outcome assessment (health care); Rehabilitation; Self report