Advertisement

Construct Validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M) in Adults With Lower Limb Amputation

Published:August 30, 2016DOI:https://doi.org/10.1016/j.apmr.2016.07.026

      Abstract

      Objective

      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).

      Design

      Cross-sectional study.

      Setting

      Private prosthetic clinics (n=37).

      Participants

      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.

      Interventions

      Not applicable.

      Main Outcome Measures

      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).

      Results

      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.

      Conclusions

      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.

      Keywords

      List of abbreviations:

      ABC (Activities-specific Balance Confidence), AMP (Amputee Mobility Predictor), LLA (lower limb amputation), MFCL (Medicare Functional Classification Level), PEQ-MS (Prosthesis Evaluation Questionnaire–Mobility Subscale), PLUS-M (Prosthetic Limb Users Survey of Mobility), PROMIS (Patient-Reported Outcomes Measurement Information System), PROMIS-PF (Patient-Reported Outcomes Measurement Information System–Physical Function), TUG (timed Up and Go)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Archives of Physical Medicine and Rehabilitation
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Fortington L.V.
        • Rommers G.M.
        • Geertzen J.H.
        • Postema K.
        • Dijkstra P.U.
        Mobility in elderly people with a lower limb amputation: a systematic review.
        J Am Med Dir Assoc. 2012; 13: 319-325
        • Suckow B.D.
        • Goodney P.P.
        • Nolan B.W.
        • et al.
        Domains that determine quality of life in vascular amputees.
        Ann Vasc Surg. 2015; 29: 722-730
        • Norvell D.C.
        • Turner A.P.
        • Williams R.M.
        • Hakimi K.N.
        • Czerniecki J.M.
        Defining successful mobility after lower extremity amputation for complications of peripheral vascular disease and diabetes.
        J Vasc Surg. 2011; 54: 412-419
        • Davies B.
        • Datta D.
        Mobility outcome following unilateral lower limb amputation.
        Prosthet Orthot Int. 2003; 27: 186-190
        • Pell J.P.
        • Donnan P.T.
        • Fowkes F.G.
        • Ruckley C.V.
        Quality of life following lower limb amputation for peripheral arterial disease.
        Eur J Vasc Surg. 1993; 7: 448-451
        • Asano M.
        • Rushton P.
        • Miller W.C.
        • Deathe B.A.
        Predictors of quality of life among individuals who have a lower limb amputation.
        Prosthet Orthot Int. 2008; 32: 231-243
        • Penn-Barwell J.G.
        Outcomes in lower limb amputation following trauma: a systematic review and meta-analysis.
        Injury. 2011; 42: 1474-1479
        • Laferrier J.Z.
        • Gailey R.
        Advances in lower-limb prosthetic technology.
        Phys Med Rehabil Clin N Am. 2010; 21: 87-110
        • Amtmann D.
        • Cook K.F.
        • Johnson K.L.
        • Cella D.
        The PROMIS initiative: involvement of rehabilitation stakeholders in development and examples of applications in rehabilitation research.
        Arch Phys Med Rehabil. 2011; 92: S12-S19
        • Greenhalgh J.
        • Meadows K.
        The effectiveness of the use of patient-based measures of health in routine practice in improving the process and outcomes of patient care: a literature review.
        J Eval Clin Pract. 1999; 5: 401-416
        • Valderas J.M.
        • Kotzeva A.
        • Espallargues M.
        • et al.
        The impact of measuring patient-reported outcomes in clinical practice: a systematic review of the literature.
        Qual Life Res. 2008; 17: 179-193
        • Greenhalgh J.
        The applications of PROs in clinical practice: what are they, do they work, and why?.
        Qual Life Res. 2009; 18: 115-123
        • Black N.
        • Burke L.
        • Forrest C.B.
        • et al.
        Patient-reported outcomes: pathways to better health, better services, and better societies.
        Qual Life Res. 2016; 25: 1103-1112
        • Schlesinger M.
        • Grob R.
        • Shaller D.
        Using patient-reported information to improve clinical practice.
        Health Serv Res. 2015; 50: 2116-2154
        • Condie E.
        • Scott H.
        • Treweek S.
        Lower limb prosthetic outcome measures: a review of the literature 1995 to 2005.
        J Prosthet Orthot. 2006; 18: P13-P45
        • Heinemann A.W.
        • Connelly L.
        • Ehrlich-Jones L.
        • Fatone S.
        Outcome instruments for prosthetics: clinical applications.
        Phys Med Rehabil Clin N Am. 2014; 25: 179-198
        • Gaunaurd I.
        • Spaulding S.E.
        • Amtmann D.
        • et al.
        Use of and confidence in administering outcome measures among clinical prosthetists: results from a national survey and mixed-methods training program.
        Prosthet Orthot Int. 2015; 39: 314-321
      1. Hafner BJ, Spualding SE, Salem R, Morgan SJ, Gaunaurd IA, Gailey RS. Prosthetists' perceptions and use of outcome measures in clinical practice: long-term effects of focused continuing education. Prosthet Orthot Int 2016 Sep 16 [Epub ahead of print].

        • Jette D.U.
        • Halbert J.
        • Iverson C.
        • Miceli E.
        • Shah P.
        Use of standardized outcome measures in physical therapist practice: perceptions and applications.
        Phys Ther. 2009; 89: 125-135
        • Cella D.
        • Gershon R.
        • Lai J.S.
        • Choi S.
        The future of outcomes measurement: item banking, tailored short-forms, and computerized adaptive assessment.
        Qual Life Res. 2007; 16: 133-141
        • Jette A.M.
        • Haley S.M.
        Contemporary measurement techniques for rehabilitation outcomes assessment.
        J Rehabil Med. 2005; 37: 339-345
        • Hays R.D.
        • Morales L.S.
        • Reise S.P.
        Item response theory and health outcomes measurement in the 21st century.
        Med Care. 2000; 38: Ii28-Ii42
        • Reeve B.B.
        • Hays R.D.
        • Bjorner J.B.
        • et al.
        Psychometric evaluation and calibration of health-related quality of life item banks: plans for the Patient-Reported Outcomes Measurement Information System (PROMIS).
        Med Care. 2007; 45: S22-S31
        • Amtmann D.
        • Abrahamson D.
        • Morgan S.
        • et al.
        The PLUS-M: item bank of mobility for prosthetic limb users.
        Qual Life Res. 2014; 23: 39-40
        • Hafner B.J.
        • Morgan S.J.
        • Abrahamson D.C.
        • Amtmann D.
        Characterizing mobility from the prosthetic limb user's perspective: use of focus groups to guide development of the Prosthetic Limb Users Survey of Mobility.
        Prosthet Orthot Int. 2015 May 5; ([Epub ahead of print])
        • Morgan S.J.
        • Amtmann D.
        • Abrahamson D.C.
        • Kajlich A.J.
        • Hafner B.J.
        Use of cognitive interviews in the development of the PLUS-M item bank.
        Qual Life Res. 2014; 23: 1767-1775
      2. Hafner BJ, Morgan SJ, Askew RA. Psychometric evaluation of self-report outcome measures for prosthetic applications. J Rehabil Res Dev; in press.

      3. Prosthetic Limb Users Survey of Mobility (PLUS-M™) Version 1.2 short forms users guide. 2014 (Available at:) (Accessed June 24, 2016)
        • Palmetto Government Benefits Administrators
        Lower limb prostheses. DMERC Medicare Advisory.
        Centers for Medicare and Medicaid Services, BaltimoreDecember 1994: 99-105
        • Noridian Healthcare Solutions
        Local coverage determination (LCD) for lower limb prostheses (L33787).
        American Medical Association, 2016 (Available at:) (Accessed June 24, 2016)
        • Coman L.
        • Richardson J.
        Relationship between self-report and performance measures of function: a systematic review.
        Can J Aging. 2006; 25: 253-270
        • Terwee C.B.
        • Mokkink L.B.
        • Knol D.L.
        • Ostelo R.W.
        • Bouter L.M.
        • de Vet H.C.
        Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist.
        Qual Life Res. 2012; 21: 651-657
        • Gershon R.
        • Rothrock N.E.
        • Hanrahan R.T.
        • Jansky L.J.
        • Harniss M.
        • Riley W.
        The development of a clinical outcomes survey research application: Assessment Center.
        Qual Life Res. 2010; 19: 677-685
        • Chaudhry S.
        • Jin L.
        • Meltzer D.
        Use of a self-report-generated Charlson Comorbidity Index for predicting mortality.
        Med Care. 2005; 43: 607-615
        • Potter K.
        • Fulk G.D.
        • Salem Y.
        • Sullivan J.
        Outcome measures in neurological physical therapy practice: part I. Making sound decisions.
        J Neurol Phys Ther. 2011; 35: 57-64
        • Cella D.
        • Riley W.
        • Stone A.
        • et al.
        The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005–2008.
        J Clin Epidemiol. 2010; 63: 1179-1194
        • Fries J.F.
        • Spitz P.
        • Kraines R.G.
        • Holman H.R.
        Measurement of patient outcomes in arthritis.
        Arthritis Rheum. 1980; 23: 137-145
        • Haley S.M.
        • McHorney C.A.
        • Ware J.E.
        Evaluation of the MOS SF-36 Physical Functioning Scale (PF-10): I. Unidimensionality and reproducibility of the Rasch item scale.
        J Clin Epidemiol. 1994; 47: 671-684
        • McHorney C.A.
        • Haley S.M.
        • Ware Jr., J.E.
        Evaluation of the MOS SF-36 Physical Functioning Scale (PF-10): II. Comparison of relative precision using Likert and Rasch scoring methods.
        J Clin Epidemiol. 1997; 50: 451-461
        • Rose M.
        • Bjorner J.B.
        • Gandek B.
        • Bruce B.
        • Fries J.F.
        • Ware Jr., J.E.
        The PROMIS Physical Function item bank was calibrated to a standardized metric and shown to improve measurement efficiency.
        J Clin Epidemiol. 2014; 67: 516-526
        • Fries J.F.
        • Witter J.
        • Rose M.
        • Cella D.
        • Khanna D.
        • Morgan-DeWitt E.
        Item response theory, computerized adaptive testing, and PROMIS: assessment of physical function.
        J Rheumatol. 2014; 41: 153-158
        • Amtmann D.
        • Morgan S.J.
        • Kim J.
        • Hafner B.J.
        Health-related profiles of people with lower limb loss.
        Arch Phys Med Rehabil. 2015; 96: 1474-1483
      4. Patient Reported Outcomes Measurement Information System. PROMIS scoring guide: version 1.0 short forms, profile short forms, computerized adaptive testing 2011 Available at: http://www.assessmentcenter.net. Accessed June 24, 2016.

        • Miller W.C.
        • Deathe A.B.
        • Speechley M.
        Lower extremity prosthetic mobility: a comparison of 3 self-report scales.
        Arch Phys Med Rehabil. 2001; 82: 1432-1440
        • Legro M.W.
        • Reiber G.D.
        • Smith D.G.
        • del Aguila M.
        • Larsen J.
        • Boone D.
        Prosthesis evaluation questionnaire for persons with lower limb amputations: assessing prosthesis-related quality of life.
        Arch Phys Med Rehabil. 1998; 79: 931-938
        • Franchignoni F.
        • Giordano A.
        • Ferriero G.
        • Orlandini D.
        • Amoresano A.
        • Perucca L.
        Measuring mobility in people with lower limb amputation: Rasch analysis of the mobility section of the Prosthesis Evaluation Questionnaire.
        J Rehabil Med. 2007; 39: 138-144
        • Powell L.E.
        • Myers A.M.
        The Activities-specific Balance Confidence (ABC) Scale.
        J Gerontol A Biol Sci Med Sci. 1995; 50A: M28-M34
        • Myers A.M.
        • Powell L.E.
        • Maki B.E.
        • Holliday P.J.
        • Brawley L.R.
        • Sherk W.
        Psychological indicators of balance confidence: relationship to actual and perceived abilities.
        J Gerontol A Biol Sci Med Sci. 1996; 51: M37-M43
        • Miller W.C.
        • Deathe A.B.
        • Speechley M.
        Psychometric properties of the Activities-specific Balance Confidence Scale among individuals with a lower-limb amputation.
        Arch Phys Med Rehabil. 2003; 84: 656-661
        • Sakakibara B.M.
        • Miller W.C.
        • Backman C.L.
        Rasch analyses of the Activities-specific Balance Confidence Scale with individuals 50 years and older with lower-limb amputations.
        Arch Phys Med Rehabil. 2011; 92: 1257-1263
        • Podsiadlo D.
        • Richardson S.
        The timed “Up & Go”: a test of basic functional mobility for frail elderly persons.
        J Am Geriatr Soc. 1991; 39: 142-148
        • Schoppen T.
        • Boonstra A.
        • Groothoff J.W.
        • de Vries J.
        • Goeken L.N.
        • Eisma W.H.
        The timed “Up and Go” test: reliability and validity in persons with unilateral lower limb amputation.
        Arch Phys Med Rehabil. 1999; 80: 825-828
        • Lin S.J.
        • Bose N.H.
        Six-minute walk test in persons with transtibial amputation.
        Arch Phys Med Rehabil. 2008; 89: 2354-2359
        • Dite W.
        • Connor H.J.
        • Curtis H.C.
        Clinical identification of multiple fall risk early after unilateral transtibial amputation.
        Arch Phys Med Rehabil. 2007; 88: 109-114
        • Gailey R.S.
        • Roach K.E.
        • Applegate E.B.
        • et al.
        The Amputee Mobility Predictor: an instrument to assess determinants of the lower-limb amputee's ability to ambulate.
        Arch Phys Med Rehabil. 2002; 83: 613-627
        • Shapiro S.S.
        • Wilk M.B.
        An analysis of variance test for normality (complete samples).
        Biometrika. 1965; 52: 591-611
        • Dancey C.P.
        • Reidy J.
        Statistics without maths for psychology using SPSS for Windows.
        Prentice Hall, Pearson Education, Harlow2002
        • Holm S.
        A simple sequentially rejective multiple test procedure.
        Scand J Stat. 1979; 6: 65-70
        • Franchignoni F.
        • Orlandini D.
        • Ferriero G.
        • Moscato T.A.
        Reliability, validity, and responsiveness of the Locomotor Capabilities Index in adults with lower-limb amputation undergoing prosthetic training.
        Arch Phys Med Rehabil. 2004; 85: 743-748
        • Stratford P.W.
        • Kennedy D.
        • Pagura S.M.
        • Gollish J.D.
        The relationship between self-report and performance-related measures: questioning the content validity of timed tests.
        Arthritis Rheum. 2003; 49: 535-540
        • Brooks D.
        • Parsons J.
        • Hunter J.P.
        • Devlin M.
        • Walker J.
        The 2-minute walk test as a measure of functional improvement in persons with lower limb amputation.
        Arch Phys Med Rehabil. 2001; 82: 1478-1483
        • Kaluf B.
        Evaluation of mobility in persons with limb loss using the Amputee Mobility Predictor and the Prosthesis Evaluation Questionnaire–Mobility Subscale: a six-month retrospective chart review.
        J Prostet Orthot. 2014; 26: 70-76