Original research| Volume 99, ISSUE 4, P629-634, April 2018

Psychometric Evaluation of the Brachial Assessment Tool Part 1: Reproducibility

Published:November 06, 2017DOI:



      To evaluate reproducibility (reliability and agreement) of the Brachial Assessment Tool (BrAT), a new patient-reported outcome measure for adults with traumatic brachial plexus injury (BPI).


      Prospective repeated-measure design.


      Outpatient clinics.


      Adults with confirmed traumatic BPI (N=43; age range, 19–82y).


      People with BPI completed the 31-item 4-response BrAT twice, 2 weeks apart. Results for the 3 subscales and summed score were compared at time 1 and time 2 to determine reliability, including systematic differences using paired t tests, test retest using intraclass correlation coefficient model 1,1 (ICC1,1), and internal consistency using Cronbach α. Agreement parameters included standard error of measurement, minimal detectable change, and limits of agreement.

      Main Outcome Measure



      Test-retest reliability was excellent (ICC1,1=.90–.97). Internal consistency was high (Cronbach α=.90–.98). Measurement error was relatively low (standard error of measurement range, 3.1–8.8). A change of >4 for subscale 1, >6 for subscale 2, >4 for subscale 3, and >10 for the summed score is indicative of change over and above measurement error. Limits of agreement ranged from ±4.4 (subscale 3) to 11.61 (summed score).


      These findings support the use of the BrAT as a reproducible patient-reported outcome measure for adults with traumatic BPI with evidence of appropriate reliability and agreement for both individual and group comparisons. Further psychometric testing is required to establish the construct validity and responsiveness of the BrAT.


      List of abbreviations:

      BPI (brachial plexus injury), BrAT (Brachial Assessment Tool), CI (confidence interval), COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments), DASH (Disabilities of the Arm, Shoulder and Hand), ICC (intraclass correlation coefficient), LoA (limits of agreement), MDC (minimal detectable change), MDC90 (minimal detectable change based on a 90% confidence interval)
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        • Ahmed-Labib M.
        • Golan J.D.
        • Jacques L.
        Functional outcome of brachial plexus reconstruction after trauma.
        Neurosurgery. 2007; 61: 1016-1022
        • Merrell G.A.
        • Barrie K.A.
        • Katz D.L.
        • Wolfe S.W.
        Results of nerve transfer techniques for restoration of shoulder and elbow function in the context of a meta-analysis of the English literature.
        J Hand Surg. 2001; 26: 303-314
        • Yang L.J.
        • Chang K.W.
        • Chung K.C.
        A systematic review of nerve transfer and nerve repair for the treatment of adult upper brachial plexus injury.
        Neurosurgery. 2012; 71: 417-429
        • Ali Z.S.
        • Heuer G.G.
        • Faught R.W.
        • et al.
        Upper brachial plexus injury in adults: comparative effectiveness of different repair techniques.
        J Neurosurg. 2015; 122: 195-201
        • Garg R.
        • Merrell G.A.
        • Hillstrom H.J.
        • Wolfe S.W.
        Comparison of nerve transfers and nerve grafting for traumatic upper plexus palsy: a systematic review and analysis.
        J Bone Joint Surg. 2011; 93: 819-829
        • Dy C.J.
        • Garg R.
        • Lee S.K.
        • Tow P.
        • Mancuso C.A.
        • Wolfe S.W.
        A systematic review of outcomes reporting for brachial plexus reconstruction.
        J Hand Surg. 2015; 40: 308-313
        • Hill B.
        • Williams G.
        • Bialocerkowski A.
        Clinimetric evaluation of questionnaires used to assess activity after traumatic brachial plexus injury in adults: a systematic review.
        Arch Phys Med Rehabil. 2011; 92: 2082-2089
        • Bengtson K.A.
        • Spinner R.J.
        • Bishop A.T.
        • et al.
        Measuring outcomes in adult brachial plexus reconstruction.
        Hand Clin. 2008; 24: 401-415
        • Wellington B.
        Quality of life issues for patients following traumatic brachial plexus injury - part 2 research project.
        J Orthop Nurs. 2010; 14: 5-11
        • Franzblau L.
        • Shauver M.J.
        • Chung K.C.
        Patient satisfaction and self-reported outcomes after complete brachial plexus avulsion injury.
        J Hand Surg. 2014; 39: 948-955.e4
        • Franzblau L.
        • Chung K.C.
        Psychosocial outcomes and coping after complete avulsion traumatic brachial plexus injury.
        Disabil Rehabil. 2015; 37: 135-143
        • Mancuso C.A.
        • Lee S.K.
        • Dy C.J.
        • Landers Z.A.
        • Model Z.
        • Wolfe S.W.
        Expectations and limitations due to brachial plexus injury: a qualitative study.
        Hand (N Y). 2015; 10: 741-749
        • Hill B.
        • Williams G.
        • Olver J.
        • Bialocerkowski A.
        Do existing patient-report activity outcome measures accurately reflect day-to-day arm use following adult traumatic brachial plexus injury?.
        J Rehabil Med. 2015; 47: 438-444
        • Mancuso C.A.
        • Lee S.K.
        • Dy C.J.
        • Landers Z.A.
        • Model Z.
        • Wolfe F.
        Compensation by the injured arm after brachial plexus injury.
        Hand (N Y). 2016; 4: 410-416
        • World Health Organization
        International Classification of Functioning, Disability and Health.
        World Health Organization, Geneva2001
        • Hill B.
        • Pallant J.
        • Williams G.
        • Olver J.
        • Ferris S.
        • Bialocerkowski A.
        Evaluation of internal construct validity and unidimensionality of the brachial assessment tool, a patient-reported outcome measure for brachial plexus injury.
        Arch Phys Med Rehabil. 2016; 97: 2146-2156
        • Zhou Y.
        • Liu P.
        • Rui J.
        • Zhao X.
        • Lao J.
        The clinical characteristics of neuropathic pain in patients with total brachial plexus avulsion: a 30-case study.
        Injury. 2016; 47: 1719-1724
        • Novak C.B.
        • Katz J.
        Neuropathic pain in patients with upper-extremity nerve injury.
        Physio Can. 2010; 62: 190-201
        • Bialocerkowski A.E.
        • Bragge P.
        Measurement error and reliability testing: application to rehabilitation.
        Int J Ther Rehabil. 2008; 15: 422-427
        • Terwee C.B.
        • Bot S.D.
        • de Boer M.R.
        • et al.
        Quality criteria were proposed for measurement properties of health status questionnaires.
        J Clin Epidemiol. 2007; 60: 34-42
        • Portney L.G.
        • Watkins M.P.
        Foundations of clinical research applications to practice.
        3rd ed. Pearson Prentice Hall, Upper Saddle River, NJ2009
        • Hernaez R.
        Reliability and agreement studies: a guide for clinical investigators.
        Gut. 2015; 64: 1018-1027
        • Kottner J.
        • Audige L.
        • Brorson S.
        • et al.
        Guidelines for reporting reliability and agreement studies (GRRAS) were proposed.
        J Clin Epidemiol. 2011; 64: 96-106
        • Guyatt G.H.
        • Kirshner B.
        • Jaeschke R.
        Measuring health status: what are the necessary measurement properties?.
        J Clinical Epidemiol. 1992; 45: 1341-1345
        • De Vet H.C.
        • Terwee C.B.
        • Mokkink L.B.
        • Knol D.L.
        Measurement in medicine: a practical guide.
        Cambridge University Press, Cambridge2011
        • Streiner D.L.
        • Norman G.R.
        • Cairney J.
        Health measurement scales a practical guide to their development and use.
        4th ed. Oxford University Press, New York2015
        • Mokkink L.B.
        • Terwee C.B.
        • Knol D.L.
        • et al.
        The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: a clarification of its content.
        BMC Med Res Methodol. 2010; 10: 22
        • Cleland J.A.
        • Childs J.D.
        • Whitman J.M.
        Psychometric properties of the neck disability index and numeric pain rating scale in patients with mechanical neck pain.
        Arch Phys Med Rehabil. 2008; 89: 69-74
        • Mokkink L.B.
        • Terwee C.B.
        • Patrick D.L.
        • et al.
        The COSMIN checklist for assessing the methodological quality of studies on measurement properties of health status measurement instruments: an international Delphi study.
        Qual Life Res. 2010; 19: 539-549
        • Zou G.Y.
        Sample size formulas for estimating intraclass correlation coefficients with precision and assurance.
        Stat Med. 2012; 31: 3972-3981
        • Mokkink L.B.
        • Terwee C.B.
        • Patrick D.L.
        • et al.
        The COSMIN study reached international consensus on taxonomy, terminology, and definitions of measurement properties for health-related patient-reported outcomes.
        J Clin Epidemiol. 2010; 63: 737-745
        • Shrout P.E.
        • Fleiss J.L.
        Intraclass correlations: uses in assessing rater reliability.
        Psych Bull. 1979; 86: 420-428
        • Rankin G.
        • Stokes M.
        Reliability of assessment tools in rehabilitation: an illustration of appropriate statistical analyses.
        Clin Rehabil. 1998; 12: 187-199
        • Nunnally J.
        • Bernstein I.
        Psychometric theory.
        3rd ed. McGraw-Hill, New York1994
        • Kottner J.
        • Streiner D.L.
        The difference between reliability and agreement.
        J Clin Epidemiol. 2011; 64: 701-702
        • Bland J.M.
        • Altman D.G.
        Statistical methods for assessing agreement between two methods of clinical measurement.
        Lancet. 1986; 1: 307-310
        • Giavarina D.
        Understanding Bland Altman analysis.
        Biochem Med (Zagreb). 2015; 25: 141-151
        • Atkinson G.
        • Nevill A.M.
        Statistical methods for assessing measurement error (reliability) in variables relevant to sports medicine.
        Sport Med. 1998; 26: 217-238
        • De Vet H.C.
        • Bouter L.M.
        • Dick Bezemer P.
        • Beurskens A.J.
        Reproducibility and responsiveness of evaluative outcome measures: theoretical considerations illustrated by an empirical example.
        Int J Tech Assess Health Care. 2001; 17: 479-487
        • Brehm M.A.
        • Scholtes V.A.
        • Dallmeijer A.J.
        • Twisk J.W.
        • Harlaar J.
        The importance of addressing heteroscedasticity in the reliability analysis of ratio-scaled variables: an example based on walking energy-cost measurements.
        Dev Med Child Neurol. 2012; 54: 267-273
        • Beaton D.E.
        • Katz J.N.
        • Fossel A.H.
        • Wright J.G.
        • Tarasuk V.
        • Bombardier C.
        Measuring the whole or the parts? Validity, reliability, and responsiveness of the disabilities of the arm, shoulder and hand outcome measure in different regions of the upper extremity.
        J Hand Ther. 2001; 14: 128-146
        • Rosengren J.
        • Brodin N.
        Validity and reliability of the Swedish version of the Patient Specific Functional Scale in patients treated surgically for carpometacarpal joint osteoarthritis.
        J Hand Ther. 2013; 26: 53-61
        • de Vet H.C.
        • Terwee C.B.
        • Knol D.L.
        • Bouter L.M.
        When to use agreement versus reliability measures.
        J Clin Epidemiol. 2006; 59: 1033-1039
        • Wyrwich K.W.
        • Tierney W.M.
        • Wolinsky F.D.
        Further evidence supporting an SEM-based criterion for identifying meaningful intra-individual changes in health-related quality of life.
        J Clin Epidemiol. 1999; 52: 861-873