Special communication| Volume 93, ISSUE 8, SUPPLEMENT , S154-S163, August 2012

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Improving Measurement Methods in Rehabilitation: Core Concepts and Recommendations for Scale Development

  • Craig A. Velozo
    Correspondence to Craig A. Velozo, PhD, Dept of Occupational Therapy, College of Public Health and Health Professions, University of Florida, PO Box 100164, Gainesville, FL 32610
    Rehabilitation Outcomes Research Center, North Florida/South Georgia Veterans Health System, Gainesville, FL

    Department of Occupational Therapy, College of Public Health and Health Professions, University of Florida, Gainesville, FL
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  • Ronald T. Seel
    Crawford Research Institute and Brain Injury Program, Shepherd Center, Atlanta, GA
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  • Susan Magasi
    Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL
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  • Allen W. Heinemann
    Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Rehabilitation Institute of Chicago, Chicago, IL
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  • Sergio Romero
    Rehabilitation Outcomes Research Center, North Florida/South Georgia Veterans Health System, Gainesville, FL

    Department of Occupational Therapy, College of Public Health and Health Professions, University of Florida, Gainesville, FL
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      Velozo CA, Seel RT, Magasi S, Heinemann AW, Romero S. Improving measurement methods in rehabilitation: core concepts and recommendations for scale development.
      Validated measurement scales are essential to evaluating clinical outcomes and conducting meaningful and reliable research. The purpose of this article is to present the clinician and researcher with a contemporary 8-stage framework for measurement scale development based on a mixed-methods qualitative and quantitative approach. Core concepts related to item response theory are presented. Qualitative methods are described to conceptualize scale constructs; obtain patient, family, and other stakeholder perspectives; and develop item pools. Item response theory statistical methodologies are presented, including approaches for testing the assumptions of unidimensionality, local independence, monotonicity, and indices of model fit. Lastly, challenges faced by scale developers in implementing these methodologies are discussed. While rehabilitation research has recently started to apply mixed-methods qualitative and quantitative methodologies to scale development, these approaches show considerable promise in advancing rehabilitation measurement.

      Key Words

      List of Abbreviations:

      CAT (computerized adaptive testing), CFA (confirmatory factor analysis), DIF (differential item functioning), ICF (International Classification of Functioning, Disability and Health), IRT (item response theory), logit (log odds unit), NIH (National Institutes of Health), PROMIS (Patient-Reported Outcomes Measurement Information System)
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