Psychometric evaluation of the myasthenia gravis composite using rasch analysis

Academic Article


  • Introduction: The MG Composite (MGC) is a validated outcome measure of the clinical manifestations of myasthenia gravis. Methods: We performed Rasch analyses of the MGC to investigate additional properties, including its unidimensionality and the appropriateness of the weights assigned to the response categories for the MGC items. Results: The fit statistics indicated that the 10 items belong together and can be summated for a total score. There was an overall absence of item order distortion between response categories. The Rasch model's expected category response values were compatible with item weights previously assigned. Conclusions: Our analysis suggests that: (1) the score can be summated to estimate an overall disease severity score; (2) the response options of the 10 items are not significantly distorted; and (3) the assigned weights of the response options are appropriate. © 2011 Wiley Periodicals, Inc.
  • Authors

    Published In

  • Muscle and Nerve  Journal
  • Digital Object Identifier (doi)

    Pubmed Id

  • 22665822
  • Author List

  • Sadjadi R; Conaway M; Cutter G; Sanders DB; Burns TM
  • Start Page

  • 820
  • End Page

  • 825
  • Volume

  • 45
  • Issue

  • 6