Short Tilte:The Mayo-Portland participation index: A brief and psychometrically sound measure of brain injury outcome
Journal:Archives of Physical Medicine and Rehabilitation
Year, Volume, Issue, Page(s):04, 85, 12, 1989-1996
Study examined the internal consistency, interrater agreement, concurrent validity, and floor and ceiling effects of the participation index (PI) of the Mayo-Portland Adaptability Inventory (MPAI). Rasch analysis was conducted on PI data derived from MPAIs completed by people with acquired brain injury, their significant others, and rehabilitation staff to determine the internal consistency of each independent rater group and composite measures that combined rater groups. Correlations with the full-scale MPAI were examined to assess concurrent validity, as was interrater agreement. The PI showed satisfactory internal consistency, concurrent validity, interrater agreement, and minimal floor and ceiling effects, although evidence of rater bias was also apparent. Composite indices showed more favorable psychometric properties than ratings by individual raters.