extended · article · 2016

Metric properties of the Spinal Cord Independence Measure - Self report in a community survey

Birgit Prodinger; C Ballert; Martin W. G. Brinkhof; Alan Tennant; Marcel W. M. Post

OBJECTIVE: The Spinal Cord Independence Measure - Self Report (SCIM-SR) is a self-report instrument for assessing functional independence of persons with spinal cord injury. This study examined the internal construct validity and reliability of the SCIM-SR, when administered in a community survey, using the Rasch measurement model. METHODS: Rasch analysis of data from 1,549 individuals with spinal cord injury who completed the SCIM-SR. RESULTS: In the initial analysis no fit to the Rasch model was achieved. Items were grouped into testlets to accommodate the substantial local dependency. Due to the differential item functioning for lesion level and degree, spinal cord injury-specific sub-group analyses were conducted. Fit to the Rasch model was then achieved for individuals with tetraplegia and complete paraplegia, but not for those with incomplete paraplegia. Comparability of ability es...