Category specification and measurement instruments in large spinal cord injury studies: a comparison using the International Classification of Functioning, Disability, and Health as a reference.

The objective of this paper was to examine whether large longitudinal studies have comprehensively covered the functioning of persons with spinal cord injuries (SCI), using the International Classification of Functioning, Disability and Health (ICF) as reference framework. First, the literature was reviewed to select relevant studies. Second, category specifications measured in the included studies were linked to the ICF and compared with the Brief ICF Core Sets for postacute and chronic situations. Finally, all measurement instruments used to assess these category specifications were listed according to the corresponding ICF category. Four studies were included: the National SCI Database in the United States, the Australian SCI Register, the European Multicenter Study about SCI, and the Dutch research program "Restoration of mobility in SCI rehabilitation." All measures could be linked to the ICF Core Sets. However, all studies only partly covered (range, 14-27) the 49 categories of the Brief ICF Core Sets. Least well covered were categories of body structures and environmental factors. Besides the International Standards for Neurological Classification of SCI (American Spinal Injury Association Impairment Scale), the areas of functioning were measured using the same measurement instruments in all studies. None of the included longitudinal studies comprehensively cover functioning. There is the need to develop truly comprehensive longitudinal studies in SCI.