OBJECTIVES: To determine whether the International Classification of Functioning, Disability and Health (ICF) categories relevant to spinal cord injury (SCI) can be integrated in clinical measures and to obtain insights to guide their future operationalization. Specific aims are to find out whether the ICF categories relevant to SCI fit a Rasch model taking into consideration the dimensionality found in previous investigations, local item dependencies, or differential item functioning.

DESIGN: All second-level ICF categories collected in the Development of ICF Core Sets for SCI project in specialized centers within 15 countries from 2006 through 2008.

SETTING: Secondary data analysis.

PARTICIPANTS: Adults (N=1048) with SCI from the early postacute and long-term living context.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Two unidimensional Rasch analyses: one for the ICF categories from body functions and body structures components and another for the ICF categories from the activities and participation component.

RESULTS: Results support good reliability and targeting of the ICF categories in both dimensions. In each dimension, few ICF categories were subject to misfit. Local item dependency was observed between ICF categories of the same chapters. Group effects for age and sex were observed only to a small extent.

CONCLUSIONS: The validity of ICF categories to develop measures of functioning in SCI for clinical practice and research is to some extent supported. Model adjustments were suggested to further improve their operationalization and psychometrics.