Psychometric properties of the International Classification of Functioning, Disability and Health Rehabilitation Set: a Rasch analysis.

The International Classification of Functioning, Disability and Health (ICF) Rehabilitation Set was proposed by the WHO ICF Research branch as a minimum standard for assessing and reporting functioning in a wide range of clinical settings. This study investigates the psychometric properties of ICF Rehabilitation Set using Rasch analysis. It was a multicenter, cross-sectional study involving 515 inpatients in the subacute or chronic phase of recovery from various health conditions selected by quota sampling (stratified by neurological, cardiopulmonary, musculoskeletal and other conditions). Registered physicians or nurses used the developed operational items of the ICF Rehabilitation Set to rate patients' functioning. A Rasch model was performed in assessing the psychometric properties of the ICF Rehabilitation Set. Good reliability was observed in the activity and participation components, but the body functions component needs additional items to distinguish among people with moderate or severe problems. After recalibration, the body functions, activities and participation components showed fit to the Rasch model. However, deletions mandated by the Rasch model decreased the functioning information reflected by the ICF Rehabilitation Set.