Psychometric properties of the Stroke Impairment Assessment Set (SIAS)

Abstract

Objective: To review the psychometric properties of the Stroke Impairment Assessment Set (SAS), which was developed in 1990 as a comprehensive instrument to assess stroke impairment.

Method: Articles related to the SIAS were retrieved from the MEDLINE and the Folia Centro Japonica.

Results: Thirty-five articles were retrieved and analyzed. 1) Scale quality: Rasch analysis demonstrated the unidimensionality of the SIAS. Factor analysis produced factors corresponding to the 6 SIAS subscales. 2) Interrater reliability: The weighted kappas were high except for the unaffected side quadriceps item for which the score distribution was skewed. 3) Concurrent validity: Significant correlations were found between a) SIAS motor items and the Motricity Index or the Brunnstrom stage, b) SIAS lower extremity scores and the Functional Independence Measure (FIMSM) locomotion scores, c) trunk scores and abdominal manual muscle testing, d) visuospatial scores and line bisection and copying task scores, and e) speech scores and the FIMSM communication scores. 4) Predictive validity: Three studies attempting to predict discharge functional status demonstrated that adding the SIAS as one of the predictors enhanced the predictive power 5) Responsiveness: The SIAS was more responsive to changes than the Motricity Index, the Brunnstrom stage, or the National Institutes of Health Stroke Scale.

Conclusion: The SIAS is a useful measure of stroke impairment with well-established psychometric properties.