Psychometric properties of the sensory scale of the Fugl-Meyer Assessment in stroke patients

Abstract

Objective: To examine the psychometric properties of the sensory scale of the Fugl-Meyer Assessment (FMA-S) in stroke patients with a broad range of neurological and functional impairment at times from 14 to 180 days after stroke. Subjects: A total of 176 first stroke patients consecutively admitted to a university based medical centre. Design: This prospective, longitudinal investigation was based on data collected at 14, 30, 90 and 180 days after stroke. Main outcome measures: Reliability (inter-rater reliability and internal consistency), validity (convergent and predictive validity) and responsiveness of the FMA-S were examined. Results: The inter-rater agreement of the total score of the FMA-S was excellent, with an intraclass correlation coefficient of 0.93. The Cronbach's alphas of the FMA-S at four time points after stroke ranged from 0.94 to 0.98, indicating excellent internal consistency. However, the FMA-S showed a significant ceiling effect (more than 44.4% of the subjects achieving the highest score), poor to moderate inter-rater reliability for light touch items (weighted kappa ranging from 0.30 to 0.55), low to moderate validity (Spearman's rho ranging from 0.29 to 0.53), and low to moderate responsiveness (standardized response mean ranging from 0.27 to 0.67) at different post-stroke stages of recovery. Conclusions: The psychometric properties of the FMA-S in measuring sensory function do not support its clinical use in stroke patients. Further studies on methods to improve the psychometric properties of the FMA-S are needed.