Inter- and intrarater reliability of the Ashworth Scale and the Disability Assessment Scale in patients with upper-limb poststroke spasticity

Objective: To evaluate the reliability of the Ashworth Scale and the Disability Assessment Scale (DAS) in poststroke patients with upper-limb spasticity and functional disability. Design: Single-center trial. Setting: University medical center. Participants: Nine patients greater than or equal to6 months poststroke with upper-limb spasticity and impairment in the areas of hygiene, dressing, limb posture, or pain were included in the analysis. Interventions: Ten experienced medical professionals rated each patient in randomized order twice on the same day (results based on mean of evaluations at times 1 and 2). Elbow, wrist, finger, and thumb flexion tones were assessed by using the Ashworth score (range, 0-4), and functional disability was assessed using the DAS (range, 0-3). Main Outcome Measures: Intra- and interrater reliability of the Ashworth Scale and DAS. Results: For the Ashworth parameters, 38 of 40 evaluations indicated excellent (weighted kappagreater than or equal to.75) or good (weighted kappagreater than or equal to.4) intrarater reliability. For DAS parameters, 31 of 40 evaluations indicated excellent or good intrarater reliability. The interrater reliability was also good for both the Ashworth Scale (Kendall W=.598-.792) and DAS (Kendall W=.494-.772) with statistically significant agreement found among raters (all P<.001). Conclusions: In patients with upper-limb spasticity after stroke, the Ashworth Scale and DAS had good intra- and interrater reliability when used by trained medical professions.