3. The Inter-rater Variability and Reliability of the use of the Modified Ashworth Scale for the Upper Motor Neuron Syndrome

Abstract

This poster reports on the results of a quality improvement project. The objective was to determine the inter-rater variability and reliability of the Modified Ashworth Scale for assessing spasticity in people with traumatic brain injury.Hamilton Health Sciences operates the comprehensive spasticity management program. In this regional program, the MAS is used by physical therapists, occupational therapists and physicians as a quantitative measure of spasticity. The MAS is used to make determinations related to treatment options as well as follow the efficacy of treatment.The participants were 28 practitioners from the disciplines of medicine, physical therapy and occupational therapy. Each practitioner was provided an explicit set of written instructions and then asked to examine two patients with traumatic spinal cord injury. The MAS scores were reported anonymously. As well, the two patients were assigned MAS scores by two expert spasticity management clinicians.There was substantial inter-rater variability with MAS scores. Fleiss' Generalized Kappa, which is chance-corrected measure of agreement among three or more raters, was 0.18. This is interpreted as poor agreement. Furthermore, only 46 percent of the participants agreed with the MAS scores assigned by the physician expert in the first subject and 50 percent of the participants agreed with the MAS scores assigned by the physician expert in the second subject.Clinicians should be cognizant of the variability of the MAS when making determinations related to patient management.