Objective: To assess the validity and reliability of a Numeric Rating Scale (NRS) for the measurement of spasticity in multiple sclerosis.
Design: Longitudinal study with multiple comparators over two clinic visits.
Setting: Rehabilitation Centre in the North East of England, UK.
Subjects: A total of thirty-five patients, with a diagnosis of multiple sclerosis (MS) that were attending a rehabilitation clinic.
Results: The test/re-test reliability of the NRS showed there was a high correlation between the two visits (r = 0.672). Construct validity was assessed by examining the relationship between the mean spasticity NRS and each of the other spasticity assessment tools. There was a statistically significant correlation between subject's mean NRS diary scores and the Modified Ashworth Scale scores at both visits (Visit 1, r = 0.459, p = 0.0056; Visit 2, r = 0.446, p = 0.0106). There was a moderate, statistically significant correlation between the mean NRS diary scores and the Tardieu Scale (Visit 1, r = 0.429, p = 0.0113; Visit 2, r = 0.407, p = 0.0209).
Conclusions: The spasticity NRS has been shown to be a valid and reliable tool in the assessment of spasticity with a moderate to high level of correlation with other clinician rated instruments used to assess spasticity.