Related Experiment Video
Updated: Aug 29, 2026
Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
Published on: June 12, 2019
Interrater and Intrarater Reliability of the TWSTRS-Delphi Motor Severity Scale for Cervical Dystonia
Glenn T Stebbins1, Charles H Adler2, Alberto Albanese3
1Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA.
Background:
Cervical dystonia (CD) motor severity is typically quantified with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). An expanded version of the Motor Severity section of the TWSTRS ("TWSTRS-Delphi") has been previously evaluated for its clinimetric properties but not for inter- and intrarater reliability.
Objective:
In this study we quantified inter- and intrarater reliability of the Motor Severity section of the TWSTRS-Delphi for CD.
Methods:
Ten raters familiar with the TWSTRS-Delphi and ten raters unfamiliar with it independently scored standardized videos from 90 patients with CD. We computed one-way random intraclass correlation coefficient (ICC, absolute agreement) for total and item scores. We repeated assessments and calculations with a subset of raters to assess intrarater reliability.
Results:
Interrater reliability for the Total score was good for Familiar raters (ICC = 0.697) and fair for Unfamiliar raters (ICC = 0.566). Most individual items achieved fair-excellent interrater agreement in both groups (Familiar 0.415-0.763; Unfamiliar 0.416-0.769). Sagittal Shift, Duration, and Sensory Tricks showed poor agreement. Intrarater reliability was fair-excellent for most items in both groups (Familiar 0.494-0.927; Unfamiliar 0.413-0.877), but poor for Sagittal Shift and Duration among Familiar raters.
Conclusions:
The TWSTRS-Delphi yields reproducible Total and item scores across movement disorder raters. The data pinpoint Sagittal Shift, Duration, and Sensory Tricks as the principal sources of between-rater variability, defining immediate priorities for scale modification and focused training.
