Evidence Hub

Tremor Research Group Essential Tremor Rating Scale (TETRAS): Assessing Impact of Different Item Instructions and Procedures

W. Ondo, B. Pascual, On Behalf Of The Tremor Research Group

Tremor and Other Hyperkinetic Movements, 2020

24 citations

Abstract

Introduction: The Tremor Research Group Essential Tremor Rating Scale (TETRAS) is a well-validated instrument to assess essential tremor. However, similar to all other tremor rating scales, specific instructions for individual tasks are based mostly on expert opinion and tradition. Several tasks have multiple possible variations that have never been compared to determine if they impact score. Methods: Using blinded, randomized videotapes, a group of tremor experts evaluated multiple ET patients to determine: 1. whether assessments of spirals and writing samples are similar if the rater only sees the end result as opposed to actually watching the task, 2. whether arm tremor ratings (postural and wing-beating) are similar if the subjects hold both hands out concurrently vs. if they only hold one arm out at a time, 3. whether heal to shin tremor scores vary between supine and sitting, and 4. compared cursive vs script writing samples. Results: Intraclass correlation coefficients (ICC) were excellent (>0.95) for all arm assessments. Writing tremor was rated worse if only rating the spiral/writing photos (p < 0.05) rather than also viewing the writing process, arm tremor scores were higher if each arm was rated individually (p < 0.001), heal to shin scores were higher when done sitting (p = 0.01), and cursive writing tended to be rated higher than script (p = 0.08). Discussion: Minor procedure differences when administering the TETRAS can significantly alter results.

How strong is the evidence?

Evidence Hub reads this as a randomized trial. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free