Is the Yale Global Tic Severity Scale a valid tool for parent-reported assessment in the paediatric population? A prospective observational study in Taiwan
Objective The Yale Global Tic Severity Scale (YGTSS) is the most commonly used clinician-rated evaluation tool for Tourette syndrome (TS), with established reliability and validity.This study aims to determine whether the YGTSS is a valid parent-reported assessment in the TS population.Design A prospective cohort study.Setting A major medical centr