Content validity of the expanded and revised Gross Motor Function Classification System

The aim of this study was to validate the expanded and revised Gross Motor Function Classification System (GMFCS-E&R) for children and youth with cerebral palsy using group consensus methods. Eighteen physical therapists participated in a nominal group technique to evaluate the draft version of a 12- to 18-year age band. Subsequently, 30 health professionals from seven countries participated in a Delphi survey to evaluate the revised 12- to 18-year and 6- to 12-year age bands. Consensus was defined as agreement with a question by at least 80% of participants. After round 3 of the Delphi survey, consensus was achieved for the clarity and accuracy of the descriptions for each level and the distinctions between…