ABSTRACT
This chapter is a comprehensive reference manual providing information on the Expanded Disability Status Scale (EDSS), which is a clinician rating scale that was developed for people with multiple sclerosis (MS). The scale has three goals: to adequately describe the sum total of a patient’s disabilities, to be responsive to changes in the patient’s condition, and to be simple and manageable to use. A brief history of the instrument's development is provided, along with a description of item content and administration/scoring procedures. Psychometric properties are reviewed and a critical commentary is provided. Key references are cited and in most cases the actual scale is included, giving the reader easy access to the instrument.
