ABSTRACT
This chapter is a comprehensive reference manual providing information on the Fatigue Impact Scale (FIS), which is a self-rating scale, designed to measure the respondent’s experience of fatigue in terms of the disability associated with fatigue, not the severity of the symptoms. Development of the FIS arose in response to the limited sampling of fatigue items that was available from generic health-related quality of life scales. The FIS provides a comprehensive measure of the impact of fatigue on everyday functioning. It was carefully developed and its multidimensional structure, incorporating cognitive, physical and psychosocial items, samples each of the function, activity and participation components of the ICF. 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.
