VALIDATION OF THE FUNCTIONAL ASSESSMENT OF MULTIPLE-SCLEROSIS QUALITY-OF-LIFE INSTRUMENT

Based on scientific literature and interviews with clinicians and pati ents, we developed a quality of life instrument for use with people wi th MS called the Functional Assessment of Multiple Sclerosis (FAMS). T he initial item pool consisted of 88 questions: 28 from the general ve rsion of the Functional Assessment of Cancer Therapy quality of life i nstrument, plus 60 generated by patients, providers, and literature re view. The validation samples comprised a mail survey cohort (N = 377) and a clinical cohort (N = 56). Both cohorts provided evidence for int ernal consistency of the derived subscales, test-retest reliability, c ontent validity, concurrent validity, and construct validity. Principa l components and Rasch measurement model analyses were applied sequent ially to survey sample data, reducing test length to 44 questions, div ided into six subscales: mobility, symptoms, emotional well-being (dep ression), general contentment, thinking/fatigue, and family/social wel l-being. Fifteen initially rejected questions were added back as misce llaneous (unscored) questions for their potential clinical and empiric al value. The mobility subscale was strongly predictive of the Kurtzke Extended Disability Status Scale and the Scripps Neurologic Rating Sc ales. The other five subscales were not, indicating they measure aspec ts of patient quality of life not captured by the neurologic exam. The final 59-item English language instrument (FAMS version 2) is availab le for inclusion in clinical trials and clinical practice.