The functional index for living with multiple sclerosis: development and validation of a new quality of life...

Addressing health-related quality of life is considered a desirable component of routine care for patients with multiple sclerosis. However, use of available health-related quality of life surveys is not part of routine multiple sclerosis care, possibly due to administration, scoring, and interpretation challenges presented by available questionnaires. The 25-item Functional Index for Living with Multiple Sclerosis (FILMS) questionnaire was developed and validated to allow providers to monitor and easily apply health-related quality of life information to the patient encounter. The development and pilot test processes and the results of the validation study are reported here. Convergent validity, internal consistency reliability, and test-retest reproducibility were evaluated. Strong correlations of Functional Index for Living with Multiple Sclerosis subscales with control questionnaires were demonstrated by Pearson's correlation coefficients from 0.73 to 0.88. Internal consistency reliabilities ranged from 0.80 to 0.90, demonstrating that items were grouped into the appropriate subscale domains and that the subscale domains and the questionnaire as a whole exhibited good directionality. Test-retest reproducibility was 0.91.