The inter-rater reliability and construct validity of the Functional Independence Measure for multiple sclerosis subjects

Abstract

The functional independence measure (FIM) is a new assessment scale, which has been extensively used in the uniform data system (UDS) throughout the United States. Eighty-one multiple sclerosis (MS) subjects were assessed by two trained physiotherapists using the FIM. Inter-rater reliability was found to be high for the total score (intraclass correlation coefficient [ICC] = 0.83 and moderate to substantial for items assessing physical disability (Kappa = 0.70-0.50), except for the item concerned with assessing independence in walking or in wheelchair (Kappa = 0.16). The inter-rater agreement of FIM items in the communication and social cognition subsections was only fair. The internal consistency of the FIM assessment scale was found to be high, with a Cronbach's alpha of at least 0.94. Relatively high Spearman rank correlation coefficients were found between total FIM and total Expanded Disability Status Scale (EDSS). The present reliability and validity study on FIM provides scientific data for a sample of MS patients with differing levels of disability. The FIM assessment appears to be reliable and valid tool to assess general physical needs in MS. Its use to assess neuropsychological needs is, however, questionable with MS subjects.