Interrater Reliability of the Scale for the Assessment and Rating of Ataxia, Berg Balance Scale, and Functional Independence Measure Motor Domain in Individuals With Hereditary Cerebellar Ataxia

Abstract

ObjectiveTo determine the interrater reliability of the Scale for the Assessment and Rating of Ataxia (SARA), Berg Balance Scale (BBS), and motor domain of the FIM (m-FIM) administered by physiotherapists in individuals with a hereditary cerebellar ataxia (HCA). DesignParticipants were assessed by 1 of 4 physiotherapists. Assessments were video-recorded and the remaining 3 physiotherapists scored the scales for each participant. Raters were blinded to each other's scores. SettingAssessments were administered at 3 clinical locations in separate states in Australia. ParticipantsTwenty-one individuals (mean age=47.63 years; SD=18.42; 13 male and 8 female) living in the community with an HCA were recruited (N=21). Main Outcome MeasuresTotal and single-item scores of the SARA, BBS, and m-FIM were examined. The m-FIM was conducted by interview. ResultsIntraclass coefficients (2,1) for the total scores of the m-FIM (0.92; 95% confidence interval [CI], 0.85-0.96), SARA (0.92; 95% CI, 0.86-0.96), and BBS (0.99; 95% CI, 0.98-0.99) indicated excellent interrater reliability. However, there was inconsistent agreement with the individual items, with SARA item 5 (right side) and item 7 (both sides) demonstrating poor interrater reliability and items 1 and 2 demonstrating excellent reliability. ConclusionsThe m-FIM (by interview), SARA, and BBS have excellent interrater reliability for use when assessing individuals with an HCA. Physiotherapists could be considered for administration of the SARA in clinical trials. However, further work is required to improve the agreement of the single-item scores and to examine the other psychometric properties of these scales.