Clinical Meaningfulness of Individual Items of the Brief Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia

Introduction The Brief Ataxia Rating Scale (BARS) and Scale for the Assessment and Rating of Ataxia (SARA) are used to quantify cerebellar ataxia severity. We investigated how often clinician ratings match patient reports of functional impairment, which scale items patients consider important, and whether incremental changes in item scores are meaningful to patients. Methods 30 patients with cerebellar ataxia completed BARS, SARA, FARS Functional Staging, and an Importance of Activities of Daily Living questionnaire. We studied BARS and SARA item scores for over- or underestimation in relation to patient perception of impairment. We explored patient rankings of item importance in relation to daily function, and their perception of the likely importance of 0.5- and 1-point changes in BARS gait and speech. Results Patients identified gait as most important on BARS and SARA, followed by oculomotor (BARS) and stance (SARA). Heel-to-shin was least important, with highest overestimation on both scales. Total overestimated points were similar between BARS (2.65 +/- 2.80) and SARA (2.78 +/- 2.78). 0.5-point changes in BARS gait and speech scores were rated very or extremely important by 60% and 46.6%, respectively, increasing to 83.3% and 70% for a 1-point change. Conclusion Gait is most meaningful to patients with cerebellar ataxia. BARS oculomotor and SARA stance rank second. BARS and SARA appendicular measures have limited patient-perceived clinical meaningfulness. 0.5-point increments in BARS gait and speech provide greater granularity of assessment and are considered meaningful by a substantial proportion of patients, supporting their relevance in practice and in clinical trials.