Barnes akathisia scale: Usefulness of standardized videotape method in evaluation of the reliability and in training raters

The Barnes Akathisia Scale was translated into Japanese and the reliability of its Japanese version was tested using the standardized videotape method. Generalized kappa values of the inter-rater reliability among eight trained raters ranged from 0.740 to 0.754 in individual subjective and objective items, whereas that in the item of global clinical assessment was 0,686. The Cohen's kappa values were significantly higher in the trained raters than those in the untrained ones in the items: objective, distress related to the restlessness in the subjective, and global clinical assessment. Evaluation in the test-retest reliability performed by two trained raters showed excellent results, with the Cohen's kappa values higher than 0.88 in all items. The present results demonstrate that the Japanese version of the Barnes Akathisia Scale has a high reliability in evaluating the symptoms of neuroleptic-induced akathisia, despite the existence of a few causes which produce raters' disagreements. The results also suggest that training raters prior to clinical evaluation is indispensable to keep the high reliability of this scale, and that the standardized videotape methods are quite useful for this training procedure.