Assessment of agitation following brain injury

Advances in clinical interventions for agitation, as well as progress in research toward better understanding of the construct, have been limited by the lack of a reliable and valid measure. This article provides a practical overview of the measurement characteristics of the Agitated Behavior Scale (ABS) (Corrigan, J. Clin Exp Neuropsychol 1989; 11: 261–277) [1]. This 14-item scale has shown significant inter-rater reliability for all items; Total Score inter-rater correlations exceeding 0.70; and internal consistencies based on Cronbach's alphas have consistently exceeded 0.80. The original development of the ABS emphasized the content validity of items and demonstrated the concurrent validity of the Total Score. Subsequent studies have shown the ABS to be predictive of change in cognitive status, and able to differentiate confusion and inattention from agitation. Construct validity has been further substantiated by the identification of underlying factors that have proven stable over multiple samples.