Epidemiology of agitation following brain injury1

Agitation, while considered an important factor influencing outcome following traumatic brain injury (TBI), has been a poorly defined construct. As a result, the literature on agitation has been confusing and incomplete in regard to incidence rates, causes and correlates, intervention methods, and long-term outcomes. In this article, we review previous research on incidence rates, concluding that differences in definition have greatly limited current knowledge. We then review how agitation has been operationalized in previous clinical and research efforts, and we recommend a definition that we believe will allow future studies to proceed in a more systematic manner.