Psychometric Testing of the Agitation Severity Scale for Acute Presentation Behavioral Management Patients in the Emergency Department

Agitation is a vexing problem frequently observed in emergency department acute psychiatric patients, yet no instruments to measure agitation in this setting and population were found upon review of the literature. Previously developed agitation rating scales are limited by the length of observation they require, their need for participation by the patient, complexity in scoring, and a lack of validity in this setting and population. The purpose of this study was to psychometrically evaluate and refine an observation-based agitation scale for use with emergency department acute psychiatric patients. Using a methodological design, the 21-item Agitation Severity Scale was utilized to assess 270 adult psychiatric patients in the emergency setting in a prospective, observational fashion. Reliability analysis, item analysis, exploratory factor analysis, and validity assessments were completed. The relationship between Agitation Severity Scale scores and scores on the previously established Overt Agitation Severity Scale was evaluated. The instrument was reduced to 17 items representing four factors (Aggressive Behaviors, Interpersonal Behaviors, Involuntary Motor Behaviors, and Physical Stance) that accounted for nearly 70% of observed variance, Cronbach's alpha = 0.91. Evidence of internal consistency reliability, equivalence reliability, construct validity, and convergent validity was established. Through this study, the 17-item Agitation Severity Scale demonstrated acceptable levels of reliability and validity when used with acute psychiatric patients in the emergency setting. This instrument holds promise as a method of enhancing clinical communication about agitation, evaluating the efficacy of interventions aimed at decreasing agitation, and as a research tool.