The Impact of Event Scale-Revised: Psychometric properties in a sample of motor vehicle accident survivors

This study examined the factor structure, internal consistency, concurrent validity, and discriminative validity of the Impact of Event Scale-Revised (IES-R, [Weiss, D. S. & Marmar, C. R. (1997). The Impact of Event Scale-Revised. In: J. P. Wilson & T. M. Keane (Eds.). Assessing psychological trauma and PTSD (pp. 399–411). New York: Guilford Press]) in a sample of 182 individuals who had experienced a serious motor vehicle accident. Results supported the three-factor structure of the IES-R, Intrusion, Avoidance, and Hyperarousal, with adequate internal consistency noted for each subscale. Support was obtained for the concurrent and discriminative validity, as well as the absence of social desirability effects. Although some differences were noted between the IES-R Avoidance subscale and diagnostically based measures of this cluster of symptoms, these differences do not necessarily signify measurement problems with the IES-R. The IES-R seems to be a solid measure of post-trauma phenomena that can augment related assessment approaches in clinical and research settings.