Impact of event scale: psychometric properties

Background For more than 20 years, the Impact of Event Scale (IES) has been widely used as a measure of stress reactions after traumatic events. Aims To review studies that evaluated the IESs psychometric properties. Method Literature review. Results The results indicated that the IES's two-factor structure is stable over different types of events, that it can discriminate between stress reactions at different times after the event, and that it has convergent validity with observer-diagnosed post-traumatic stress disorder. The use of IES in many psychopharmacological trials and outcome studies is supportive of the measure's clinical relevance. Conclusions The IES is a useful measure of stress reactions after a range of traumatic events, and it is valuable for detecting individuals who require treatment. Declaration of interest This study was granted support from the Cancer Research Coordinating Committee and the Cohn Foundation, the University of California in San Francisco, the Swedish Research Council for the Humanities and Social Sciences and the Swedish Medical Research Council.