 Researchers Mayou, Ehlers and Hobbs (2000), were interested in evaluating the 3-year results of a randomized controlled trial of debriefing for consecutive subjects admitted to the hospital following a traffic accident.The patients were assessed in the hospital using the Impact of Event Scale (IES), Brief Symptom Inventory (BSI) and a questionnaire, and were then reassessed at 3 years and 3 months.The intervention used was psychological debriefing.