Below is a list of difficulties people sometimes have after stressful life events. Please read each item, and then indicate how distressing each difficulty has been for you DURING THE PAST SEVEN DAYS with respect to (… the specific event …), how much were you distressed or bothered by these difficulties? This assessment is not intended to be a diagnosis. If you are concerned about your results in any way, please speak with a health professional.
About IES-R
The IES-R was developed in 1997 by Daniel Weiss and Charles Marmar to reflect the DSM-IV criteria for post-traumatic stress disorder (PTSD). The original Impact of Events Scale (IES) predated the adoption of PTSD as a ‘legitimate’ diagnosis in the DSM-III of 1980 and measured two of the four DSM-IV criteria for PTSD; specifically ‘re-experiencing / intrusion’ and ‘avoidance / numbing’.
The IES-R was designed to also assess hyperarousal, another of the DSM criteria for PTSD. Other criteria include exposure to a traumatic event, duration of symptoms and impairment due to symptoms.
The hyperarousal scale adds new items to the original IES; items 4, 10, 15, 18, 19 and 21. These new items help measure hyperarousal symptoms e.g. anger and irritability, heightened startle response, difficulty concentrating and hypervigilance.
The main strengths of this revised measure are that it is short, quick and easy to administer and score and may be used repeatedly to assess progress. It is intended to be used as a screening tool, not a diagnostic test.
Scoring Guide
Avoidance Subscale = mean of items 5, 7, 8, 11, 12, 13, 17 and 22
Intrusion Subscale = mean of items 1, 2, 3, 6, 9, 14, 16 and 20
Hyperarousal Subscale = mean of items 4, 10, 15, 18, 19 and 21
Total mean IES-R score = The sum of the means of the three subscale scores
The maximum mean score on each of the three subscales is ‘4’, therefore the maximum ‘total mean’ IES- R score is 12. Lower scores are better.
A total IES-R score of 33 or over from a theoretical maximum of 88 signifies the likely presence of PTSD.
References
Horowitz, M.J., Wilner, M. & Alverez, W. (1979). Impact of Events Scale: A measure of subjective stress. Psychosomatic Medicine, 41(3), 209-218.
Weiss, D.S. (2007). The Impact of Event Scale: Revised. In J.P. Wilson & C.S. Tang (Eds.), Cross-cultural assessment of psychological trauma and PTSD (pp. 219-238). New York: Springer.
