The IES-R is a 22-item self-report measure that assesses subjective distress caused by traumatic events. It is a revised version of the older version, the 15-item IES (Horowitz, Wilner, & Alvarez, 1979). The IES-R contains seven additional items related to the hyperarousal symptoms of PTSD, which were not included in the original IES. Items correspond directly to 14 of the 17 DSM-IV symptoms of PTSD. Respondents are asked to identify a specific stressful life event and then indicate how much they were distressed or bothered during the past seven days by each "difficulty" listed.
Items are rated on a 5-point scale ranging from 0 ("not at all") to 4 ("extremely"). The IES-R yields a total score (ranging from 0 to 88) and subscale scores can also be calculated for the Intrusion, Avoidance, and Hyperarousal subscales. The authors recommend using means instead of raw sums for each of these subscales scores to allow comparison with scores from the Symptom Checklist 90 - Revised (SCL-90-R; Derogatis, 1994). In general, the IES-R (and IES) is not used to diagnosis PTSD, however, cutoff scores for a preliminary diagnosis of PTSD have been cited in the literature.
"Any reminders brought back feelings about it." (Respondents rate their degree of distress during the past seven days.)
The 15-item IES is the original scale, but is missing hyperarousal symptoms (Horowitz, Wilner, & Alvarez, 1979).
Weiss, D. S., & Marmar, C. R. (1996). The Impact of Event Scale - Revised. In J. Wilson & T. M. Keane (Eds.), Assessing psychological trauma and PTSD (pp. 399-411). New York: Guilford. (NOTE: Includes measure in its entirety.)
Orsillo (2001) (PDF) p. 267.
Orsillo, Susan M. (2001). Measures for acute stress disorder and posttraumatic stress disorder. In M.M. Antony & S.M. Orsillo (Eds.), Practitioner's guide to empirically based measures of anxiety (pp. 255-307). New York: KluwerAcademic/Plenum. PILOTS ID 24368
Measure availability: Information on measures is available to everyone. However, the assessment tools themselves can only be distributed to qualified mental health professionals and researchers. We maintain measures developed by affiliated staff of the National Center for PTSD.