IES-R: Impact of Event Scale-Revised

The IES-R is a 22-item validated measure of subjective distress related to a specific traumatic event. Assesses three PTSD symptom clusters: Intrusion, Avoidance, and Hyperarousal. Score 0–88. Free for clinical and research use. Weiss & Marmar (1997).

What is the IES-R?

The Impact of Event Scale-Revised (IES-R) was developed by Daniel Weiss and Charles Marmar (1997) as an update to the original Impact of Event Scale (Horowitz et al., 1979). The revision added a Hyperarousal subscale to bring the scale into alignment with the DSM-IV PTSD diagnostic criteria. It assesses subjective distress specifically related to a specific traumatic event, making it distinct from general PTSD measures.

The IES-R contains 22 items across three subscales: Intrusion (8 items, intrusive thoughts, images, nightmares), Avoidance (8 items, numbing, avoidance of reminders), and Hyperarousal (6 items, irritability, poor concentration, startle response). Each item is rated on a 5-point scale: 0 (Not at all), 1 (A little bit), 2 (Moderately), 3 (Quite a bit), 4 (Extremely).

The IES-R is free for clinical and research use. It is the most widely used PTSD symptom measure in international trauma research and has been translated into over 20 languages. A total score of ≥33 suggests probable PTSD; ≥37 has been associated with immune function suppression (Weiss, 2007). For DSM-5-TR-aligned PTSD assessment, the PCL-5 is recommended as the primary clinical tool.

Educational reference only. Requires clinical evaluation to confirm PTSD diagnosis.

IES-R Score Interpretation

Weiss & Marmar (1997). Total score cutoffs from Creamer, Bell & Failla (2003) and Weiss (2007).

Trauma Screening Workflows in HiBoop

IES-R alongside PCL-5 and ACE Score, automated scoring and longitudinal tracking for trauma-exposed patients.