2.3.3. Impact of Event Scale-Revised (IES-R)

The Impact of Event Scale-Revised (IES-R) [26] is a 22-item self-report measure that assesses subjective distress caused by traumatic events. Items correspond to 14 of the 17 DSM-IV symptoms of PTSD. Respondents are asked to identify a specific stressful life event (in this case COVID-19) and indicate how much they were distressed or bothered during the preceding 7 days by each difficulty listed. Items are rated on a 5-point Likert scale ranging from 0 (“not at all”) to 4 (“extremely”), with a lower score indicating a less stressful impact. The IES-R yields a total score (ranging from 0 to 88), subscale scores can also be calculated for Intrusion, Avoidance, and Hyperarousal. The IES-R is not used to diagnose PTSD; however, cut-off scores for a preliminary diagnosis of PTSD have been considered [26]. An example question is: “Any reminders brought back feelings about it.” A meta-analysis on IES confirmed its reliability, validity, and sensitivity as a measure of responses to stress in various populations [27] and in the Italian population, as well [28]. The Italian validation indicated the total score of 33 as a significative cut-off for PTSD presence.

Cronbach’s alpha for this study was 0.92 for the total score and ranged from 0.79 (Avoidance) to 0.87 (Intrusion) for the three subscales.