Psychological Symptoms Tests

We assessed the presence of posttraumatic stress (PTS) symptoms by administering the Impact of Event Scale–Revised (IES-R),²⁰ a 15-item self-rated 4-point scale based on how often an event has occurred in the past 7 days (0 indicates not at all; 1, rarely; 3, sometimes; 5, often). All IES-R items are anchored to a specific stressor. Besides the IES total subjective stress score, 2 subscales were identified. One subscale measured intrusive symptoms, including intrusive thoughts, nightmares, and intrusive feelings and imagery, using 7 items, with scores ranging from 0 to 35; the other subscale measured avoidance symptoms, such as numbing of responsiveness and avoidance of feelings, situations, or ideas, using 8 items, with scores ranging from 0 to 40.