Measures
Four questionnaires were utilized for the study:
1. Impact of Event Scale-Revised (IES-R) is a 22-item, self-report measure (for DSM-IV) that assesses subjective distress caused by traumatic events23. The scale had a high internal consistency (alpha = 0.96).
2. Perceived Stress Scale (PSS) is a psychological instrument for measuring the perception of stress. The questions ask about feelings and thoughts during the previous few months24. Internal consistency estimates using Cronbach’s alpha range from 0.67 to 0.91.
3. Spielberger State - Trait Anxiety Inventory (STAI-Y) is a 40-item, self-completed questionnaire that aims to separately assess state anxiety (STAI-Y1, a temporary state influenced by the current situation) and trait anxiety (STAI-Y2, a general propensity to be anxious) with 20 items each25. The internal consistency reliability ranges from 0.91 to 0.95 for the scale of state and from 0.85 to 0.90 for the scale of trait.
4. Pediatric Quality of Life InventoryTM (PedsQL) 4.0 Generic Core Scales is a parent proxy-report including Physical, Emotional, Social, and School Functioning Scales. It assesses parents’ perception of their child’s Health-Related Quality of Life26. The scale has good internal consistency reliability for the total scale score (alpha = 0.90 on parent report).