We identified items that were distressing at the time of the critical incident by comparing the mean

intensity of peritraumatic Hedgehog antagonist distress among participants who did or did not endorse the item using one-way analysis of variance (ANOVA), estimating the effect size with the eta2 statistic. In order to reduce the number of items on the inventory, we removed items if the eta2 was<0.015. The remaining characteristics were sorted into three logical domains (situational, systemic and personal characteristics) independently Inhibitors,research,lifescience,medical by two investigators (JH, RGM). Discrepancies were resolved by consensus. 2. Prevalence of endorsing situational, systemic, and personal domains and the relationship of domains to peritraumatic distress. In order to

define the importance of each of the domains (situational, systemic, and personal) to peritraumatic distress, we calculated the prevalence of any item being endorsed, and the number of items which were endorsed for Inhibitors,research,lifescience,medical each domain. The relationship between these variables and peritraumatic distress was calculated with bivariate analysis of variance and Spearman rank-order correlations respectively. Inhibitors,research,lifescience,medical 3. Association of inventory domains with subsequent symptoms. We tested the associations of inventory domains with (i) peritraumatic dissociation, (ii) occurrence and recovery from components of the Acute Stress Reaction (distressing feelings, insomnia, social withdrawal, irritability, physical symptoms of arousal), and (iii) symptoms of depression, posttraumatic stress Inhibitors,research,lifescience,medical and burnout measured at a variable but longer time after the critical incident (i.e. at the time of the study, “current ”), using multivariate analysis of variance. We expected that characteristics of an incident that are validly associated with its critical nature would be strongly associated with the immediate impact of the incident (dissociation and prolonged Acute

Stress Reaction) and weakly associated with Inhibitors,research,lifescience,medical current psychological symptoms at the time of the survey. Finally, we tested whether the number of characteristics endorsed was associated with the same post-incident variables using Spearman’s rank-order correlations. Results Casein kinase 1 Nine hundred and six EMT/paramedics were informed of the study. Of 635 individuals who signed consent forms, 243 (38.3%) completed questionnaires. Of these, 121 (49.8%) identified an incident that was “still troubling ”, 88 (36%) identified an incident that “had been troubling in the past ”, 4 (1.6%) reported on “a composite of a number of critical incidents ”, and 16 (6.6%) reported on “one of your worst calls ”. In this analysis, in order to understand the characteristics of particular critical incidents, we excluded the 4 subjects who reported on a composite index, 14 subjects who did not indicate the nature of the index incident, and 2 subjects who did not complete the Critical Incident Inventory. We report on the remaining 223 participants.