title: Psychometric properties of the Impact of Event Scale - Revised.
abstract: This study investigated the psychometric properties of the Impact of Event Scale -- Revised (IES-R) in two samples of male Vietnam veterans: a treatment-seeking sample with a confirmed posttraumatic stress disorder (PTSD) diagnosis (N = 120) and a community sample with varying levels of traumatic stress symptomatolgy (N = 154). The scale showed high internal consistency (alpha = 0.96). Confirmatory factor analysis did not provide support for a three-factor solution corresponding to the three subscales of intrusion, avoidance, and hyperarousal. Exploratory factor analysis suggested that either a single, or a two-factor solution (intrusion/hyperarousal and avoidance), provide the best account of date. However, correlations among the subscales were higher in the community sample than in the treatment sample, suggesting that the IES-R may be sensitive to a more general construct of traumatic stress in those with lower symptom levels. The correlation between the IES-R and the PTSD Checklist was high (0.84) and a cutoff of 1.5 (equivalent to a total score of 33) was found to provide the best diagnostic accuracy.
authors.affiliation: Australian Centre for Posttraumatic Mental Health, Heidelberg, Victoria, Australia. markcc@unimelb.edu.au
authors.forename: Mark
authors.initials: M
authors.lastname: Creamer
authors.forename: Richard
authors.initials: R
authors.lastname: Bell
authors.forename: Salvina
authors.initials: S
authors.lastname: Failla
mesh_terms: D000328:Adult; D005163:Factor Analysis, Statistical; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis*; D014728:Veterans / Q000523:psychology*