Psychometric properties of seven self-report measures of posttraumatic stress disorder in college students with mixed civilian trauma exposure

In this study psychometric properties of seven self-report measures of posttraumatic stress disorder (PTSD) were compared. The seven scales evaluated were the Davidson Trauma Scale (DTS), the PTSD Checklist (PCL), the Posttraumatic Stress Diagnostic Scale (PDS), the Civilian Mississippi Scale (CMS), the Impact of Event Scale-Revised (IES-R), the Penn Inventory for Posttraumatic Stress Disorder (Penn), and the PK scale of the MMPI-2 (PK). Participants were 239 (79 male and 160 female) trauma-exposed undergraduates. All seven measures exhibited good test-retest reliability and internal consistency. The PDS, PCL and DTS demonstrated the best convergent validity; the IES-R, PDS, and PCL demonstrated the best discriminant validity; and the PDS, PCL, and IES-R demonstrated the best diagnostic utility. Overall, results most strongly support the use of the PDS and the PCL for the assessment of PTSD in this population.     

Dimensionality of the posttraumatic stress response among police officers and fire fighters: an evaluation of two self-report scales

Confirmatory factor analyses were done to assess the dimensionality of the stress response in a sample of police officers and fire fighters (n = 1,168) involved in the 1992 air disaster in Amsterdam. The confirmatory factor analyses were applied to the responses on two psychometrically different instruments, i.e., the Self-Rating Inventory for Posttraumatic Stress Disorder (SRIP) and the Impact of Event Scale (IES). The previously found distinction between (active) avoidance and numbing in samples highly affected by posttraumatic stress disorder appears to be applicable to the stress response of a less affected sample. For the SRIP, a five-factor structure (i.e., intrusion, avoidance, hyperarousal, emotional numbing and sleep disturbance) appeared to fit slightly better than the four-factor structures from previous findings. For the IES, our results replicated findings of a four-dimensional structure (i.e., intrusion, avoidance, numbing and sleep disturbance) underlying the posttraumatic stress response. The factors of the best-fitting structure of both instruments proved reliable. Due to the psychometric properties of the two instruments, the relationship between similar factors in both instruments was only low to moderate. Compared with the IES, factors of the SRIP were, however, less discriminative from other symptoms of psychopathology. Replication in different traumatized or community samples is recommended.     

The structure of posttraumatic stress disorder symptoms in combat veterans: a confirmatory factor analysis of the impact of event scale

There has been controversy over the most appropriate way to define symptom clusters for posttraumatic stress disorder (PTSD). We tested the factor structure of the Impact of Event Scale (IES) in a sample of 195 male combat veterans with chronic PTSD by using confirmatory factor analysis. The two-factor model including Intrusion (i.e., unwanted memories of the event) and Avoidance (i.e., attempts to avoid reminders and numbing of emotional responsiveness) deviated significantly from good fit. However, a four-factor model, including Intrusion and Effortful Avoidance subscales, as well as Sleep Disturbance and Emotional Numbing subscales, fit significantly better. Correlations with other PTSD measures are explored and implications for the conceptualization of PTSD are discussed.     

The development of the Self-Rating Inventory for Posttraumatic Stress Disorder

In this study a newly developed Self-rating Inventory for Posttraumatic Stress Disorder (PTSD) is presented. The instrument consists of 47 items, reflecting DSM-III-R criteria, associated features and items corresponding to the disorder of extreme stress not otherwise specified. All items are phrased in a trauma-independent way and are measured on an intensity scale. The instrument was validated on 76 subjects with war-related trauma and 59 psychiatric outpatients, one third of whom were traumatized. Test-retest for the scale was 0.90. The coefficient alpha appeared to be 0.96 for the 47-items scale and 0.92 for the 22 DSM-III-R subscale. The scale correlated significantly with the Clinician Administered PTSD Scale, the Mississippi Scale for Combat-related PTSD, the MMPI PTSD subscale and the Impact of Event Scale. The overall efficiency of the Self-rating Inventory for PTSD was comparable to the overall efficiency of the Mississippi Scale and superior to the MMPI PTSD subscale. Factor analysis on the 22 DSM-III-R items showed 4 factors, representing numbing, intrusion, avoidance and sleeping problems. It is concluded that the Self-rating Inventory for PTSD is a powerful instrument for diagnosing PTSD in survey research. The instrument appears to be capable of differentiating not only between PTSD and non-PTSD subjects but also between traumatized non-PTSD subjects and non-traumatized psychiatric patients.     

Comparative study of trauma-related phenomena in subjects with pseudoseizures and subjects with epilepsy

OBJECTIVE: The purpose of this study was to examine potential differences in measures of trauma-related phenomena between subjects with pseudoseizures and subjects with intractable epilepsy. METHOD: Thirty-one adult subjects with pseudoseizures and 32 subjects with intractable epilepsy (confirmed by video-EEG) were recruited from the epilepsy unit of a tertiary care hospital. Each participant completed the Impact of Event Scale, the Davidson Trauma Scale, the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (PTSD), the Dissociative Experience Scale, and the Pittsburgh Sleep Quality Index, as well as demographic, seizure history, and family functioning measures. RESULTS: Subjects with pseudoseizures had significantly higher mean scores on the Davidson Trauma Scale, Mississippi Scale for Combat-Related PTSD, Impact of Event Scale, and Pittsburgh Sleep Quality Index than subjects with epilepsy. In addition, a significantly higher percentage of subjects with pseudoseizures had scores above the clinical cutoff level of 30 on the Dissociative Experience Scale. CONCLUSIONS: Subjects with pseudoseizures exhibited trauma-related profiles that differed significantly from those of epileptic comparison subjects and closely resembled those of individuals with a history of traumatic experiences. Interventions aimed at trauma-related issues may be beneficial for patients with pseudoseizures.     

Factor structure of the Impact of Event Scale‐Revised in two different Peruvian samples

Background: This article studied the factor structure of the Impact of Event Scale‐Revised (IES‐R) in two samples in Peru, i.e., a sample of survivors of a fire (N=174) and a university student sample (N=562). Methods: First, confirmatory factor analysis was used to compare nine different models of posttraumatic stress disorder symptoms as evaluated by the IES‐R in both of the samples separately. The model with the best fit in both samples had four correlated factors, i.e., Intrusion, Avoidance, Hyperarousal and Sleep Disturbance. Second, the degree of factorial invariance of the IES‐R was compared in both the samples using multiple group confirmatory factor analysis. Results and Conclusions: The results showed almost no differences between both samples. Finally, the results supported the internal consistency, as well as the concurrent and convergent validity of the IES‐R in Peru. Depression and Anxiety, 2009. © 2009 Wiley‐Liss, Inc.     

A cross-lagged analysis of the relationship between symptoms of PTSD and retrospective reports of exposure

As part of a larger longitudinal investigation, 522 U.S. peacekeepers who served in Somalia were administered a comprehensive psychosocial questionnaire. The questionnaire included the PTSD Checklist [PCL; Weathers, F. W., Litz, B. T., Herman, D. S., Huska, J. A., & Keane, T. M. (1993, November). The PTSD Checklist (PCL): reliability, validity, and diagnostic utility. Paper presented at the annual meeting of the International Society for Traumatic Stress Studies, San Antonio, TX], the Mississippi Scale [Keane, T. M., Caddell, J. M., & Taylor, K. L. (1988). Mississippi Scale for combat-related posttraumatic stress disorder: three studies in reliability and validity. Journal of Consulting and Clinical Psychology, 56, 85-90], the War-Zone Exposure Scale [WZES; Litz, B. T., Orsillo, S. M, Freidman, M., Ehlich, P., & Batres, A. (1997). Posttraumatic stress disorder associated with peacekeeping duty in Somalia for US military personnel. American Journal of Psychiatry, 154(2), 178-184], and the Other Stressors Associated with Peacekeeping Scale [Litz, B. T., King, L. A., King, D. W., Orsillo, S. M., & Friedman, M. J. (1997). Warriors as peacekeepers: features of the Somalia experience and PTSD. Journal of Consulting and Clinical Psychology, 65, 1001-1010]. These measures were administered approximately 15 weeks postdeployment and roughly a year and a half later. Using a cross-lagged panel design, PTSD symptom severity was associated with increases in reports of exposure at Time 2. However, this finding was modest and was not specific to the recall of traumatic events.     

Validation of a Swedish version of the Impact of Event Scale-Revised (IES-R) in patients with burns

The Impact of Event Scale (IES) and the Impact of Event Scale-Revised (IES-R) are often used as self-report instruments for symptoms of post-traumatic stress disorder (PTSD). However, there are few validations of the IES and the IES-R against structured clinical interviews. In this study the two scales, together with the three subscales of the IES-R, were assessed for their agreement with a diagnosis of PTSD in patients with burns 1 year after injury. Sixty patients with burns were evaluated 1 year after injury using the Structured Clinical Interview for the DSM-IV Axis I (SCID-I) psychiatric disorders and a Swedish version of the IES-R. The total score of the IES-R had the best discriminant ability (0.89) with a sensitivity of 1.0 and a specificity of 0.78. In conclusion, the total IES-R had good properties as a screening tool for PTSD and subsyndromal PTSD 1 year after burn injury.     

The development of the Chinese version of Impact of Event Scale – Revised (CIES-R)

Background: This is an exploratory study on the psychometric properties and normative data of the Chinese translation of the Impact of Event Scale – Revised (CIES-R). Methods: The original Impact of Event Scale – Revised was translated into Chinese and the comparability of content was verified through back-translation procedures. The study consisted of a sample of 116 patients from the Accident and Emergency Department. Results: The reliability of the Chinese version was verified. The validity of the Chinese version as a measure of psychological distress was supported by the positive correlations between the various subscale scores of CIES-R (i. e., Intrusion, Avoidance, and Hyperarousal) and General Health Questionnaire-20. However, the independence of the three subscales was not supported. Conclusions: The present result suggests that normative information for different age groups and clinical samples might be different. Further study with clinical sample and investigation of the relationship between CIES-R and other diagnostic measures of PTSD are discussed. Received: 22 August 2002 / Accepted: 13 September 2002 Correspondence to Kitty K. Wu     

Trauma, traumatic stress and depression following an airline catastrophy]

OBJECTIVES: Acute stress responses following a trauma indicate a sensitivity to posttraumatic stress disorder (PTSD), and is often comorbid with depression. Earlier exposure to a traumatic event can be an additional risk factor in PTSD development. METHOD: Eight injured patients hospitalized after a major air disaster were monitored and assessed for a month. The symptoms of acute stress response (ASR), PTSD, and depression were assessed using DSM-IV criteria immediately following the accident, then each week thereafter. The Impact of Event Scale (IES) was completed on the 30th day (D30). RESULTS: Four patients presented with an ASR, and 3 of them had a PTSD at D30. Of those 3 patients with PTSD, 2 presented with an associated depression. These 2 patients had been exposed to a traumatic event before the disaster; and a significant relation was found between the history of the earlier trauma and the PTSD associated with depression. CONCLUSION: The traumatized victims with a history of earlier traumas seem more susceptible to developing a PTSD associated with depression.