**3. Results**

100 Post Traumatic Stress Disorders in a Global Context

The original Peritraumatic Distress Inventory has been demonstrated to be internally consistent, stable over time, and with good to excellent correlations between item and total scores (Brunet et al., 2001). Moreover, it was found to be valid against posttraumatic symptoms and peritraumatic dissociation as assessed by the Impact of Event Scale-Revised and the civilian version of the Mississippi Scale for Combat-Related Posttraumatic Stress

With the original authors' permission, we translated the original English Peritraumatic Distress Inventory into Japanese. We followed the standard procedure of back-translation. Namely, the first author (DN) translated the English version into Japanese. This preliminary Japanese version was then backtranslated into English by an independent translator. The backtranslated version was examined by the original authors. Then we corrected the Japanese translation accordingly. This process was repeated until both sets of authors agreed that the original and backtranslated versions matched closely. Subsequently, we verified the internal consistency, test-retest reliability, concurrent validity with measures of peritraumatic dissociation and posttraumatic symptoms, and divergent validity of the

The posttraumatic stress symptoms as assessed using the Impact of Event Scale- Revised at follow-up were considered to be the outcome. The Impact of Event Scale-Revised is a 22 item self-report questionnaire used to determine the level of symptomatic responses to a specific traumatic stressor (motor vehicle accident in the present study) in the past week (Asukai et al., 2002; Wolfe & Kimerling, 1997). The degree of distress for each item is rated

Depressive and anxiety symptoms as assessed using the Hospital Anxiety and Depression Scale were also considered as the outcome. The Scale is comprised of a 7-item anxiety subscale and a 7-item depression subscale that assess general psychological distress for the preceding week (Kugaya et al., 1998; Zigmond & Snaith, 1983). Each item is rated on a scale

The Posttraumatic Growth Inventory, which assesses posttraumatic growth, measures the degree of change experienced in the aftermath of a traumatic event. The 21-item Inventory evaluates five factors: relating to others, new possibilities, personal strength, spiritual change, and appreciation of life. The degree of posttraumatic growth for each item is rated

Univariate regression analysis was used to examine the relationships of total score and individual item scores on the Peritraumatic Distress Inventory with posttraumatic symptoms and depressive and anxiety symptoms. In a model for determining the predictive value of the Peritraumatic Distress Inventory, multivariate regression analysis was used to examine the relationships of the Peritraumatic Distress Inventory with posttraumatic stress symptoms and depressive and anxiety symptoms adjusted for 7 other covariates based on

Japanese version of the Peritraumatic Distress Inventory (Nishi et al., 2009).

of 0–3, with high scores denoting greater psychological distress (range, 0-42).

on a 6-point scale (range, 0-105) (Taku et al., 2007; Tedeschi & Calhoun, 1996).

**2.3.2 The Impact of Event Scale-Revised** 

on a 5-point scale (0, not at all to 4, extremely; range, 0-88).

**2.3.3 The Hospital Anxiety and Depression Scale** 

**2.3.4 The Posttraumatic Growth Inventory**

the following theoretical considerations.

**2.4 Statistical analysis**

Disorder.

Of the 130 patients participating, 79 (60.8%) attended the 1-month follow-up assessment and 51 (39.2%) attended the 18-month one. The patients who dropped out of the study did not differ significantly from those who participated in terms of the variables selected for investigation in this study, including total Peritraumatic Distress Inventory score.

Of the 79 participants at first follow-up, 16 (20.3%) were women and median age was 37.0 years (mean, 39.7; range 18-69), and 7 (8.9%) reported a past history of psychiatric illness. Median ISS was 6.0 (range 1-41) and median Peritraumatic Distress Inventory score was 15.0 (range 0-40).

The relationships of total score and individual item scores on the Peritraumatic Distress Inventory with posttraumatic stress symptoms and depressive and anxiety symptoms are shown in Table 1. The Peritraumatic Distress Inventory was an independent predictor for posttraumatic stress symptoms and depressive and anxiety symptoms after adjusting for potential confounders.


Peritraumatic Distress in Accident Survivors: An Indicator for

**4.2 An indicator for posttraumatic stress symptoms** 

**4.3 An indicator for depressive and anxiety symptoms** 

but also major depression or other anxiety disorders.

**4. Discussion** 

regression analysis.

**4.1 Summary in the present study** 

Posttraumatic Stress, Depressive and Anxiety Symptoms, and Posttraumatic Growth 103

This study showed that the Peritraumatic Distress Inventory could predict posttraumatic stress and depressive and anxiety symptoms at 1 month after motor vehicle accident and posttraumatic growth at 18 months after the accident. The predictive value of the Peritraumatic Distress Inventory for the Impact of Event Scale-Revised and the Hospital Anxiety and Depression Scale remained after adjusting for covariates in a multivariate

As mentioned in the Introduction, it is no surprise that the Peritraumatic Distress Inventory predicted posttraumatic symptoms in the present study. Although some previous prospective studies have failed to show that this Inventory is an independent predictor of posttraumatic stress disorder, these studies used the Inventory from 2 weeks (Kuhn et al., 2006) to several months (Birmes et al., 2005; Simeon et al., 2005) following a traumatic event. The time of assessment in the present study was within several days following the traumatic event in most participants, in order to minimize the effects of inaccurate memory over time. It is likely that the Peritraumatic Distress Inventory has a better predictive value when used early after a traumatic event, making it well suited for use in emergency departments.

The Peritraumatic Distress Inventory also predicted depressive and anxiety symptoms in the present study, although the predictive value for these symptoms was lower than that for posttraumatic symptoms. A previous study reported that posttraumatic stress disorder symptoms were a reliable predictor for depressive symptoms (Erickson et al., 2001). The Impact of Event Scale-Revised is one of the tools used most frequently for measuring posttraumatic stress symptoms; however, the it was intended to assess posttraumatic stress disorder symptoms over the previous 7 days, whereas the Peritraumatic Distress Inventory can be used immediately after motor vehicle accident. Given our findings, the Peritraumatic Distress Inventory seems to be a useful indicator not only for posttraumatic stress disorder

**4.4 Two Peritraumatic Distress Inventory items showed high predictive values** 

Items 1 and 11 of the Peritraumatic Distress Inventory showed higher predictive values for both posttraumatic stress and depressive and anxiety symptoms than other items. Item 1 inquires about helplessness. The author and colleagues previously discussed that nondrivers (passengers, bicyclists, or pedestrians) might be susceptible to subsequent posttraumatic stress disorder and other psychiatric morbidity (Matsuoka et al., 2008). Loss of control in a motor vehicle accident is suggested to be an important risk factor. Regarding item 11, some studies showed that high heart rate shortly after a motor vehicle accident is a predictor for later posttraumatic stress disorder (Bryant et al., 2000; Shalev et al., 1998; Zatzick et al., 2005), although other studies reported that heart rate was not an independent predictor (Buckley et al., 2004; Kraemer et al., 2008) and a review indicated that it cannot be accurately used to identify individuals who are at high risk for later posttraumatic stress


\*In the multivariate analysis, the predictive value of the PDI was adjusted for 7 covariates; age at MVA, being a female, history of psychiatric illness, family history of psychopathology, education level, heart rate at admission and Injury Severity Score.

P, p value; CI, confidential interval; HADS, Hospital Anxiety and Depression Scale; IES-R, the Impact of Event Scale-Revised; PDI, the Peritraumatic Distress Inventory

Table 1. The predictive value of the Peritraumatic Distress Inventory for Impact of Event Scale-Revised and Hospital Anxiety and Depression Scale at follow-up (N=79)

The relationships between total score on the Peritraumatic Distress Inventory and total score and individual subscale scores on the Posttraumatic Growth Inventory are shown in Table 2.


CI, confidential interval; PDI, Peritraumatic Distress Inventory; PTGI, Posttraumatic Growth Inventory; R2, multiple correlation coefficient, the index of goodness fitness in the model

Table 2. The predictive value of the PDI for PTGI at follow-up (N=51)
