Reliability and validity of the Japanese version of the Peritraumatic Distress Inventory.

Objective: To assess the reliability and validity of the Japanese version of the Peritraumatic Distress Inventory (PDI).

Method: One hundred thirty-five participants with physical injury resulting from motor vehicle accidents were consecutively recruited in this cross-sectional study, from Aug. 18, 2005, to Jan. 8, 2008. A subsample (n=71) were retested on the PDI an average of 96.4 days after initial measure completion.

Results: Correlational analyses revealed an overall Cronbach's alpha coefficient of 0.83. The item-total correlations for the 13 items ranged from 0.29 to 0.75. The test-retest correlation coefficient was 0.61. The PDI was significantly correlated with the external validators such as peritraumatic dissociation as measured by the Peritraumatic Dissociative Experiences Questionnaire (PDEQ); the intrusion, avoidance and hyperarousal scores of the Impact of Events Scale-Revised (IES-R); and the depression and anxiety subscales of the Hospital Anxiety Depression Scale (HADS) (P<.01).

Conclusion: The present study indicated that the Japanese version of the PDI has a high degree of internal consistency, acceptable reliability and a high degree of concurrent validity with measures of peritraumatic dissociation and posttraumatic symptoms. The Japanese version of the PDI can be used as a validated instrument in future research.