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

ObjectiveTo assess the reliability and validity of the Japanese version of the Peritraumatic Distress Inventory (PDI).MethodOne 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.ResultsCorrelational 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).ConclusionThe 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.