Background: There is no standard approach for relatives of sudden death patients and there were few to investigate prospectively frequency of posttraumatic stress disorder (PTSD) among relatives of sudden death patients.  Purpose of this study is to instigate prospectively frequency of PTSD among relatives of sudden death patients after an intervention just giving pamphlet which narrates ordinal and complicated grief process, and self-regulating techniques, such as deep breathing.
MATERIAL AND METHODS: From May 2017 to February 2018, we prospectively and consecutively provide a pamphlet into relatives of out-of-hospital sudden cardiac arrest victim who failed to obtain spontaneous circulation by advanced cardiopulmonary resuscitation.  Among the bereaved relatives who provided permission for this research, we investigated their psychiatric status using the Impact of Event Scale-Revised (IES-R).  IES-R over 24 was defined as PTSD.
RESULTS: During the investigation period, there were 54 relatives of the 54 dead patients (victims) who provided permission of entry of this research and these 54 relatives were included as subjects.  The all subjects and victims were Japanese. Among them, there 24 subjects whose the IES-R was 0 and there were 5 (9.3%) PTSD in approximate one month from the bereavement.  And there were no relatives who received psychiatric treatment spontaneously. 
There was negative correlation between score of the IES-R and the age of the 54 victims.  And there were no significant difference concerning sex of the victims, place of cardiac arrest, witness collapse and spouse.  While, the score of the IES-R in exogenous cardiac arrest, death inquests and parent were significantly higher in comparison with endogenous cardiac arrest, no inquest and no parent respectively.  The score of the IES-R in child was significantly lower that in no child.  The score of the IES-R in suicidal cardiac arrest and female relatives were higher than those in no suicidal cardiac arrest and male relatives respectively, but this differences were not significant.  A multivariate analysis revealed the following significant predictors of high score of the IES-R were age of the victims (LogWorth 2.6, p =0.002) and exogenous cardiac arrest (LogWorth 2.5, p = 0.003).
CONCLUSION: The present study demonstrated that there was 9.3% PTSD in one month from the bereavement among Japanese relatives of sudden death victims after an intervention just giving pamphlet which narrates ordinal and complicated grief process.  This frequency was minimum in comparison with previous reports.  And younger age of the victims and exogenous cardiac arrest was independent potential risk factor of PTSD.

7 - Prevalence and risk factors for post-traumatic stress disorder in Japanese relatives of out-of-hospital cardiac arrest patients after receiving a pamphlet concerning process of grief reaction