Prevalence of suicide attempters in emergency departments in Japan: A systematic review and meta-analysis

Background The number of hospital admissions related to suicide attempts is increasing worldwide. The Emergency Department (ED) is recognized in Japan as an opportunity to intervene with suicide attempters however, the prevalence of suicide attempters in the ED is unknown. Therefore, a meta-analysis was conducted to provide this information. Methods We conducted searches of databases (PubMed, PsycINFO, CINAHL, ICHUSHI, CiNii) to identify studies about suicide attempters in the ED in Japan. A meta-analysis was used to calculate the pooled prevalence proportion of suicide attempters in the ED, and their prevalence proportion of psychiatric disorder and method of suicide in suicide attempters. Results The search of Japanese studies identified 3338 records, of which 70 were included in the meta-analysis. A total of 25 studies reported the psychiatric diagnosis and 62 studies reported the method of suicide. The pooled prevalence proportion of suicide attempters was 4.7%. Mood disorders were the most frequent psychiatric disorders (ICD: 30%, DSM: 35%), and poisoning was the most frequent method of attempting suicide (52%). Limitations There might be a publication bias because only published studies were included. There also might be an information bias, such as reporting bias or misclassification, because most of studies included in the analysis used retrospective designs. Conclusions The results provide clear evidence of the prevalence of suicide attempters in the ED in Japan. The results indicate that suicide attempters in the ED have a higher proportion of mood disorders, and that the most common method of suicide is poisoning.