Classification of attempted suicide by cluster analysis: A study of 888 suicide attempters presenting to the emergency department

BACKGROUND:
It is essential to understand the latent structure of the population of suicide attempters for effective suicide prevention. The aim of this study was to identify subgroups among Korean suicide attempters in terms of the details of the suicide attempt.

METHODS:
A total of 888 people who attempted suicide and were subsequently treated in the emergency rooms of 17 medical centers between May and November of 2013 were included in the analysis. The variables assessed included demographic characteristics, clinical information, and details of the suicide attempt assessed by the Suicide Intent Scale (SIS) and Columbia-Suicide Severity Rating Scale (C-SSRS). Cluster analysis was performed using the Ward method.

RESULTS:
Of the participants, 85.4% (n = 758) fell into a cluster characterized by less planning, low lethality methods, and ambivalence towards death (“impulsive”). The other cluster (n = 130) involved a more severe and well-planned attempt, used highly lethal methods, and took more precautions to avoid being interrupted (“planned”). The first cluster was dominated by women, while the second cluster was associated more with men, older age, and physical illness.

LIMITATIONS:
We only included participants who visited the emergency department after their suicide attempt and had no missing values for SIS or C-SSRS.

CONCLUSIONS:
Cluster analysis extracted two distinct subgroups of Korean suicide attempters showing different patterns of suicidal behaviors. Understanding that a significant portion of suicide attempts occur impulsively calls for new prevention strategies tailored to differing subgroup profiles.