Space-time self-harm and suicide clusters in two cities in Taiwan

Area of Science:

• Epidemiology
• Public Health
• Criminology

Background:

• Suicidal acts can occur in clusters, raising community concerns.
• Previous research on suicide clusters often used limited temporal and spatial data.
• Less is known about clusters of non-fatal suicidal behavior (self-harm).

Purpose of the Study:

• To identify space-time clusters of self-harm and suicide using daily incidence data and exact addresses.
• To investigate the characteristics of individuals involved in cluster-related suicidal acts.

Main Methods:

• Utilized emergency department data for self-harm and suicide deaths in Taipei and New Taipei Cities.
• Employed space-time permutation scan statistics for cluster identification.
• Used logistic regression to analyze characteristics of cluster-related episodes.

Main Results:

• Identified multiple self-harm, suicide, and combined clusters across both cities.
• Space-time clusters represented a small percentage of all suicidal acts (0.05%–0.59%).
• Cluster-related suicidal acts were more prevalent in males and young people (10-29 years).

Conclusions:

• Space-time clusters of suicidal acts are relatively uncommon but have distinct demographic characteristics.
• Analyzing only suicide deaths may lead to underestimation or overlooking of clusters.
• Future research should integrate self-harm and suicide data, potentially including social network information.