Identifying typologies among persons admitted to hospital for non-fatal intentional self-harm in Victoria, Australia

The aim of this study was to determine whether people who have been hospitalised as the result of non-fatal self-harm form meaningful groups based on mechanism of injury, and demographic and mental health-related factors. A retrospective analysis of 18,103 hospital admissions for self-harm in Victoria, Australia over the 3-year period 2014/2015–2016/2017 recorded on the Victorian Admitted Episodes Dataset (VAED). The VAED records all hospital admissions in public and private hospitals in Victoria. The primary analysis used a two-step method of cluster analysis. Initial analysis determined two distinct groups, one composed of individuals who had a recorded mental illness diagnosis and one composed of individuals with no recorded mental illness diagnosis. Subsequent cluster analysis identified four subgroups within each of the initial two groups. Within the diagnosed mental illness subgroups, each subgroup was characterised by a particular mental disorder or a combination of disorders. Within the no diagnosis of mental illness groups, the youngest group was also the most homogenous (all females who self-poisoned), the oldest group had a high proportion of rural/regional residents, the group with the highest proportion of males also had the highest proportion of people who used cutting as the method of self-harm, and the group with the highest proportion of metropolitan residents also had the highest proportion of people who were married. Preventative interventions need to take into account that those who are admitted to hospital for self-harm are a heterogeneous group.