Abstract
Many population data sources do not routinely collect data of children under 12, despite research showing that mental health, self-injurious behaviour, and substance ingestion can have severe consequences in this age group. We used 6 years (January 2012 to December 2017) of ambulance attendance data from the Australian state of Victoria to characterise mental health, self-injurious behaviour, and substance ingestion in children aged 7-11. We compared this group to older children aged 12-17. We found that in comparison to those aged 12-17 (n = 26,778), a smaller number of children aged 7-11 years (n = 1558) were experiencing serious harms, with mental health symptomology the most common harmful outcome. Self-injurious behaviour significantly increased in both age groups throughout the study period. For mental health, self-injurious behaviour and substance ingestion in the 7-11 age group, males were significantly over-represented. These aged 7-11 were more likely to ingest pharmaceuticals, rather than alcohol or illicit substances, and suicidal ideation was the most common self-injurious behaviour in this age group. Our study suggests that data collection needs to occur specifically in the 7-11 age group, and importantly, services and interventions to improve mental health and wellbeing will need to be specifically designed and targeted at this age group.