A protocol for population-level data linkage to investigate patterns of service use and health care needs of young people experiencing mental ill-health in Victoria Australia

Introduction: Mental disorders are a leading cause of disease burden in 10-24-year-olds. In Australia, fragmentation within and across sectors (health, mental health and human services) results in gaps in service provision and increases this disease burden. There is an urgent need for reform; however, we need comprehensive and robust methodologies to identify gaps and inefficiencies in service provision to shape policy, ensure efficient allocation of resources and support those most in need. Here we describe the protocol for a population-based data linkage study involving evaluation of health, mental health, and human service use among Victorian young people with the goal of identifying subgroups experiencing unmet mental health needs. Methods and analysis: Our primary cohort includes youth aged 12-25 years in the period January 2018 to November 2023. For comparative purposes, we also include data from children aged 5-11 and adults 26-53 for this timeframe. We outline data sources and linkage methodology. Traditional statistical methods coupled with contemporary machine learning and natural language processing techniques will be used to identify subgroups with unmet mental health needs.Study outcomes: Ongoing consultation and engagement with young people and key stakeholders will inform interpretation, dissemination and translation of findings. We will provide a comprehensive examination of the clinical characteristics of young people, their service use behaviours, and typical pathways through care, that cannot be gleaned from examining datasets in isolation. Findings will inform ongoing mental health service reform that will lead to improvements in healthcare delivery and outcomes for Victorian youth.