Reducing youth suicide: Systems modelling and simulation to guide targeted investments across the determinants

Article in review: Occhipinti, J.; Skinner, A.; Iorfino,F.; Lawson, K.; Sturgess, J.; Burgess, W.; Davenport, T… & Hickie, I. (2021). Reducing youth suicide: systems modelling and simulation to guide targeted investments across the determinants. BMC Medicine. https://doi.org/10.1186/s12916-021-01935-4

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Summary
This study used a systems modelling and simulation tool to assess the influences of factors such as social determinates, service systems, demographics and behaviours in relation to the reduction of suicide risk and rates. The modelling enabled researchers to determine which interventions and strategies, and in which combinations, might prove most beneficial in reducing suicide risk.

Complex contributory factors
We know that factors such as adverse childhood exposures, domestic and family violence, substance use, and access to housing and mental health services have unidirectional or bidirectional relationships with each other and with mental illness and psychological distress. However, these contributing factors are often considered independently and in a linear and constant way. This research asserts that our understanding of the interrelatedness of risk factors could be improved.

This study reviewed national, state and local data sets to identify the:
• Likely impact of locally prioritised mental health and suicide prevention interventions that were under consideration for funding
• Value and balance of investments across social determinates of mental health
• Best combination of strategies to deliver the most significant impacts on reducing suicide

Systems modelling is a technique able to capture population and demographic contributors, including as they change over time. This assessment delivered an interactive decision-making support tool looking which considers the optimal targeting, time, scale, frequency and intensity of suicide prevention services and strategies.

Scenarios considered
The system dynamics model used for the study was developed with a participatory modelling approach, involving 50 local stakeholders from health, emergency and service groups, along with people with lived experience of suicide. The forecast period was between 2021 and 2041. The scenarios examined were grouped as either mental health or suicide prevention interventions or social determinants.

The mental health and suicide prevention interventions were:
• Post-attempt assertive aftercare
• Social connectedness programs
• Community-led acute care services
• Technology-enabled crisis responses

The positive social determinates were:
• Reducing childhood adversity
• Increasing youth employment
• Reducing total unemployment
• Reducing domestic violence
• Reducing homelessness
• Reducing childhood adversity by 50% plus increasing youth employment

The systems modelling also looked at these factors individually and at the anticipated outcomes for various combinations of determinates and inventions.

Findings
The study found:
• Programs effective in increasing social connectedness were predicted to have the single greatest positive impact on the reduction of suicidal behaviour in both the youth and general populations.
• Reductions were also predicted through the implementation of technology-enabled coordinated care.
• Implementing all of the preventions was not predicted to achieve substantial additional reductions.
• A reduction in suicide deaths among young people was predicted by combining social connected programs, technology-enabled coordinated care and achieving a reduction in childhood adversity
• A reduction in suicide deaths among young people also was predicted by combining social connected programs, technology-enabled coordinated care and achieving an increase in youth employment.
• Of the social determinants considered, the reduction of childhood adversity by 50% was predicted to have the greatest impact on reducing self-harm and suicide by young people.
• A combination of the reduction of childhood adversity along with an increase in youth employment was predicted to deliver the biggest reduction in suicides, with an effect that would be amplified over time

The assessment also determined the rates of suicide are projected to slightly decrease over the forecast people among the population studied. It is projected that the suicide rate for the general population will decrease from 18.7 to 15.1 per 100,000 population per year, while among the youth population the suicide rate will decrease from 47.8 to 42.7 per 100,00 population per year.

Across the analysis, this study has indicated that combining a specific mix of mental health and suicide prevention initiatives with actions to address key social determinates can likely offer the best chance at reducing suicide rates. The other key finding was that “more is not necessarily better” because there was not a significant predicted reduction in suicide rates when all interventions and determinants were addressed.

Systems modelling enables inter-dependent and interacting effects to be analysed. This approach is useful for assisting population-level decision-making about the most strategic areas of investments in an environment of limited resources. Findings could direct funding into addressing factors that are identified as more important for suicide prevention.