Five healthcare trajectories in the year before suicide and what they tell us about opportunities for prevention: a population-level case series study.

Background: Suicide prevention requires a shift from relying on an at-risk individual to engage with the healthcare system. Understanding patterns of healthcare engagement by people who have died by suicide may provide alternative directions for suicide prevention. Methods: This is a population-based case-series study of all suicide decedents (n = 3895) in New South Wales (NSW), Australia (2013-2019), with linked coronial, health services and medicine dispensing data. Healthcare trajectories were identified using a k-means longitudinal 3d analysis, based on the number and type of healthcare contacts in the year before death. Characteristics of each trajectory were described. Findings: Five trajectories of healthcare utilisation were identified: (A) none or low (n = 2598, 66.7%), (B) moderate, predominantly for physical health (n = 601, 15.4%), (C) moderate, with high mental health medicine use (n = 397, 10.2%), (D) high, predominantly for physical health (n = 206, 5.3%) and E) high, predominantly for mental health (n = 93, 2.4%). Given that most decedents belonged to Trajectory A this suggests a great need for suicide preventive interventions delivered in the community, workplace, schools or online. Trajectories B and D might benefit from opioid dispensing limits and access to psychological pain management. Trajectory C had high mental health medicine use, indicating that the time that medicines are prescribed or dispensed are important touchpoints. Trajectory E had high mental health service predominantly delivered by psychiatrists and community mental health, but limited psychologist use. Interpretation: Although most suicide decedents made at least one healthcare contact in the year before death, contact frequency was overall very low. Given the characteristics of this group, useful access points for such intervention could be delivered through schools and workplaces, with a focus on alcohol and drug intervention alongide suicide awareness. Funding: Australia's National Health and Medical Research Council.