Effect of the LifeSpan suicide prevention model on self-harm and suicide in four communities in New South Wales, Australia: a stepped-wedge, cluster randomised controlled trial.

Background: There have been few rigorous evaluations of population, multi-strategy, suicide prevention programmes, despite increasing global recognition that such approaches are needed to reduce suicide.

Objective: To examine the effects of a multi-strategy suicide prevention model on age-standardised rates of hospital presenting self-harm and suicide after 24 months of implementation.

Methods: A stepped-wedge cluster randomised trial was conducted in four sites across New South Wales (NSW), Australia, from 2016 to 2020. Sites were randomised to a starting order and implemented the same set of interventions over a 24-month period. Changes in rates of hospital presenting self-harm and suicide deaths were measured using linked administrative health data sets of persons aged 10 or older.

Results: Negative binomial regression models adjusted for linear trends and seasonality showed that LifeSpan was associated with a 13∙8% (incident response rate 0.86; 95% CI 0.79 to 0.94) reduction in hospital-presenting self-harm rates over the intervention period, compared with preintervention. These effects were not observed in the rest of NSW. There were statistically non-significant changes in suicide death rates during the intervention across all sites.

Conclusions: Locally implementing a multi-strategy suicide prevention model can reduce rates of hospital presentations for self-harm, but longer implementation and evaluation periods may be required to realise the full impacts of interventions for suicide, as a more intractable outcome.

Clinical implications: Our findings can inform policy at all levels of government to invest in actions that may build cross-sectoral capacity in local communities to detect and respond to suicide risk.