Long-Term Impact of the Bloor Viaduct Suicide Barrier on Suicides in Toronto: A Time-Series Analysis: Effet à long terme de la barrière anti-suicide du viaduc Bloor sur les suicides à Toronto : une analyse chronologique.

Background: A suicide prevention barrier was installed at Toronto's Bloor Viaduct bridge in 2003. It was associated with short-term location substitution, possibly mediated by media effects that did not persist over 1 decade. The long-term impact of the barrier is unknown.

Methods: We examined rates of suicides by jumping from the Bloor Viaduct, other bridges and by other methods using coroner's records in Toronto (1998-2020). We used interrupted time-series Poisson regression analyses to model changes in quarterly bridge-related suicides after barrier installation. A secondary analysis explored the potential substitution effects of suicide by other methods.

Results: Of 5219 suicides from 1998 to 2020, 303 were by jumping from bridges. After controlling for covariates, installation of the Bloor Viaduct suicide barrier was associated with a 49% step decrease in bridge-related suicide in the next quarter in Toronto (incidence rate ratio [IRR] = 0.51, 95% CI, 0.30 to 0.86) with no rebound increase in bridge-related suicide during the subsequent 17 years after the original drop (IRR = 0.99, 95% CI, 0.96 to 1.03). There was also no associated change in suicides by other methods after the barrier (IRR = 1.04, 95% CI, 0.90 to 1.20).

Conclusions: Contrary to initial findings, these results indicate an enduring suicide prevention effect of the Bloor Viaduct suicide barrier. They support the long-term utility of structural interventions at high-frequency sites for suicide.