Date Published: 18 May 2009
Grafton Bridge Suicide Study Proves Barriers' Effectiveness
Researchers estimate 14 lives could have been saved if barriers had remained in place.
A joint American-New Zealand study provides new evidence about effective ways to prevent suicide from bridges, and raises important issues of government accountability and liability.
A team of researchers from the University of Otago, Christchurch, and Yale University in the US examined how the removal and subsequent re-instalment of safety barriers on Auckland's Grafton Bridge impacted the number of suicides.
Safety barriers to prevent suicide by jumping were removed from Grafton Bridge in 1996 after having been in place for 60 years. After they were removed, there was a five-fold increase in the number and rate of suicides from the bridge. These increases led to a decision to reinstall safety barriers. Since the reinstallation of barriers, of an improved design, in 2003, there have been no suicides from the bridge.
The researchers commented that this natural experiment, in which the new barriers used a powerful a-b-a (reversal) design (i.e. barriers in place-barriers removed-barriers in place), shows that safety barriers are an effective suicide-prevention tool: their removal increases suicides; their reinstatement prevents suicides. The researchers estimated that had barriers not been removed, 14 lives could have been saved.
Lead investigator Associate Professor Annette Beautrais, who conducted the research and was instrumental in getting barriers reinstated on the bridge, said that this finding adds to an increasing body of evidence that the most effective form of prevention at bridge-jumping sites is installing safety barriers.
"This evidence justifies preventive interventions at sites that become identified for suicide, and suggests that these approaches are now moving towards becoming best practice in suicide prevention," she said.
"In turn, the development of best practice guidelines for preventing suicide by jumping raises important issues about the accountability and liability, both of authorities with responsibility for bridges, structures, buildings and other sites from which people jump, and of government agencies accountable for suicide prevention."
Dr Beautrais noted that the findings from the Grafton Bridge 'experiment' had been influential in leading other countries to install barriers at bridges that had become popular or iconic suicide sites.