Building suicide barriers on buildings and bridges seems like a good idea, but a new study finds that such obstacles may not have an effect on an area's rate of suicide by jumping from heights.
Canadian researchers examined suicide rates at the Bloor Street Viaduct in the years before and after a suicide barrier was erected. The viaduct, located in Toronto, averaged about 10 suicides a year from 1993 to 2002, prompting the building of a barrier in 2002 and 2003 to prevent people from jumping.
Coroner's records on all suicides in the province of Ontario were examined from 1993 to 2007, and researchers divided that period into the years before the barrier was constructed (1993 to 2001) and the years after the barrier went up (2003 to 2007).
The rate of suicide in Toronto by jumping from a height didn't change after the barrier was put up. An average 9.3 suicides per year occurred at the viaduct before the barrier, and none after. However, the yearly rate of suicides by jumping from bridges other than the viaduct went from 8.7 before the barrier to 14.2 after. There was a decrease in the overall suicide rate in Toronto and in the rate of suicide by methods other than jumping in the years after the barrier was built.
The authors conclude that although such a barrier may stop suicides at a specific location, it may not stop people from jumping to their deaths at similar locations.
But an accompanying editorial points out that there are arguments for putting up barriers in common jumping spots: Suicide by jumping is often impulsive, and an obstacle could stop someone from killing themselves. Also, these types of suicides often get a great deal of media attention, possibly triggering similar suicide attempts.
The editorial also noted that the number of pre-barrier suicides at the Bloor Street Viaduct may be too small to made any deductions about overall suicide rates in the area. Also, because it's not known if suicides at other bridges were increasing in the years before the barrier was built, no one can be sure what caused the overall rise in suicides by jumping after the barrier went up. Other studies have shown that constructing barriers at suicide "hot spots" may lead to an overall decrease in jumping deaths.
The study was published this week online in the British Medical Journal.