Blocking Access to Suicide 'Hot Spots' Stops Many Attempts

Pam Harrison

September 24, 2015

Blocking access to suicide "hot spots" reduces the number of deaths at these sites by more than 90%, new research shows.

"Preventing even one suicide is obviously a good thing to do, and preventing suicides at 'known' sites is particularly important, partly because of the potential for copycat acts and partly because of the devastating impact that suicides at these sites have for those who work at or live near them or visit them for other reasons," lead author Jane Pirkis, PhD, director of the Centre for Mental Health, University of Melbourne, in Australia, told Medscape Medical News.

"And while we did find some evidence of substitution [of suicide] at nearby sites in an earlier analysis, there is definitely an overall net gain in terms of a reduction in suicides at these sorts of sites, so whichever way you look at it, a reduction of over 90% in suicides at a given site is a big win," she added.

The study was published online September 23 in the Lancet Psychiatry.

Encouraging Help-Seeking

Investigators identified 23 articles, representing 18 studies, to analyze the effect that interventions have on suicide rates.

Interventions of interest included restricting access to "hot spots," encouraging help-seeking from the person considering suicide (usually through installation of phones or putting up signs that display messages of support), and increasing the likelihood of a third party intervening before the attempt is made via the installation of CCTV cameras.

Investigators then compared the number of completed suicides at various hot spots before and after various interventions were introduced.

"In total, 863 deaths by suicide occurred over 149.85 study-years before the interventions were introduced (an unweighted mean of 5.8 suicides per year), and 211 deaths by suicide occurred over 88.0 study-years after the interventions were introduced (an unweighted mean of 2.4 suicides per year)," the investigators note.

In six of the 18 studies, the number of suicides dropped to zero in the postintervention period, they add.

The only study in which the yearly number of suicides did not drop — in fact, it increased substantially ― was conducted by investigators who recorded deaths by suicide at the Skyway Bridge, in St. Petersburg, Florida.

Following the installation of suicide crisis phones at the bridge, a website unrelated to the intervention became increasingly popular, the authors explain.

This website disseminated information on suicides that had taken place on the bridge and provided a forum or blog for interested parties. It also contained disturbing information that could have promoted copycat acts.

The authors note that it is possible that this particular website might have negated any potentially positive effects the crisis telephones might have had on the suicide rate on the St. Petersburg bridge.

91% Reduction

In total, 13 studies examined the effects of restricting access to suicide hot spots, 11 of which considered the effect of restriction in isolation, and two, the effect of restriction in combination with other interventions.

When all 13 studies were considered, restricting access to a suicide hot spot was associated with a 91% reduction in the number of suicides per year, at an incidence rate ratio (IRR) of 0.09 (95% confidence interval [CI], 0.03 - 0.27; P < .0001).

When the analysis was restricted to the 11 studies that considered the same intervention in isolation, the IRR remained significant at 0.07 (95% CI, 0.02 - 0.19; P < .0001).

The authors also conducted separate analyses of studies encouraging help-seeking, including the one in which the website may have negated help-seeking behavior on the Florida bridge.

When this particular study was included in the analysis, encouraging help-seeking was not associated with a significant change in the number of suicides per year, as determined on the basis of pooled data from a total of six studies or when the analysis was limited to three studies that assessed help-seeking interventions on their own.

However, when investigators excluded the Florida-based study, encouraging help-seeking was associated with a 51% reduction in suicides per year (IRR, 0.49; 95% CI, 0.29 - 0.83; P = .0086). This reduction was also seen when they included the two studies that considered help-seeking in isolation.

Similarly, increasing the likelihood of a third party intervening before the suicide attempt had been made was associated with 47% fewer suicides a year (IRR, 0.53; 95% CI, 0.31 - 0.89; P = .0155).

"Our meta-analysis provides evidence that restricting access to means, encouraging help-seeking, and increasing the likelihood of intervention by a third party can reduce deaths by suicide at suicide hotspots," the investigators write.

"These key interventions have the potential to complement each other and buy time to allow an individual to reconsider their actions and allow others the opportunity to intervene," they add.

"Suicide School"

In a written commentary, Eric Caine, MD, University of Rochester Medical Center, in New York, noted that in 2010, he and his colleagues recommended that Cornell University install suicide nets on seven nearby bridges.

"Although the rate of suicide among Cornell students was the same as the national average, Cornell had gained notoriety as a so-called suicide school because 44% of the deaths by suicide that occurred in the vicinity over the past two decades had involved jumping into Ithaca's East Hill gorges, where Cornell is located," Dr Caine writes.

Dr Caine had some reservations about the small number of suicides that had occurred during the follow-up period of the current study. Because the interventions had been put into place far apart in time and space, their effect was quite small in terms of the number of suicides they prevented.

However, he adds, "numbers alone are not sufficient to decide whether such interventions have merit or should be implemented."

Rather, interventions that prevent suicide have at least moral or social value, demonstrably saving lives otherwise lost, he adds.

"Blocking access to a hotspot can serve as an expression of important values...[provided it is] done in a way that builds community awareness and support for broader effects to prevent suicide, attempted suicide, and antecedent risks," he writes.

Dr Pirkis and Dr Caine have reported no relevant financial relationships.

Lancet Psychiatry. Published online September 23, 2015. Abstract


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