Physical barriers
| Study | Design | Study time period | Country (region) | Intervention | Results | Direction of association |
| Law et al 2014S88 | Pre–post, with no control group | 1990–2012 | Australia (Brisbane) | In 1993, a fence barrier on the Gate Bridge in Brisbane was first installed, and later replaced in 2010 to deter individuals from dying by suicide while jumping off the bridge. | Following the installation of the barrier the suicide rate per 100 000 declined from 0.67 in 1990–1993 to 0.32 in 1994–1997, representing a 53% rate reduction. The suicide rate from the Gate Bridge continued to fall with each subsequent year. Following the installation of the new barrier in 2010 there were no suicide mortalities recorded from the bridge (2010–2012). | Total: -- |
| Perron et al 2013S89 | Time series | 1990–2009 | Canada (Montreal) | In 2004, the construction of a barrier on the Jacques-Cartier Bridge was completed to help deter suicide by jumping. | The suicide rate following the completion of the bridge barrier showed a steep decline in suicide by jumping (incidence rate ratio=0.24; 95% CI 0.13 to 0.43). | Total: -- |
| Sinyor et al 2010S90 | Time series | 1993–2007 | Canada (Toronto) | Between 2002 and 2003 a barrier was built on the Bloor Street Viaduct called the ‘luminous vail‘. | Following the installation of a bridge barrier on the Bloor Street Viaduct the mean number of suicide mortalities declined from 9.3 (1993–2002) to 0 (2004–07) (incidence rate ratio=0.05; 95% CI 0.01 to 0.31). | Total: -- |
| Sinyor et al 2017S91 | Pre–post, with no control group | 1993–2014 | Canada (Toronto) | Between 2002 and 2003 a barrier was built on the Bloor Street Viaduct called the ‘luminous vail’. | A per-capita rate of 9.0 suicide deaths per year took place prior to the barrier construction, which declined to 0.1 suicide deaths per year after the construction of the barrier (IRR=0.009, 95% CI 0.0005 to 0.19). | Total: -- |
| Matsubayashi et al 2013S92 | Quasi-experimental | 2000–2010 | Japan (Tokyo) | Between 2008 and 2010, blue lights-emitting diod (LED) lamps were installed on train platforms at 11 Tokyo railway stations. | Following the installation of blue LED lamps, the number of suicides per year declined by 84% (95% CI 14% to 97%; incidence rate ratio=0.17; 95% CI 0.03 to 0.87). | Total: -- |
| Matsubayashi et al 2014S93 | Quasi-experimental | 2000–2013 | Japan | Between 2008 and 2013, 14 railway or metro stations in Japan installed blue light-emitting-diode (LED) lamps to help prevent suicide by jumping onto the rail. | The annual mean no of suicides mortalities at the 14 intervention stations declined from 0.44 to 0.19 following the installation of the blue LED lamps (incidence rate ratio=0.026; 95% CI 0.13 to 0.52), equivalent to a 74% reduction in the number of deaths by suicide. | Total: -- |
| Ueda et al 2015S94 | Time series | 2004–2014 | Japan (Tokyo) | On April 2004, 19 of 168 railway stations had half-height platform screen doors installed to prevent access to the rail tracks. Between 2004 and 2014, a total of 52 additional stations were retrofitted with half-height platform screen doors, for a total of 71 stations. | Following the installation of half-height platform screen doors there was a total of 7 deaths by suicide (2004–2014). The incidence rate ratio associated with the installation of the doors was 0.24 (95% CI 0.09 to 0.67), equivalent to a 76% reduction in suicide deaths. | Total: -- |
| Beautrais et al 2009S95 | Pre–post, with no control group | 1991–2006 | New Zealand (Auckland) | In 1937, barriers were installed on Grafton Bridge in Auckland, New Zealand. After public complaint about the unsightly barriers, they were removed from the bridge in 1996. In 2003, new barriers were erected on the bridge. | From 1991 to 1995, while the old barriers were erected, there was a mean of 1 suicide by jumping per year. This increased to 3.17 per year from 1997 to 2002 during the period where no barriers were installed. The per year mean number of suicide mortalities by jumping dropped to 0 once the new barriers were constructed on the Grafton Bridge. | Total: -- |
| Skegg et al 2009S96 | Time series | 1996–2008 | New Zealand (Dunedin) | Lawyer’s Head cliff is a scenic outlook in the city of Dunedin that overlooks the Pacific Ocean. In 2006, vehicle access to the Lawyer’s Head cliff was closed for construction. | In the 10-year period prior to the road closure there were 13 suicide mortalities at Lawyer’s Head cliff, which was reduced to 0 following the intervention (incidence rate difference=1.3 per year; 95% CI 0.6 to 2.0). | Total: -- |
| Chung et al 2016S97 | Time series | 2003–2012 | South Korea (Seoul) | Between 2005 and 2009, the Seoul Metro installed platform screen doors at 121 subway stations (119 full-height, and two half-height). | There was a total of 3 deaths by suicide following the installation of platform screen doors, compared with 132 deaths by suicide in stations without platform screen doors (incidence relative ratio=0.11; 95% CI 0.03 to 0.43). This was equivalent to an 89% (95% CI 57% to 97%) reduction in suicide deaths following the installation of a platform screen door. | Full-height doors Total: -- Half-height doors Total: + |
| Reisch et al 2005S98 | Pre–post, with no control group | 1988–2002 | Switzerland (Bern) | In 1998, a safety net was installed under the Muenster Terrace to save those who attempt suicide by jumping. | In the 4 years prior to the installation of the safety net six people died by suicide by jumping from the Muenster Terrace. Following the installation, three people jumped from the Terrace, but nobody died at the site. | Total: -- |
| Hemmer et al 2017S99 | Time series | 1990–2013 | Switzerland | This study investigated the impact of 15 jump sites in Switzerland with installed suicide-prevention measures (13 bridges, 1 terrace, 1 multistory car park). | The installation of barriers resulted in a prevention rate of 68.7% (rate ratio=0.34; 95% CI 0.18 to 0.64), whereas the installation of safety nets resulted in a prevention rate of 77.1% (rate ratio=0.21; 95% CI 0.07 to 0.62). | All barriers Total: -- Partial barriers Total: -- Full barriers Total: -- Safety nets Total: -- |
| Bennewith et al 2007S100 | Time series | 1994–2003 | UK (Bristol) | In December 1998, a barrier was installed on the Clifton suspension bridge in Bristol. | Prior to the installation of the bridge barrier there was a mean of 8.2 suicides by jumping per year (1994–1998), which declined to 4.0 suicides by jumping per year (difference in mean=−4.2; 95% CI −5.9 to –1.4). | Total: -- Male: -- Female: + |
++, statistically significant increase; --, statistically significant reduction; -, not statistically significant reduction; +, not statistically significant increase.