Evaluating the effectiveness of platform screen doors for preventing metro suicides in China

Metro suicide can cause tremendous effects on the general public. Platform screen doors (PSDs) have been identified as one of the most effective methods of suicide prevention at metro stations. However, there are few studies focusing on their effectiveness in preventing suicides. In particular, the effect of types of PSDs, including full-height and half-height PSDs, has rarely been assessed and compared.

Based on the suicide data provided by the Shanghai metro operator, the effectiveness of installing different types of PSDs for preventing metro suicides was investigated using a Poisson regression model. Ten-year monthly panel data for 94 metro stations from 2008 to 2017 were used in this study.

The number of metro suicides declined by 90.9% after the PSDs were installed at metro stations. In addition, different types of PSDs had different effects on decreasing the number of suicides, and a higher half-height PSD was more effective in preventing suicides. Specifically, full-height PSDs could eliminate metro suicides by completely preventing passengers from entering the track area, while half-height PSDs that were 1.5 m and 1.2 m high could decrease the number of suicides by 79.2% and 60.2%, respectively. Moreover, there was no significant indication that the installation of PSDs at metro stations displaced suicides to railway stations without PSDs (p = 0.706).

The potential economic benefits of different types of PSDs were not considered in our study. In addition, we did not examine whether suicide attempters would try to take their own lives by using other methods of suicide.

The installation of PSDs, especially full-height PSDs, could be very effective in preventing suicides at metro stations. Although half-height PSDs are less effective than full-height PSDs, increasing the height of half-height PSDs could be an effective way of enhancing their effectiveness in reducing the number of suicides.