The evolution of charcoal burning suicide in Hong Kong

Abstract

Suicide by charcoal burning was first extensively reported in Hong Kong in 1998. Since then, it has spread to South Korea, Taiwan, Japan and other communities, and resulted in more than 100,000 deaths globally. Yet, a systematic understanding of the published evidence available is lacking. This thesis began with a systematic scoping review which explored the existing evidence on trends, risk factors, prevention strategies, and other related aspects of suicide by charcoal burning. A few research gaps have been suggested based on the review of literature: (i) lack of recent updates on change in trends and case profiles; (ii) inadequate understanding of the spatial pattern of charcoal burning suicide and the impact of community-level factors; and (iii) insufficient evidence on long-term sustainability of suicide prevention strategies of charcoal burning. In response to the identified research gaps, four studies have been conducted in Hong Kong, where this method was first widely reported, in this thesis. The first study documented the overall, sex- and age-specific trends of suicide by charcoal burning in Hong Kong. It was observed that charcoal burning suicide rate dropped from the peak in 2003 until 2016, but a slight increase was observed since then. The pattern of age among charcoal burning suicides has been changing in which the method was adopted by the older age groups in recent years. The second study explored the difference in profile between charcoal burning and non-charcoal burning cases by age and sex in Hong Kong. The profile of people who killed themselves by charcoal burning was different from those using other suicide methods. The third study examined the geographical distribution of charcoal burning suicide (1999-2018) in Hong Kong and its association with social disadvantage indicators (social deprivation and social fragmentation) in comparison to other suicide methods. The results suggested a spatial heterogeneity of suicide by charcoal burning in Hong Kong and the risk pattern changed over time. Suicide risk by charcoal burning was associated with social fragmentation but not social deprivation in the earlier years (1999-2003). However, the risk profile changed in which it was associated with social deprivation but not social fragmentation in recent years (2014-2018). The fourth study revisited a suicide prevention program conducted in 2002 in Cheung Chau, where charcoal burning suicides were occasionally reported in holiday houses. After the post-implementation period of the intervention, suicide rates for both residents and visitors in Cheung Chau increased in which most of the visitors killed themselves by charcoal burning. This thesis documented a unique opportunity to understand the individual- and community-level factors related to a novel suicide method since it was first reported in the community. It reveals a changing pattern of suicide by charcoal burning in individual and community characteristics. Despite restriction of suicidal means proven to be effective in the short-term, continual monitoring of the changing profiles and a consistent community support and engagement are crucial for program sustainability. The results provide insights for future suicide prevention efforts on charcoal burning suicide from the individual and community levels.