Using a time trend analysis, Ying-Yeh Chen and colleagues examine the evidence for regional increases in charcoal-burning suicide rates in East and Southeast Asia from 1995 to 2011.
Please see later in the article for the Editors' Summary
Suicides by carbon monoxide poisoning resulting from burning barbecue charcoal reached epidemic levels in Hong Kong and Taiwan within 5 y of the first reported cases in the early 2000s. The objectives of this analysis were to investigate (i) time trends and regional patterns of charcoal-burning suicide throughout East/Southeast Asia during the time period 1995–2011 and (ii) whether any rises in use of this method were associated with increases in overall suicide rates. Sex- and age-specific trends over time were also examined to identify the demographic groups showing the greatest increases in charcoal-burning suicide rates across different countries.
Methods and Findings
We used data on suicides by gases other than domestic gas for Hong Kong, Japan, the Republic of Korea, Taiwan, and Singapore in the years 1995/1996–2011. Similar data for Malaysia, the Philippines, and Thailand were also extracted but were incomplete. Graphical and joinpoint regression analyses were used to examine time trends in suicide, and negative binomial regression analysis to study sex- and age-specific patterns. In 1995/1996, charcoal-burning suicides accounted for <1% of all suicides in all study countries, except in Japan (5%), but they increased to account for 13%, 24%, 10%, 7%, and 5% of all suicides in Hong Kong, Taiwan, Japan, the Republic of Korea, and Singapore, respectively, in 2011. Rises were first seen in Hong Kong after 1998 (95% CI 1997–1999), followed by Singapore in 1999 (95% CI 1998–2001), Taiwan in 2000 (95% CI 1999–2001), Japan in 2002 (95% CI 1999–2003), and the Republic of Korea in 2007 (95% CI 2006–2008). No marked increases were seen in Malaysia, the Philippines, or Thailand. There was some evidence that charcoal-burning suicides were associated with an increase in overall suicide rates in Hong Kong, Taiwan, and Japan (for females), but not in Japan (for males), the Republic of Korea, and Singapore. Rates of change in charcoal-burning suicide rate did not differ by sex/age group in Taiwan and Hong Kong but appeared to be greatest in people aged 15–24 y in Japan and people aged 25–64 y in the Republic of Korea. The lack of specific codes for charcoal-burning suicide in the International Classification of Diseases and variations in coding practice in different countries are potential limitations of this study.
Charcoal-burning suicides increased markedly in some East/Southeast Asian countries (Hong Kong, Taiwan, Japan, the Republic of Korea, and Singapore) in the first decade of the 21st century, but such rises were not experienced by all countries in the region. In countries with a rise in charcoal-burning suicide rates, the timing, scale, and sex/age pattern of increases varied by country. Factors underlying these variations require further investigation, but may include differences in culture or in media portrayals of the method.
Please see later in the article for the Editors' Summary
Every year, almost one million people die by suicide globally; suicide is the fifth leading cause of death in women aged 15–49 and the sixth leading cause of death in men in the same age group. Most people who take their own life are mentally ill. For others, stressful events (the loss of a partner, for example) have made life seem worthless or too painful to bear. Strategies to reduce suicide rates include better treatment of mental illness and programs that help people at high risk of suicide deal with stress. Suicide rates can also be reduced by limiting access to common suicide methods. These methods vary from place to place. Hanging is the predominant suicide method in many countries, but in Hong Kong, for example, jumping from a high building is the most common method. Suicide methods also vary over time. For example, after a woman in Hong Kong took her life in 1998 by burning barbecue charcoal in a sealed room (a process that produces the toxic gas carbon monoxide), charcoal burning rapidly went from being a rare method of killing oneself in Hong Kong to the second most common suicide method.
Why Was This Study Done?
Cases of charcoal-burning suicide have also been reported in several East and Southeast Asian countries, but there has been no systematic investigation of time trends and regional patterns of this form of suicide. A better understanding of regional changes in the number of charcoal-burning suicides might help to inform efforts to prevent the emergence of other new suicide methods. Here, the researchers investigate the time trends and regional patterns of charcoal-burning suicide in several countries in East and Southeast Asia between 1995 and 2011 and ask whether any rises in the use of this method are associated with increases in overall suicide rates. The researchers also investigate sex- and age-specific time trends in charcoal-burning suicides to identify which groups of people show the greatest increases in this form of suicide across different countries.
What Did the Researchers Do and Find?
The researchers analyzed method-specific data on suicide deaths for Hong Kong, Japan, the Republic of Korea, Taiwan, and Singapore between 1995/1996 and 2011 obtained from the World Health Organization Mortality Database and from national death registers. In 1995/1996, charcoal-burning suicides accounted for less than 1% of all suicides in all these countries except Japan (4.9%). By 2011, charcoal-burning suicides accounted for between 5% (Singapore) and 24% (Taiwan) of all suicides. Rises in the rate of charcoal-burning suicide were first seen in Hong Kong in 1999, in Singapore in 2000, in Taiwan in 2001, in Japan in 2003, and in the Republic of Korea in 2008. By contrast, incomplete data from Malaysia, the Philippines, and Thailand showed no evidence of a marked increase in charcoal-burning suicide in these countries over the same period. Charcoal-burning suicides were associated with an increase in overall suicide rates in Hong Kong in 1998–2003, in Taiwan in 2000–2006, and in Japanese women after 2003. Finally, the annual rate of change in charcoal-burning suicide rate did not differ by sex/age group in Taiwan and Hong Kong, whereas in Japan people aged 15–24 and in the Republic of Korea people aged 25–64 tended to have the greatest rates of increase.
What Do These Findings Mean?
These findings show that charcoal-burning suicides increased markedly in several but not all East and Southeast Asian countries during the first decade of the 21st century. Moreover, in countries where there was an increase, the timing, scale, and sex/age pattern of the increase varied by country. The accuracy of these findings is likely to be limited by several aspects of the study. For example, because of the way that method-specific suicides are recorded in the World Health Organization Mortality Database and national death registries, the researchers may have slightly overestimated the number of charcoal-burning suicides. Further studies are now needed to identify the factors that underlie the variations between countries in charcoal-burning suicide rates and time trends reported here. However, the current findings highlight the need to undertake surveillance to identify the emergence of new suicide methods and the importance of policy makers, the media, and internet service providers working together to restrict graphic and detailed descriptions of new suicide methods.
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001622.
A PLOS Medicine research article by Shu-Sen Chang and colleagues investigates time trends and regional patterns of charcoal-burning suicide in Taiwan
The World Health Organization provides information on the global burden of suicide and on suicide prevention (in several languages); it also has an article on international patterns in methods of suicide
The US National Institute of Mental Health provides information on suicide and suicide prevention
The UK National Health Service Choices website has detailed information about suicide and its prevention
MedlinePlus provides links to further resources about suicide (in English and Spanish)
The International Association for Suicide Prevention provides links to crisis centers in Asia
The charity Healthtalkonline has personal stories about dealing with suicide