Epidemic of charcoal burning suicide in Japan

INTRODUCTION: There has been an epidemic of suicide by the charcoal burning method since the late ’90s in Hong Kong and Taiwan, and since 2003 in Japan. While the epidemics in Hong Kong and Taiwan have been well documented, little is known about the situation in Japan. We aim to evaluate the impact of the emergence of charcoal burning on overall suicide rates in Japan, and assess any sign of substitution effect from the charcoal burning method.

METHODS: Data was obtained from the Vital Statistics of Japan. We grouped suicide methods into charcoal burning and other methods, and age into 15-24, 25-44, 45-64 and 65+. The period 1998–2002 was taken as the pre-epidemic period, while 2003–2007 as the epidemic period. To examine the influence of charcoal burning method on overall and method-specific suicides, Negative Binomial regression analyses were performed by using the number of suicides per year and the age groups as the outcome variables.

RESULTS: In the 15-24 and 25-44yr age groups of both males and females, substantial increases in the APCs (average percentage change between the pre-epidemic and epidemic periods) of overall suicides were observed, while significant decreases in the APCs of other method suicide were not observed after adjustment for time trend. However, in the other age groups, similar trends in the APCs of overall and other method suicides were not observed.

CONCLUSIONS: Our results suggest that, in the 15-24 and 25-44yr age-groups of both males and females, the charcoal burning method appealed to individuals who might not have used other available lethal methods and this therefore lead to an increase in overall suicide rates during the epidemic period in Japan.