Year-on-year incidence rate ratio for charcoal-burning suicide in four East/Southeast Asian countries.

aThe peak year (2005) for Japan was determined by inspecting the time trends to identify the year when charcoal-burning suicide rate was the highest before 2008, as from 2008 onwards suicides classified as other gas poisoning included not only charcoal-burning suicides but also some deaths from hydrogen sulphide poisoning [31].IRR, incidence rate ratio.