The evolution of the epidemic of charcoal-burning suicide in Taiwan: a spatial and temporal analysis

Abstract

Background: An epidemic of carbon monoxide poisoning suicide by burning barbecue charcoal has occurred in East Asia in the last decade. We investigated the spatial and temporal evolution of the epidemic to assess its impact on the epidemiology of suicide in Taiwan.

Methods and findings: Age-standardised rates of suicide and undetermined death by charcoal burning were mapped across townships (median population aged 15 y or over = 27,000) in Taiwan for the periods 1999-2001, 2002-2004, and 2005-2007. Smoothed standardised mortality ratios of charcoal-burning and non-charcoal-burning suicide and undetermined death across townships were estimated using Bayesian hierarchical models. Trends in overall and method-specific rates were compared between urban and rural areas for the period 1991-2007. The epidemic of charcoal-burning suicide in Taiwan emerged more prominently in urban than rural areas, without a single point of origin, and rates of charcoal-burning suicide remained highest in the metropolitan regions throughout the epidemic. The rural excess in overall suicide rates prior to 1998 diminished as rates of charcoal-burning suicide increased to a greater extent in urban than rural areas.

Conclusions: The charcoal-burning epidemic has altered the geography of suicide in Taiwan. The observed pattern and its changes in the past decade suggest that widespread media coverage of this suicide method and easy access to barbecue charcoal may have contributed to the epidemic. Prevention strategies targeted at these factors, such as introducing and enforcing guidelines on media reporting and restricting access to charcoal, may help tackle the increase of charcoal-burning suicides. Please see later in the article for the Editors' Summary.

Figure 1. Maps of Taiwanese townships by urbanisation level, 2000.

(A) urbanisation levels 1–7; (B) urban (levels 1–3) versus rural (levels 4–7). Five cities are highlighted, including four cities located in the centres of three major metropolitan areas in the north (the capital Taipei city), middle (Taichung city), and south (Tainan and Kaohsiung cities) and one major city in the east (Hualien city).

Figure 2. Maps of (unsmoothed) age-standardised rates of suicide (including registered suicide and undetermined death) by charcoal burning across 358 townships in Taiwan, 1999–2001, 2002–2004, and 2005–2007, with five major cities highlighted.

(A) Males; (B) females.

Figure 3. Maps of SMRs for charcoal-burning and non-charcoal-burning suicides (including registered suicides and undetermined deaths) across 358 townships in Taiwan, 1999–2007, with five major cities highlighted.

(A) Males; (B) females.

Figure 4. Secular trends in age-standardised rates (3-y moving averages) of suicide (including registered suicide and undetermined death) for males and females in Taiwan, 1991–2007.

(A) Overall rates; (B) rates of charcoal-burning suicide; (C) rates of non-charcoal-burning suicide.