Letter

To the Editor: Burning barbecue charcoal in an enclosed space to create carbon monoxide intoxication has become a popular method of suicide in some Asian countries, particularly in Hong Kong and Taiwan ( 1, 2 ). Since 2002 suicide by charcoal burning has become the second most commonly used method of suicide in Taiwan, accounting for more than 30% of all suicide deaths ( 3 ). However, little is known about the patterns of health care use in this suicide subgroup.

We linked mortality data classified as ICD-9 code E952 (N=2,192), E953 (N=4,814), and E950 (N=2,797) from 2000 through 2004 to National Health Insurance data files. Chi square tests were used to compare health care use in the past year and history of psychiatric or medical contacts between persons who completed suicide by charcoal burning (E952), hanging (E953), and solid or liquid poisoning (E950).

We found that compared with persons who committed suicide by hanging and solid or liquid poisoning, charcoal-burning suicide victims had fewer health care contacts. Only 18% (N=396) of victims of charcoal-burning suicide had visited a psychiatrist in the year before suicide; this percentage was significantly lower than for victims of hanging (25%, N= 1,216) and solid or liquid poisoning (23%, N=650) (p<.001). Recorded psychiatric diagnoses were less frequent among victims of suicide by charcoal burning than among those who used the other methods (40% [N=906] of the charcoal-burning suicide victims compared with 57% [N= 2,765] of hanging victims and 59% [N=1,639] of poisoning victims) (p< .001 for both comparisons).

The presuicide physical condition of the charcoal-burning victims was better than the condition of victims in the hanging and poisoning suicide subgroups, as reflected by the lower likelihood of hospital admission in the past year (18%, 35%, and 58%, respectively) (p<.001 for both comparisons). Even when the analysis controlled for age, the lower rate of health care use among victims of charcoal-burning suicide was observed.

Our results corroborate findings from Hong Kong that victims of charcoal-burning suicide were less likely to have pre-existing mental or physical illness ( 1, 4, 5 ). Our results further indicate that this suicide subgroup was significantly less likely to make contact with the health care system. Therefore, the traditional suicide prevention strategy that focuses on recognition and treatment of high-risk groups may not be able to reach this population. Our results support the point previously raised by researchers from Hong Kong that this new method may have attracted individuals who would otherwise not have considered suicide ( 2, 5 ). Acute stress, particularly economic difficulty, rather than mental disorders may be the major precipitating factor of suicide in this suicide subgroup ( 2, 5 ). Population-based prevention strategies to prevent charcoal-burning suicide that might be considered include efforts to destigmatize mental illness to enhance appropriate help-seeking behaviors, restrictions on access to charcoal (for example, by removing charcoal from open shelves and making it necessary for the customer to request it from a shop assistant), and guidance for the media on how to report on suicide events.

This study was limited by the difficulty of determining the reliability and validity of the claim data. Furthermore, not all deaths classified under ICD-9 code E952 were from charcoal burning; some deaths may have resulted from other types of carbon monoxide poisoning.

This research was funded by grant 94-3084 from the Taiwan Suicide Prevention Center, Department of Health, Taiwan.

The authors report no competing interests.

Dr. Chen is with Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan, and the Institute of Public Health, National Yang-Ming University, Taipei. Dr. Liao and Professor Lee are with the Department of Psychiatry, National Taiwan University Hospital, Taipei, and Taiwan Suicide Prevention Center.