Decomposing the widening suicide gender gap: An experience in Taipei City, Taiwan

Background: There has been a widening suicide gender gap in Taiwan in the past decade. This study aimed to examine the contributions of changing incidence patterns of suicidal behavior and case fatalities of different suicide methods in quantitatively explaining the male excess in suicide rates and the associated changes in gender ratio of suicide in Taipei City from 2004 to 2006. Methods: A decompositional method was used to quantify the contributions of age, method-specific case fatality, and attempt incidence to male excess in suicide rates. Our aim is to examine the male excess in suicide rate by decomposing the difference (i.e., male minus female) and widening gender ratio (i.e., male to female) during the study period, respectively. Results: Charcoal burning suicide replaced hanging as the most common method of suicide in 2006. Its percentage of contribution for the male excess in suicide rate (i.e., male minus female) increased from 36.3% in 2004 to 45.1% in 2006 whereas poisoning from solid and liquid poisoning reduced from 7.7% to 4.9% for the same period. Also, the widening suicide gender ratio was mostly due to the increased incidence of attempts of three highly lethal methods of suicide among men: charcoal burning (59.5%), hanging (38.6%), and jumping from a height (35.6%). The disproportionate increase in attempt incidence especially for the methods of charcoal burning and hanging among 40-59 year-old men contributed most significantly to the widened suicide gender gap. Limitations: Although accessibility to emergency services in major hospitals is good, it is to be expected that there are an unknown number of underreported of suicide attempts which might affect the results. Also, we have selected only age-, gender- and method-specific case fatality and incidence of suicide attempt to explain the male excess in suicide rates. Some other factors, for example, urban and rural region which might be related to the gender ratio, but have not been examined in this study. Conclusions: Suicide attempt incidences in males and females have increased considerably in the period 2004-2006. As males especially those 40-59 years old are drawn to use more lethal methods of suicide (i.e. charcoal burning and jumping), the excessive male suicide rate and the suicide gender ratio continues to increase even though the gender ratio of attempt incidence remains the same. (C) 2011 Elsevier B.V. All rights reserved.