Gender difference in suicide in Taiwan over a century: A time trend analysis in 1905-1940 and 1959-2012

Background Suicide rates are higher in men than in women in most countries, although the gender ratios vary markedly worldwide. We investigated long-term trends in suicide rates and the male-to-female ratios in relation to age, method and economic factors in Taiwan during the Japanese colonial (1905-1940) and postwar (1959-2012) periods. Methods Suicide data were from the Statistical Reports of Taiwan Governor's Office (1905-1940), Vital Statistics (1959-1970) and cause-of-death mortality data files (1971-2012). Annual age-standardised and age-specific/method-specific suicide rates by gender and the gender ratios were calculated and examined graphically. The associations between trends in economic indicators, suicide and suicide gender ratio were investigated using Prais-Winsten regression. Results The male-to-female suicide rate ratio increased from below 1 in the 1900s to around 2 by 2000; the reversal was mainly due to a marked reduction in suicide rates in young women coupled with a rise in male suicide between 1905 and 1940. The gender ratio increased again from the 1980s onwards. Poisoning was the most common method in the 1970s-1980s, but its use decreased afterwards, more in women than in men proportionally. The use of gassing for suicide increased markedly in the 2000s and contributed to the rises in overall suicide and the gender ratio. Unemployment rates were more strongly associated with male suicide than female suicide in 1959-2012. Unemployment rates and gross domestic product per capita were positively associated with suicide gender ratios. Conclusions Gender differences in suicide changed remarkably in Taiwan over the past century; such change may be related to cultural, socioeconomic and method-specific factors.