BACKGROUND: The effects of socio-economic factors on suicide were gender-dependent. Japanese suicide mortality gender ratio (male: female) had gradually increased during the twentieth century. METHODS: With the data covering 1947-2010 collected from Japanese official websites, we conducted non-parametric rank test, curve estimations, spearman ranking correlation and quantile regression in succession with Stata version 12.0. RESULTS: The suicide mortality rate in male with a "U" shape had been always higher than that in female with a "J" shape. The male suicide mortality peaked around in 1955 (38.5 per 100,000 populations), dropped quickly afterwards until the 1970s; it increased in the 1980s with another peak in 2003 (33.2 per 100,000 populations). For female, an overall decreasing trend was seen with a peak during the 1950s (23.5 per 100,000 populations in 1958). It dropped gradually afterwards with small variations in 1970s and 80s, and was stabilized after 1995 (9.3 per 100,000 populations). The unemployment rate could be used as a single positive predictor of suicide mortality for men (p<0.01), while the total fertility rate (TFR) (p<0.01) and divorce rate (p<0.01) were significantly associated positively and negatively with women's suicide, respectively. LIMITATIONS: The impact of mental disorders was not analyzed and age-specific analysis was not conducted. CONCLUSION: The findings of these gender differences in, and the associated factors with, suicide in Japan, warranted further studies including delineation of the implications of differential economic pressure between genders, as well as child-rearing pressure and marriage satisfaction.
BACKGROUND: The effects of socio-economic factors on suicide were gender-dependent. Japanese suicide mortality gender ratio (male: female) had gradually increased during the twentieth century. METHODS: With the data covering 1947-2010 collected from Japanese official websites, we conducted non-parametric rank test, curve estimations, spearman ranking correlation and quantile regression in succession with Stata version 12.0. RESULTS: The suicide mortality rate in male with a "U" shape had been always higher than that in female with a "J" shape. The male suicide mortality peaked around in 1955 (38.5 per 100,000 populations), dropped quickly afterwards until the 1970s; it increased in the 1980s with another peak in 2003 (33.2 per 100,000 populations). For female, an overall decreasing trend was seen with a peak during the 1950s (23.5 per 100,000 populations in 1958). It dropped gradually afterwards with small variations in 1970s and 80s, and was stabilized after 1995 (9.3 per 100,000 populations). The unemployment rate could be used as a single positive predictor of suicide mortality for men (p<0.01), while the total fertility rate (TFR) (p<0.01) and divorce rate (p<0.01) were significantly associated positively and negatively with women's suicide, respectively. LIMITATIONS: The impact of mental disorders was not analyzed and age-specific analysis was not conducted. CONCLUSION: The findings of these gender differences in, and the associated factors with, suicide in Japan, warranted further studies including delineation of the implications of differential economic pressure between genders, as well as child-rearing pressure and marriage satisfaction.