Gender ratio comparisons of the suicide rates and methods in Korea, Japan, Australia, and the United States

Abstract

Background

The gender ratio (male/female) of suicide rates greatly differs by country and by age group. These differences are accompanied by differences in the use of violent methods of suicide.

Methods

The gender ratio of suicide rates and the methods used were calculated from the most recently available official electronic mortality data published by the four countries (two Eastern (Korea and Japan) and two Western (Australia and the United states) countries) and from the World Health Organization [WHO] mortality database. Suicide gender ratios based on 95% Confidence intervals (CIs) were used to compare the countries between age groups.

Results

The gender ratio of suicide rates was higher in the United States (3.9) and Australia (3.3), where gender differences in suicide methods were more prominent, than in Korea (1.8) and Japan (2.7). In the United States and Australia, the gender ratios greatly increased in the elderly (age 70 years and over), with a higher use of firearms by men. The gender ratio of suicide rates was lowest (1.0) in the young (age 20–29) in Korea, where hanging was a more common method in women than in men.

Limitations

The study does not consider the various other factors that may have influenced gender differences of suicide rate.

Conclusions

These findings suggest that differences in suicide methods play a role in determining the differences in the gender ratio of suicide rates between countries. Because suicide methods varied with gender, age, and country and may play a role in the suicide rates of each group, these parameters should be taken into account in the design of suicide prevention measures.

Introduction

Although females typically have a higher rate of suicide attempts than males, their suicide mortality is lower. However, the gender ratio (male/female) of suicide rates differs greatly between countries. In Western countries it is 3–4:1, while in Eastern countries it is usually <2:1 (Yip, 1998). The gender gap may be more prominent in communities where different suicidal behaviors are expected of males and females (Canetto and Sakinofsky, 1998). It also differs according to age, even within a single country (Canetto and Sakinofsky, 1998, Kapusta et al., 2007, Kim et al., 2011, McIntosh and Jewell, 1986, Yip et al., 2000, Yip and Liu, 2006).

The lethality of the various suicide methods is an important determinant that distinguishes attempted suicide from completed suicide. Therefore, gender differences in suicide methods in each age group and in each country provide insight into the respective differential in male to female suicide rates. For example, Phillips et al. suggested that the high lethality of poisoning by pesticide, a suicide method commonly used by rural women in China, contributes to the high female suicide rate in that country (Phillips et al., 2002).

Gender differences in suicide methods were previously studied in several countries (Centers for Disease Control and Prevention (CDC), 2007, Chen et al., 2009, Im et al., 2011, Kim et al., 2011, Varnik et al., 2008), but the association between gender ratios of suicide rates and suicide methods in different countries and in different age groups has yet to be examined. In the present study, we asked whether age-specific gender ratios of suicide rates differed between Eastern and Western countries, based on data from South Korea and Japan and from Australia and the United States, respectively. We hypothesized that differences in the pattern of suicide methods are related to the differences in male vs. female suicide rates between countries. Accordingly, age- and gender-specific suicide methods were also evaluated in the four countries.