Changes in age patterns of suicide in Australia, the United States, Japan and Hong Kong

- Rates and age patterns of suicide vary markedly over time and between populations.
- Suicide rates of older men have fallen substantially over recent decades.
- Female suicide rates now remain low and vary little with age, except in Hong Kong.
- In Japan (and in the US, but less so) male middle age suicide rates have increased.
- Age patterns can reveal cohort & period effects (e.g. socioeconomic, environmental).

The patterns of association between age and suicide rate vary by country, subpopulation and gender, and over time. To shed light on factors associated with these differences, we analysed suicide data from four populations, two 'Western' (Australia, the United States [US]) and two Asian (Japan and Hong Kong). We computed suicide rates in five-year age-groups (between 10 and 14 years and 85+ years) for men and women separately, and present graphical representations of the age patterns during selected five-year periods. Rates and age patterns differed markedly, as did gender patterns except in Hong Kong. In 1964-8, male suicide rates in Australia and US were represented by upward-sloping graphs, whereas in Japan the pattern was bimodal. By 1979-83, male patterns in Australia and US were bimodal, but Japan's was trimodal, including a middle-age peak reached in 1994-98. In contrast, female age patterns in the Western countries were shallowly convex or uniform, while in Hong Kong and Japan the upward-sloping graphs became, over time, less steep; by 2009-13, the pattern in Japan was uniform (flat). In recent decades, suicide rates of older men in Australia, US and Japan, and older women in Japan and Hong Kong, have fallen considerably. Suicide rates of men aged 45-64 in Australia and US also fell, though by 2009-13 the US rate had risen again. The suicide rate of Australian men in their twenties halved between 1994-98 and 2009-13, while rates for younger men and women in Japan have risen since 1994-98. In Hong Kong, suicide rates of young men have increased. Age patterns of suicide likely reflect period and cohort effects shaped by socioeconomic stressors, availability of health and welfare services, access to lethal methods of suicide, and other factors. Greater understanding of their impact on age patterns of suicide can result in potential preventive solutions.