The overall global number of deaths by suicide increased by almost 20,000 during the past 30 years, new research shows.
The increase occurred despite a significant decrease in age-specific suicide rates from 1990 through 2019, according to data from the Global Burden of Disease Study 2019.
Population growth, population aging, and changes in population age structure may explain the increase in number of suicide deaths, the investigators note.
“As suicide rates are highest among the elderly (70 years or above) for both genders in almost all regions of the world, the rapidly aging population globally will pose huge challenges for the reduction in the number of suicide deaths in the future,” write the researchers, led by Paul Siu Fai Yip, PhD, of the HKJC Center for Suicide Research and Prevention, University of Hong Kong, China.
The findings were published online August 16 in Injury Prevention.
Global Public Health Concern
Around the world, approximately 800,000 individuals die by suicide each year, while many others attempt suicide. Yet suicide has not received the same level of attention as other global public health concerns, such as HIV/AIDS and cancer, the investigators write.
They examined data from the Global Burden of Disease Study 2019 to assess how demographic and epidemiologic factors contributed to the number of suicide deaths during the past 30 years.
The researchers also analyzed relationships between population growth, population age structure, income level, and gender- and age-specific suicide rates.
The Global Burden of Disease Study 2019 includes information from 204 countries about 369 diseases and injuries by age and gender. The dataset also includes population estimates for each year by location, age group, and gender.
In their analysis, the investigators looked at changes in suicide rates and the number of suicide deaths from 1990 to 2019 by gender and age group in the four income level regions defined by the World Bank. These categories include low-income, lower-middle-income, upper-middle-income, and high-income regions.
Number of Deaths vs Suicide Rates
From 1990 to 2019, the overall number of deaths from suicide increased by 19,897. The number of deaths was 738,799 in 1990 and 758,696 in 2019.
The largest increase in deaths occurred in the lower-middle-income region, where the number of suicide deaths increased by 72,550 (from 232,340 to 304,890).
Population growth (300,942; 1512.5%) was the major contributor to the overall increase in total number of suicide deaths. The second largest contributor was population age structure (189,512; 952.4%).
However, the effects of these factors were offset to a large extent by the effect of reduction in overall suicide rates (−470,556; −2,364.9%).
Interestingly, the overall suicide rate per 100,000 population decreased from 13.8 in 1990 to 9.8 in 2019.
The upper-middle-income region had the largest decline (−6.25 per 100,000), and the high-income region had the smallest decline (−1.77 per 100,000). Suicide rates also decreased in lower-middle-income (−2.51 per 100,000) and low-income regions (−1.96 per 100,000).
Reasons for the declines across all regions “have yet to be determined,” write the investigators. International efforts coordinated by the United Nations and World Health Organization likely contributed to these declines, they add.
“Imbalance of Resources”
The overall reduction in suicide rate of −4.01 per 100,000 “was mainly due” to reduction in age-specific suicide rates (−6.09; 152%), the researchers report.
This effect was partly offset, however, by the effect of the changing population age structure (2.08; −52%). In the high-income-level region, for example, the reduction in age-specific suicide rate (−3.83; 216.3%) was greater than the increase resulting from the change in population age structure (2.06; −116.3%).
“The overall contribution of population age structure mainly came from the 45-64 (565.2%) and 65+ (528.7%) age groups,” the investigators write. “This effect was observed in middle-income as well as high-income level regions, reflecting the global effect of population aging.”
They add that world populations will “experience pronounced and historically unprecedented aging in the coming decades” because of increasing life expectancy and declining fertility.
Men, but not women, had a notable increase in total number of suicide deaths. The significant effect of male population growth (177,128; 890.2% vs 123,814; 622.3% for women) and male population age structure (120,186; 604.0% vs 69,325; 348.4%) were the main factors that explained this increase, the investigators note.
However, from 1990 to 2019, the overall suicide rate per 100,000 men decreased from 16.6 to 13.5 (–3.09). The decline in overall suicide rate was even greater for women, from 11.0 to 6.1 (–4.91).
This finding was particularly notable in the upper-middle-income region (–8.12 women vs –4.37 men per 100,000).
“This study highlighted the considerable imbalance of the resources in carrying out suicide prevention work, especially in low-income and middle-income countries,” the investigators write.
“It is time to revisit this situation to ensure that sufficient resources can be redeployed globally to meet the future challenges,” they add.
The study was funded by a Humanities and Social Sciences Prestigious Fellowship, which Yip received. He declared no relevant financial relationships.
Inj Prev. Published online August 16, 2021. Abstract
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