Demographic and epidemiological decomposition analysis of global changes in suicide rates and numbers over the period 1990-2019.

BACKGROUND: Suicide presents an ongoing public health challenge internationally. Nearly 800 000 people around the world lose their life to suicide every year, and many more attempt suicide. METHODS: A decomposition analysis was performed using global suicide mortality and population data from the Global Burden of Disease Study 2019. RESULTS: Despite a significant decrease in age-specific suicide rate between 1990 and 2019 (-4.01; from 13.8% to 9.8% per 100 000), the overall numbers of suicide deaths increased by 19 897 (from 738 799 to 758 696) in the same time period. The reductions in age-specific suicide rates (-6.09; 152%) contributed to the overall reductions in suicide rates; however, this was offset by overtime changes in population age structure (2.08; -52%). The increase in suicide numbers was partly attributable to population growth (300 942; 1512.5%) and population age structure (189 512; 952.4%), which was attenuated by the significant reduction in overall suicide rates (-470 556; 2364.9%). The combined effect of these factors varied across the World Bank income level regions. For example, in the upper-middle-income level region, the effect of the reduction in age-specific suicide rates (-289 731; -1456.1%) exceeded the effect of population age structure (124 577; 626.1%) and population growth (83 855; 421.4%), resulting in its substantial decline in total suicide deaths (-81 298; -408.6%). However, in lower-middle income region, there was a notable increase in suicide death (72 550; 364.6%), which was related to the net gain of the reduction in age-specific suicide rates (-115 577; -580.9%) and negated by the increase in the number of suicide deaths due to population growth (152 093; 764.4%) and population age structure (36 034; 181.1%). CONCLUSION: More support and resources should be deployed for suicide prevention to the low-income and middle-income regions in order to achieve the reduction goal. Moreover, suicide prevention among older adults is increasingly critical given the world's rapidly ageing populations in all income level regions.