Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Abstract

Background Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019.Methods 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10-14 and 50-54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed agespecific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. FindingsThe global TFR decreased from 2•72 (95% uncertainty interval [UI] 2•66-2•79) in 2000 to 2•31 (2•17-2•46) in 2019. Global annual livebirths increased from 134•5 million (131•5-137•8) in 2000 to a peak of 139•6 million (133•0-146•9) in 2016. Global livebirths then declined to 135•3 million (127•2-144•1) in 2019. Of the 204 countries and territories included in...

Mortality in Tonga over three triennia, 2010–2018

“…90% uncertainty intervals (UI) are not comparable to CI. (8) Source: [ 41 ]. Estimates modelled from spatiotemporal and Gaussian process regressions.…”

“…Annual estimates over 2010–2018 are shown with 90% uncertainty intervals offset at + 0.25 per year. 90% uncertainty intervals (UI) are not comparable to 95%UI and CI (8) Source: [ 41 ]. Estimates modelled from spatiotemporal and Gaussian process regressions.…”

“…Estimates over 2010–2017 are shown offset at − 0.25 for each year. (7) Source: [ 41 ]. Estimates modelled from spatiotemporal and Gaussian process regressions.…”

“…Mortality indices modelled and published by international agencies are based on limited empirical mortality data from Tonga. The WHO [ 40 ], GBD [ 41 ] and UN-IGME mortality databases [ 39 ] published in 2018–2020 include death registration data for years prior to 2006 only, and Census estimates up to 2006; the 2012 DHS was also included in the GBD and UN-IGME databases, and the 2019 MICS preliminary results included by UN-IGME. Differences among agency estimates reflect differences in inclusion criteria and modelling.…”

“…National sources include the MoH annual report [ 36 ], Tonga Census reports [ 22 , 28 ], Tonga 2019 Multiple Indicator Cluster Survey (MICS) [ 37 ], and Tonga 2012 Demographic and Health Survey (DHS) [ 38 ]. Modelled mortality estimates by international agencies include: the United Nations Inter-agency Group for Child Mortality Estimation (UN-IGME) [ 39 ]; WHO Global Health Estimates [ 40 ]; the Global Burden of Disease (GBD) Study by the Institute of Health Metrics and Evaluation [ 41 ]; the World Bank [ 42 ]; and the United Nations Statistical Yearbook [ 43 ].…”