Global, regional, national, and selected subnational levels of stillbirths, neonatal, infant, and under-5 mortality, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015

Abstract

Background: Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, financial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specific and cause-specific mortality among children under 5 years, and stillbirths by geography over time.

Methods: Drawing from analytical approaches developed and refined in previous iterations of the GBD study, we generated updated estimates of child mortality by age group (neonatal, post-neonatal, ages 1-4 years, and under 5) for 195 countries and territories and selected subnational geographies, from 1980-2015. We also estimated numbers and rates of stillbirths for these geographies and years. Gaussian process regression with data source adjustments for sampling and non-sampling bias was applied to synthesise input data for under-5 mortality for each geography. Age-specific mortality estimates were generated through a two-stage age-sex splitting process, and stillbirth estimates were produced with a mixed-effects model, which accounted for variable stillbirth definitions and data source-specific biases. For GBD 2015, we did a series of novel analyses to systematically quantify the drivers of trends in child mortality across geographies. First, we assessed observed and expected levels and annualised rates of decrease for under-5 mortality and stillbirths as they related to the Soci-demographic Index (SDI). Second, we examined the ratio of recorded and expected levels of child mortality, on the basis of SDI, across geographies, as well as differences in recorded and expected annualised rates of change for under-5 mortality. Third, we analysed levels and cause compositions of under-5 mortality, across time and geographies, as they related to rising SDI. Finally, we decomposed the changes in under-5 mortality to changes in SDI at the global level, as well as changes in leading causes of under-5 deaths for countries and territories. We documented each step of the GBD 2015 child mortality estimation process, as well as data sources, in accordance with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER).

Findings: Globally, 5·8 million (95% uncertainty interval [UI] 5·7-6·0) children younger than 5 years died in 2015, representing a 52·0% (95% UI 50·7-53·3) decrease in the number of under-5 deaths since 1990. Neonatal deaths and stillbirths fell at a slower pace since 1990, decreasing by 42·4% (41·3-43·6) to 2·6 million (2·6-2·7) neonatal deaths and 47·0% (35·1-57·0) to 2·1 million (1·8-2·5) stillbirths in 2015. Between 1990 and 2015, global under-5 mortality decreased at an annualised rate of decrease of 3·0% (2·6-3·3), falling short of the 4·4% annualised rate of decrease required to achieve MDG4. During this time, 58 countries met or exceeded the pace of progress required to meet MDG4. Between 2000, the year MDG4 was formally enacted, and 2015, 28 additional countries that did not achieve the 4·4% rate of decrease from 1990 met the MDG4 pace of decrease. However, absolute levels of under-5 mortality remained high in many countries, with 11 countries still recording rates exceeding 100 per 1000 livebirths in 2015. Marked decreases in under-5 deaths due to a number of communicable diseases, including lower respiratory infections, diarrhoeal diseases, measles, and malaria, accounted for much of the progress in lowering overall under-5 mortality in low-income countries. Compared with gains achieved for infectious diseases and nutritional deficiencies, the persisting toll of neonatal conditions and congenital anomalies on child survival became evident, especially in low-income and low-middle-income countries. We found sizeable heterogeneities in comparing observed and expected rates of under-5 mortality, as well as differences in observed and expected rates of change for under-5 mortality. At the global level, we recorded a divergence in observed and expected levels of under-5 mortality starting in 2000, with the observed trend falling much faster than what was expected based on SDI through 2015. Between 2000 and 2015, the world recorded 10·3 million fewer under-5 deaths than expected on the basis of improving SDI alone.

Interpretation: Gains in child survival have been large, widespread, and in many places in the world, faster than what was anticipated based on improving levels of development. Yet some countries, particularly in sub-Saharan Africa, still had high rates of under-5 mortality in 2015. Unless these countries are able to accelerate reductions in child deaths at an extraordinary pace, their achievement of proposed SDG targets is unlikely. Improving the evidence base on drivers that might hasten the pace of progress for child survival, ranging from cost-effective intervention packages to innovative financing mechanisms, is vital to charting the pathways for ultimately ending preventable child deaths by 2030.

Funding: Bill & Melinda Gates Foundation.

Conflict of interest statement

Declaration of interests Itamar S Santos reports grants from FAPESP (Brazilian public agency), outside the submitted work. Carl Abelardo T Antonio reports grants, personal fees and non-financial support from Johnson & Johnson (Philippines), Inc, outside the submitted work. Ferrán Catalá-López is supported in part by grant PROMETEOII/2015/021 from Generalitat Valenciana. Walter Mendoza is currently employed by the Peru Country Office of the United Nations Population Fund, an institution which does not necessarily endorse this study. Jasvinder A Singh has received research grants from Takeda and Savient and consultant fees from Savient, Takeda, Regeneron, Merz, Iroko, Bioiberica, Crealta and Allergan pharmaceuticals, WebMD, UBM LLC, and the American College of Rheumatology; he serves as the principal investigator for an investigator-initiated study funded by Horizon pharmaceuticals through a grant to DINORA, Inc, a 501 (c)(3) entity; is a member of the executive of OMERACT, an organisation that develops outcome measures in rheumatology and receives arms-length funding from 36 companies; a member of the American College of Rheumatology’s (ACR) Annual Meeting Planning Committee (AMPC); Chair of the ACR Meet-the-Professor, Workshop and Study Group Subcommittee; and a member of the Veterans Affairs Rheumatology Field Advisory Committee. Ai Koyanagi’s work is supported by the Miguel Servet contract financed by the CP13/00150 and PI15/00862 projects, integrated into the National R + D + I and funded by the ISCIII—General Branch Evaluation and Promotion of Health Research—and the European Regional Development Fund (ERDF-FEDER). Donal Bisanzio is supported by Bill & Melinda Gates Foundation (#OPP1068048). Kebede Deribe is supported by a Wellcome Trust Fellowship in Public Health and Tropical Medicine (grant number 099876). Thomas Fürst has received financial support from the Swiss National Science Foundation (SNSF; project no P300P3-154634). Jost B Jonas reports personal fees from Consultant for Mundipharma Co (Cambridge, UK); other from patent application with University of Heidelberg (Heidelberg, Germany) (title: Agents for use in the therapeutic or prophylactic treatment of myopia or hyperopia; Europäische Patentanmeldung 15 000 771.4), and other from patent holder with Biocompatibles UK Ltd. (Franham, Surrey, UK) (title: Treatment of eye diseases using encapsulated cells encoding and secreting neuroprotective factor and/or anti-angiogenic factor; patent number: 20120263794), outside the submitted work. Stefanos Tyrovolas’s work is supported by the Foundation for Education and European Culture (IPEP), the Sara Borrell postdoctoral programme (reference number CD15/00019 from the Instituto de Salud Carlos III (ISCIII, Spain) and the Fondos Europeo de Desarrollo Regional (FEDER). Yogeshwar Kalkonde is a Wellcome Trust/DBT Intermediate Fellow in Public Health. Sun Ha Jee has been funded by a grant of the Korean Health Technology R&D project (HI14C2686), Korea. Miia Kivipelto receives research support from the Academy of Finland, the Swedish Research Council, Alzheimerfonden, Alzheimer’s Research & Prevention Foundation, Center for Innovative Medicine (CIMED) at Karolinska Institutet South Campus, AXA Research Fund and the Sheika Salama Bint Hamdan Al Nahyan Foundation. Shireen Sindi receives postdoctoral funding from the Fonds de la recherche en santé du Québec (FRSQ), including its renewal. Charles D A Wolfe’s research was funded/supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. The other authors declare no competing interests.

Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Figures

Figure 1. Under-5 mortality rates by GBD subnational Level 1 geography, both sexes combined, 2015

For each category shown in the legend, the range is inclusive of the minimum value and goes up to, but does not include, the maximum value. GBD=Global Burden of Disease. ATG=Antigua. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. Isl=islands. FSM=Federated States of Micronesia. WSM=Samoa.

Figure 2. Annualised rates of decrease in under-5 mortality by GBD subnational Level 1 geography, both sexes combined, 2000–15

For each category shown in the legend, the range is inclusive of the minimum value and goes up to, but does not include, the maximum value. GBD=Global Burden of Disease. ATG=Antigua. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. Isl=islands. FSM=Federated States of Micronesia. WSM=Samoa.

Figure 3. Leading 30 causes of global under-5 deaths for both sexes combined for 1990, 2005, and 2015 at GBD cause hierarchy Level 3

Causes are connected by lines between time periods. For the periods 1990–2005 and 2005–15, two measures of change are shown: percent change in the number of under-5 deaths and percent change in the under-5 mortality rate. Changes that are statistically significant are shown in bold. Neonatal preterm birth=preterm birth complications. Neonatal encephalopathy=neonatal encephalopathy due to birth asphyxia and trauma. Neonatal sepsis=neonatal sepsis and other neonatal infections. Neonatal haemolytic=haemolytic disease and other neonatal jaundice. STDs=sexually transmitted diseases. Intestinal infectious=intestinal nematode infections. Foreign body=pulmonary aspiration due to foreign body in the airway. COPD=chronic obstructive pulmonary disease. Fire and heat=injuries due to fire, heat, and hot substances. War and legal intervention=collective violence and legal intervention.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 4. Attribution of changes in under-5 mortality for 21 GBD regions and countries, territories, and subnational units in the UK to changes in major groups of causes of under-5 death, both sexes combined, 1990–2015

Locations are ordered by increasing under-5 mortality in 2015. The purple and orange lines show under-5 mortality rates in 1990 and 2015, respectively. Causes to the right of the 1990 under-5 mortality values reflect causes that contributed to increases in under-5 mortality between 1990 and 2015. Causes to the left of the 1990 under-5 mortality values contributed to decreases in under-5 mortality between 1990 and 2015.

Figure 5. Co-evolution of under-5 mortality with SDI globally and for GBD regions, 1990–2015

Coloured lines show global and region values for under-5 mortality. Each point in a line represents one year starting at 1990 and ending at 2015. In all regions, SDI has increased over time, so progress in SDI is associated with points further to the right and later years for a given region. The solid black line represents the expected under-5 mortality based on SDI alone. SDI=Socio-demogrpahic Index. GBD=Global Burden of Disease.

Figure 6. The expected relationship between rates of under-5 mortality by cause (A) and the proportion of child deaths due to each cause (B) with SDI, both sexes combined, 1980–2015

These stacked curves represent the average relationship between SDI and each cause of under-5 mortality observed across all geographies over the time period 1980–2015. The y axis goes from lowest SDI up to highest SDI. To the left of the midline are under-5 mortality rates, and the right-hand side shows the proportion of the total in order to highlight the different cause pattern in high SDI locations. SDI=Socio-demographic Index.

Figure 7. Ratio of observed levels of under-5 mortality to expected levels of under-5 mortality on the basis of SDI alone by GBD subnational Level 1 geography, both sexes combined, 2015

Expected levels of under-5 mortality and annualised rates of change were estimated based on SDI. For each category shown in the legend, the range is inclusive of the minimum value and goes up to, but does not include, the maximum value. SDI=Socio-demographic Index. GBD=global burden of disease. ATG=Antigua. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. Isl=islands. FSM=Federated States of Micronesia. WSM=Samoa.

Figure 8. Global trends in under-5 deaths, observed and expected on the basis of Socio-demographic Index alone, 1990–2015

Figure 9. Stillbirth rates by GBD subnational Level 1 geography, both sexes combined, 2015

For each category shown in the legend, the range is inclusive of the minimum value and goes up to, but does not include, the maximum value. GBD=Global Burden of Disease. ATG=Antigua. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. Isl=islands. FSM=Federated States of Micronesia. WSM=Samoa.