Reducing child mortality in high-income countries: where to from here?
Authors: Marni Brownell, Jennifer Enns
Journal: The Lancet (2018)

In 2000, the UN envisioned a path of global action to eradicate inequalities and fight the many dimensions of poverty with the Millennium Development Goals (MDGs), which have served as an overarching framework for health, social, and economic development.1UNThe Millennium Development Goals Report, 2015. United Nations, New York2015Google Scholar During the MDG era, the global under-5 child mortality rate declined by an impressive 53%,2You D Hug L Ejdemyr S et al.Global, regional, and national levels and trends in under-5 mortality between 1990 and 2015, with scenario-based projections to 2030: a systematic analysis by the UN Inter-agency Group for Child Mortality Estimation.Lancet. 2015; 386: 2275-2286Summary Full Text Full Text PDF PubMed Scopus (448) Google Scholar but still fell short of the targeted two-thirds reduction from 1990 to 2015.3Wang H Liddell CA Coates MM et al.Global, regional, and national levels of neonatal, infant, and under-5 mortality during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013.Lancet. 2014; 384: 957-979Summary Full Text Full Text PDF PubMed Scopus (538) Google Scholar Progress in improving child survival has been uneven and inequalities persist across both developing and high-income countries. In their birth cohort study of under-4 child mortality in Sweden and England, Ania Zylbersztejn and colleagues4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar highlight the disparity in mortality among infants and children under the age of 4 years between these two countries. Among 3 932 886 births in England there were 11 392 deaths, and among 1 013 360 births in Sweden there were 1927 deaths. The unadjusted hazard ratios (HRs) for England versus Sweden were 1·66 (95% CI 1·53–1·81) at 2–27 days, 1·59 (1·47–1·71) at 28–364 days, and 1·27 (1·15–1·40) at 1–4 years. Zylbersztejn and colleagues sought to establish the drivers of these differences. Using adverse birth characteristics (birthweight, gestational age, and congenital anomalies) and sex as proxies for risk factors occurring before birth, and socioeconomic factors (maternal age and socioeconomic status) as measures of risk factors after birth, they report that the most important driver of the excess mortality in England relative to Sweden is the prevalence of adverse birth characteristics. In the first month of life, 77% of the excess risk of death in England compared with Sweden was explained by birth characteristics and a further 3% by socioeconomic factors. From the second month to the end of the first year of life, 68% of the excess risk was explained by birth characteristics and a further 11% by socioeconomic factors. At 1–4 years, there was no significant difference between countries.4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar The findings of this study are important because they suggest efforts made to improve maternal health before and during pregnancy offer the most promise for reducing child mortality in England.4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar Such efforts could support chronic disease management and mental health and addiction treatment, improve pre-pregnancy and antenatal nutrition, encourage smoking cessation, and ensure pregnant women receive adequate prenatal care.5Bhutta ZA Das JK Bahl R et al.Can available interventions end preventable deaths in mothers, newborn babies, and stillbirths, and at what cost?.Lancet. 2014; 384: 347-370Summary Full Text Full Text PDF PubMed Scopus (763) Google Scholar But although the authors report that prenatal factors have a larger role in child mortality than socioeconomic factors present after birth,4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar the results do not discount the important influence of social factors. The authors point to the extensive literature connecting adverse birth characteristics to socioeconomic factors, highlighting the importance of efforts to reduce poverty. Poverty reduction strategies for women during the prenatal period have shown great promise in reducing adverse birth characteristics6Brownell MD Chartier MJ Nickel NC et al.Unconditional prenatal income supplement and birth outcomes.Pediatrics. 2016; 137: e20152992Crossref PubMed Scopus (45) Google Scholar and increasing maternal health-care-seeking behaviours during pregnancy.7Leyland AH Ouédraogo S Nam J et al.Evaluation of health in pregnancy grants in Scotland: a natural experiment using routine data. NIHR Journals Library, Southampton2017Google Scholar The authors also emphasise the benefits that efforts to reduce adverse birth characteristics could have for child health and wellbeing, and that these benefits extend far beyond reducing child mortality.4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar A large body of evidence, particularly around low birthweight and preterm birth, shows that adverse birth outcomes can continue to have impacts throughout childhood and into adulthood, including increased risks of poorer physical and mental health,8Moster D Lie RT Markestad T Long-term medical and social consequences of preterm birth.N Engl J Med. 2008; 359: 262-273Crossref PubMed Scopus (980) Google Scholar, 9Saigal S Doyle LW An overview of mortality and sequelae of preterm birth from infancy to adulthood.Lancet. 2008; 371: 261-269Summary Full Text Full Text PDF PubMed Scopus (1921) Google Scholar, 10Jutte DP Brownell M Roos NP Schippers C Boyce WT Syme SL Rethinking what is important: biologic versus social predictors of childhood health and educational outcomes.Epidemiology. 2010; 21: 314-323Crossref PubMed Scopus (30) Google Scholar, 11Hack M Flannery DJ Schluchter M Cartar L Borawski E Klein N Outcomes in young adulthood for very-low-birth-weight infants.N Engl J Med. 2002; 346: 149-157Crossref PubMed Scopus (933) Google Scholar lower educational attainment,8Moster D Lie RT Markestad T Long-term medical and social consequences of preterm birth.N Engl J Med. 2008; 359: 262-273Crossref PubMed Scopus (980) Google Scholar, 10Jutte DP Brownell M Roos NP Schippers C Boyce WT Syme SL Rethinking what is important: biologic versus social predictors of childhood health and educational outcomes.Epidemiology. 2010; 21: 314-323Crossref PubMed Scopus (30) Google Scholar, 11Hack M Flannery DJ Schluchter M Cartar L Borawski E Klein N Outcomes in young adulthood for very-low-birth-weight infants.N Engl J Med. 2002; 346: 149-157Crossref PubMed Scopus (933) Google Scholar and lower income.8Moster D Lie RT Markestad T Long-term medical and social consequences of preterm birth.N Engl J Med. 2008; 359: 262-273Crossref PubMed Scopus (980) Google Scholar What this study4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar could not ascertain from the analysis was whether adverse birth characteristics remain the most important driver of suboptimal health and wellbeing for those children who survive. Indeed, other research suggests that social factors operating after birth pose a similar threat to child health and education outcomes as preterm birth and low birthweight; however, because these social factors are far more prevalent, their role in child outcomes at the population level far outweighs the role of adverse birth characteristics.10Jutte DP Brownell M Roos NP Schippers C Boyce WT Syme SL Rethinking what is important: biologic versus social predictors of childhood health and educational outcomes.Epidemiology. 2010; 21: 314-323Crossref PubMed Scopus (30) Google Scholar, 12Brownell MD Ekuma O Nickel N Chartier M Koseva I Santos RG A population-based analysis of factors that predict early language and cognitive development.Early Child Res Q. 2016; 35: 6-18Crossref Scopus (30) Google Scholar Although is it clear from this study that there is room for improvement in reducing child mortality in high-income countries,4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar more research is needed on other predictors of optimal child health and development. Routinely collected person-level administrative data from multiple sources are useful for conducting population-based studies. Linking electronic health records and data from other sectors at the individual level adds further value for quantifying inequalities, allowing identification of the best periods in which to intervene to find out which risk factors are driving disparities between populations. The methods adopted by Zylbersztejn and colleagues4Zylbersztejn A Gilbert R Hjern A Wijlaars L Hardelid P Child mortality in England compared with Sweden: a birth cohort study.Lancet. 2018; (published online May 3.)http://dx.doi.org/10.1016/S0140-6736(18)30670-6Summary Full Text Full Text PDF PubMed Scopus (48) Google Scholar can be used to compare child mortality across countries and to explore other health and wellbeing outcomes, across and within countries. This research aligns with the shift from the MDGs to the Sustainable Development Goals, which consolidate global efforts to end all forms of poverty and fight inequalities, driving the change from improving childhood survival to ensuring that children live, grow, and thrive.13Sidebotham P Fraser J Covington T et al.Understanding why children die in high-income countries.Lancet. 2014; 384: 915-927Summary Full Text Full Text PDF PubMed Google Scholar MB has collaborated and co-authored papers with one of the authors (Ruth Gilbert) of the Article discussed in this Comment. We declare no other competing interests. Child mortality in England compared with Sweden: a birth cohort studyExcess child mortality in England compared with Sweden was largely explained by the unfavourable distribution of birth characteristics in England. Socioeconomic factors contributed to these differences through associations with adverse birth characteristics and increased mortality after 1 month of age. Policies to reduce child mortality in England could have most impact by reducing adverse birth characteristics through improving the health of women before and during pregnancy and reducing socioeconomic disadvantage. Full-Text PDF Open Access