Inequality kills everywhere. Poor children and families from all corners of the world are far more likely to live in poorer health under worse living conditions than those who are wealthier. We often refer to such inequalities as "socio-economic inequalities in health" and they have been observed in all countries with available data. Such inequalities are also considered to be unfair, unnecessary, and avoidable. They begin to emerge during childhood and despite massive improvements in our ability to prevent and treat ill-health, they continue to grow.
The CHAIN project, which includes partner organizations such as EuroHealthNet, UN (WHO and UNICEF) and IHME, has provided a better understanding of socioeconomic inequalities in health. In terms of the mechanisms that provide long lives in good health, our research has had a broad focus: from environmental factors, climate change, pandemic, technology, vaccine nationalism, welfare policy, and health systems to migration, education, work environment, cancer screening, health care use, smoking, alcohol, physical activity, and diet.
CHAIN’s work has combined research fields (from sociology and social policy to epidemiology, neuroscience, medicine, and technology), sectors (academia, civil society, national authorities, the European Commission, the UN and WHO), activities (from the establishment of new data infrastructure and theory development to explanatory and causal analyzes and interventions), and methodologies (quantitative, qualitiative and mixed methods).
Good health and well-being are a human right, and health equity is a matter of social justice. The aim of the research has been to contribute to political and social change, through the identification of policies that can improve people's living conditions across socioeconomic divides. A key focus has been on education and child mortality.
Among the most important works are the discovery of systematic links between welfare systems and health inequalities in Europe, the confirmation of the hypothesis that new technologies increase inequalities in health, and that children's health deteriorates in Greek refugee camps over time. In 2021, CHAIN and and IHME discovered a universal link between parent education and child mortality, which was published in the Lancet.
CHAIN has identified several interventions that could be effective in reducing health inequalities, both at the national and global level. Their commonality is that we must start early in the life course, we need to work across sectors, we must focus on universal policies, and that we need to invest beyond the health systems: in the social conditions where we are raised, live, work and age.
The CHAIN project has achieved remarkable progress in advancing health equity through its research and collaborations. During the project period, CHAIN has established itself as a global leader in understanding and addressing health inequalities.
The project has published around 200 scientific articles in the project period (2019 – 2025), we have frequently engaged in high-level dissemination events in governments and organizations and influenced policy and practice worldwide. Our interdisciplinary approach has allowed us to produce actionable knowledge aimed at reducing socioeconomic disparities in health, both on the national and global level. This synergy has resulted in significant achievements such as the development of new monitoring tools—like the health inequalities module integrated into the European Social Survey—and comprehensive analyses demonstrating how social risk factors influence mortality. Notably, our systematic reviews and meta-analyses have contributed to recognizing low education as a critical global risk factor.
A key groundbreaking discovery in 2023 revealed a universal global association between parental education and child mortality, underscoring the profound impact of social determinants on health outcomes worldwide. Our research also shows that societal changes—both positive (technological advances) and negative (pandemics, pollution, climate change)—tend to widen health gaps, as those with greater resources benefit more during good times and are better protected during crises.
CHAIN has actively partnered with international organizations to translate research into action. We provided vital evidence to the WHO Technical Advisory Group on COVID-19 mortality, highlighting how the pandemic disproportionately affected vulnerable populations. Our collaboration with WHO’s IARC on cancer screening identified effective interventions to increase participation, directly informing public health strategies. Our alliance with UNICEF has been particularly impactful: we contributed to the Child Health Report Card series, highlighted that around 800 million children (one in three worldwide) suffer from lead poisoning, and co-developed frameworks for implementation research to improve child health interventions. These efforts demonstrate that combining data, analytical capacity, and collaborative frameworks can produce actionable insights that influence policies and lead to meaningful health improvements.
Looking ahead, CHAIN aims to maintain its leadership role in advocating for health equity on a global scale. We will continue to prioritize socioeconomic determinants of health, expand our sophisticated data infrastructure, and develop new frameworks for evaluating interventions through an equity lens. Our goal is to ensure that our research not only advances scientific understanding but also drives policies and programs that effectively reduce health disparities and protect vulnerable populations worldwide.
The CHAIN project will provide a better understanding of socioeconomic inequalities in health and identify specific public health policy interventions that are effective in reducing such inequalities in global regions, with a focus on children.
More specifically, CHAIN will (1) monitor international variations in health inequalities between and within countries, (2) identify and analyse the causal drivers of health inequalities in different countries, (3) identify and evaluate interventions that have the potential to reduce health inequalities, and (4) propose evidence-based policy and practice guidelines for health equity.
This will be done by bringing together Norwegian and international public health groups and international organisations to establish a novel approach to the better determination of the causes of health inequalities, their impacts on groups such as children and their families, and the identification of ‘best practice’ ways of reducing health inequalities in different regions of the world. The CHAIN project will involve leaders from UNICEF, the Norwegian Institute of Public Health (NIPH), the International Agency for Research on Cancer (IARC), EuroHealthNet, and the Institute for Health Metrix and Evaluation (IHME), which leads the Global Burden of Disease (GBD) Study.
The CHAIN project will introduce socioeconomic position as a risk factor in the GBD Study, we will analyse the most important determinants of health inequalities in different contexts, and the policy and programme responses that are most effective in reducing them. Through CHAIN`s partnerships with international academic institutions, UNICEF, IARC, public health experts, and civil society agencies, we further expect to 1) obtain global visibility, 2) reduce the distance between research, policy and practice, and 3) create a national and global arena to attract and advance research talents within health inequalities research.
