Data Systems Linking Social Determinants of Health with Health Outcomes: Advancing Public Goods to Support Research and Evidence-Based Policy and Programs

Across many countries, describing and understanding what contributes to a more or less equitable distribution of population health, and turning that knowledge into action to reduce unfair differences, are attracting the interest of policy makers, health professionals, researchers, civil society, and media. However, valid data from different sectors, in the public domain, analyzed from different perspectives with appropriate methods, are needed. Important international and national efforts have helped tremendously in this evidence-based call for action. A recent effort drawing on global evidence includes the World Health Organization (WHO) Commission on the Social Determinants of Health. The Commission’s Final Report pointed out that the unequal distribution of health-damaging experiences and their persistence within and across countries is not at all a natural phenomenon.1 Rather, structural determinants (such as poor social policies and programs, unfair economic arrangements, and bad politics) generate hierarchies of social position (such as gender or income inequalities). Depending upon the place in the social hierarchy that individuals and groups occupy, the combination of social stratification and the epidemiological environment determines exposure and vulnerability to health-enhancing or health-damaging conditions in daily life—e.g. where people are born, grow, live, work, and age.1 Health inequities flow from these patterns of social stratification—that is, from the systematically unequal distribution of power, prestige, and resources among groups in society. Health systems are also a social determinant of health, as these can either mitigate or amplify existing inequities, such as through progressive financing of health services or discriminatory practices when individuals seek care. Moreover, social determinants of health (SDH) interact with one another and with biological or genetic factors, shape individual behaviors, are accumulated during a lifetime, and are often transferred across multiple generations. The WHO Commission and a follow-up World Health Assembly resolution2 set out a detailed agenda for global collaboration to reduce health inequities through action on SDH in three areas: (1) improve people’s daily living conditions; (2) tackle the inequitable distribution of power, money, and resources; and (3) measure and understand the problem and evaluate action. Addressing SDH rests on evidence of the relationship between these determinants and health outcomes. National and regional efforts have been crucial to engage a broad range of stakeholders, shape policy, and increase accountability. For example, Brazil, Chile, and the United Kingdom have organized recent national commissions including intensive stakeholder consultations to help guide policy, data analysis, and action on SDH. Under the leadership of the Spanish Presidency of the European Union (EU) in 2009, and with the involvement of WHO, in particular its Regional Office for Europe, an independent expert report3 and informal meeting of health ministers in the EU put the monitoring of SDH prominently on the political agenda. Subsequently, the European Parliament passed a resolution noting that as part of the process to make a more equitable distribution of health part of the EU’s overall goals for social and economic development, the EU needs to improve the data and knowledge bases that support measuring, monitoring, evaluation, and reporting.4 In the United States, the Robert Wood Johnson Foundation (RWJF) set up an independent and nonpartisan Commission to Build a Healthier America, with the goal of identifying interventions beyond the health system that can improve health and that are supported by a strong knowledge base.5 Recognizing that not everyone in the U.S. has the same opportunities to make healthy choices, the RWJF Final Report focused on identifying health-enhancing actions in the places where people spend the bulk of their time—homes and communities, schools, and workplaces—with key recommendations also outlining approaches toward greater accountability and collaboration across public, private, and not-for-profit sectors.6 Informed by public consultation, the U.S. Department of Health and Human Services around the same time was developing its fifth 10-year national health agenda to communicate a vision, strategy, and comprehensive set of national health objectives. The first phase of this report advocated that health policy efforts need to be integrated with those related to education, housing, business, transportation, agriculture, and media, among others.7 Recently released, Healthy People 2020 includes SDH as a key topic: objectives are being developed that address the relationship between health status and a wide range of social determinants. To support the selection of indicators and underlying data required to track and monitor progress critical to Healthy People 2020, the Institute of Medicine identified 12 key topics and 24 leading indicators for assessment: social determinants is one of the key topics, and three leading indicators are proposed to monitor the proportion of the population experiencing a healthy social environment.8 Such national monitoring efforts are supplemented by more detailed analysis of existing data. An extensive literature review is beyond our mandate, yet worthwhile to note is a supplement to the Morbidity and Mortality Weekly Report that consolidates recent U.S. national data analysis on inequalities in mortality, morbidity, access to preventive and treatment health services, as well as social determinants of critical health problems.9 Truman and colleagues introduce the volume and outline a convincing narrative that (1) health inequalities and inequities are important indicators of community health and provide information for decision-making and evaluation of intervention implementation to reduce preventable morbidity and mortality; (2) data analyzed and interpreted on a wide range of topics provide compelling arguments for action; (3) actions include a mix of universally applied and targeted interventions; yet (4) there is insufficient evidence regarding the effectiveness of particular interventions in reducing specific inequalities among certain defined populations.9 Although this supplement of Public Health Reports extends innovations in analysis linking SDH with health outcomes, several challenges remain.