1 Introduction

A society’s health is determined not only by genes and lifestyle but also by social factors such as individuals’ socioeconomic position and social relationships . A large number of social epidemiology studies have revealed a branch of epidemiology concerned with the way that social structures, institutions, and relationships influence health [1]. This was followed by policy responses and practical efforts, such as the recommendations in the final report of the Commission on Social Determinants of Health (WHO) [2] and similar responses from the European Union (EU) [3]. The WHO adopted resolution 62.14—“Reducing health inequities through action on the social determinants of health”—in the World Health Assembly.

The Japanese Ministry of Health, Labour, and Welfare (MHLW) have also indicated one of the basic goals of Health Japan 21 (second term: 2013–2023, see appendices of this book) to be “the reduction of health disparities” along with “the extension of a healthy life expectancy,” as shown in Fig. 1.1. By definition, health disparities refer to a gap in health status between groups created by a difference in community or socioeconomic status [1]. Health Japan 21 (first term: 2000–2010) was a 10-year plan that addressed the “comprehensive implementation of national health promotion” and was created with a focus on the lifestyles of individuals. However, this focus took away from other aspects such as its perspective on the social environment. The experience of the first term proved that individual health and improvement of an individual’s social environment are inextricably linked and both are necessary. Therefore, the improvement of social environments should be given priority [4]. In the second term, the importance of the improvement of social environment quality was stressed. Factors that determine the quality of a social environment are indeed the social determinants of health.

Fig. 1.1
figure 1

Conceptual diagram of Health Japan 21 (the second term) [1]

This book reviews studies on social determinants of health (SDH) in noncommunicable diseases (NCDs) and healthy aging. The issues of NCDs and healthy aging are becoming global public health challenges, particularly in developing countries. Chapter 1 describes the background and objectives of this book as well as the importance of the social determinants of NCDs and healthy aging. It also provides an overview of policy responses, including that of the WHO and Health Japan 21.

2 Policy Responses to SDH from the WHO and Europe

Since the 1980 release of the Black Report in the United Kingdom, SDH and the problems concerning health disparities to which they give rise have piqued the interest of researchers in developed countries, particularly in Europe. Since the truth has come to light, society’s interest in this issue has been growing and the policy response has begun [3, 5, 6].

In 1991, the WHO Regional Committee for Europe had already set a goal of a 25% reduction in health disparities. The committee stated that it was the duty of governments to mobilize resources—taxation, pensions, employment, education, and state finances—and to eliminate poverty and inequality. In 1998, the United Kingdom’s Acheson Inquiry reported that health inequalities had in fact grown, rather than diminished [5]. The inquiry’s report argued that social environmental factors, such as poverty, food environment, and employment, had affected individuals’ health. The government took responsibility for these findings and announced an action plan in the same year in which the report was published [6]. Five years later, in 2003, the government again released a plan of action to deal with the problem [7]. This program announced measures that included the participation of the Prime Minister’s Office, the Cabinet Office, the Treasury, and the Department of Trade and Industry—in addition to that of the Department of Health—as well as numerical targets to be reached by 2010.

In Sweden, numerous policy responses, such as those shown in Table 1.1, were discussed. Furthermore, the 2003 revision to the law on Public Health Objectives explicitly stated the importance of “economic and social security.” [8]

Table 1.1 Policy areas that affect health

In 2005, the WHO implemented the Commission on Social Determinants of Health, and in October of the same year, the United Kingdom, who held the EU presidency at the time, organized an EU summit with the theme of overcoming health inequalities. Ministers, politicians, and senior government officials from 36 countries and numbering 570 officials attended the summit and agreed to redouble their efforts to reduce health inequality and its related problems. Numerical targets for eliminating health inequalities were established in several countries, including the Netherlands, Finland, the United Kingdom, and Ireland, and these countries started implementing their respective policy responses.

In 2008, the WHO Commission on Social Determinants of Health released its final report. This document presented three recommendations: first, it recommended improving the daily living conditions of all people, from childhood throughout their entire lives. The background of this recommendation was the accumulation of research into life course epidemiology (see Chap. 15), which demonstrates a clear link between factors in the childhood environment—including birth weight and preschool education—and health conditions in later life. Second, the report recommended that inequitable distributions of power, money, and resources need to be addressed. One factor giving rise to health inequalities is differences in lifestyle. However, this factor alone can only explain approximately 20–30% of the gap. In other words, it has become clear that it is important to correct or lessen inequalities in themselves. The third recommendation stated that it is crucial to measure health inequalities, to have a more in-depth understanding of them, and to evaluate (estimate) the impact of policies when designing measures such as those suggested by the WHO report. In summary, the report suggested the following steps: recognition that health inequalities are a problem and the measurement of these inequalities is a priority; creation of surveillance systems to monitor health inequalities and the social determinants of health; evaluation (estimation) of the effects of policies and other factors on health inequalities; promotion of the understanding of the social determinants of health among policymakers, health practitioners, and the public; and a stronger emphasis on the SDH within existing public health research.

These developments demonstrate that, in Europe, health inequalities and the SDH are not subjects for only a small segment of researchers to study. Rather, national governments, the EU, and the WHO have all launched policies to address these issues and numerous individuals involved with public health and other practitioners have started initiatives that span different government departments and professions to solve these problems. This is—at least in part—the result of a growing body of empirical research in social epidemiology. The subtitle of the WHO report on the social determinants of health summarizes it as “The Solid Facts.” [9] In addition, a second edition of this report [10] was published in 2003, demonstrating its relevance and the growth in this field.

The purposes of this book include presenting relevant sections of these studies and, following the WHO’s third recommendation, to “promote understanding of the social determinants of health among policymakers, health practitioners, and the public.”

3 Interests and Responses to SDH in Japan

While still more preliminary than the developments in Europe discussed above, Japan is also showing increased interest in the relationship between social inequalities and health, of which the body of research is currently growing [11, 12].

In terms of basic literature that can be read in Japanese, the Tokyo Medical and Dental University’s WHO Collaborating Centre for Healthy Cities and Urban Policy Research has published a translation of the WHO report on the social determinants of health [10]. Kenko Kakusa Syakai [Health Gap Society] written by Professor Katsunori Kondo was published in 2005 and Shakai Kakusa to Kenkō [Social Inequalities and Health] was published in 2006 with major contributions from members of the Social Epidemiology Research Group (chaired by Professor Norito Kawakami). In 2007, the Journal of the National Institute of Public Health (known as Hoken Iryō Kagaku in Japanese) published a special feature (vol. 56, no. 2) entitled “Health Inequality and Health Policy: What’s Implied?“ [13] More translated works available in Japanese include The Health of Nations: Why Inequality is Harmful to Your Health [14], The Status Syndrome: How Social Standing Affects Our Health and Longevity [15], Social Capital and Health [16], and The Impact of Inequality: How to Make Sick Societies Healthier [17]. The authors of the current book have also published a series of articles [18] and books [19,20,21] concerning societies with health disparities.

Leading figures in social epidemiological research, such as Professors Kawachi (Harvard School of Public Health) and Marmot (University College London), have been invited to academic meetings of the Japanese Society of Public Health. In 2009, the 68th meeting of the society addressed the issue of social inequality and health via a main symposium, a symposium held in conjunction with the Science Council of Japan, and other venues. Furthermore, in the same year, the society established a working group to address the social determinants of health under its monitoring and reporting committee. Reports on suicide, children, nonregular employment, and the older people were published and the Science Council of Japan submitted their recommendations (see the appendices).

At its workshop for the fiscal year 2007 (held in February 2008), the Japanese Association of Public Health Center Directors chose “Health Disparities and What Is Required of Health Centers” as one of the themes for the workshop, and the Japanese Society of Oral Health chose “Thinking about Health Disparities” as the main theme of its 58th general meeting in October 2009.

Although progress has been slow, developments concerning health disparities have become more widespread in Japan, partly because poverty and social disparities have become highly visible social issues during the 2000s in Japan. In response to health disparity problems, questions are being asked in the National Diet, as well as at the Council for the Reform of Healthcare Services for Older People.

4 The Importance of the Issue in Public Health

The effects of SDH and that of health disparities are greater than was generally thought in the past. Research conducted in Japan showed that health disparities can be seen in health-impacting behaviors [22]—notably smoking [23] and exercise [24, 25]—as well as in numerous lifestyle diseases, including risk factors for coronary artery disease [26], stroke [27, 28], high blood pressure [28], and cancer [29]. Health disparities according to social class have also been reported in mental health areas such as depression [20, 21, 30] and sleep disorders [20], in occupational health areas such as work-related stress [29,30,31,34], and in dental health [35]. These areas have all been considered in the Health Japan 21 initiative. These disparities are also major contributing factors in trauma-related deaths [36] and suicides [37], for which the incidence in Japan is higher than most developed countries. SDH are crucial when considering measures to deal with these health issues. As the effects of factors before birth and during early childhood on diseases during adulthood became known, it has become apparent that support for maternal and child health, child-rearing support, and the provision of preschool education are also vital. The Japanese Society of Public Health has made proposals [38] that focus on the social determinants of health, including suicide prevention measures and improving measures aimed at the unemployed. Those of lower social classes and who have numerous health problems are particularly unlikely to see doctors [20, 21, 39]. It can be said that this is an important reason why care prevention, preventing functional decline, use of long-term care, and measures to fight metabolic syndrome have not performed as well as was expected [19]. Furthermore, there have been suggestions that the effect of increased co-payments for patient medical fees after reforms to the healthcare system will be to inhibit patients from seeing their doctors [28, 40].

In other words, SDH are closely related to numerous public health, healthcare, and administrative issues, including NCDs and healthy aging, maternal and child health, support for child-rearing, suicide prevention measures, mental health, and reforms of the healthcare system and Health Japan 21. To make these policies, initiatives, and projects more effective, increasing knowledge and understanding of SDH and formulating policies based on this increased appreciation is crucial.

5 Summary

This book discusses various diseases and health problems, focusing on NCDs (see Table 1.2) and healthy aging, and presents the achievements of social epidemiology.

Table 1.2 Topics in this book

By doing so, the authors of this book clarify and emphasize the importance of health disparities and the SDH in the many public health problems that Japan and other countries are currently facing. The book also addresses both the importance of a life course perspective and the significant relationship between the state of the social environment—including social capital—and health. The authors wish to demonstrate the possibility of measures that may contribute to addressing health issues. This includes health impact assessments, which provide a concrete form to population strategies based on the social realities mentioned above.

The hope of the authors is that those interested in health disparities and SDH will grow in number and that this influence will spill over into other areas and eventually spread across the globe.