Sick Individuals, Sick Populations
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OUP UNCORRECTED PROOF – REVISES, 26/07/2011, CENVEO 1 Chapter 2 2 Sick individuals, sick populations: 3 The societal determinants of 4 chronic diseases 5 ◆ What are the social causes of rising chronic diseases? 6 David Stuckler , Karen Siegel , Roberto De Vogli , 7 and Sanjay Basu Key policy points 1 Societies in which people are born, live, work, and age create risks of chronic disease. Health is largely determined by factors outside of the healthcare system. 2 About half of all deaths due to chronic diseases relates to tobacco use, unhealthy diet, alco- hol use, or physical inactivity. 3 People’s choices about these unhealthy behaviours depend strongly on circumstances beyond their immediate control. By influencing the price, availability, and marketing of unhealthy products, social and economic circumstances affect people’s perceived costs and benefits — two powerful determinants of choice. 4 Reductions in the price of unhealthy foods, alongside increases in their availability and marketing, are making nutritionally-poor choices become the easier, more desirable, and economically smarter choices. Similarly, declining opportunities for movement make it more difficult for people to be physically active. 5 Opening markets to trade can increase the price of traditional, healthy foods in resource- poor countries and potentially price them out of the market. When rich countries subsi- dize oils, fat, and sugar, they put farmers and small businesses in poor countries at a competitive disadvantage as well as providing incentives for people to make unhealthy dietary choices. 6 Remarkable gains in health could be achieved if broader social forces were harnessed to ameliorate the societal risks of chronic diseases. 02-Stuckler & Siege 02.indd 26 7/26/2011 4:40:47 PM OUP UNCORRECTED PROOF – REVISES, 26/07/2011, CENVEO WHAT CAN EXPLAIN RISING CHRONIC DISEASES? LEADING POPULATION EXPLANATIONS . 27 Key practice points 1 Much of a person’s risk of chronic disease can be attributed to a few common risk factors. This narrow set of risk factors can account for a large fraction of the population-wide burden of disease mainly because they reflect the broader societal conditions in which people live. 2 Knowing about the main chronic disease risk factors can help us identify who is at risk, but tells us little about why people have them or how to intervene. In the future, greater insights will come from identifying the specific biological hazards associated with these risks (‘zooming in’) or developing a better understanding of the underlying societal determi- nants of chronic diseases and their risks (‘zooming out’). 3 Overemphasizing the most common risks of chronic disease in rich countries — such as tobacco, high blood pressure, and obesity —could divert attention from the main risk fac- tors operating in low-income settings— such as indoor air pollution — where the greatest risks of death and disability due to chronic disease have been observed. 4 Public health experts should seek to identify and address what is driving unhealthy ageing, urbanization, and growth processes: they must concentrate on the ‘causes of the causes’ and ‘risk factors of the risk factors’. 5 Dietary dependency is a process by which food choices comes to depend on choices of governments, producers, and multinational companies. This dependency is fostered by models of economic development emphasizing trade liberalization, export-oriented agriculture, and foreign direct investment in foods and beverage sectors, especially in the context of unregulated marketing and government subsidies. 1 What can explain rising chronic diseases? Leading population 2 explanations . 3 Why are some populations becoming sicker while others are remaining healthy? 4 In the 1970s Geoffrey Rose threw down the gauntlet to public health to identify not just the 5 causes of poor individual health, but the ‘causes of the causes’ influencing the health of entire 6 populations. As he put it, there are ‘Sick individuals and sick populations’, and it is necessary to 7 address the causes of both ( 9 ). 8 At the time Rose was writing, tremendous strides were being made in identifying the key indi- 9 vidual risks of heart disease: alcohol, tobacco, physical inactivity, and obesity and their medical 10 correlates, diabetes, high blood pressure, and high cholesterol. But to Rose, it was clear that this 11 approach was not gaining ground toward the key goal for public health — to understand and 12 improve the health of entire populations. 13 This remains an unmet challenge. As one example, consider the trends in mortality rates due to 14 ischaemic heart disease (IHD) in four European countries — Spain, France, Sweden, and the 15 UK— over the past three decades, depicted in Figure 2.1. Remarkable inequalities exist, both 16 across countries and over time. These variations raise a number of questions: How did France, 17 despite starting out with higher rates of IHD than Spain, reach a figure half of Spain’s present 18 rate? How did Sweden reduce rates of IHD by two-thirds within three decades? What happened 19 in the UK so that liver cirrhosis rates tripled while in France and Spain they fell by over 60 % ? 20 Or, as another example, take a look at the trends in mortality in Western and Eastern Europe 21 since the 1980s, shown in Figure 2.2 . As Central and Eastern European countries began ‘returning 02-Stuckler & Siege 02.indd 27 7/26/2011 4:40:47 PM OUP UNCORRECTED PROOF – REVISES, 26/07/2011, CENVEO 28 SICK INDIVIDUALS, SICK POPULATIONS: THE SOCIETAL DETERMINANTS OF CHRONIC DISEASES 1 to Europe’ following the collapse of the Soviet Union in 1989 ( 63 ), the health of its people began 2 to converge with their neighbours in Western European countries. However, the former Soviet 3 countries experienced an explosive rise in chronic disease, resulting in more than three million 4 excess deaths. What can explain such remarkable differences between these populations? 5 Such marked rises, falls and fluctuations in the mortality of entire societies cannot simply result 6 from a series of disconnected changes by individuals. Did people suddenly become personally Ischaemic heart disease 300 250 200 150 100 50 Ischaemic heart disease mortality rates (age-stanardised per 100,000 population) 1970 1975 1980 1985 1990 1995 2000 2005 Ye a r UK France Sweden Spain Lung cancer 60 50 40 30 Lung cancer mortality rates 20 (age-stanardised per 100,000 population) 1970 1975 1980 1985 1990 1995 2000 2005 Ye a r UK France Sweden Spain Fig. 2.1 Population inequalities in health in Europe. 02-Stuckler & Siege 02.indd 28 7/26/2011 4:40:47 PM OUP UNCORRECTED PROOF – REVISES, 26/07/2011, CENVEO WHAT CAN EXPLAIN RISING CHRONIC DISEASES? LEADING POPULATION EXPLANATIONS . 29 Liver cirrhosis 40 30 20 10 Liver cirrhosis mortalityLiver rates 0 (age-stanardised per 100,000 population) 1970 1975 1980 1985 1990 1995 2000 2005 Ye a r UK France Sweden Spain Infectious disease 25 20 15 10 5 Infectious disease mortalityInfectious rates (age-stanardised per 100,000 population) 1970 1975 1980 1985 1990 1995 2000 2005 Ye a r UK France Sweden Spain Fig. 2.1 (Continued) 1 irresponsible in Eastern Europe? Or more responsible in Sweden than France? If so, why? Would 2 it be helpful to tell people in the UK that they should really take better care of themselves 3 like people in France and Spain decided to do? Whenever substantial changes in an entire 4 population’s risk take place, they are not ultimately a result of preferences, willpower, or even 5 genetics but of factors beyond the control of individuals. To understand why some populations 6 are becoming more or less healthy, we need to examine the societal conditions that create popula- 7 tion risks of chronic diseases. 02-Stuckler & Siege 02.indd 29 7/26/2011 4:40:48 PM OUP UNCORRECTED PROOF – REVISES, 26/07/2011, CENVEO 30 SICK INDIVIDUALS, SICK POPULATIONS: THE SOCIETAL DETERMINANTS OF CHRONIC DISEASES 1700 1500 Former Soviet Union 1300 1100 EU members since 2004 or 2007 (per 100,000 pop) 900 European region All-cause standardised mortality rates 700 EU members before 2004 500 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Fig. 2.2 Trends in age standardised all-cause mortality rates, Europe 1980–2007. Source: WHO European Health for All Database HFA-MDB 2008 edition. 1 In this chapter we continue our previous search from Chapter 1 for the reasons why chronic diseases 2 have risen so markedly over the past several decades. We begin by assessing the contribution of 3 individual risk factors to the disease burden. Then we evaluate the social and environmental 4 context of these risks using a theoretical framework that spans individual and population 5 levels. We provide a series of case studies to illustrate the importance of major societal changes 6 to population risks of chronic diseases, including political choices in Eastern Europe’s transition from communism, the sudden wealth of the Western Pacific islands, and the periods 7 of prolonged economic hardship experienced in Finland, Japan’s ‘double-dip’ recession, and 8 Cuba’s ‘Special Period.’ In concluding, we revisit the leading population theories of health, 9 health transition, risk factors, and population ageing, in the context of the societal determinants 10 of health. 11 12 In search of a few common risks: individual risk factors of 13 chronic disease 14 The vast majority of chronic disease research, both epidemiological and biological, has focused on 15 a few common risk factors in the aetiology of many chronic diseases. These risk factors include 16 genetic and environmentally determined physiological factors, such as lipid and blood pressure 17 levels. These are in turn influenced by proximal factors, sometimes referred to as behavioural risk 18 factors.