Summary of chapters
Chapter One: Protecting the people sets the scene with a general introduction to the subject of measuring, communicating and reducing risks to health -- people's exposure to them and the role of government in protecting the population from them. It shows how governments, particularly in the 20th century, have been instrumental in reducing some major risks to health. But it also explains how the current demographic transition is being accompanied by a "risk transition" and a double burden of disease on developing countries -- the combination of long-established infectious diseases and the greater relative importance of chronic, noncommunicable diseases.
Chapter Two: Defining and assessing risks to health offers a detailed explanation of this report's approach to health risks. It points out that much scientific effort and most health resources today are directed towards treating disease, rather than preventing it. It argues that focusing on risks to health is the key to prevention. Population-based strategies aim to make healthy behaviour a social norm, thus lowering risk in the entire population. Small shifts in some risks in the population can translate into major public health benefits.
Thus, the chapter strongly advocates the assessment of population-wide risks as well as high-risk individuals in strategies for risk reduction. The key challenge, it says, is to find the right balance between the two approaches.
This chapter also describes how risk assessment has emerged in recent years from its roots in the study of environmental problems. It shows how the steps generally involved in environmental risk assessment can be adapted to apply more specifically to the analysis of health risks, and it explains the benefits of comparing different risks to health.
Chapter Three: Perceiving risks explains that both risks and benefits have to be considered when seeking to understand what drives some behaviours and why some interventions are more acceptable and successful than others. Perceptions of risk are often polarized between expert understanding and public views; between quantitative and qualitative assessments; and between analytical and emotive responses.
This chapter examines the roles of social, cultural and economic factors in shaping individuals' understanding of health risks. The structural factors which influence the adoption of risk control policies by government, and the impact of interventions, are considered. The importance of understanding and managing the risk perceptions of different groups in society, when seeking to reduce risks, is also discussed. The chapter concludes that reducing risk exposure has to be planned within the context of local society, and that prevention through interventions is only partly a matter of individual circumstances and education. It suggests a need for a concerted international research agenda to raise population awareness of major risks in developing countries, such as the tobacco epidemic.
The chapter says that information about risks and their consequences, presented in scientific terms and based on a risk assessment, has to be communicated with particular emphasis and care. It concludes by stressing that an atmosphere of trust and shared responsibility between the government and all interested parties, especially the media, is essential if interventions are to be adopted and successfully implemented.
Chapter Four: Quantifying selected major risks to health provides the main results of a major WHO-initiated project quantifying the health effects of selected major health risks, on a global scale and in a comparable fashion. Most of these results have been briefly referred to in this overview.
An introduction to the generic approach is provided, followed by a description of the major health risks in terms of their extent and the types of threat they pose. The key results of the analysis are summarized and discussed in terms of their potential to improve healthy life expectancy by focusing on causes of disease and injury. The overall aim of the analyses reported in this chapter has been to obtain reliable and comparable estimates of attributable burden of disease and injury on which to build the basis of a variety of policy-relevant measures.
The chapter points out that, very often, the greatest burden of health risks is borne by the poor countries, and by the disadvantaged in all societies. The vast majority of threats to health are more commonly found in the poor, in those with little education, and with low-status occupations. Studying exposure to risk factors among poor households and individuals, and the disease burden they cause, enables the design of policies most likely to reduce them.
Chapter Five: Some strategies to reduce risk puts forward the best available evidence on the cost and effectiveness of selected interventions to reduce some of the major risk factors discussed in Chapter 4. It looks at the extent to which these interventions are likely to improve population health, both singly and in combination. The analysis in this chapter is used to identify both actions that are very cost-effective and those that do not seem to be cost-effective in different settings. It illustrates how decision-makers can begin the policy debate about priorities with information about which interventions would yield the greatest possible improvements in population health for the available resources. It says this evidence will be a key input, but not the only one, to the final decision about the best combination of interventions.
The chapter examines a range of strategies to reduce different types of risk, and the possible impact of those strategies on costs and effectiveness. It considers individual behaviours related to risk, such as food intake, smoking and sexual behaviour. It also discusses individual factors, such as genetics, and environmental factors including water and sanitation. The chapter says that many risk reduction strategies involve a component of behaviour change. However, some types of behaviour change might require active government intervention to succeed. Different ways of attaining the same goal are discussed, for example, the population-wide versus the individual-based approach and prevention versus treatment. Combinations of these two approaches are likely to be the best ways of improving health.
With regard to policy implications, the chapter says that very substantial health gains can be made for relatively modest expenditures on interventions. However, the maximum possible gains for the resources that are available will be attained only through careful consideration of the costs and effects of interventions. A strategy to protect the environment of the child is cost-effective in all settings. The components include micronutrient supplementation, treatment of diarrhoea and pneumonia, and disinfection of water at the point of use as a way of reducing the incidence of diarrhoea. This last measure is particularly cost-effective in regions of high child mortality. A policy shift towards household water management appears to be the most attractive short-term water-related health intervention in developing countries.
Preventive interventions to reduce the incidence of HIV infections, including measures to encourage safer injection practices, are very cost-effective. The use of antiretroviral therapy in conjunction with preventive activities is cost-effective in most settings.
In all settings, at least one type of intervention to reduce the risks associated with cardiovascular disease was found to be cost-effective. Population-wide strategies to lower cholesterol by reducing salt intake are always very cost-effective both singly and in combination. In addition, governments would be well advised to consider taking steps to reduce the salt content of processed foods on a population-wide basis, either through regulation or self-regulation.
The chapter highlights the important role for government in encouraging risk reduction strategies. Taxes on cigarette products are very cost-effective globally, and higher tax rates result in larger improvements in population health. Even greater improvements would arise if higher taxes were combined with comprehensive tobacco advertising bans.
Chapter Six: Strengthening risk prevention policies argues that governments, in their stewardship role for better health, need to invest heavily in risk prevention, in order to contribute substantially to future avoidable mortality.
Substantial agreement on what needs to be done exists between the international scientific community and those charged with improving public health. Strategies to achieve these potential gains, particularly in developing countries, ought to involve a question of balance. It is a balance between the priority of sharply reducing the burden from exposures such as underweight and poor water and sanitation, which are largely confined to poorer populations, and the priority of reducing or preventing further population exposure to factors such as tobacco, elevated blood pressure and cholesterol.
Much is already known about how to reduce risks to health effectively. That reduction will require sustained policy action and commitment by governments and other partners. Key elements will be the creation or strengthening of national institutions to implement and evaluate risk reduction programmes, and more effective engagement of sectors such as transport, education and finance to capitalize on the potential for greatly reducing population exposures.
The chapter also highlights important considerations to be kept in mind when deciding on risk reduction measures. These include the criteria for choosing which key risks to tackle; the right balance between efforts targeted on primary, secondary or subsequent prevention; the management of uncertain risks; and the related issue of strengthening the evidence base for policy action. The ethical implications of various programme strategies, including their impact on inequities in population health, must also be taken into account.
Chapter Seven: Preventing risks and taking action contains the report's conclusions. It says that in order to protect and improve health globally, much more emphasis is needed on preventing the actual causes of important diseases as well as treating the diseases themselves. Prevention can best be achieved through concerted efforts to identify and reduce common, major risks and by taking advantage of the prevention opportunities they present. Tackling major risks could improve global health much more than is generally realized.
This chapter says the report offers a unique opportunity for governments. They can use it to take bold and determined actions against only a relatively few major risks to health, in the knowledge that the likely result within the next ten years will be large gains in healthy life expectancy for their citizens. The potential benefits apply equally to poor countries and rich countries, even if some of the risk factors are different.
Bold policies will be required. Governments can decide to aim for increased taxes on tobacco; legislation to reduce the proportion of salt and other unhealthy components in foods; stricter environmental controls and ambitious energy policies; and stronger health promotion and health safety campaigns.
This is undoubtedly a radical approach. It requires governments to see the value of shifting the main focus from the minority of high-risk individuals to include preventive measures that can be applied to the whole population.
There are compelling reasons for governments to play a greater role in tackling these major risks. Governments are the stewards of health resources and have a responsibility to protect their citizens. In addition, reducing risks will promote sustainable development and can also reduce inequities in society.