《卫生经济学》课程参考文献（WHO年度报告）：World Health Report 2002_Reducing Risk Promoting Healthy Life_Chapter6 Strengthening Risk Prevention Policies.pdf

STRENGTHENING RISK PREVENTION POLICIES CHOOSING PRIORITY STRATEGIES FOR RISK PREVENTION constructing health policies for the prevention of well-known risks, choices need to be made between different strategies. For instance, will preventing small risks in large opulations avoid more adverse health outcomes than avoiding large risks in a smaller number of high-risk individuals? What priority should be given to cost-effective interventions for primary rather than secondary prevention, such as lowering blood pressure distribution by reducing dietary salt intake compared with treatment of people with high blood pressure Should priority be given to preventing environmental and distal risks to health, such tackling poor sanitation or inadequate nutritional intakes, rather than the more obvious proximal risks in a causal chain? What is the most appropriate and effective mix of these strateges In practice there is rarely an obvious and clear choice. These strategies are usually combined so as to complement each other (1). In general, however, it is more effective to give prority to population-based interventions rather than those aimed at high-risk individuals primary over secondary prevention controlling distal rather than proximal risks to health POPULATION-BASED INTERVENTIONS OR HIGH-RISK INDIVIDUAL TARGETS? 3 There is a"prevention paradox which shows that interventions can achieve large overall alth gains for whole populations but might offer only small advantages to each individual. This leads to a misperception of the benefits of preventive advice and services by peop who are apparently in good health (2, 3). In general, population-wide interventions have the greatest potential for prevention. For instance, in reducing risks from blood pressure and cholesterol, shifting the mean of whole populations will be more cost-effective in avoiding future heart attacks and strokes than screening programmes that aim to identify and treat all those people with defined hypertension or raised cholesterol levels, as show in Figure 6.1 (4-6). A similar approach can be used to modify behavioural risks and envi- ronmental exposures. For example, lowering the population mean for alcohol consump tion will also predictably reduce the number of people suffering from alcohol abuse(7 Often both approaches are used and successfully combined in one strategy

Strengthening Risk Prevention Policies 147 6 STRENGTHENING RISK PREVENTION POLICIES CHOOSING PRIORITY STRATEGIES FOR RISK PREVENTION n constructing health policies for the prevention of well-known risks, choices need to be made between different strategies. For instance, will preventing small risks in large populations avoid more adverse health outcomes than avoiding large risks in a smaller number of high-risk individuals? What priority should be given to cost-effective interventions for primary rather than secondary prevention, such as lowering blood pressure distribution by reducing dietary salt intake compared with treatment of people with high blood pressure? Should priority be given to preventing environmental and distal risks to health, such as tackling poor sanitation or inadequate nutritional intakes, rather than the more obvious proximal risks in a causal chain? What is the most appropriate and effective mix of these strategies? In practice there is rarely an obvious and clear choice. These strategies are usually combined so as to complement each other (1). In general, however, it is more effective to give priority to: • population-based interventions rather than those aimed at high-risk individuals; • primary over secondary prevention; • controlling distal rather than proximal risks to health. POPULATION-BASED INTERVENTIONS OR HIGH-RISK INDIVIDUAL TARGETS? There is a “prevention paradox” which shows that interventions can achieve large overall health gains for whole populations but might offer only small advantages to each individual. This leads to a misperception of the benefits of preventive advice and services by people who are apparently in good health (2, 3). In general, population-wide interventions have the greatest potential for prevention. For instance, in reducing risks from blood pressure and cholesterol, shifting the mean of whole populations will be more cost-effective in avoiding future heart attacks and strokes than screening programmes that aim to identify and treat all those people with defined hypertension or raised cholesterol levels, as shown in Figure 6.1 (4–6). A similar approach can be used to modify behavioural risks and environmental exposures. For example, lowering the population mean for alcohol consumption will also predictably reduce the number of people suffering from alcohol abuse (7). Often both approaches are used and successfully combined in one strategy

148 The World Health Report 2002 DISTAL OR PROXIMAL RISKS TO HEALTH? Although most epidemiological research and intervention analysis has focused on the more immediate risks for major diseases, tackling distal risks to health such as education and poverty can yield fundamental and sustained improvements to future health status. Enough is known about the predominant role of distal factors on health and survival to justify vastly greater efforts to reduce poverty and improve access to education, especially for girls. There is huge potential for major health gains through sustained intersectoral action involving other ministries and agencies concerned with development. PRIMARY OR SECONDARY PREVENTION? Risk reduction through primary prevention, such as immunization, is clearly preferable as this actually lowers future exposures and hence the incidence of new disease episodes over time. For long-term health gains it is usually preferable to remove the underlying risk. Cholesterol distributions and coronary heart disease rates, men 30–59 years of age, North Karelia, Finland,1972–1992 Distribution of serum cholesterol level Mortality from coronary heart disease Source: National Public Health Institute, Helsinki, Finland. Blood pressure distributions and stroke rates, men 60–69 years of age, Japan, 1965–1995 Distribution of systolic blood pressure Mortality from stroke Source: National Nutrition Survey, Japan. 0 5 10 15 20 25 30 35 40 <90 90- 99 100- 109 110- 119 120- 129 130- 139 140- 149 150- 159 160- 169 170- 179 180- 189 190- 199 200- 209 210- 219 220- 229 230- 239 Systolic blood pressure (mmHg) Population (%) 0 100 200 300 400 500 600 700 800 900 1000 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 Year Annual mortality rate per 100 000 0 5 10 15 20 25 2 3 4 5 6 7 8 9 10 11 Serum cholesterol (mmol/l) Population (%) 1965 1975 1985 1995 1972 1977 1982 1987 1992 0 200 400 600 100 300 500 700 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 Year Annual mortality rate per 100 000 Figure 6.1 Case studies of distribution shifting and cardiovascular disease in Finland and Japan

Strengthening Risk Prevention Policies The choices may well be different, however, for different risks, depending to a large extent on how common and how widely distributed is the risk and the availability and costs of effective interventions. Large gains in health can be achieved through inexpensive treatments when primary prevention has failed. Secondary prevention is based on screening exposed populations for the early onset of subclinical illnesses and then treating them. This approach can be very effective if the disease processes are reversible, valid screening tests exist, and effective treatments are available MANAGING THE RISK PREVENTION PROCESS As identifying and preventing risks to health is a political procedure, risk prevention requires its own decision-making processes if determined leaders from ministries of health and the public health community are to be successful (8). Other important factors which determine whether policies are adopted include public perceptions of the risks and benefits involved, perceived levels of dread and scientific uncertainty, how widely the risks are distributed and how inequitable or unfair are the health outcomes(9). Special interest groups nd the media also have major roles in influencing these issues. Finally, there are important lessons for achieving success in risk communications that should be more widely disseminated, including the implications for more transparent govemment and greater openness by the scientific community (10). Successfully tackling risks to health involves many stakeholders from different sections in society, a combination of scientific and political processes, many qualitative and quantitative judgements, a range of intersectoral actions by different agencies and opportunities for open communication and dialogue (11) Success in risk prevention will be largely determined by the strength of the politic leadership from the ministry of health Risk management is by no means a linear process and, although it typically involves an iterative decision-making process, action will be necessary in all four of the main components of assessment, management, communication and surveillance(see Figure 6.2) Figure 6.2 Implementing risk prevention Risk assessment identifying risk factors surveillance of risks and outcomes feedback to risk management probability of adverse events ntion strategy consultations with stakeholders cost-effectiveness of interventions promoting trust and debate political decision making

Strengthening Risk Prevention Policies 149 The choices may well be different, however, for different risks, depending to a large extent on how common and how widely distributed is the risk and the availability and costs of effective interventions. Large gains in health can be achieved through inexpensive treatments when primary prevention has failed. Secondary prevention is based on screening exposed populations for the early onset of subclinical illnesses and then treating them. This approach can be very effective if the disease processes are reversible, valid screening tests exist, and effective treatments are available. MANAGING THE RISK PREVENTION PROCESS As identifying and preventing risks to health is a political procedure, risk prevention requires its own decision-making processes if determined leaders from ministries of health and the public health community are to be successful (8). Other important factors which determine whether policies are adopted include public perceptions of the risks and benefits involved, perceived levels of dread and scientific uncertainty, how widely the risks are distributed and how inequitable or unfair are the health outcomes (9). Special interest groups and the media also have major roles in influencing these issues. Finally, there are important lessons for achieving success in risk communications that should be more widely disseminated, including the implications for more transparent government and greater openness by the scientific community (10). Successfully tackling risks to health involves many stakeholders from different sections in society, a combination of scientific and political processes, many qualitative and quantitative judgements, a range of intersectoral actions by different agencies and opportunities for open communication and dialogue (11). Success in risk prevention will be largely determined by the strength of the political leadership from the ministry of health. Risk management is by no means a linear process and, although it typically involves an iterative decision-making process, action will be necessary in all four of the main components of assessment, management, communication and surveillance (see Figure 6.2). Figure 6.2 Implementing risk prevention Risk surveillance - monitoring interventions - surveillance of risks and outcomes - feedback to risk management Risk communication - communicating prevention strategy - consultations with stakeholders - promoting trust and debate Risk assessment - identifying risk factors - distribution and exposure levels - probability of adverse events Risk management - understanding risk perceptions - cost-effectiveness of interventions - political decision making

150 The World Health Report 2002 IDENTIFYING PRIORITY RISK FACTORS FOR PREVENTION The scientific basis for the burden attributable to the main risk factors addressed in this report is reasonably well understood; for these risks, remaining data gaps should not diminish the importance of adopting control policies today if disease burden is to be lowered in the near future. Much of the scientific and economic information necessary for making health policy decisions is already available. Many of these are also well known, common, substantial and widespread. They are also more likely to have cost-effective risk reduction strategies. Lack of uncertainty and availability of cost-effective interventions for large risks leads to agreement in society about the need for action. Examples would be increasing tobacco consumption, particularly in Asia and astern Europe, and the role of unsafe sex in the HIVIAIDS epidemic, particularly in Africa Many of these risks are common to populations in both industrialized and developing countries, though the degree of exposure may vary. Risk factors with smaller disease burdens should also not be neglected; although smaller than other factors, they still contribute to the total burden of disease in various regions Large industrial activity involving coal, ambient air pollution and lead exposure, for exam- ple, has health effects comparable to other major risk factors. Some risks, such as occupa tional ones, are concentrated among certain sectors of society. This implies not only that these sectors are disproportionately affected, but also that the concentration makes target ing risk easier, as successful occupational safety interventions and policies in many region lave shown For other risk factors such as childhood sexual abuse, ethical considerations may outweigh direct contributions to disease burden. Even though the burden of disease attributable to a risk factor may be limited, highly effective or cost-effective interventions may be known. Reducing the number of unnecessary medical injections coupled with the use of sterile syringes are effective methods for controlling transmission of communicable diseases. Similarly, reductions in exposure to lead or ambient air pollution in industrialized countries in the second half of the 20th century were achieved by effective use of technology which often also led to energy saving and other benefits. In the case of these risk factors, therefore, the benefits to population health stemming from risk assessment, together with other considerations, provide the best possible policy guides for specific actions. The management of risk factors or hazards that have uncertain or highly uncertain risk probabilities or adverse consequences, such as exposure to climate change or genetically modified foods, is considered in the next section, in the context of cautionary approache and the use of the precautionary principle The national context is very important for assessing the options for risk prevention. For instance, in many middle and low income countries a lack of scientific expertise and equipment may mean that appropriate data for making local risk assessments are not available. In addition, many risks may also have low priority for any political action. In these situations, public awareness of risk factors may need to be enhanced and knowledge about the most dangerous risk factors brought openly to public attention, while interest groups and the mass media may need to be encouraged to debate publicly local risks to health ny leadership for political action will have to come from the ministries of health. Collective actions at regional and international levels are also called for, as many risk factors and risks to health are not limited by national borders. This is where the World Health Organization can play an effective advisory and coordinating role

150 The World Health Report 2002 IDENTIFYING PRIORITY RISK FACTORS FOR PREVENTION The scientific basis for the burden attributable to the main risk factors addressed in this report is reasonably well understood; for these risks, remaining data gaps should not diminish the importance of adopting control policies today if disease burden is to be lowered in the near future. Much of the scientific and economic information necessary for making health policy decisions is already available. Many of these are also well known, common, substantial and widespread. They are also more likely to have cost-effective risk reduction strategies. Lack of uncertainty and availability of cost-effective interventions for large risks leads to agreement in society about the need for action. Examples would be increasing tobacco consumption, particularly in Asia and Eastern Europe, and the role of unsafe sex in the HIV/AIDS epidemic, particularly in Africa. Many of these risks are common to populations in both industrialized and developing countries, though the degree of exposure may vary. Risk factors with smaller disease burdens should also not be neglected; although smaller than other factors, they still contribute to the total burden of disease in various regions. Large industrial activity involving coal, ambient air pollution and lead exposure, for example, has health effects comparable to other major risk factors. Some risks, such as occupational ones, are concentrated among certain sectors of society. This implies not only that these sectors are disproportionately affected, but also that the concentration makes targeting risk easier, as successful occupational safety interventions and policies in many regions have shown. For other risk factors, such as childhood sexual abuse, ethical considerations may outweigh direct contributions to disease burden. Even though the burden of disease attributable to a risk factor may be limited, highly effective or cost-effective interventions may be known. Reducing the number of unnecessary medical injections coupled with the use of sterile syringes are effective methods for controlling transmission of communicable diseases. Similarly, reductions in exposure to lead or ambient air pollution in industrialized countries in the second half of the 20th century were achieved by effective use of technology which often also led to energy saving and other benefits. In the case of these risk factors, therefore, the benefits to population health stemming from risk assessment, together with other considerations, provide the best possible policy guides for specific actions. The management of risk factors or hazards that have uncertain or highly uncertain risk probabilities or adverse consequences, such as exposure to climate change or genetically modified foods, is considered in the next section, in the context of cautionary approaches and the use of the precautionary principle. The national context is very important for assessing the options for risk prevention. For instance, in many middle and low income countries a lack of scientific expertise and equipment may mean that appropriate data for making local risk assessments are not available. In addition, many risks may also have low priority for any political action. In these situations, public awareness of risk factors may need to be enhanced and knowledge about the most dangerous risk factors brought openly to public attention, while interest groups and the mass media may need to be encouraged to debate publicly local risks to health. Any leadership for political action will have to come from the ministries of health. Collective actions at regional and international levels are also called for, as many risk factors and risks to health are not limited by national borders. This is where the World Health Organization can play an effective advisory and coordinating role