106 The World Health Report 2002 choose to drive safely, or use seat belts or motorcycle helmets, but government action can encourage them to do so, thereby preventing injuries to themselves and to other people. Increasing prices through taxation certainly reduces smoking (14)even if smuggling increases subsequently(15). A particular focus of this chapter is to explore if this type of government action is cost-effective. In some countries there has been debate about whether governments should play this type of role, and information on the costs and impact on population health are important inputs to this debate. DIFFERENT WAYS OF ATTAINING THE SAME GOAL Different sets of interventions can be used to achieve the same goal and some interven tions will reduce the burden associated with multiple risk factors and diseases. Interven- tions to reduce blood pressure, cigarette smoking and cholesterol all reduce cardiovascular disease, and each has been used separately and together with others at different times and in different settings. The effect of doing two at the same time might be more than would be expected by adding the benefits of doing the two interventions singly, or might be less Much ischaemic heart disease mortality that has traditionally been attributed to particular sk factors is, in fact, caused by those factors in combination with other risk factors(16) Partly as a result of these interactions, risk reduction strategies are generally based on a ombination of interventions rather than just one The decision about which combination should be undertaken for the available resources complex. It is necessary to determine the health gains, and the costs, of doing each pos sible intervention by itself and in combination with the other ways of reducing the burden for a given risk factor or disease. The analysis undertaken for this chapter followed that process by evaluating what would be achieved by each intervention alone and in combina tion with other interventions TECHNICAL CONSIDERATIONS FOR COST-EFFECTIVENESS ANALYSIS The estimates, which provide the basis of the results reported in this chapter, were un- dertaken on a regional basis as part of the WHO CHOICe project. The six WHO regions were divided into mortality strata as described in earlier chapters, resulting in 14 epidemio- logical subregions. The total costs and total effects of each intervention were estimated separately for the 14 subregions. Eventually it is hoped that there will be sufficient data to make estimates at a country level, and even at the subnational level for large countries, but this is not currently possible Subregional analysis offers a valuable basis from which country analysts can work to calibrate the results to their settings. It is much more policy-relevant than a global analysis because the epidemiology, cost structures, and starting points (such as the availability of trained health staff and the history of health interventions)varies less within each subregion than across the world as a whole. The results are used here to identify interventions that are ery cost-effective, cost-effective, and not cost-effective in each subregion. Costs are reported in terms of intermational dollars rather than in US dollars, to account better for differences in cost structures between settings. Unit costs for most regions are higher using international dollars(s) based on purchasing power parity exchange rates than they would be if official exchange rates had been used. Effectiveness is measured in terms of disability-adjusted life years(DALYs) gained by the intervention. A brief descrip106 The World Health Report 2002 choose to drive safely, or use seat belts or motorcycle helmets, but government action can encourage them to do so, thereby preventing injuries to themselves and to other people. Increasing prices through taxation certainly reduces smoking (14) even if smuggling increases subsequently (15). A particular focus of this chapter is to explore if this type of government action is cost-effective. In some countries there has been debate about whether governments should play this type of role, and information on the costs and impact on population health are important inputs to this debate. DIFFERENT WAYS OF ATTAINING THE SAME GOAL Different sets of interventions can be used to achieve the same goal and some interven￾tions will reduce the burden associated with multiple risk factors and diseases. Interven￾tions to reduce blood pressure, cigarette smoking and cholesterol all reduce cardiovascular disease, and each has been used separately and together with others at different times and in different settings. The effect of doing two at the same time might be more than would be expected by adding the benefits of doing the two interventions singly, or might be less. Much ischaemic heart disease mortality that has traditionally been attributed to particular risk factors is, in fact, caused by those factors in combination with other risk factors (16). Partly as a result of these interactions, risk reduction strategies are generally based on a combination of interventions rather than just one. The decision about which combination should be undertaken for the available resources is complex. It is necessary to determine the health gains, and the costs, of doing each pos￾sible intervention by itself and in combination with the other ways of reducing the burden for a given risk factor or disease. The analysis undertaken for this chapter followed that process by evaluating what would be achieved by each intervention alone and in combina￾tion with other interventions. TECHNICAL CONSIDERATIONS FOR COST-EFFECTIVENESS ANALYSIS The estimates, which provide the basis of the results reported in this chapter, were un￾dertaken on a regional basis as part of the WHO CHOICE project. The six WHO regions were divided into mortality strata as described in earlier chapters, resulting in 14 epidemio￾logical subregions. The total costs and total effects of each intervention were estimated separately for the 14 subregions. Eventually it is hoped that there will be sufficient data to make estimates at a country level, and even at the subnational level for large countries, but this is not currently possible. Subregional analysis offers a valuable basis from which country analysts can work to calibrate the results to their settings. It is much more policy-relevant than a global analysis because the epidemiology, cost structures, and starting points (such as the availability of trained health staff and the history of health interventions) varies less within each subregion than across the world as a whole. The results are used here to identify interventions that are very cost-effective, cost-effective, and not cost-effective in each subregion. Costs are reported in terms of international dollars rather than in US dollars, to account better for differences in cost structures between settings. Unit costs for most regions are higher using international dollars (I$) based on purchasing power parity exchange rates than they would be if official exchange rates had been used.5 Effectiveness is measured in terms of disability-adjusted life years (DALYs) gained by the intervention. A brief descrip-