Very substantial health gains can be made for relatively modest expenditures on interventions to reduce risks. However, the maximum possible health gains will be attained only if careful consideration is given to the costs and effects of interventions. Risk reduction strategies need to be based on a thorough analysis of the best possible evidence on the health effects and the costs of technically feasible interventions, undertaken by themselves and in various combinations. The analysis of interactions between interventions is a critical but neglected question, which is the reason it has been given prominence in this chapter.
A selected number of interventions targeting some of the major risks to health have been discussed. Some that have not been considered are likely to also be cost-effective in different settings and will be included in The World Health Report 2003, but already a number of important messages emerge.
- A strategy to protect the child's environment is cost-effective in all settings. The components shown here to be very cost-effective include some form of micronutrient supplementation (depending on the prevalence of micronutrient deficiencies, either vitamin A, iron, or zinc) disinfection of water at point of use to reduce the incidence of diarrhoeal diseases; and treatment of diarrhoea and pneumonia.
- Preventive interventions to reduce incidence of HIV infections, including measures to encourage safer injection practices, are very cost-effective, although care needs to be taken when extrapolating the effectiveness of behaviour change interventions from one setting to another. The use of some types of antiretroviral therapy in conjunction with preventive activities is cost-effective in most settings. While directly observed artiretroviral therapy combined with testing for resistance does not seem to be cost-effective in all settings, there might well be other reasons, that cannot be included in a standard cost-effectiveness framework, for pursuing it.
- Improved water supply based on disinfection at point of use is cost-effective in regions of high child mortality. While acknowledging that regulated piped water supplies will be the long-term aim of most countries, a policy shift towards household water management appears to be the most attractive short-term water-related health intervention in developing countries.
- In all settings at least one type of intervention to reduce the risks associated with cardiovascular disease was cost-effective. Population-wide salt and cholesterol lowering strategies are always very cost-effective singly and combined. Combining them with an individual risk reduction strategy is also cost-effective, particularly with interventions to reduce risk based on assessed levels of absolute risk. The cost-effectiveness of the absolute risk approach would improve further if it is possible to assess accurately individual risks without the need for laboratory tests, and further work towards testing this possibility is recommended. Additional interventions that were not evaluated here, such as those aimed at encouraging people to increase their physical activity levels, should also be considered when comprehensive strategies are being assessed in different settings.
- There is an important role for governments in encouraging risk reduction strategies. For example, taxes on cigarette products are very cost-effective globally and higher tax rates result in larger improvements in population health. 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 legislation or through self-regulation. Both approaches would require consultation with a variety of stakeholders.
This report acknowledges that there are other goals of health policy in addition to improving population health. In choosing appropriate combinations of interventions, governments are also concerned with reducing poverty and other inequalities, and with questions of human rights, community acceptance and political needs. They must also consider how different types of interventions can be incorporated into the health infrastructure available in the country, or how the infrastructure could be expanded or adapted to accommodate the desired strategies. This is particularly important when considering if it is feasible to expand coverage to high levels. However, improving population health is the defining goal of a health system, the reason why it exists. The type of information reviewed in this chapter is one of the critical inputs required to inform the decision-making process about efficient ways to reduce risks to health.