The world health report

Chapter 2

Why focus on risks to health?

Focusing on risks to health is key to preventing disease and injury. The most emotive and tangible images in health are of people suffering from disease, but preventing disease and injury occurring in the first place requires systematic assessment and reduction of their causes. Much scientific effort and most health resources are directed towards treating disease -- the "rule of rescue" still dominates (3). Data on disease or injury outcomes, such as death or hospitalization, tend to focus on the need for palliative or curative services. In contrast, assessments of burden resulting from risk factors will estimate the potential of prevention. One notable exception concerns communicable diseases, since treating infected individuals can prevent further spread of infection, and hence treatment can be a method of prevention in itself.

Even when the focus is on causes as well as disease outcomes, much scientific activity has been directed to assessing whether a risk exists at all. Does electromagnetic frequency radiation cause leukaemia? Do certain infections predispose to heart attacks? These assessments are usually accompanied by estimates of how much higher the risk is in individuals who are exposed compared with those who are not. It has been much less common to assess impact at a population level by asking "of all the disease burden in this population, how much could be caused by this risk?"

Many factors are relevant in prioritizing strategies to reduce risks to health: the extent of the threat posed by different risk factors, the availability of cost-effective interventions, and societal values and preferences are particularly important. These factors are also key for research priorities -- if major threats exist without cost-effective solutions, then these must be placed high on the agenda for research. Governments are also likely to place particular value on ensuring their main efforts focus on the largest threats to health in their countries. Reliable, comparable and locally relevant information on the size of different risks to health is therefore crucial to prioritization, especially for governments setting broad directions for health policy and research. However, such information has typically been very limited, creating a gap in which interest groups may seek either to downplay or to overestimate some risks. In addition, there is an inherent imbalance in media information about risks: common, major threats to health are usually not reported because they are already known, whereas rare or unusual threats to health are highly newsworthy.

Stewardship is one of the key functions of government, necessitating a broad overview, a long-term horizon and an evidence-based approach, and requiring information from reliable, comparable assessments of the magnitude of different major risks to health. This report helps to redress the dearth of such information. The report recognizes that risk analysis is a political enterprise as well as a scientific one, and that public perception of risk also plays a role in risk analysis, bringing issues of values, process, power and trust into the picture. The roles and contributions of risk assessment, communication, risk management, cost-effectiveness and policy development form the focus of the report.