Social factors are key to eliminating health inequities.

Abstract

Two news features focus on this month's theme of translating knowledge into action. First, Clare Nullis-Kapp reviews a series of interim reports which show that--unless something dramatic happens--the world will fall far short of most of the Millennium Development Goals to reduce poverty and improve health in developing countries by 2015. Next, Pete Moore looks how governments have been quick to recognize that social factors are a key determinant of health, but few have tried to tackle the problem head-on. Take any of a series of social determinants such as wealth, education, ethnicity, gender, upbringing or job and the story is the same. People's health prospects worsen as they descend the social ladder. Recognizing this is not new. Edwin Chadwick's 1842 report on the sanitary conditions of working people in London showed the disparity in life spans between labourers and gentry, and the UK's 1980 Black Report showed that while the first 35 years of the UK's National Health Service had improved health across all classes, social status was still strongly correlated with infant mortality, life expectancy and use of medical services. "The three main social determinants of health are income, social class and education," says Mel Bartley, Professor of Medical Sociology at University College London, who points out that the best measures of social class relate to a person's autonomy and freedom to decide what to do when. "The link between social class and health is via the flight-fight mechanism," Bartley explains. For example, the less control you have the more insecure you feel, and the more you have others ordering you about the more times a day your heart rate goes up. Both insecurity and pressure cause increased levels of stress hormones. These stress hormones cause peripheral arteries to narrow, thereby increasing blood pressure and triggering fats and sugars to flood into the bloodstream. Responses such as these may have aided the survival of early humans, but today they can contribute to heart disease. Increased levels of stress hormones also suppress a person's immune system. From a biological point of view, there is no point fighting infections if you are about to be killed by an immediate aggressor. Individuals with increased levels of stress are more prone to many illnesses, including cancer, and people in vulnerable social positions experience these effects more often than the socially privileged. These and other factors contribute to persistent socially determined inequities in health. Governments are well aware of this situation but few have made any serious effort to tackle the social and economic determinants that underpin these health inequalities. And international comparisons expose a starker picture. Take income, for example. While The World Bank announced in April 2004 that the proportion of the world's population living on less than US$ 1 per day had dropped from 40% to 21% between 1981 and 2001, the progress was uneven. In sub-Saharan Africa, for example, the numbers of people with this income had risen from 164 million to 314 million, an increase from 42% to 47% of the region's population. Recognizing the problem, WHO hopes to engender change by setting up a new body called the Commission on Social Determinants of Health. The Commission is planned to run for three to five years starting early in 2005 and will look at the inequities within societies that create inequalities in health. It also hopes to draw attention to examples of global, national and local policies that have strengthened health equity between and within countries. "While the Commission will compile scientific evidence on the social patterns that generate health inequities, its main focus will be on action," says Jeanette Vega, head of WHO health equity team. The Commission will work with political decision-makers, health planners and other stakeholders to identify interventions that really do improve the health of vulnerable populations through coordinated action on key social determinants of health. …