Cause of Death: Inequality

by Alejandro Reuss

Dollars and Sense magazine, May / June 2001



You won't see inequality on a medical chart or a coroner's report under "cause of death. " You won't see it listed among the top killers in the United States each year. All too often, however, it is social inequality that lurks behind a more immediate cause of death, be it heart disease or diabetes, accidental injury or homicide. Few of the top causes of death are "equal opportunity killers." Instead, they tend to strike poor people more than rich people, the less educated more than the highly educated, people lower on the occupational ladder more than those higher up, or people of color more than white people.

Statistics on mortality and life expectancy do not provide a perfect map of social inequality. For example, the life expectancy for women in the United States is about six years longer than the life expectancy for men, despite the many ways in which women are subordinated to men. Take most indicators of socioeconomic status, however, and most causes of death, and it's a strong bet that you'll find illness and injury (or "morbidity") and mortality increasing as status decreases.

Men with less than 12 years of education are more than twice as likely to die of chronic diseases (e.g., heart disease), more than three times as likely to die as a result of injury, and nearly twice as likely to die of communicable diseases, compared to those with 13 or more years of education. Women with family incomes below $10,000 are more than three times as likely to die of heart disease and nearly three times as likely to die of diabetes, compared to those with family incomes above $25,000. African Americans are more likely than whites to die of heart disease; stroke; lung, colon, prostate, and breast cancer, as well as all cancers combined; liver disease; diabetes; AIDS; accidental injury; and homicide. In all, the lower you are in a social hierarchy, the worse your health and the shorter your life are likely to be.


You often hear it said that even poor people in rich countries like the United States are rich compared to ordinary people in poor countries. While that may be true when it comes to consumer goods like televisions or telephones, which are widely available even to poor people in the United States, it's completely wrong when it comes to health.

In a 1996 study published in the New England Journal of Medicine, University of Michigan researchers found that African-American females living to age 15 in Harlem had a 65% chance of surviving to age 65, about the same as women in India. Meanwhile, Harlem's African-American males had only a 37% chance of surviving to age 65, about the same as men in Angola or the Democratic Republic of Congo. Among both African-American men and women, infectious diseases and diseases of the circulatory system were the prime causes of high mortality.

It takes more income to achieve a given life expectancy in a rich country like the United States than it does to achieve the same life expectancy in a less affluent country. So the higher money income of a low-income person in the United States, compared to a middle-income person in a poor country, does not necessarily translate into a longer life span. The average income per person in African-American families, for example, is more than five times the per capita income of E1 Salvador. The life expectancy for African-American men in the United States, however, is only about 67 years, the same as the average life expectancy for men in E1 Salvador.


Nearly one sixth of the U.S. population lacks health insurance, including about 44% of poor people. A poor adult with a health problem is only half as likely to see a doctor as a high-income adult. Adults living in low-income areas are more than twice as likely to be hospitalized for a health problem that could have been effectively treated with timely outpatient care, compared with adults living in high-income areas. Obviously, lack of access to health care is a major health problem.

But so are environmental and occupational hazards; communicable diseases; homicide and firearm-related injuries; and smoking, alcohol consumption, lack of exercise, and other risk factors. These dangers all tend to affect lower-income people more than higher-income, less-educated people more than more-educated, and people of color more than whites. African-American children are more than twice as likely as white children to be hospitalized for asthma, which is linked to air pollution. Poor men are nearly six times as likely as high-income men to have elevated blood-lead levels, which reflect both residential and workplace environmental hazards. African-American men are more than seven times as likely to fall victim to homicide as white men; African-American women, more than four times as likely as white women. The less education someone has, the more likely they are to smoke or to drink heavily. The lower someone's income, the less likely they are to get regular exercise.

Michael Marmot, a pioneer in the study of social inequality and health, notes that so-called diseases of affluence - disorders, like heart disease, associated with high-calorie and high-fat diets, lack of physical activity, etc. - are most prevalent among the Ieast affluent people in rich societies. While recognizing the role of such "behavioral" risk factors as smoking in producing poor health, he argues, "It is not sufficient ... to ask what contribution smoking makes to generating the social gradient in ill health, but we must ask, why is there a social gradient in smoking?" What appear to be individual "lifestyle" decisions often reflect a broader social epidemiology.


Numerous studies suggest that the more unequal the income distribution in a country, state, or city, the lower the life expectancies for people at all income levels. One study published in the American Journal of Public Health, for example, shows that U.S. metropolitan areas with low per capita incomes and low levels of income inequality have lower mortality rates than areas with high median incomes and high levels of income inequality. Meanwhile, for a given per capita income range, mortality rates always decline as inequality declines.

R.G. Wilkinson, perhaps the researcher most responsible for relating health outcomes to overall levels of inequality (rather than individual income levels), argues that greater income inequality causes worse health outcomes independent of its effects on poverty. Wilkinson and his associates suggest several explanations for this relationship. First, the bigger the income gap between rich and poor, the less inclined the well off are to pay taxes for public services they either do not use or use in low proportion to the taxes they pay. Lower spending on public hospitals, schools, and other basic services does not affect wealthy people's life expectancies very much, but it affects poor people's life expectancies a great deal. Second, the bigger the income gap, the lower the overall level of social cohesion. High levels of social cohesion are associated with good health outcomes for several reasons. For example, people in highly cohesive societies are more likely to be active in their communities, reducing social isolation, a known health risk factor.

Numerous researchers have criticized Wilkinson's conclusions, arguing that the real reason income inequality tends to be associated with worse health outcomes is that it is associated with higher rates of poverty. But even if they are right and income inequality causes worse health simply by bringing about greater poverty, that hardly makes for a defense of inequality. Poverty and inequality are like partners in crime. "[W]hether public policy focuses primarily on the elimination of poverty or on reduction in income disparity," argue Wilkinson critics Kevin Fiscella and Peter Franks, "neither goal is likely to be achieved in the absence of the other."


Even after accounting for differences in income, education, and other factors, the life expectancy for African Americans is less than that for whites. U.S. researchers are beginning to explore the relationship between high blood pressure among African Americans and the racism of the surrounding society. African Americans tend to suffer from high blood pressure, a risk factor for circulatory disease, more often than whites. Moreover, studies have found that, when confronted with racism, African Americans suffer larger and longer-lasting increases in blood pressure than when faced with other stressful situations. Broader surveys relating blood pressure in African Americans to perceived instances of racial discrimination have yielded complex results, depending on social class, gender, and other factors.

Stresses cascade down social hierarchies and accumulate among the least empowered. Even researchers focusing on social inequality and health, however, have been surprised by the large effects on mortality. Over 30 years ago, Michael Marmot and his associates undertook a landmark study, known as Whitehall I, of health among British civil servants. Since the civil servants shared many characteristics regardless of job classification - an office work environment, a high degree of job security, etc. - the researchers expected to find only modest health differences among them. To their surprise, the study revealed a sharp increase in mortality with each step down the job hierarchy- even from the highest grade to the second highest. Over ten years, employees in the lowest grade were three times as likely to die as those in the highest grade. One factor was that people in lower grades showed a higher incidence of many "lifestyle" risk factors, like smoking, poor diet, and lack of exercise. Even when the researchers controlled for such factors, however, more than half the mortality gap remained.

Marmot noted that people in the lower job grades were less likely to describe themselves as having "control over their working lives" or being "satisfied with their work situation," compared to those higher up. While people in higher job grades were more likely to report "having to work at a fast pace," lower-level civil servants were more likely to report feelings of hostility, the main stress-related risk factor for heart disease. Marmot concluded that "psycho-social" factors - the psychological costs of being lower in the hierarchy- played an important role in the unexplained mortality gap. Many of us have probably said to ourselves, after a trying day on the job, "They're killing me." Turns out it's not just a figure of speech. Inequality kills - and it starts at the bottom.


Alejandro Reuss is co-editor of Dollars & Sense.

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