Differences in Rates of Premature Death and Disease
Between Socioeconomic Groups in the U.S.: Important New Research

By S. Van McCrary, Health Law & Policy Institute

A study published in a recent issue of the Journal of the American Medical Association indicates that the disparity in mortality and morbidity rates on the basis of socioeconomic status is more complex than previously believed.*

Research over the past few decades demonstrated that lifestyle and health behavior factors such as cigarette smoking, drinking alcoholic beverages, being overweight, and leading a sedentary lifestyle are strongly associated with premature morbidity and mortality. Research has also established that significant differences exist in health outcomes based on socioeconomic status. Specifically, income and education have been shown to be inversely associated with premature death. To date, however, much of the public health community has hypothesized that these two phenomena were closely related--i.e., that elevated health risk behaviors among lower socioeconomic groups were largely responsible for their increased risk of premature disease and death. In contrast, the JAMA study suggests that socioeconomic differences in mortality are attributable to a wider range of factors than health risk behaviors, and thus would continue to exist even if health behaviors were improved among the economically disadvantaged.

The study, guided by Dr. Paula Lantz at the University of Michigan School of Public Health, was conducted from 1986 to 1994, with a nationally representative sample of 3,617 men and women. The principal outcome measure was death from all causes, including tumors, cardiovascular disease, other diseases, and external causes such as unintentional injury, suicide, and homicide. One of the central research questions was "To what extent do health behaviors explain education and income differences in mortality?" Results indicated that even when major health risk behaviors (smoking, alcohol consumption, sedentary lifestyle, and overweight) were fully taken into account, there was still a strong effect of income and education level on mortality.

These results suggest that individual health risk behaviors account for only a small part of the observed differences in mortality according to socioeconomic status. Thus, traditional public health interventions and policies that seek to reduce these behaviors, although important, may not have as strong an influence on overall health status as anticipated. Thus, too, socioeconomic disparities in health status are due to a wider variety of factors, some of which may remain unidentified. Dr. Lantz and her colleagues propose that occupational and environmental factors, combined with chronic acute stress and lack of social support, may be responsible for a significant portion of the measured differences. They conclude, "We must look to a broader range of explanatory risk factors, including structural elements of inequality in our society."

The policy implications of this research are significant because they suggest that many of the traditional public health interventions, previously thought to have a major salutary effect on the problems of poor health among lower socioeconomic strata, are not the "magic bullet" they were assumed to be. Although these public health programs remain vital and beneficial, they are far from the total solution. Instead, we may be forced to look to broader social causes of these problems such as living in dangerous neighborhoods, working in dangerous settings, and lack of family support structures. In sum, the future mission of public health advocates may have just become much broader.

*  Lantz PM, House JS, Lepkowski JM, Williams DR, Mero RP, Chen J.  Socioeconomic factors, health behaviors, and mortality: Results from a nationally representative prospective study of US adults.  JAMA 1998; 279 (21): 1703-1708.