of Health Inequalities
BRUCE G. LINK AND JO C. PHELAN
The primacy of social conditions as determinants of health has been observed for centuries. The idea was forcefully articulated by nineteenth-century proponents of “social medicine,” who noted strong relationships between health and the dire housing circumstances, poor sanitation, inadequate nutrition, and horrendous work conditions that poor people encountered at that time. This social patterning of ill health led to Virchow's famous declaration that “medicine is a social science” and “politics nothing but medicine on a grand scale” (1848). The idea is also prominent in the work of McKeown, who focused attention on dramatic secular trends toward improved population health (1976). The McKeown thesis, as it has come to be called, states that the enormous improvements in health experienced over the past two centuries owe more to changes in broad economic and social conditions than to specific medical advances.
Nevertheless, this perspective has not always been prominent. In the late twentieth century, the rise and influence of “risk-factor epidemiology” focused attention on individually based biological and behavioral risks for ill health. While this perspective has been enormously successful in providing information that has helped reduce individual risk, and thereby improve population health, its dominance has also helped downplay social conditions as important causes of ill health. Social factors came to be seen not as causes but as clues—starting points in the search for “true” causes that were seen to reside in individual health behaviors and the biological mechanisms that produce pathogenesis. Reflecting this trend, Rothman's influential text on modern epidemiological methods indicated that social class is “causally related to few if any diseases but is a correlate of many causes of disease” (1986, 90).
But risk-factor epidemiology has recently experienced its own crisis, criticized from within for its rote “black box” approach, and for having run out of large risk factors to uncover (Susser and Susser 1996). While numerous factors have contributed to this crisis, two major problems have been the approach's inattention to multiple levels of influence and its inability to understand empirical associations between population characteristics and the health profiles of populations.