Cancer health disparities came to the forefront of the National Cancer Institute (NCI) in 1999 with the passage of the Minority Health and Health Disparities Research and Education Act, United States (US) Public Law 106-525. The law defined health disparities as a “significant disparity in the overall rate of disease incidence, prevalence, morbidity, mortality or survival rates in the population as compared to the health status of the general population. The NCI went on to define cancer health disparities as “differences in the incidence, prevalence, mortality, and burden of cancer and related adverse health conditions that exist among specific population groups in the US.
It is assumed from a population health perspective, that disparities are also population-based. Following this argument, disparities are primarily systematic differences in the health of groups that hold unequal positions in society. Many have argued that this kind of inequality also refers to inequities and unjust situations. Holding unequal positions in society implies that disparities are social in origin. In the recent past, the focus has been on individual risk factors of disease, and these do not deal with the social factors that initially cause disparities. These social factors have been termed the “social determinants” of health. They are social determinants because they have their effect at the group level. Such social determinants include the economic system, poverty, place, education, socioeconomic status, neighborhood, and other variables (see Conceptual Framework, below). In the past decade, many authors, including the Institute of Medicine, have put forward a social ecologic approach to understanding disparities.
The thinking that social determinants of health are important factors in understanding disparities has been widely adopted. The Healthy People 2010 objectives, for example, are based on understanding disparities. Of two major goals of the Healthy People 2010 plan, the second goal is to “eliminate health disparities among different segments of the population.” The National Institutes of Health (NIH) accordingly has instituted a number of actions to achieve this goal. The 2006 progress report of the Healthy People 2010 program notes that for cancer, the first half of the decade showed an increase in disparities for those cancer objectives where race and ethnicity can be measured. Indeed, the authors note that the inability to provide all segments of the US population with evidence-based cancer services may have had the unintended effect of contributing to the increase in disparities. When examining access to quality health care, the progress report concludes that there has been little progress overall, and that for some groups, the gap is widening. Hispanics, for example, showed increases in disparities when it came to having a source of ongoing care and for having a primary care doctor.