Numerous studies have determined that race is not just a biological category. "Race is a societally constructed taxonomy that reflects the intersection of biological, cultural, socioeconomic, political, and legal determinants, as well as racism. . . . Larger societal factors -- socioeconomic, political, and legal -- affect health through intermediary mechanisms and processes, including health practices, psychological stress, environmental stress, psychological resources, and medical care." (Williams, 1993).
Genetic factors alone cannot explain trends in racial and ethnic differences in health. More than 90 percent of genetic diversity occurs within racial and ethnic groups rather than between groups. In diseases in which genetic factors play a role, these trends may often be explained by differing environmental factors, which then have their greatest impact on persons who are at greatest risk genetically (Robert Wood Johnson Health Policy Research Program, 1998 letter). For example, the rate of diabetes and obesity among the Pima Indians in Arizona differs from that of the Pima Indians in Mexico.
It may be necessary to expand the currently accepted categories of race. As the scientific community gains a greater understanding of the race concept, more specific categories should become clearer, even within the black and white categories.
Although persistent low income can be a good predictor of mortality regardless of race, racial differences in health are markedly, but not wholly, explained by income. Perceived discrimination and race-related stress also play a role. Behavioral risk accounts for only a small portion of income disparities across age, sex, and race categories.
Public health research into the reasons for racial and ethnic health disparities has focused largely on differences in socioeconomic status (SES). Although lower SES is probably the most powerful single contributor to premature morbidity and mortality (Lantz, et al., 1998), the association between race and ethnicity and SES is complex and cannot fully explain differentials in health status.
While urging attention to the influence of socioeconomic factors, especially income, minority health researchers caution against using SES as a surrogate for race and ethnicity. The direct and indirect effects of racism need to be considered as well. Research suggests that racism and discrimination can induce psychological distress, leading to poor health among members of racial and ethnic minority groups, particularly among blacks (James, et al., 1983). Racism and discrimination can also restrict access to health care, public education, housing, and recreational facilities.
Housing discrimination is one of the primary mechanisms by which racism produces differential socioeconomic outcomes. Through discriminatory practices (such as redlining), racially distinct residential zones for blacks and other minorities are sustained, creating adverse effects on opportunities for access to health care services, education, employment, and socioeconomic mobility.
Poor housing may contribute to a number of adverse health and educational outcomes. Severe crowding and indoor air pollution may cause or exacerbate many chronic illnesses, sometimes resulting in long-term effects. Deteriorating and crime-ridden neighborhoods contribute to experiences of stress and barriers to accessing services. Neighborhood quality and quality of associated services vary considerably depending on the racial and ethnic composition of the neighborhood. Certain black and Hispanic households tend to report more problems in their neighborhoods, including crime, litter, housing deterioration, and poor public services.
Although racial and ethnic minority groups have experienced substantial improvements in social and economic well-being during the second half of this century, health disparities between groups persist and in, some cases, have widened. Blacks, Hispanics, Asian, and Native Hawaiian or other Pacific Islanders (especially new immigrants and refugees), and American Indians/Alaska Native populations continue to experience social and economic disadvantages in many arenas (Council of Economic Advisors, 1998).
The poverty rate for non-Hispanic whites remains well below that for U.S. racial and ethnic minorities. Although many of the disparities in poverty rates can be explained by differences in factors such as age distribution, family structure, and educational attainment, substantial differentials persist even among individuals with similar characteristics. In 1997, 8.6 percent of non-Hispanic whites lived in poverty compared to 26.5 percent of Blacks, 14 percent of Asian, Native Hawaiian, or other Pacific Islanders, 27.9 percent of Mexican Americans, and 34.2 percent of Puerto Ricans.
Educational attainment is a powerful predictor of economic status and health. Although educational attainment in the U.S. has been steadily increasing, and high school completion rates for blacks have approached parity with whites, approximately 47 percent of Hispanic adults over age 25 have not completed high school. Among 25-29 year olds, 33 percent of non-Hispanic whites, 14 percent of non-Hispanic blacks, and 11 percent of Hispanics had a 4-year college degree.
Economic return for the same educational attainment is lower for racial and ethnic minorities. Among 25-34 year old men with a bachelor's degree, the median income in 1998 was $39,966 for whites, $30,415 for blacks, and $32,853 for Hispanics.
Wealth (assets minus liabilities) is a better indicator of permanent economic status than single year income. Greater wealth allows a family to maintain their standards of living when income falls because of job loss, health problems, or family changes. Disparities in asset holding across racial and ethnic groups are large, exceeding disparities in income. Black and Hispanic households are less likely than white households to own stocks or mutual funds, have equity in their homes, or own a private pension plan (e.g., IRA). The median value of assets held by whites is higher than for blacks and Hispanics. In 1993, the household net worth maintained by whites was more than 10 times the net worth maintained by either blacks or Hispanics.
Disproportionately high housing costs limit a household's ability to afford other necessities such as health care services and purchase of medicines. All U.S. racial and ethnic minority populations are nearly twice as likely as whites to spend at least 50 percent of their incomes on housing costs. (The Department of Housing and Urban Development (HUD) considers a household to have a "worst case" housing need if housing costs exceed 50 percent of household income.)
High unemployment rates persist for many racial and ethnic minorities. Unemployment rates for blacks have been roughly double the rates of unemployment for whites for more than 20 years. While such disparities reflect differences in educational attainment, substantial differentials persist even among blacks, whites, and Hispanics with similar levels of education.
Health insurance coverage, either public or private (usually employment-based), is a key indicator of access to medical care and is linked to income and employment status. Hispanics have the highest uninsured rates for every income level.
Having health insurance is no guarantee to access to quality health care. Blacks within similarly insured populations (e.g., Medicare) are less likely to receive certain diagnostic and treatment procedures for cardiovascular disease, even after severity of disease and supplemental insurance are taken into account. Within similarly insured populations, blacks are more likely to be hospitalized for septicemia, debridement, and amputations, suggesting that poor quality of care is received by blacks with diabetes (Gornick, et al., 1996).
Having a usual source of care is one indicator of access and quality. Almost 30 percent of Hispanics lacked a usual source of care, compared to 20.2 percent of blacks and 15.5 percent of a combined category of whites and other racial/ethnic groups. Among those who had a usual source of care, blacks and Hispanics were more likely than whites to have hospital-based (as opposed to office-based) care (Weinick, et al., 1999). This finding has implications for the quality of care received.
Linguistically appropriate services are essential to quality of care for racial and ethnic minorities with, or at risk of developing, chronic illnesses. Approximately 4 million Hispanics, 1.6 million Asians, 282,000 blacks, and 77,000 American Indians had language communication constraints in 1990. The scarcity of health care providers skilled in both language and cultural competency also has a negative influence on the quality of care available to racial and ethnic minorities.