and whites. Indeed, there is considerable variation in health status among all of the major racial and ethnic groups including whites, African Americans, Hispanics, Asian/Pacific Islanders, and Native Americans/Alaska Natives. For example, while rates of diabetes are disproportionately high among African Americans, American Indians, and Hispanics, the prevalence of diabetes among Asians is less than that for whites (National Center for Health Statistics, 2001). There also can be considerable variation within racial and ethnic subgroups. For example, although Hispanics experience lower overall mortality rates than whites, Puerto Ricans have higher infant mortality rates than whites (National Center for Health Statistics, 2000). Some racial and ethnic subgroups have increased burdens of specific diseases. For instance, Vietnamese American women have cervical cancer mortality rates many times higher than those for other Asian and white women (IOM, 1999).

At present, the sources of such disparities remain unclear, but a wide range of explanatory factors have been suggested, including sociocultural, socioeconomic, behavioral, and biological risk factors, and environmental living conditions (Robert and House, 2000; Fremont and Bird, 2000; Williams, 1999). For example, minority populations as a whole tend to have lower socioeconomic status (SES) than other groups, and low SES is associated with poorer health, independent of race or ethnicity (Gornick, 2002). It is also generally agreed that differences in access to care, including preventive services, and racial and ethnic differences in the quality of care obtained contribute to observed disparities in health. In some minority groups and subgroups the prevalence of various conditions is especially high. Thus, the benefits of improved care for these groups may be substantially more than for others.

The challenge of understanding variations in health between and among racial and ethnic groups is further heightened as more Americans are of mixed racial and ethnic backgrounds. Although only a small proportion of respondents identified themselves as belonging to more than one racial and ethnic group on the latest census, the number of individuals in this group is expected to increase. The Office of Management and Budget (OMB, 1977) has issued guidance and developed a way to bridge the changes that should help examinations of changes over time.

The health system serves many important functions, but for the purposes of this paper we focus on three, with a particular emphasis on the last: ensuring the health of the population, ensuring equitable access to care, and ensuring quality of care. Admittedly, the system does not perform