To conduct relevant epidemiologic research on racial and ethnic health disparities, racial and ethnic samples must be made comparable on other socioeconomic status and contextual features using statistical controls of those unrelated factors. Aside from equal access to research opportunities, equal representation of their respective populations, and similar familiarity with and responsiveness to the procedures and metrics used to collect health data, racial and ethnic groups must also be equally sensitive to them. In the absence of such quantitative parity, numerous unmeasured, uncontrolled factors of race and ethnicity hinder studies of racial and ethnic health disparities. This makes samples, procedures, and measures incomparable between racial/ethnic groups and makes it more difficult to attribute observed health differences to racial/ethnicity rather than to their correlates. Patterns of health known as health inequalities resemble patterns of socioeconomic position. There are health disparities when people with high social status positions have better health and people with low status positions have inferior health. A group's position (rank) in terms of its power (ownership and control of resources and products), privilege (access to those resources and things), and prestige socio-moral judgement, with some people considered as "better" than others, is referred to as social status in a hierarchical (stratified) society. In order to understand health disparities, social status hierarchies based on race and ethnicity, socioeconomic status (SES) position, and other factors have been studied in the United States.
