key: cord-0050754-ndfvgl6n
authors: Lee, Haeok; Kim, Deogwoon; Lee, SangA; Fawcett, Jacqueline
title: The concepts of health inequality, disparities and equity in the era of population health
date: 2020-09-28
journal: Appl Nurs Res
DOI: 10.1016/j.apnr.2020.151367
sha: 9ee690c23944dc0f4887c18210bd3c02d9b9f759
doc_id: 50754
cord_uid: ndfvgl6n

nan

distribution of health outcomes across populations as well as an unequal distribution of societal factors influencing health. Consequently, the concepts of disparity, inequity, inequality and their antecedents require our attention and should be incorporated as a guide for health policies and interventions targeted to populations. The purpose of this paper is to define health inequality, health disparity, and health inequity from a population health perspective and to illustrate the meaning of each term by presenting authentic real-world examples. This paper will extend our understanding of these concepts from an individual perspective to a population perspective (Fawcett, 2019) .

Dictionaries define inequality as the "quality of being unequal or uneven" (Merriam-Webster, n.d.). The term, health inequality, used in most countries other than the U.S., is based on the seminal work of Margaret Whitehead in the United Kingdom (Whitehead, 2007) , and refers not only to the quality of being unequal or uneven in health outcomes between groups but also to differences in social hierarchy. For the purposes of this paper, health inequality is defined as differences in the distribution of health status and achievement of health outcomes that exist among specific groups due to genetic or other factors that cannot be prevented or modified (Kawachi et al. 2002) .

Example 1 illustrates an unequal distribution of health conditions. These conditions are

Healthy People 2020 defines equity to mean social justice or fairness; it is an ethical concept, grounded in principles of distributive justice. The Secretary's Advisory Committee for Healthy People 2030 (2018) recommended that achieving health equity require eliminating avoidable, unjust, and unfair health inequities and health disparities through short-and long-term actions. However, Lowe (2015) has pointed out that equity in health is considered a value judgment on the equal or unequal health status of individuals, families, communities, or whole populations.

The term of inequity has evolved over time starting from differences between groups of people, with a focus on the quality of being fair, impartial, and inequality (Oxford English Dictionary, n.d.) to the World Health Organization (WHO, 2020) definition of "the absence of avoidable or remediable differences among groups of people, whether those groups are defined socially, economically, demographically, or geographically. We posit that health inequity is the difference in health outcomes of populations due to avoidable antecedent factors, which is an unfair and social injustice.

Example 3 illustrates the health inequity of funding for sickle cell anemia (SCD) research.

Approximately 70,000 to 100,000 Americans have sickle cell disease, the most common form of an inherited blood disorder. It is more common among people of African descent, about 1 in 13 carriers of the sickle cell gene are African American (CDC, 2019). The difference in sickle cell anemia incidence across populations can be considered an inequality because sickle cell anemia is a genetic disease, which is caused by a mutation in the hemoglobin-Beta gene found on chromosome 11 (Ashley-Koch et al, 2000; Steinberg & Sebastiani, 2012) . This description sounds like health inequality because the difference is due to unavoidable biological J o u r n a l P r e -p r o o f Journal Pre-proof factors. However, if this case is further unpacked we find that there are a number of avoidable factors including that life expectancy is 30 years shorter than people without sickle cell anemia, that the majority of the sickle cell anemia population are Medicaid beneficiaries, that these people experience longer waiting times to see a physician or get pain medication, and that the number of physicians trained and willing to treat sickle cell anemia patients is limited. Moreover, although this disease was discovered move than 100 years ago, there are only two medications that have been approved for treatment of the disease (see example 3). This seems to indicate that this disease, which is most frequently found among Blacks, has received little attention including the research and funding necessary for better treatment. The differences in health outcomes in this case are a result of systemic and unjust distribution of treatment and research opportunities.

The terms inequality, disparity, and inequity are often used interchangeably in population health without clarification of their meanings, underlying values, and antecedents. For example, Healthy People's overarching goals increasingly recognize the differences in health outcomes of groups of the U.S. population and the importance of the societal impact on health. Healthy People 2000 was the first to introduce the term focused on reducing disparities, and it was strengthened in 2010 with a call to eliminate disparities. Health People 2020 included achieving equity and recognized the need for improving social and physical environments that promote health for all. However, it is important to define terms before developing metrics about them and deciding what we would like to accomplish. Therefore, we propose the definitions of equality, disparity, and equity in health we have given in this paper (see the Table 1 ). Clarifying these concepts and having accurate and meaningful metrics to measure the socioeconomic and J o u r n a l P r e -p r o o f Journal Pre-proof demographic factors of health, as well as measures that address disparities in health and health care, can have a major impact on population health. It seems that the definitions of health equity are more than ones simply reflecting differences in health outcomes or that are empirically measurable. Measuring health inequities requires consideration of how to define unfair inequalities, inasmuch as social justice and fairness can be interpreted differently from different ethical, legal, and technical perspectives, these values may generate different definitions of health inequity. However, the distinctions are important because they inform health strategies and health policies that guide priorities and resource distribution to improve population health more broadly or to reduce health inequities with a focus on fairness and justice.

Noteworthy is that health inequity is linked with health disparity, inasmuch as health inequity is measured by health disparities metrics. In particular, whereas health disparity is the metric for assessing health equity, health inequity includes the additional dimension of the human right to have good health and social justice. Furthermore, inequities in health care are a result of unfair, avoidable differences in access to the resources needed to improve and maintain health or health outcomes and offer policy relevant information, whereas health inequality simply refers to the uneven distribution of health conditions or health outcomes.

The WHO Constitution declared in 1948 that, "The enjoyment of the highest attainable standard of health is one of the fundamental rights of every human being without distinction of race, religion, political belief, economic or social condition" (Meier, 2017) . This statement constitutes a very powerful mandate of moving toward health equity as a human right. Health equity is a subset of health differences between countries and within countries. It is relevant to social justice because these differences are deeply rooted in social conditions related to systematic associations J o u r n a l P r e -p r o o f Journal Pre-proof with avoidable health differences. Clear definitions will assist us to develop effective health policies and strategies and determine priorities for use of limited resources and to accurately measure the health of populations and determinants of health as well as assess progress in these areas. However, the notion of "avoidability" can be highly subjective. Clarifying the meaning of health inequality, disparity, and inequity, with an understanding of the philosophical value-laden subjectivity of health equity will enable nurse practitioners, educators, researchers, and health policy makers to be more effective in advocating for what conditions make health disparities unfair and unjust and in development strategies to move toward health equity. This, in turn, may lead to further clarification and consistency in our communication about population health and fairness in the distribution of health outcomes and health resources. Systematic differences in any measurable aspect of health outcomes due to the different distribution of social conditions across these populations. Health Inequity Disparities in metrics of health outcomes due to avoidable differences in social, economic, geographical or healthcare resources that are unfair and unjust

Note. Both incidence and mortality are age-standardized rates per 100, 000. There is a higher incidence and mortality related to breast cancer among women than men.

J o u r n a l P r e -p r o o f Journal Pre-proof

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