The Science of Health Disparities Research. Группа авторов

health disparities are usually related to SES and traditional minority race/ethnic groups, people living in rural areas are also a minority in their own way. There is increasing evidence of disparities from the leading causes of death among persons living in the most rural areas compared to those living in cities and these disparities merit increased research attention [11]. The operational definition of rurality used in data reported from the Centers for Disease Control and Prevention categorized about 18% of the US population as residing in rural counties. NIMHD endorses this definition and encourages researchers to examine the intersectionality of rural residence, less privileged SES, and race/ethnic minorities.

      The addition of sexual and gender minorities (SGM) as a health disparity population is expected to lead to more innovative research to examine health determinants that contribute to disparities. SGM populations share the experience of discrimination with other disparity populations. This implies that there may be shared mechanisms of health determinants to specific conditions that can be examined. Although sexual orientation and gender identity questions are more recent additions to national surveys, it is clear that how these questions are asked significantly affects how respondents identify themselves. More research is needed to understand the best ways to assess sexual orientation and gender identity.

      In comparing outcomes across populations, it is important to use standard terminology. Disease or condition rates, important aspects of morbidity, are typically described in terms of incidence and/or prevalence and are important components of population morbidity. Population health is often measured by mortality, so researchers will frequently evaluate not only rates, but also whether a population has premature and/or excessive mortality for specific conditions. Using a general index that reflects population health—such as a global burden of disease measured by disability‐adjusted life years (DALYS) or premature years of life lost—can provide insights into understanding mortality patterns in areas where populations vary [12].

      For clinicians, rates of risk factors such as level of blood pressure, health‐related behaviors such as cigarette smoking, and biomarkers linked to disease outcomes such as glycosylated hemoglobin for diabetes are important components of population morbidity directly in the causal pathway of disease incidence. For clinicians and social scientists, the assessment of how patients or people feel and function using standardized measures provides important data and outcomes to consider. Such outcomes could include psychometrically tested symptom scores for specific conditions, quality of life measures, and activities of daily living. The interdisciplinary nature of minority health and health disparities science will benefit from concurrence on standardized terminology and measures.

1.4 The NIMHD Research Framework: Health Determinants in Action

There is no single identifiable mechanism or etiologic pathway for observed health or healthcare disparities. The robust association of SES with overall mortality underlies all other factors studied. If SES could be made equal across society, would health disparities be eliminated? If access to care were similar for all groups in terms of accessibility, cost and quality, would healthcare outcomes differ by SES or race/ethnicity? Opportunity in education and employment and access to quality healthcare will go a long way to addressing health and healthcare disparities, but other factors will continue to affect outcomes. Understanding complex interactions that may lead to health disparities, such as biological processes and genetics, cultural influences on individual behaviors and lifestyle, effects of the physical and social environment, and access to and interaction with the healthcare system all may play significant roles depending on the populations and conditions. To depict the wide array of determinants that promote or worsen minority health and/or cause, sustain, or reduce health and healthcare disparities, NIMHD scientific staff developed the NIMHD Research Framework (also referred to here as the Framework).⁴

      The Framework reflects a hybrid of two models: the socioecological model [13] and the National Institute on Aging (NIA) Health Disparities Research Framework [14]. The socioecological model posits that health and human development are influenced by factors at multiple levels, from the individual to the macro or societal level. The NIA Framework organizes many of these factors into levels of analysis of health disparities relevant to aging research into several domains, including the biological, behavioral, sociocultural, and environmental.

The NIMHD Research Framework (Figure 1.3) has two axes, with the Y axis depicting domains of influence on health (biological, behavioral, physical/built environment, sociocultural environment, healthcare system) and the X axis depicting levels of influence on health (individual, interpersonal, community, societal). These 20 cells portray a set of determinants, any one of which may be relevant for a particular minority health outcome or health disparity. Examples of factors within each cell are provided in Figure 1.3; this list is not intended to be comprehensive.

Figure 1.3 The NIMHD Research Framework.

      Source: National Institute on Minority Health and Health Disparities. NIMHD Research Framework. 2017. Public Domain Available at: https://www.nimhd.nih.gov/about/overview/research‐framework.html. Accessed March 2, 2018.

In addition to characterizing determinants of health disparities, the Framework describes how health outcomes span multiple levels (individual, family/organizational, community, and population). Health outcomes beyond the individual level reflect collective or aggregate outcomes. Also included in the Framework are designated health disparity populations, as well as demographic factors relevant to understanding the impact of the intersectionality of population group membership—such as sex/gender, disability status, and geographic region—on minority health and health disparities. Finally, the Framework identifies the importance of a life‐course perspective when examining determinants across domains of influence, including consideration of early adverse events, chronic and cumulative social and environmental exposures, transgenerational transmission of risk and resilience, and critical periods for developing risk or resilience.

      The NIMHD Research Framework is intended to convey the complexity of minority health and health disparities and the reality that focusing research exclusively on one cell of the Framework may produce incomplete knowledge. Much of the early research on minority health and health disparities used a unidimensional approach, focusing, for example, on individual behaviors and lifestyle comparisons in an effort to understand observed epidemiological differences and develop tailored interventions; or to take another example, examining the roles of language fluency and culture to understand how immigrants interacted with the healthcare system.

The role of racism and discrimination has for decades been postulated as a major contributor to adverse health outcomes, and the volume of research on this topic has steadily increased [15]. However, racism and discrimination have not been routinely included in health studies that primarily emphasize other types of determinants or etiological factors. For any particular minority health or health disparity issue, multiple factors may be relevant, from lifestyle choices, cultural beliefs, and racism and discrimination to place‐based factors such as community violence exposure, availability of green space, public transportation, and access to healthy foods. Social factors, such as social support and size and cohesiveness of social networks and macro‐level factors, such as health and other policies, are all relevant as well. The Research Framework is intended to stimulate consideration and research about potential factors and determinants of health outcomes that transcend traditional disciplinary silos or service sector boundaries.

      Another principle conveyed by the NIMHD Research Framework is the importance of the interaction between