Health Inequalities amongst People of African Descent in the Americas, 2005–2017: A Systematic Review of the Literature

Ethnic inequalities are often associated with social determinants of health. This study seeks to identify the latest scientific evidence on inequalities in the health of people of African descent in the Americas. For this, a systematic review of the literature on health and people of African descent in the Americas was carried out in the LILACS, PubMed, MEDLINE, and IBECS databases. Institutional and academic repositories were also consulted. Evidence was obtained on the presence and persistence of health inequalities in the population of African descent in the Americas from the identification of five types of quantitative and qualitative evidence: (1) ethnic/racial concept and variables; (2) relations with other social determinants; (3) health risks; (4) barriers and inequalities in health services; and, (5) morbi-mortality from chronic diseases. Studies with qualitative methods revealed invisibility, stereotypes, and rejection or exclusion as main factors of inequality. This review evidenced the existence of health inequalities, its interconnection with other adverse social determinants and risk factors, and its generation and perpetuation by discrimination, marginalization, and social disadvantage. These conditions make people of African descent a priority population group for action on equity, as demanded by the 2030 Agenda for Sustainable Development.


Introduction
International organizations, such as the United Nations, use resolutions to promote a focus on ethnic/racial and intercultural equality [1]. The purpose of this paper is to identify evidence on inequalities in the health of people of African descent, that can support decision making for health policies, strategies, and action plans to help overcome ethnic and racial inequality in the region of the Americas.
The search was based on the definition of "Afro-descendant" used as a reference for the PAHO/WHO regional Policy on Ethnicity and Health [2], adopted in 2017 by the Member States of the Pan American Health Organization: "In Latin America and the Caribbean, this refers to the different

Design
This study aims at specifically exploring the public health literature on inequalities amongst people of African descent in the Americas. The search strategy did not include other specialized databases (such as sociology, economics, or anthropology).
The following research question was proposed: What public health evidence exists about health inequalities related to the (historical, social, and cultural) ethnic conditions of people of African descent in the Americas, compared to other population groups?
This question was used to design two search queries, one in Spanish using Descriptores en Ciencias de la Salud (DeCS) and one in English using Medical Subject Headings (MeSHs). These queries were supplemented by a search of the institutional repositories of several universities (Antioquia, Nariño, Los Andes, and Rosario in Chile; University ICESI in Colombia; the Autonomous University of Mexico), the Latin American Council of Social Sciences-Comparative Research Programme on Poverty CLACSO-CROP in Latin America and the Caribbean; ECLAC; the Ministries of Health of Colombia, Mexico, Brazil, and the Ministry of Culture of Colombia; and the National Urban League (NUL) (See Table 1). Table 1. Descriptores en Ciencias de la Salud (DeCS) and Medical Subject Headings (MeSHs) descriptors.

Eligibility Criteria
The eligibility criteria for the publications considered for this review were: Inclusion Criteria (1) People of African descent in the Americas as the population of interest.
(3) Written in English, Portuguese, or Spanish. (4) For quantitative studies: report or demonstrate the use of methodologies and measurement instruments to establish an association between African descent and social inequalities in health. (5) For qualitative studies: use methodologies and assessment instruments to establish an association between African descent and social inequalities in health. (6) Contextual framework considers historical, social, and cultural factors that affect the living conditions of people of African descent in the Americas. (7) Research approach considers how inequalities and inequities in health are generated among people of African descent in the Americas. (8) Address differences in equality, equity in health, or disease (morbidity and mortality) outcomes between people of African descent in the Americas and other population groups. (9) Consider factors that generate cumulative effects in terms of ethnic inequalities and inequities among people of African descent in the Americas (e.g., female gender, living in remote rural areas).
The initial search of WHO Global Information Full Text (GIFT), Virtual Health Library (VHL), and the aforementioned institutional repositories retrieved 1418 records. After screening of titles and abstracts and application of the inclusion and exclusion criteria, 427 records remained. These were selected for full-text reading and assessment of eligibility, based on the extent of their contribution to understanding the situation of health inequalities among people of African descent and those not of African descent in the Americas. After this step, 114 articles remained. After a final round of review and consultation with experts on health inequalities and ethnicity, 62 articles were selected (See Figure 1). and consultation with experts on health inequalities and ethnicity, 62 articles were selected. (See Figure 1) The theoretical framework of this review was the model developed by Weightman [9] for the evaluation of public health interventions. This model is particularly useful for systematic reviews because it allows the evaluation of non-analytical studies with different designs, as well as expert opinions. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed throughout.

Quantitative Research
Studies that work on sequential, deductive and probative processes; that measure, use statistics, analyze causal relationships, and generate results for purposes of generalization, replication, or prediction [10].

Qualitative Research
Studies that use inductive processes to analyze subjective reality; rather than measuring or using statistics, they work out ideas in depth, address the understanding, interpretation, and meanings of data, and contextualize phenomena. Their results are not generalizable [10].

Results
Ultimately, 62 studies conducted between 2005 and 2017 were included in the review. Of the 64 records identified in the LILACS, MEDLINE, PubMed, and IBECS databases through the GIFT/VHL portal, 20 were retrieved from GIFT, 16 from the VHL, 1 from Equity Health, and 25 from institutional repositories. Of the selected publications, 42 were scholarly articles, 18 were documents, and two were presented as educational material for virtual study.
From the 62 selected articles, 32 were carried out using qualitative methods and 30 with quantitative methods. (See Table 2) The theoretical framework of this review was the model developed by Weightman [9] for the evaluation of public health interventions. This model is particularly useful for systematic reviews because it allows the evaluation of non-analytical studies with different designs, as well as expert opinions. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed throughout.

Quantitative Research
Studies that work on sequential, deductive and probative processes; that measure, use statistics, analyze causal relationships, and generate results for purposes of generalization, replication, or prediction [10].

Qualitative Research
Studies that use inductive processes to analyze subjective reality; rather than measuring or using statistics, they work out ideas in depth, address the understanding, interpretation, and meanings of data, and contextualize phenomena. Their results are not generalizable [10].

Results
Ultimately, 62 studies conducted between 2005 and 2017 were included in the review. Of the 64 records identified in the LILACS, MEDLINE, PubMed, and IBECS databases through the GIFT/VHL portal, 20 were retrieved from GIFT, 16 from the VHL, 1 from Equity Health, and 25 from institutional repositories. Of the selected publications, 42 were scholarly articles, 18 were documents, and two were presented as educational material for virtual study.
From the 62 selected articles, 32 were carried out using qualitative methods and 30 with quantitative methods (See Table 2). Of the 62 publications, six (9.67%) were reviews (desk review, state-of-the-art, or literature review); only one was a systematic review (See Table 3). Three broad types of quantitative evidence were identified: one regarding inequalities in negative health outcomes; one obtained from data such as censuses and surveys; and one obtained from the use of statistical tools to measure marginalization and segregation (See Table 4).
The most relevant quantitative research identified within the aforementioned typology is presented in Table 5.
Six broad types of qualitative evidence were identified in the present review: historical evidence related to the legal/political recognition, design, implementation, and evaluation of health policies targeting people of African descent in settings of social and institutional discrimination; on the public health consequences of inequalities; on how the concepts of ethnicity and race are used in data collection instruments; on representations, behaviors, and various forms of racism; on the territorial, political, and cultural organization of people of African descent; and on traditional medicine and midwifery. (See Table 6).
The most relevant qualitative research identified within the aforementioned typology is presented in Table 7.

Robust
Ethnic inequalities in timely access to hematopoietic cell transplantation.

Type of Evidence n %
Studies on inequalities as they pertain to risk factors and negative health and/or nutrition outcomes between different ethnic groups. 19 30.64 Nationwide health surveys, studies, or tools designed to collect data with a view to addressing ethnic inequalities in social determinants and/or health systems and services. 9 14.52 Quantitative evidence on georeferencing, spatial autocorrelation, marginalization indices, dissimilarity indices, location coefficients, and measures of segregation. Source: Own work. Table 6. Quantitative studies included in this review, stratified by type of evidence provided.

Type of Evidence n %
Historical evidence of the contrast between advances in political-legal recognition and structural and institutional discrimination, racial inequalities in health, and racism as a socio-historical phenomenon. 10 16.14 Evidence of racial inequalities in the health status of the population as a public health issue. 8 12.90 Evidence on the concepts used in censuses, surveys, and studies to define management of ethnic/racial variables. 7 11.29 Evidence on the ways in which ethnic and ethnic-territorial representations and stereotypes with effects on social behaviors, such as racism and sexist racism, are generated and reproduced.

4.84
Qualitative evidence on elements which define people as being of African descent, such as physical characteristics, identity, social and territorial sense of belonging, cultural traditions, historicity, organizational processes, and religious myths.

Discussion
The findings of this review show how complex this topic is. In terms of time, there is a tendency to make the health inequality situation for people of African descent more visible as well as based on a more scientific quantitative evidence. Regarding the subjects addressed, there is also a tendency to highlight epidemiological and clinical studies, particularly on non-communicable diseases and external causes. Notwithstanding this tendency, the focus seems to have shift towards analyzing the problem from a social sciences perspective to provide a greater explanatory capacity. Our findings also pinpoint the challenge of conducting studies with mixed methods that will allow a better understanding of the mechanisms that generate, transmit, and perpetuate health inequalities.
The results of this review contribute to the construction of an evidence-based framework to support decision making about health policies, programs, plans, and technical protocols with the aim of eliminating or reducing health inequalities in people of African descent, in a manner consistent with the Sustainable Development Goals (SDGs) pledge of "leaving no one behind" [8].
Quantitative research has fundamentally focused on the social determinants of health, risk factors, and negative or positive health outcomes. Some authors have stressed the need for more research into the mechanisms whereby poverty, social injustice, and ethnic and cultural factors act as barriers to contribute to the generation and perpetuation of inequalities, especially as they pertain to negative outcomes [11]. These mechanisms may include discriminatory forms of access to high-quality health services [12]. Some authors have mentioned the need to address ethnicity in an intersectional manner with other variables, such as social class and gender [13].
Some authors have focused on addressing ethnic disparities for access and use of health services in different situations and in different outcomes. These studies show how people of African descent are at a disadvantage to access prevention services, care, hospitalizations, use of innovative therapies or high technology in health (See Table 8).
Several studies also recognized the importance of improving the quality of data, particularly by including ethnicity/race as a variable in censuses, surveys, and continuous records [14][15][16]. Others have proposed the application of quantitative methods to conduct georeferencing of racial segregation and discrimination [17,18].
Qualitative research, in turn, allows us to move forward with some reflections and begin other, necessary discussions. Advances include the availability of international instruments, which can be administered differently in different geographical areas and recognize people of African descent as subjects collectively deserving of the same social, economic, and cultural rights. This allows progress in the understanding and application of instruments to eliminate racism and discrimination.
Qualitative studies also provide a better understanding of the positive impact of taking a cultural approach to the organization of territories and communities of African descent, based on their ethnic and racial identities. To do so, some authors have proposed the concept of "place and effect" [19]. Other studies addressed territorial approaches to the practice of traditional medicine and midwifery in Afro-descendant communities [20]. Similar settings produced evidence on social and community strategies to fight discrimination [21].
Some papers analyzed social and occupational conditions as determinants of health, assigning particular importance to ethnic inequalities in labor mobility [22] and the migration of Haitians [23]. The Brazilian scientific community has made significant contributions regarding health policies for the Black population, generating elements to further current understanding of how to design, implement, develop indicators for, monitor, and evaluate such policies from an ethnic perspective.
There is a particular need for expanded use of mixed methods, which combine quantitative research to identify the dimension and severity of inequalities and qualitative approaches to understand why and through which mechanisms these inequalities occur. An example of such an approach is provided by a study on ethnic inequalities and high-risk behaviors in HIV [24].
There is a need to address the challenge of adopting an intercultural approach within the context of the social determinants of health. By considering the gender and ethnic inequalities that interact with one another, the differences in access to health throughout the life course, as well as the promotion and respect of individual rights and, in the case of indigenous peoples, collective rights [73], this particular need can be covered.
Our study has certain limitations. The most relevant one, perhaps, is the scope of the search strategy being restricted to the public health area. However, the results of our exploratory review point to the need to expand this search to broader social sciences areas such as sociology, economics, anthropology, and the like. Finally, we identified an unmet need for a research protocol to support systematic reviews of health issues-such as the present one-which do not conform to the requirements traditionally used for systematic reviews of mostly clinical topics.

Conclusions
To conclude, this review evidenced the existence of health inequalities associated to the ethnic-racial status of the Afro-descendant populations in the Americas. The findings of this review show the complexity of this topic and highlight the importance of the social sciences perspective to gain greater explanatory capacity. The interconnection between ethnic-related health inequalities with other adverse social determinants (e.g., territorial spatial segregation, poor living conditions, social and institutional exclusion, poverty, migration) and risk factors (e.g., informal mining, exposure to chemicals and urban pollutants, poor basic sanitation) generate intersectional inequalities that perpetuate discrimination, marginalization, and social disadvantages. These conditions make people of African descent a priority population group for action on equity, as demanded by the 2030 Agenda for Sustainable Development.