Health differences across population subgroups: Exploring inequalities through bibliometric techniques

Several studies have identified the presence of a socio-economic gradient on both health outcomes and health care access in almost every country of the world. This gradient is acknowledged as a downward slope on differences in health outcomes or health care access across population subgroups and defined as health inequalities. Health inequalities can be guessed as outcomes of a complex combination of individuals’ characteristics and their chances to access resources. The former regards the conditions and experiences in which individuals are born, live and work―such as their gender, education, income, social networks, migratory status, and social relations. The latter, instead, deals with their real chances to access resources and decision-making processes, in terms of access to social protection (such as affordable child services or housing, sickness and unemployment protection; etc.), access to quality health services and prevention measures; access to healthy housing and settlement, or access to financial and non-financial services, among others. Discrimination most often affects women, older people, people with disability, or are based on ethnicity or sexual identity. Discrimination has often a personal basis but may also be caused by social bodies, and this could imply that whole population receive inferior services or has difficulties in accessing health services, which, in turn, could prevent them from enjoying healthier lives. Previous bibliometric analyses regarding the scientific production on health inequalities have been focused either on a specific region or country or groups of countries (Benach de Rovira, 1995; Almeida- Filho et al., 2003; Ritz et al., 2010), o r on health systems or reforms (Macias-Chapula, 2002; Yao et al., 2014). Other recent literature focused on citation practices, together with the most productive authors and journals in health inequalities (Bouchard et al., 2015); north-south gaps in research and international collaborations (Cash-Gibson et al., 2018); and citation space and roles of several factors on health structure (Collyer and Smith, 2020). As health is a fundamental human right, identifying health inequalities and its main drivers remains essential to achieve health equity. Health equity is achieved when everyone can attain their full potential for health and wellbeing. Research on health inequality is one of the principal sources of knowledge for policy and planning in aged and multicultural modern societies (WHO, 2019). The main purposes of this paper are, first, to describe the temporal evolution of the amount of academic production f ocu sed on health inequalities/disparities/equity during an extended period 1991- 2022 and, second, to identify its main research topics and map the specific roles of these topics within the academic production.