Aim A comprehensive approach to health highlights its close relationship with the social and economic conditions, physical environment and individual lifestyles. However, this relationship is not exempt from methodological problems that may bias the establishment of direct effects between the variables studied. Thus, further research is necessary to investigate the role of socioeconomic variables, their composition and distribution according to health status, particularly on non-communicable diseases. Subjects and methods To shed light on this field, here a systematic review is performed using PubMed, the Cochrane Library and Web of Science. A 7-year retrospective horizon was considered until 21 July 2017. Results Twenty-six papers were obtained from the database search. Additionally, results from “hand searching” were also included, where a wider horizon was considered. Five of the 26 studies analyzed used aggregated data compared to 21 using individual data. Eleven considered income as a study variable, while 17 analyzed the effect of income inequality on health status (2 of the studies considered both the absolute level and distribution of income). The most used indicator of inequality in the literature was the Gini index. Conclusion Although different types of analysis produce very different results concerning the role of health determinants, the general conclusion is that income distribution is related to health where it represents a measure of the differences in social class in the society. The effect of income inequality is to increase the gap between social classes or to widen differences in status.

The purpose of this paper is to identify the role of health status in productivity. In order to check the existence of reverse causation suggested by previous studies the Hausman test was carried out and different sets of instruments were used as exogenous determinants of health expenditure. Variables related to health expenditure were used to estimate the elasticity and these produced accepted results. Evidence was obtained to support the positive effect of health on economic growth.

Aims: Non-communicable diseases (NCDs) have become a primary health concern for most countries around the world. The aim of this research is to analyze the relevant evidence that determines the effect of socioeconomic position (SEP) on the incidence and prevalence of NCDs. Methods: A systematic literature search was performed using PubMed, Cochrane Library, and Web of Science to identify evidence regarding the relationship between income inequalities and NCDs, between 2005 and 2015. The final selection of papers was based on applied studies focusing on Organisation for Economic Co-operation and Development (OECD) countries and articles referring to three main groups of chronic diseases: cardiovascular and heart diseases, cancer, and diabetes. Results: A final set of 47 selected studies were fully taken into account in this review. Despite significant heterogeneity in exposure and outcomes measures, overall the evidence suggests that having low SEP increases the risk of developing cardiovascular diseases (CVDs), lung and breast cancer, and type 2 diabetes. SEP is also associated with multiple NCD risk factors such as smoking and physical inactivity. Conclusion: Low socioeconomic status appears to have a significant consistent impact on mortality and morbidity caused by NCDs in OECD countries. Social and economic disadvantages are associated with health inequalities in terms of access to care, increased incident risk of NCDs, and early death. These findings point to the need for public health strategies and research to address socioeconomic status disparity among individuals.