[National health systems, legislation, and social determinants: a comparative study of Brazil, Spain, Portugal, and Italy]

This is a documentary, exploratory, descriptive study, which is part of a multicenter international study assessing the national health systems with a care model based on primary health care of Brazil, Spain, Italy, and Portugal, funded by the Brazilian National Research Council (CNPq, acronym in Portuguese). It aims to identify the basic health legislation, the right to health, and the doctrinal and organizational principles of each country with a focus on the impact of social determinants of health on the national health systems. The results showed these countries have similar legislation and doctrinal principles, with a constitutional right to health, based on primary health care, and with a care model of the family health type. The challenges identified were low birth rate and high life expectancy at birth in European countries and criteria for access to medication and care financing. Based on our findings, the countries with higher investment in a structural basis, ensuring more dignified, solid, and vigilant socioeconomic and sanitary conditions, provide an important differentiation in responsiveness and sustainability of the national health system and direct impact on the quality of life.