Discussion Our results show that, for researchers working in health, the figures in all areas assessed in the study were always below the total average, if collaboration with an inter- national institution was excluded. In this regard, there was also a high level of cooperation between researchers settled abroad and international scientific institutions, which contrast with the limited collaboration held with national scientific institutions, including those of origin for each researcher. This wide difference showed that the international ties made by health science researchers abroad are quite likely to exceed those resulting from the national network. As a