were willing to return, as discussed above. In addition, personal reasons would not be an obstacle for them to return (according to the data in our study, most of them were single and with no children). Therefore, SECTI agents and, in the case of researchers in health sciences, Sistema Nacional de Salud agents can promote actions to achieve this return through the fostering of collaboration. Within this new collaborative framework, it is quite pos- sible that new professional opportunities may arise from the contribution of these scientists endowed with a greater international experience and knowledge. Similarly, host countries are much more receptive to the collaboration with international and Spanish scientific institutions than the national scientific institutions when it comes to promoting collaboration with health science researchers in Spain. In this last sense, keeping a list of contacts among colleagues is also a valid means of getting scientists to return in the way Fontes [15] indicated. Con- sequently, the authorities and managers of the Sistema Nacional de Salud are advised to encourage these types of contacts. Of note, Fontes [15] also revealed the import- ance of establishing contacts with international associa- tions of Portuguese scientists. In the case of Spain, this approach can be performed by employees of the Sistema Nacional de Salud through the recently established Spanish learned associations of the scientific diaspora: SRUK/CERU, CERFA, ACES and ECUSA. We also show that the models that should be taken as examples in areas of knowledge related to the collabor- ation of Spanish scientists abroad did not show a much higher level than those concerning health sciences. The primary positions largely focus on the area of social and legal sciences and humanities, and therefore it would be interesting to assess whether this area is developing good practices in this sense. The information obtained herein has implications for health management. An improvement in the collabor- ation with Spanish scientists abroad can bring about significant benefits to the Sistema Nacional de Salud. This collaboration could lead to an increase in human resources for this area through the re-establishment of contacts that could increase the possibility of working together, even if it would primarily be at a distance. Similarly, the quality of national human resources would also benefit from the enrichment of collaborating with those who have been further educated and who have gained experience abroad. In addition, integration into the labour market could be improved thanks to the awareness of the value added by these scientists in other countries, unseen by the thus far limited collabor- ation that has been found in this study. The awareness of their value can not only drive the discovery of new attractive opportunities for investment, but also lead to the creation of jobs, greater national and international
scientific output, and a larger sharing of scientific knowledge. Likewise, collaboration between these sci- entists based abroad and the doctors willing to conduct research, but who have little time, can support the work of the latter by allowing them to also carry out experi- ments, and motivating them in all their research tasks. Finally, it would also be interesting to study the existing examples of international collaboration of national re- searchers working in Spain with scientists from other countries. The strengthening of this collaboration can be an important measure to enrich the investigations of national researchers without leaving their professional positions in Spain.