[Representation and representativeness in health councils: between formalization and participatory legitimacy].

The action of social representatives greatly influences the performance of health councils and the quality of participatory management in the Brazilian Unified National Health System. This study aimed to analyze the mechanisms of representation and forms of representativeness within health councils in municipalities of different population sizes. This multiple case study was carried out in Vitória da Conquista, Guanambi, and Urandi, in Bahia State, Brazil. Data and information were obtained by document analysis, observation of plenary meetings, and interviews with 30 health board members. A theoretical matrix structured in five dimensions was used for data analysis: the process to choose representatives; relationships between representatives and those who are represented; types of represented interests; criteria to define positions; and participatory practice. Results showed the predominance of non-electoral criteria to choose representatives. The relationship between representatives and those who are represented shows the former's isolation and reduced accountability. Individual conscience predominated as the board defined positions. The population size of the municipalities also influenced representation in health councils as that with the smallest population evinced consistent weaknesses for the exercise of representation. Results showed insufficiencies in the representative process. This study stresses the need to draw representatives and those they represent near each other and the importance of valuing experiential knowledge as an element that can grant legitimacy to representation.