The personal communication d’informació of the public employees from several public administrations in a group of research in way aggregated or dissociated, so that this carries out a study about l’absentisme, does not require to have the previous consent of the affected ones. D’altra band, the treatment of its data of health in order to control work l’absentisme only would be possible, to legal lack d’habilitació, if he counts himself out with the express, free, unambiguous, specific consent and informed of the workers. If d’aquest is ordered consent, the communication of determinate data to the medical service that l’administració hires will not have consideration of cession if l’accés is necessary to carry out the provision of the service and d’encarregat is counted out with a contract.