According to the Act on hospital establishments every patient is entitled to confidentiality. The scope of this provision does not seem restricted to patients who stay in a hospital.
The Code of medical ethics enforces every physician a professional secrecy in accordance with the conditions stipulated in the Penal Code. The professional secrecy is not only related to information which the patient has entrusted the physician, but also concerns all information which has become known to the physician in the exercise of his profession, this means everything what he has seen, heard or understood. The professional secrecy continues to exist also after the death of the patient.
A doctor must also see to it that those who assist him are instructed with regards to their obligation of confidentiality. He must also see to it that the medical and personal details concerning his patients are protected against every indiscretion. The medical secrecy explicitly concerns the revealing of information to third parties and not the relation between doctor and patient. This obligation does not prohibit the physician to provide his patient certificates or documents (for example with the eye on an insurance). It is however prohibited to directly provide such documents to third parties, except when patient gave his consent in writing.