In Medical Malpractice Overview, medical expert witness Eugene DeBlasio writes on breaches of doctor-patient confidentiality:
Doctor-patient confidentiality is based upon the general principle that a person seeking medical help or advice should not be hindered or inhibited by fear that his or her medical concerns or conditions will be disclosed to others. There is generally an expectation that the physician will hold that special knowledge in confidence and use it exclusively for the benefit of the patient.
The professional duty of confidentiality covers not only what a patient may reveal to the doctor, but also what a doctor may independently conclude or form an opinion about, based on his or her examination or ASSESSMENT of the patient. Confidentiality covers all medical records (including x-rays, lab-reports, etc.) as well as communications between patient and doctor and generally includes communications between the patient and other professional staff working with the doctor.
The duty of confidentiality continues even after a patient has stopped seeing or being treated by the doctor. Once a doctor is under a duty of confidentiality, he or she cannot divulge any medical information about patients to third persons without patients’ consent. There are limited exceptions to this, including disclosures to state health officials. However, unauthorized disclosure to unauthorized parties may create a cause of action against the doctor.