Abstract
As the General Medical Council (GMC) is currently in the process of reviewing its ethical guidance on confidentiality, it is a prescient time to consider the legal and ethical issues inherent in it. This paper examines the question of anonymized data, and highlights the fact that the legal position regarding whether it should be classed as confidential is unclear, with the possibility of a change in the law being very real. Indeed, the article argues that the notion that anonymized data is not confidential can be challenged on both legal and ethical grounds, and thus that the GMC should take this into account in its new guidance. Although identifying the fact that this might have implications for epidemiological research, the article highlights an alternative approach that would allow the conduct of such research while not infringing patients' legally protected human rights