GPs’ representatives voted overwhelmingly this week for a system in which patients opt in to any sharing of medical data with third parties—rather than one in which their consent is assumed unless they opt out, the system favoured by the Department of Health. Clinical confidentiality depends on GPs being the prime data holder of their patients’ medical records, said the BMA’s annual conference of local medical committee representatives in London. It also strongly opposed using implied consent as justification for releasing information on named patients.