The detection of adverse reactions to therapeutic drugs.

The risk that a drug newly introduced into medical use will occasionally cause adverse reactions is neither negligible nor totally avoidable. Only well organized systems of monitoring can bring early detection and appropriate action. These in turn require either detailed supervision or spontaneous reporting. The paper is concerned with statistical inference from reports spontaneously submitted, and its logical limitations; it discusses strengths and weaknesses of the UK system, the detection process, and automated signalling.