Mammography and the politics of randomised controlled trials

The following information should have been included at the end of this paper by Jane Wells (31 October, pp 1224-9). The author spent six months at the University of Maryland at Baltimore, during which time her salary was paid by the Anglia and Oxford Regional Health Authority. The author thanks Kay Dickersin for advice and help during this stay in Baltimore and for comments on an earlier draft of the paper.