1. From the Nuffield Department of Surgical Sciences, John Radcliffe Hospital (D.P.T., B.L.), the Centre for Statistics in Medicine, Botnar Research Centre (S.G., D.G.A.), and the Health Economics Research Centre, Nuffield Department of Population Health (A.M.G.), University of Oxford, Oxford, the School of Clinical Sciences, University of Bristol, and Bristol Royal Infirmary, Bristol (U.B.), the Department of Cardiac Surgery, Royal Infirmary of Edinburgh, Edinburgh (V.Z.), Royal Papworth Hospital,...