1. From the Division of Health & Social Care Research (C.M., N.F., J.R., A.S., S.C., A.R.R., C.D.A.W.), King's College London, London, UK; the Academic Unit of Elderly Care and Rehabilitation (A.F., J.Y.), University of Leeds, Leeds, UK; the Medical Research Council General Practice Research Framework (I.N.); and the Prevention Research Unit (L.E.S., P.M.R.), University of Oxford, Oxford, UK.