The OPTIMA Study is funded by National Institute for Health Research (NIHR), Programme (project reference 10/34/501). The information contained in this website is for general information about the OPTIMA study and is provided by the University of Warwick Clinical Trials Unit & University College London. The views expressed are those of the author(s) and are not necessarily those of NIHR or the Department of Health and Social Care or representative of the views of the funder, sponsor or other participating organisations. Trial Registration Number ISRCTN42400492