Funding Acknowledgement and Department of Health Disclaimer: This study is funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) Programme (NIHR132889). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Bristol Trials Centre Acknowledgement: This study was designed and delivered in collaboration with the Bristol Trials Centre, a UKCRC registered clinical trials unit, which is in receipt of National Institute for Health & Care Research CTU support funding.

Sponsor Acknowledgement: This study is sponsored by North Bristol NHS Trust.

REDCap Acknowledgement: Study data are collected and managed using REDCap (Research Electronic Data Capture, Harris PA, et al. J Biomed Inform. 2009 Apr;42(2):377-81) hosted at the University of Bristol.