Institute of Health Research
Collections of Former Colleges
Item views 0
Full item downloads 0
Except where otherwise noted, this item's licence is described as Published by the BMJ Publishing Group Limited. For permission to use (where not already
granted under a licence) please go to http://group.bmj.com/group/rights-licensing/
permissionsThis is an Open Access article distributed in accordance with the Creative
Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to
distribute, remix, adapt, build upon this work non-commercially, and license their derivative
works on different terms, provided the original work is properly cited and the use is
non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0