Funding for this research was provided by:
National Institute of Health Research (PB-PG-0211-24122)
Received: 11 December 2018
Accepted: 19 June 2019
First Online: 31 July 2019
Ethics approval and consent to participate
: Ethical approval for the study was obtained for phase one from NHS REC approval [NRES, North East York, 28.10.14] and NOMS [1.9.14] and phases two-five [Bristol REC Centre, London South East, 6.1.15] from NHS REC approval, NOMS [6.3.15] and the Department of Health Sciences at the University of York for all phases [11.12.14]. As the material was adapted and developed for appropriate use within each prison we were granted one substantive amendment to the project from all parties during July 2015.
: The authors declare that they have no competing interests.