Received: 29 January 2020
Accepted: 11 June 2020
First Online: 22 June 2020
Ethics approval and consent to participate
: Data used in this study are publicly available and therefore the authors were not required to obtain ethics approval; consent to participate was implicit in prisoners’ agreement to be interviewed after being informed (verbally and in writing) that participation was voluntary.
: Not applicable.
: The authors declare that they have no competing interests.