Received: 28 July 2020
Accepted: 14 October 2020
First Online: 23 November 2020
Ethics approval and consent to participate
: Not applicable. The systematic review protocol was registered with PROSPERO: CRD42018091481(ExternalRef removed RecordID = 91481).
: Not applicable.
: Nancy Preston is a section editor (Psychosocial), Naveen Salins is an Associate Editor (Palliative care in other conditions) of BMC Palliative Care. A Ghoshal, and S Hughes declare that they have no competing interests.