Table 2

Study characteristics

Author(s)	Title	Setting	N	Participants	Study design	Trial intervention	Method of evaluation	Hawker’s Risk of Bias score
Maloney et al 23	Patient perspectives on participation in the ENABLE II randomized controlled trial of a concurrent oncology palliative care intervention: Benefits and burdens	Hospital	52	Patients	Randomised control trial	Four telephone-based educational sessions ran by advanced practice nurses with palliative care training, and monthly telephone contact. Participants completed questionnaires every 3 months until death or study completion	Retrospective interview	32
Aoun et al 24	Family caregiver participation in palliative care research: Challenging the myth	Home	322	Family caregivers	Stepped-wedge cluster trial	The intervention groups received the Carer Support Needs Assessment Tool (CSNAT) vs a control group who received standard support. Intervention group received two visits from a nurse and telephone questionnaires were completed pre-intervention and postintervention .	Retrospective interview	31
Dotolo et al 25	Strategies for enhancing family participation in research in the ICU: Findings from a qualitative study	Hospital	25	Family members	Randomised trial	A facilitator to improve clinician-family communication in the ICU vs usual care. Surveys assessing depression, anxiety and Post traumatic stress disorder were mailed to family members’ homes 3 and 6 months after the patient’s death or intensive care discharge.	Retrospective interview	32
Véron et al 26	Recollection of participating in a trial: A qualitative study of patients with severe and very severe chronic obstructive pulmonary disease	Hospital	18	Patients	Randomised control trial	Intervention group received an early specialist palliative care intervention and standard care vs standard care. The intervention group received monthly visits for 12 months from nurses specialising in palliative care.	Retrospective interview	30

ICU, intensive care unit.