Table 1.

Study details (n = 18).

Year	First author	Setting	Study design, sample size	Outcomes	Theoretical underpinnings	Mechanism of action	Delivered by	Delivered to	Main findings
2014	Allen (19)	USA	RCT, 45 dyads	Center for Epidemiological Studies-Depression Scale, Memorial Symptom Assessment Scale-Short Form, Brief Multidimensional Measure of Religiousness and Spirituality, Meaning in Life Scale, Caregiver Stressor Scale, Positive Aspects of Caregiving scale	Folkman's stress process model	Not discussed	Retired Senior Volunteers	Patient-carer dyads	• Patients in the intervention group had a greater reduction in emotional symptoms (p = 0.02) and emotional symptom bother (p = 0.04) and improved spiritual functioning • Caregivers in the intervention group had better Meaning of Life scale scores (p = 0.02)
2022	Chen (20)	China	RCT, 47 dyads	Qualitative Interviews, satisfaction questionnaire, QoL, Zarit Caregiver Burden, Family Adaptability and Cohesion Evaluation Scale II	Erikson's psychosocial development theory and Bowen's family system theory	By improving communication and bidirectional emotional support between patient and carer, encouraging gratitude, and relieving caregivers' stress, the program enabled patients to affirm positive experiences, accept or let negative experiences go, and thus help patients achieve self- integration, and perceive a better QoL	Online modules	Patient-carer dyads	• 5 themes emerged in qualitative interviews: (1) accepting and enjoying the program; (2) better communication; (3) feeling grateful for each other; (4) improved emotional support; and (5) decreased caregivers' stress • QoL (p < 0.001), family adaptability(p = 0.001), and family cohesion (p < 0.001) improved • Caregivers' care burden decreased in the intervention group (p = 0.018)
2022	Dionne-Odom (21)	USA	RCT, 46 dyads	Intervention completion rates, qualitative interviews, likeliness of recommending intervention, Rini Decision Influence Scale, Hospital Anxiety and Depression Scale	Social Support Effectiveness Theory and the Ottawa Decision Support Framework	Not discussed	Trained PC coaches	Family carers	• Carers completed 78% of intervention sessions • Carers reported a likelihood of recommending the program to others of 9.9 on a scale from 1-Not at all likely to 10-Extremely likely • Some components of the intervention showed potential benefit for effective decision support and caregiver distress
2014	DuBenske (22)	USA	RCT, 322 dyads	Demographics, Caregiver Quality of Life–Cancer Scale, Short Version Profile of Mood States, Edmonton Symptom Assessment Scale (carer-reported)	Stress and coping theoretical framework	The intervention improved carers appraisal and coping by bolstering cognitive, behavioral and practical support mechanisms. The authors state that more research is needed to understand the mechanism of action	Online modules	Patient-carer dyads	• Carers in the intervention group reported lower burden (p = 0.021) and negative mood (p = 0.006) than those in the control group • The effect on disruptiveness was not significant
2017	Grande (23)	UK	RCT, 681 people at the end of life	Novel survey with questions related to adequacy of support received by carer, physical and mental wellbeing of carer in bereavement, place of death, carers feelings regarding place of death	Not discussed	Not discussed	Volunteers	Patients	• Intervention group displayed a small but significant reduction in level of early grief and increased physical/mental wellbeing scores compared to control group • No difference in feelings of needs being met between groups
2011	Greene (24)	Australia	Quasi-experimental, 66 carers	Duke Social Support Index, Catholic Health Care Coalition Family Caregiver Questionnaire, AMA Carer Self-check, novel survey questions	Not discussed	Not discussed	Community network facilitators	Carers	• Participants in the intervention group showed improvement in caregiver fatigue, sufficient support from others, decreased resentment in the role, greater confidence in asking for assistance and were better able to find resources and support • No between-group changes were seen
2014	Hanson (25)	USA	Pre-Post, 218 people at the end of life	Novel survey with questions related to support needs and awareness of services to help with pain and symptoms, Functional Assessment of Chronic Illness Therapy–Spiritual Well-being Scale	Socioecological theory of community health promotion using existing social networks	Not discussed	Lay health advisors	Black patients	• Post-intervention 25% of patients identified hospice as source of support for pain/symptom management (pre-intervention = 4%, p = 0.04) • 60% of patients reported unmet needs for help with errands or household tasks at enrollment, while only 20% and 15% reported these areas of unmet need after 2 months in the program • QoL scores were unchanged
2011	Henricksson (26)	Sweden	Descriptive, 29 carers	Qualitative interviews	Not discussed	Not discussed	Peers	Family carers	• Participants reported that the intervention was relevant, the relationships formed were valuable, and the open approach produced a warm and relaxed atmosphere
2012	Jack (27)	Uganda	Descriptive, 21 people at the end of life	Qualitative Interviews	Not discussed	Not discussed	Community volunteers	Patients	• Participants reported that the community volunteers were very beneficial, linking them and their families to practical help, counseling and education, and hospice services when appropriate
2015	Luker (28)	UK	Quasi-experimental, 29 carers	Qualitative interviews	Not discussed	Not discussed	Informational Booklet	Carers and district nurses	• Carers were positive about the booklet, but many reported they would have liked it earlier • Carers reported feeling more positive about caregiving and more reassured and competent in their role • District nurses found the booklet useful and reported receiving fewer phone calls from study carers than others in similar situations
2022	Parker Oliver (29)	USA	RCT, 78 carers	Generalized Anxiety Disorder scale, Patient Health Questionnaire, Caregiver Quality of Life Index-Revised, and the Zarit Burden Interview	Not discussed	Not discussed	Peers	Family carers	• Participating in Facebook support groups was associated with decreased anxiety and depression carers • There was no significant difference in carer QoL or burden
2017	Pesut (30)	Canada	Pre-Post, 21 dyads	Qualitative interviews, novel survey with questions related to self-efficacy and satisfaction with the intervention, McGill Quality of Life Questionnaire	Not discussed	Not discussed	Volunteers	Patients and carers	• Carers were highly satisfied with the intervention • Carers reported that the intervention helped them with decision making, social support, engaging with life, and re-framing the experience of living with illness
2008	Ryan (31)	UK	Descriptive, 81 carers	Qualitative interviews	Not discussed	Not discussed	Lay interventionists	Carers	• Carers appreciated the emotional support, time, practical help, financial advice, and education that the program provided • Carers and health professionals both felt the program provided essential social support
2009	Steinhauser (32)	USA	RCT, 82 participants	Qualitative interviews	Byock's theory of human development and physical decline	The semi-structured nature of the sessions provided catharsis for participants by empowering them to disclose anything they felt was appropriate. The sessions allowed participants to explore their sense of self with is often interrupted at the onset of illness because crisis supersedes normal roles—by reconnecting to these roles through the personal narrative exercises, participants find emotional and spiritual growth	Lay interventionists	Patients	• Discussions of life completion may improve important health outcomes for patients at the end of life
2016	Walshe (33)	UK	RCT, 179 people at the end of life	World Health Organization QoL Brief Scale, De Jong Gierveld 6-item Loneliness Scale, Medical Outcomes Study Social Support Survey, self-reported healthcare utilization	Not discussed	Not discussed	Volunteers	Patients	• No significant differences in outcomes were found between groups at 4 weeks • Rate of change of QoL slowed in intervention group
2021	Wang (34)	USA	Descriptive, 22 carers	Qualitative interviews	Body-Mind-Spirit Model	Carers are unable to care for their loved ones if they do not first take care of themselves. The intervention targeted the bodies, minds, and spirits of carers, so they were better equipped with the self-care skills they needed to sustainably car for their loved ones	Online modules	Chinese immigrant carers	• The most beneficial aspects were self-care curriculum related to caregiving stress, lifestyle and health behavior change, community resource support, death education and end-of-life care, and spirituality and spiritual care • Caregivers appreciated the educational aspect of the intervention and wanted more assistance accessing community resources
2011	Williams (35)	Canada	Descriptive, 57 carers	Qualitative interviews	The population health promotion model (outlined in the Ottawa Charter)	When carers feel overburdened by practical concerns (financial strain, missing work, etc) they are unable to effectively care for their loved ones. This intervention helps relieve carers' burden so they have more time and energy to focus on their role in supporting their loved one without feeling burned out	Government	Carers working full time	• Carers discussed social determinants that affected their experience like gender, income and social status, working conditions, health and social services, social support network, and personal health practices and coping strategies • They rated the intervention highly and felt it benefitted them
2004	Witkowski (36)	Sweden	Descriptive, 48 carers	Qualitative interviews	Not discussed	Not discussed	Support group leaders	Carers	• Carers felt that the programme was beneficial to their own health promotion, that it was an important complement to usual palliative home care, and that they benefited from mutual experiences shared among group members

MRC, Medical Research Council; QoL, Quality of life; RCT, Randomized control trial.