Table 3.

Music Therapy mechanisms of change and facilitating context mapped to COS [6], PGD risk/protective factors [14]

Core outcome set for bereavement interventions	Risk and protective factors	Music therapy generated mechanisms of change	Facilitating context
Ability to cope with grief
Negative and overwhelming grief   • Feelings of loneliness and emptiness   • Feelings of blame, guilt, anger, bitterness, regret   • Overwhelming thoughts and/or nightmares about loss   • Preoccupation with thoughts of the deceased	• Bereavement depression and anxiety	• Social connectedness and support from the group created a sense of belonging and reduced perceptions of loneliness	Mode of delivery: group music therapy (optimal size of the group should be discussed and agreed with participants) Group characteristics: non-judgemental, supportive space to share feelings and receive social support Having a tangible output: e.g., recording to listen back on their song creation Facilitator/music therapist skills: foster a sense of self-efficacy among caregiver participants, especially when the music therapy intervention involves song writing, and provide leadership and support to foster participation and engagement Participant driven: flexible, tailored approach to suit carers’ needs Optimal dose: Discuss and agree optimal dose e.g., some prefer six weekly sessions whereas others prefer a longer-term ongoing intervention Collaborative/inclusive approach (e.g., participants choose the musical content/songs)
Communication and connectedness   • Ability to express feelings openly and honestly		• Musical catharsis: music therapy enabled carers to release repressed emotions
• Feeling understood by and connected with other bereaved people	• Poor perceived social support	• Commonalities in experiences helped to foster solidarity, empathy, and the sense of enjoying a “safe space” to explore and share common feelings and needs.
Understanding, accepting and finding meaning in grief   • Acceptance of grief experiences as normal	• Early non-acceptance of loss/denial • perceived preparedness for death	• Music therapy aided relationship completion – helped caregiver accept/prepare for loss via renewed intimacy with their loved one
• Understanding, acceptance, finding meaning in loss	• Higher spirituality	• Comfort, sense of meaning found in sharing/facilitating a music intervention that brought joy to their significant other/helped them reconnect and have hope in something more beyond bereavement
• Positive reminiscence and remembering of the deceased	• Family conflict at EoL • Difficulty accessing positive memories	• Music therapy as a shared activity which improved caregiver/patient relationships • Positive reminiscence
Finding balance between grief and life going forwards   • Ability to find balance and channel grief   • Ability to take control/ look ahead and start to move forward with life		• Music therapy provided an emotional channel for grief/increased preparedness for death of significant other • Motivated carers to re-engage/explore activities outside of the music therapy intervention going forward in their lives
Accessing appropriate support   • Accessing emotional support if needed   • Accessing practical support if needed	• Poor perceived social support	• Group music therapy provided a safe, non-judgemental, supportive space to share feelings and receive social support
Quality of Life and Mental Wellbeing
Participation in work and/or other regular activities   • Ability to perform daily tasks   • Ability to participate in work   • Ability to participate in social activities		• Motivated carers to re-engage/explore activities outside of the music therapy intervention going forward in their lives
Relationships and social functioning   • Ability to function as part of a family   • Relationships with friends and family	• Family conflict at EoL	• Improved relationships with significant others/renewed connection and sense of intimacy
Positive mental wellbeing   • Sense of meaning and purpose in life   • Optimism and hopefulness	• Higher spirituality	• Comfort, sense of meaning found in sharing/facilitating a music intervention that brought joy to their significant other/helped them reconnect and have purpose during pre-bereavement and hope in something more after bereavement
Negative mental and emotional state   • Anxiety (feelings of tension, nervousness, panic and distress)	• Anxiety	• Carers experienced relaxation, calmness and inner peace
• Depression (a sense of hopelessness, pessimism, periods of crying)	• Bereavement depression	• Carers experienced improved mood, joy, happiness, a sense of achievement and contentment
• Suicidal thoughts		• Music therapy gave carers a renewed sense of hope and resilience through restoring a balance between grief and moving on with their lives.