Background Bereavement support is considered an essential part of hospice provision. However, the research evidence is limited by a lack of consistency in the outcomes used to evaluate services, which in turn makes it difficult to compare approaches and draw conclusions on ‘what works best’. Core Outcome Sets (COS) represent the ‘minimum that should be measured and reported’ in research into specific conditions or services [www.comet-initiative.org]. This project aimed to develop a COS for evaluating bereavement support in palliative care for adults who have lost adults through terminal illness.

Methodology The research began with a systematic review of quantitative and qualitative literature to identify a list of outcomes relevant to bereavement support. At a subsequent consensus day 21 stakeholders (including service users) discussed what they considered to be the most important outcomes and compared these to and critiqued the lists generated from the review. These lists and discussions informed a two round DELPHI survey (n=238) designed to reach consensus on which outcomes/outcome dimensions should be included in the Core Outcome Set. During a final consensus day participants ranked the relative importance of the items which reached consensus in the survey.

Results Results suggest that the two most important outcomes are ‘Ability to cope’ and ‘Quality of life and mental wellbeing’. A number of core dimensions to explore when assessing these outcomes have also been identified. Examples include; ‘Feelings of loneliness and emptiness’; ‘Relationships with friends and family’; ‘Ability to find balance and channel grief’; ‘Ability to perform daily tasks’ and ‘Sense of meaning and purpose in life’.

Conclusion Available validated tools have been reviewed for their relevance to these outcomes. No tools have been identified which cover all core domains, although some have better ‘fit’ than others. Further work is being planned to adapt or develop measures as necessary.