A realist synthesis to explain how, for whom and in what circumstances different community mental health crisis services work. (MH-CREST)



To identify mechanisms to explain how, for whom and in what circumstances community crisis services for adults work to resolve crises with a view to informing current and future intervention design and development. The study objectives are to:

  1. Use stakeholder expertise, current practice and research evidence to develop programme theories to explain how different crisis services work to produce the outcome of resolution of mental health crises;
  2. Using a Context, Intervention, Mechanisms, Outcome framework (CIMO), to construct a sampling frame to identify subsets of literature within which to test programme theories;
  3. Iteratively consult with diverse stakeholders to test and refine programme theories;
  4. Identify and define UK case studies that provide exemplars of the programme theories to explain how mental health crisis interventions work in order to explore and explain contextual variation;
  5. Synthesise, test and refine the programme theories, and where possible identify mid-range theory, to explain how crisis services work to produce the outcome of resolution of the crisis. Provide a framework for future empirical testing of theories in case study sites and for further intervention design and development;
  6. Produce dissemination materials that communicate the most important mechanisms needed to trigger desired context-specific crisis care outcomes, in order to inform current and future crisis care interventions and service designs.


We will conduct a realist evidence synthesis by collecting and analysing secondary (realist synthesis) and primary (stakeholder engagement) data. This will involve iterative searching of published and unpublished literature to firstly identify initial programme theories to explain how crisis services work, for whom and in which circumstances. We will then carry out specific focused searches of published and unpublished literature to test the veracity of the programme theories. An iterative process of stakeholder engagement will seek to identify and test theory using the expertise of a range of stakeholders including health professionals, commissioners, policy makers and people who have accessed mental health crisis services and their carers.

We will analyse the data using realist logic to:

  • Identify initial programme theory/ies (Objectives i, ii, iii)
  • Explore application of the programme theories in different contexts (Obj. iii, iv, v)
  • Explore and explain contextual variation as it relates to putative mechanisms (Obj. iii, iv, v)
  • Inform current and future design and development of crisis interventions (Obj. iii, iv, v, vi)


Mental health crises cause significant disruption to the lives of individuals and families and can be life-threatening. The drive for community care alongside large reductions in hospital beds has led to a proliferation of community crisis services. This has resulted in service designs that can be difficult for people to access and navigate. People also report that their needs in a crisis are not always met and variation between services has been reported. It is unclear which underpinning mechanisms of crisis care are most effective, for whom and in which circumstances. Developing community crisis care interventions through the Complex Interventions Framework presents an opportunity for greater cost-effectiveness if the interventions can be successfully developed, tested and implemented.


Dr Nicola Clibbens