Review two is a systematic review of secondary (review) literature to examine how ‘trust’ has been conceptualised and theorised in any healthcare setting. Trust is a complex term, frequently used but rarely defined. We are particularly interested in describing frameworks/models that may be relevant in explaining the relationship between vulnerable communities and mainstream health and social care services. Trust is however, a challenging term to search for (a recently updated Cochrane review on interventions to enhance trust retrieved 14057 records for initial screening ). Since we were interested in understanding and describing the concept of trust within a health care context generally, we focused on secondary literature.