Background: Reviews that address policy questions crossing several public sectors such as health, housing and planning pose challenges for review preparation and engagement including the problem of ‘empty reviews’, dealing with diverse study designs and communicating uncertainty. There is, however, little guidance on how to proceed in these circumstances. Objectives: We describe how we reviewed the literature addressing the health and social effects of mixed income communities (MICs) and reflect on our experiences of dealing with a diverse but thin evidence base. Our review was a pilot rather than a full systematic review and was part of a larger study informing a planned new MIC in the East End of London in the UK. Methods: We employed traditional and novel systematic review methods in anticipation of a diverse literature. We searched comprehensively, appraised and coded studies using a standardised framework but planned flexibility into our synthesis methods. We engaged with users throughout the process, held a multi-professional workshop to discuss findings and planned different formats to present recommendations. Results: A total of 56 studies met our inclusion criteria. All but two of the evaluation studies were case studies of one or more MICs and we were not able to draw firm conclusions about the impact of MICs on health or social outcomes. Content and thematic analysis were used to draw out findings on factors related to the planning and implementation of MICs and recommendations were presented in the format of practice principles and hypotheses to test in new primary research. Conclusions: This study illustrates several strategies for synthesising and communicating the useful lessons captured within study findings in reviews which reveal a weak evidence base in relation to questions of cause and effect. Further work is needed to evaluate the added value and costs of such strategies.