The benefits, challenges, and best practice for patient and public involvement in evidence synthesis: A systematic review and thematic synthesis

Introduction: Despite the growing evidence on patient and public involvement (PPI) in health research, little emphasis has been placed on understanding its quality and appropriateness to evidence synthesis (ES) and systematic reviews (SR). This study aimed to synthesise qualitative evidence on the benefits, challenges, and best practices for PPI in ES/SR projects from the perspectives of patients/public and researchers. Methods: We searched Ovid MEDLINE, Ovid EMBASE, Cochrane Library and CINAHL Plus. We also searched relevant grey literature and conducted hand-searching to identify qualitative studies which report the benefits and challenges of PPI in individual ES/SR projects. Studies were independently screened by two reviewers for inclusion and appraised using the Joanna Briggs Institute's Qualitative Tool. Included studies were synthesised narratively using thematic synthesis. Results: The literature search retrieved 9923 articles, of which eight studies were included in this review. Five themes on benefits emerged: two from patients'/public's perspective—gaining knowledge, and empowerment; and three from researchers' perspective—enhancing relevance, improving quality, and enhancing dissemination of findings. Six themes on challenges were identified: three from patients'/public's perspective—poor communication, time and low self-esteem; and three from researchers' perspective—balancing inputs and managing relations, time, and resources and training. Concerning recommendations for best practice, four themes emerged: provision of sufficient time and resources, developing a clear recruitment plan, provision of sufficient training and support, and the need to foster positive working relationships. Conclusion: Highlighting the benefits and challenges of PPI in ES/SR projects from different stakeholder perspectives is essential to understand the process and contextual factors and facilitate meaningful PPI in ES/SR projects. Future research should focus on the utilisation of existing frameworks (e.g., Authors and Consumers Together Impacting on eVidencE [ACTIVE] framework) by researchers to help describe and/or report the best approaches and methods for involving patients/public in ES/SRs projects. Patient and Public Contribution: This review received great contributions from a recognised PPI partner, the Chair of the Cochrane Consumer Network Executive, to inform the final stage of the review (i.e., interpretation, publication and dissemination of findings). The PPI partner has been included as an author of this review.