**Background** National Clinical Guidelines (NCGs) are the foundation of quality improvement in health care. Guideline development involves both technical (evidence synthesis) and social (translation of research evidence into recommendations) processes. Evidence synthesis methodology has evolved the range of different evidence synthesis approaches has been a steadily increasing. Guidance is lacking on identifying the most appropriate evidence synthesis methodologies for developing or updating guidelines, how to communication the findings of evidence synthesis and how to support guideline development group (GDG) members (clinical, non-clinical and patients) with moving from evidence to recommendations. The overarching aim of this research is to support clinical guideline development processes by developing a ‘toolkit’ for evidence producers and end-users. This toolkit will support: - The optimal selection of evidence synthesis methods - The communication of the findings of evidence synthesis and - The translation of research evidence into recommendations. **Methods** The aim will be achieved across four inter-related work-packages (WP). This will involve evidence syntheses, consensus based techniques (Delphi, nominal group technique) and qualitative (interviews) methodologies. **Progress across work-packages** WP1 focuses on the optimal selection of evidence synthesis methods. Currently we are conducting an international Delphi to update the Right Review tool (https://rightreview.knowledgetranslation.net/) - a web-based decision support tool that guides users through a series of questions for recommending evidence synthesis methods. *Publications* - Clyne B, et al. [Using Preprints in Evidence Synthesis: Commentary on experience during the COVID-19 pandemic][1]. Journal of clinical epidemiology. 2021;138 203-10. - Clyne B, et al. [Perspectives on the production, and use, of rapid evidence in decision making during the COVID-19 pandemic: a qualitative study][2]. BMJ Evidence-Based Medicine. 2023;28(1):48-57. - Cardwell K, et al. S[ystematic review finds processes used internationally, to update clinical guidelines, lack consistency and detail][3]. Evidence & Policy. 2023:1-19. WP2 focuses on the communication of the findings of evidence synthesis. In particular, it aims to identify effective formats to present and communicate findings of evidence summaries that are acceptable to various GDG stakeholders. To date this has involved a mixed methods systematic review and workshops with key stakeholders. *Publications* - Sharp M, et al. Irish Media Coverage of COVID-19 [Evidence-Based Research Reports From One National Agency][4]. International Journal of Health Policy and Management. 2021;11(11):2464-75. - Sharp M, et al. [Evidence synthesis summary formats for clinical guideline development group members: a mixed-methods systematic review protocol][5]. HRB open research. 2022;4(76). - Sharp MK, et al. T[he effectiveness and acceptability of evidence synthesis summary formats for clinical guideline development groups: a mixed-methods systematic review][6]. Implementation Science. 2022;17(1):74. WP3 explores GDG members experiences of turning the findings of evidence synthesis into recommendations using the GRADE evidence to decision making framework (EtD), identifying areas where the EtD framework could be modified and adapted. This WP involves ongoing scoping reviews and qualitative evaluations. *Publications* - Chong MC, et al. [Strong recommendations from low certainty evidence: a cross-sectional analysis of a suite of national guideline][7]s. BMC medical research methodology. 2023;23(1):68. The findings of the three WPs will be integrated into a final toolkit which will be presented to key stakeholders at a one day project dissemination event (WP4). [1]: https://www.jclinepi.com/article/S0895-4356%2821%2900153-0/fulltext [2]: https://ebm.bmj.com/content/28/1/48.long [3]: https://bristoluniversitypressdigital.com/view/journals/evp/aop/article-10.1332-174426421X16854447463061/article-10.1332-174426421X16854447463061.xml [4]: https://www.ijhpm.com/article_4177.html [5]: https://hrbopenresearch.org/articles/4-76/v2 [6]: https://implementationscience.biomedcentral.com/articles/10.1186/s13012-022-01243-2 [7]: https://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-023-01895-8