Updating the Scientific Advisory Committee on Nutrition's Framework for the evaluation of evidence.

The Scientific Advisory Committee on Nutrition (SACN) provides independent advice on nutrition and related health matters to UK government organisations. In keeping with its commitment to openness and transparency, SACN follows a set 'Framework' to ensure a prescribed and consistent approach is taken in all its evidence evaluations. Following an update of the SACN Framework in 2020, which addressed some straightforward issues, the SACN Framework subgroup was established in 2021 to consider more complex matters that were not addressed in the 2020 update. The SACN Framework subgroup considered four main topics for update: (1) the different types of evidence evaluations produced by SACN, (2) interpretation of statistical data, (3) tools for assessment of study quality and (4) tools to assess the certainty of a body of evidence for exposure-outcome relationships. The Framework subgroup agreed clear definitions and processes for the different types of evidence evaluations produced by SACN and agreed that interpretation of P values should be informed by consideration of study size, power and methodological quality. The subgroup recommended use of the AMSTAR 2 tool for quality assessment of evidence from systematic reviews and use of the Grading of recommendations, assessment, development and evaluation approach to assess the certainty of evidence. The updated Framework was published in January 2023. This was followed by publication of a further update in October 2024. As a 'living' document, the Framework will be subject to regular review by the Framework subgroup and continue to evolve in line with best practice.