Evidence synthesis is a research methodology that involves systematically reviewing and combining the findings from multiple studies to provide an overall summary or interpretation of the existing evidence on a particular topic or question. This process typically involves a systematic and transparent approach to searching, selecting, and critically appraising relevant studies, as well as synthesizing and interpreting their results. Evidence synthesis methods can include meta-analyses, systematic reviews, and other types of literature reviews that aim to provide a comprehensive and unbiased summary of the available evidence to inform policy, practice, and further research.