How a Meta-Analysis Works

This chapter serves as a comprehensive guide for researchers, especially junior and beginner researchers in the medical research field. Meta-analysis is explained in detail, emphasizing its role in synthesizing findings from various studies. Basic concepts such as effect sizes, effect models, and heterogeneity assessment are introduced, followed by an overview of the steps involved in conducting and interpreting a meta-analysis. Additionally, the chapter introduces advanced topics including subgroup analysis, meta-regression, and handling complex data structures. Practical recommendations and toolkits from the literature are provided to facilitate efficient meta-analysis. Furthermore, the chapter addresses current limitations and criticisms of meta-analyses, including issues of publication bias, heterogeneity, and subjectivity. By elucidating these challenges and offering potential solutions, the chapter aims to equip researchers with the necessary knowledge to conduct robust meta-analyses and contribute effectively to the field of medical research.