Overcoming challenges to conducting global legal epidemiology research

Global legal epidemiology aims to study how international laws, policies and norms influence global health and equity. As the field builds on established legal epidemiology methods, researchers can face practical challenges when scaling up the frame of analysis from the national to the global level. We review three case studies that illustrate these challenges and share authors' experiences in developing strategies to address them. Case 1 focuses on harmonising international dietary guideline data; Case 2 demonstrates a multidisciplinary approach to evaluating treaty compliance theories; and Case 3 details quasi-experimental methods that can be used in evaluating global impacts without counterfactuals or control groups. Researchers' experiences are synthesised to demonstrate how global legal epidemiology can produce rigorous, policy-relevant insights. We conclude with a call for methodological innovation, stronger transdisciplinary collaborations and improved data infrastructure to support this emerging field.