One Health addresses health challenges arising from the intertwined spheres of humans, animals and ecosystems. This handbook is the product of an interdisciplinary effort to provide science-based guidance for the evaluation of One Health and other integrated approaches to health. It guides the reader through a systems approach and framework to evaluate such approaches in a standardised way. It provides an overview of concepts and metrics from health and life sciences, social sciences, economics, and ecology that are relevant for the evaluation of the processes involved, as well as the...