The World Cities Project: rationale, organization, and design for comparison of megacity health systems.

This article provides an overview of the World Cities Project (WCP), our rationale for it, our framework for comparative analysis, and an overview of current studies in progress. The WCP uses New York, London, Paris, and Tokyo as a laboratory in which to study urban health, particularly the evolution and current organization of public health infrastructure, as well as the health status and quality of life in these cities. Comparing world cities in wealthier nations is important because of (1) global trends in urbanization, emerging health risks, and population aging; (2) the dominant influence of these cities on "megacities" of developing nations; and (3) the existence of data and scholarship about these world cities, which provides a foundation for comparing their health systems and health. We argue that, in contrast to nation-states, world cities provide opportunities for more refined comparisons and cross-national learning. To provide a framework for WCP, we define an urban core for each city and examine the similarities and differences among them. Our current studies shed light on inequalities in health care use and health status, the importance of neighborhoods in protecting population health, and quality of life in diverse urban communities.