Clinical research: a globalized network

Clinical research has become increasingly globalized, but the extent of globalization has not been assessed. To describe the globalization of clinical research, we used all (n = 13,208) multinational trials registered at ClinicalTrials.gov to analyzed geographic connections among individual countries. Our findings indicate that 95% (n = 185) of all countries worldwide have participated in multinational clinical research. Growth in the globalization of clinical research peaked in 2009, suggesting that the global infrastructure that supports clinical research might have reached its maximum capacity. Growth in the globalization of clinical research is attributable to increased involvement of non-traditional markets, particularly in South America and Asia. Nevertheless, Europe is the most highly interconnected geographic region (60.64% of global connections), and collectively, Europe, North America, and Asia comprise more than 85% of all global connections. Therefore, while the expansion of clinical trials into non-traditional markets has increased over the last 20 years and connects countries across the globe, traditional markets still dominate multinational clinical research, which appears to have reached a maximum global capacity.