Geographical Distribution and Trends of Clinical Trial Recruitment Sites in Developing and Developed Countries

Abstract

To improve clinical trial efficiency and enhance participant recruitment, many clinical trials open recruitment sites in multiple countries and regions. Understanding the geographic distribution of clinical trial recruitment locations is important for clinical trial planning and monitoring. In this study, we analyzed the geographic distribution and trend of clinical trial recruitment sites in developing and developed countries. The data was extracted from ClinicalTrials.gov, the largest public clinical trial registry that documents clinical trials from 190 countries and areas. To analyze the recruitment geographic distribution, we extracted 1,839,565 recruitment sites from 182,841 clinical trial summaries submitted to ClinicalTrials.gov. The recruitment site locations were normalized using geocoding techniques. The results show that the top five countries that host participant recruitment sites are the United States, Germany, France, Canada, and Japan. During this time, the United States is the major force of clinical trial recruitment, hosting nearly 50% of the clinical trial recruitment sites. The top five fastest-growing countries are China, Republic of Korea, Ukraine, the Russian Federation, and India. We categorized all documented countries into 14 regions. The results indicate that recruitment sites in Northern America, the European Union, and Asia accounts for 90.46% of the total recruitment sites. In terms of the growth rate of global recruitment site share, Asia has the highest average growth rate of site share at 28.37%. The global share for many developing regions also increase at a relatively fast speed, such as Central America at 19.60%, Western Africa at 18.40%, and the Middle East at 16.52%. Two regions showing a decline in the average global share are Northern America at -4.59% and the Caribbean at -6.62% yearly. Overall the results show that developed countries with strong pharmaceutical and medical research history continue to host a majority of clinical trial recruitment sites. Northern America, the European Union, and Asia host 90.46% of all clinical trial recruitment sites. Many developing regions, such as Central America, Africa, and the Middle East show fast growth rates.