Clinical Research Associates, LLC - Oklahoma City, Oklahoma The company is an independent medical research company. Our staff has more than ten years of research experience performing phase II, III, and IV trials with leading pharmaceutical companies and contract research organizations. Our physicians’ offices are located approximately 15 minutes from the Oklahoma City airport. Our centralized, convenient location allows us to recruit from a population base of over 1.2 million people in the Oklahoma City Metropolitan area. The area population base is demographically diverse with approximately 40% ethnicity.