The Drug Effectiveness Review Project (DERP) based on collaboration between organizations that have united in order to obtain the most reliable evidence regarding the comparison of the efficacy and safety of medicines in the same class and the use of the information in decision-making process. The project involves public and private organizations from 13 U.S. states (Arkansas, Idaho, Kansas, Oregon, Michigan, Minnesota, Missouri, Montana, New York, North Carolina, Washington, Wisconsin, Wyoming) and the Canadian Agency for Drugs and Technologies in Health. The final product of DERP are comprehensive, updated and unbiased systematic reviews conducted by the Evidence Based Practice Centers (EPC).