Observational and interventional research studies conducted with human volunteers that seek answers to specific questions that relate to the causes, prevention, diagnosis, treatment and/or management of diseases, disabilities or other related conditions. Clinical trials may be conducted by government health agencies, researchers affiliated with a hospital or university medical program, independent researchers or private industry; and test the efficacy of new drugs, new combinations of existing drugs, new dose schedules and routes of administration, and new ways of integrating multiple treatment modalities. They may also assess new screening tests, evaluate the application of new diagnostic tests in choosing treatment regimens, evaluate supportive care methods, test the safety and effectiveness of medical devices, teach lifestyle changes or investigate options for improving the quality of life for people who have serious medical conditions. Clinical trials are conducted according to a protocol which describes the types of patients who may enter the study, schedules of tests and procedures, drugs, dosages, and length of study, as well as the outcomes that will be measured. For some patients, clinical research trials represent an avenue for receiving promising new therapies that would not otherwise be available. Included are programs that maintain lists of currently available clinical trials and refer patients who want to become volunteers as well as the research projects themselves.