Design and Interpretation of Clinical Trials

Clinical trials are studies that test new treatments or preventive measures for disease in humans. Interventions that are being evaluated include drugs, devices (e.g. hearing aid), surgeries and behavioral interventions (e.g. smoking cessation program), as well as community health programs (e.g. Cancer screening programs or health delivery systems (e.g. special care units for hospital admissions) can be evaluated. Clinical trials are considered experiments, as the researchers choose the treatment that patients will receive. Randomized clinical trials provide the best evidence to determine whether a treatment works. This is because the trials include features that ensure impartial and objective evaluations of the risks and benefits of treatments. Before drugs or biologics can be sold in the United States, they must be proven to be effective in clinical studies.