Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

Clinical Trial Randomization

Clinical trial randomization is the process of assigning patients by chance to groups that receive different treatments. In the simplest trial design, the investigational group receives the new treatment and the control group receives standard therapy. At several points during and at the end of the clinical trial, researchers compare the groups to see which treatment is more effective or has fewer side effects.

Randomization helps prevent bias. Bias occurs when a trial's results are affected by human choices or other factors not related to the treatment being tested.

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