HIV/AIDS Glossary

Control Arm

In a clinical trial, the group of participants that is not given the experimental intervention being studied. The control arm can receive an intervention that is considered effective (the standard), a placebo, or no intervention. Outcomes in the control arm are compared with those in the experimental arm to determine any differences, for example, in safety and effectiveness.

Related Term(s): Clinical Trial, Controlled Trial, Experimental Arm, Placebo

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