Definitions for "Study Arm"
Some studies divide the participants into groups for purposes of comparison; each group is called a study arm or "arm." For example, in some studies, the participants (or subjects) who are in one arm may receive the experimental intervention and those who are in the other arm may receive the current standard intervention, so that the two interventions can be compared.
clinical trials usually compare the responses of two or more groups of subjects (e.g., control and treatment groups). If a study has more than one treatment group (for example, receiving varying dosages of a drug), the different groups are called study arms.
A study arm is one of the groups in a clinical trial. Typically, study arms consist of the treatment arm, and the control arm.