Important Considerations
Upon project creation, all REDCap projects only have a single arm by default. Typically, only a single arm is needed for most project workflows. Arms can be used in the event that a study has groups of different participants, which follow unique workflows, however we discourage using Arms for this use-case and instead suggest the use of (FORM DISPLAY LOGIC).
Exporting & Reporting metrics function differently when working with multiple Arms:
x, y, zRandomization: REDCaps Randomization functionality can only be configured for a single Arm. It is NOT possible to randomize participants using multiple arms.
Reporting: Reports will pull data from both arms, unless an Event Arm ‘filter’ is applied to your report
Data Exports: will include the ‘redcap_event_name’ field which indicates which arm the record data was exported from
When adding new records to the project, it’s critical the participant be added to the correct arm. Often users forget they have multiple arms causing error.
Once a participant is added under a specific arm, there is no built-in REDCap functionality to move the participant to different arm
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The Process
To use ‘Arms’ your project must first be enabled as a longitudinal project
If you project isn’t already longitudinal, this typically indicates you do not/should not utilize the arms functionality! More info: https://utahctsi.atlassian.net/servicedesk/customer/portal/3/article/2341765121?src=1897803665
Navigate to your ‘Project Setup’ page and click ‘Define My Events’
Here you will see the option to add an addition arm (shown below in red)
Title Arm & Save
Designate instrument to Arm events (just like you would in a single armed, longitudinal project)
Designate & Save
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Additional Considerations
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