Adding & Duplicating Project Arms

Did you complete all of the following?

(tick) Added surveys 

(tick) Added devices

(tick) Built enrollment

If the answer to all of the above is 'yes', you are ready to create the different interventions via 'Study Arms'!  Before you can customize each arm of your project, you will need to add in the arms.

Navigate to the Study Arms under the Manage Study drop-down. 

Part I: Add a New Arm

  1. Click '+ New Arm' and name the arm. 
    1. Example: Lottery Incentive Arm 



  2. Participants: Indicate how many participants of the total number of participants should go into this arm.
  3. Intervention Length
    1. Choose your intervention length on the arm settings, this is important because if you have repeating events, day of the week events or event triggers by date, the intervention length will dictate if these events occur or not. 
  4. Start Type: Indicate if you would like the participant to be automatically started by WTH once they have completed all of the enrollment steps, on a scheduled date, or if WTH should wait for the project team to manually start them from the profile or Manage Participants view. See Starting Your Participants for detailed descriptions on the 3 start options. 

  5. Financial Incentives: Check the box if...
  • Payments: Your participants will be paid any amount, such as an enrollment or survey completion payment. Payments must also be checked for any studies using lotteries.

  • Lottery: Your study will have an arm with lottery incentives.  
    • Fixed Position: You create a lottery with a certain number of digits and people win if their numbers match in the exact order (the same digit occurring in the same position). You can set a prize for each possible number of matches.
      • Most commonly used lottery scheme with digit drawing 2 
      • Example:
    • Lotto: You pick the number of digits in a lottery and then what the prize would be for matching any number of those digits. Position does not matter
  • Example: 
  • Number of digits: You set the number of digits the lottery. This applies to both the participant-chosen lottery numbers, and the selected winning numbers. Lotteries must be at least 1 digit. Most lotteries will likely be 2 or 3 digits.

  • (lightbulb) Note: Only one type of lottery can be added per arm 


Medication Tools: 

  • Medication Reminders: Reminders will show up on the participant dashboard, at which time they can specify when and how they would like to receive the reminder.  It can also be edited from the backend by an RC in the participant profile.  This allows participants to have different preferences for notifications vs. medication reminders. 



    • WARNING  This is an outdated feature that is no longer supported.  Want to send medication reminders at participant specific times? We have something even better! See Rescheduling Participant Events for help! 

  • Medication Names: Used to track relevant medications that your participants are taking for a medication adherence study.  By choosing this and selecting the number of medications, a tab will appear on each participant's profile





6. Subdivide this arm?: Click this button if the arm has cohorts (teams) 

  1. Indicate how many participants can be added to a team.  Typically teams range from 2-4 participants. 

7. Click the 'Add' button to add your new arm. 

Part II: Duplicate an Arm 

  • Are the arms of your project similar? Do they have the same/similar messages, surveys, device uploads, etc? If so, reduce your build time by duplicating the arm! 
    • From there you can update, remove, or add the events to customize the arm for its specific intervention. 
  1. To copy the first arm, click the 'Duplicate' button. 



  2.  Rename the duplicated arm and click the 'Duplicate' button. 
    1. Example: Rename Lottery Arm (copy) to Arm 2 



  3. You should now see the original arm (Arm 1) and the exact copy (Arm 2).  The arms will be identical. 

  4. Now you are ready to make changes to Arm 2 to make it different than Arm 1 based on the project protocol design. 
    1. Remember to:
      1. Remove events that shouldn't be in Arm 2
      2. Add events that weren't in Arm 1 and should be in Arm 2 
      3. Swap out surveys, if needed
      4. Update logic on events, if needed 
        1. e.g. you don't want to mention a payment to a participant in the control arm! 

  5. Yay! Think of how much time that you just saved! (big grin)