ProofPilot » How to Use » Study Protocol Design » Changing from an Single Arm Study from an Multi-Arm Study

Changing from an Single Arm Study from an Multi-Arm Study

Single arm studies, otherwise known as longitudinal outcome studies only have one arm. There is no comparison or experiment arm. All participants have the same experience over time.
Here’s how you create an outcome study on ProofPilot.

if you are working in a multi-arm RCT study template, delete the control arm, by clicking the trash can.

You are left with one study arm “The Experiment” arm in this example. You might want to rename your study and arm names at this point.

In the ProofPilot study flow design language, this is a classic longitudinal study design. However, since we started with an RCT, there’s one important change we need to make. If you started with an outcome study template, you do not need to make this change.

Since I started with a randomized controlled trial template, there is randomization procedure. Longitudinal outcome studies don’t include randomization because everyone gets the same experience.  Therefore, we need to switch randomization to a conditional assignment.

It’s easy. First, click “Simple Randomization.” You might want to make some notes in the “Notes and Comments” section and save, so your collaborators are alerted to and know why you made this change to the study design.

Now, click on “Define”, and select “Conditional Arm Assignment.”

Here, you’ll have the opportunity to define when the arm assignment takes place. Unless you have other reasons to change it, you can leave the “Arm Assignment Task Triggers in” and “Assign Participants to an Arm When” sections the same. No changes necessary.

What you will want to change is where participants will be assigned.

In this particular scenario, you are assigning participants who have completed the informed consent, to the experiment arm

Note, if you had more than one arm, you would create multiple rules by clicking “Add new Arm Assignment Option”

Now when you return to your study flow page, you only see one study arm and the arm assignment. The recruitment and join process has changed to “Conditional Arm Assignment.”