For this app, a research study needs participants assigned to random cohorts upon enrollment, based on a predetermined permuted block randomization sequence.
Permuted block randomization helps to ensure that at the end of each “block” of assignments, the distribution is 50/50. This provides for a more reliable distribution than using a simple randomization (like a coin flip). Simple randomizations will trend toward a 50/50 distribution as you approach large numbers of participants, but can can result in unequal distributions—particularly with small numbers of participants.
For more information about block randomization, consider these resources:
At a high level, there are two major components to this app:
The app uses several AWS services to control the randomization.
The AWS lambda leverages the MyDataHelps Participants API to obtain participants who do not have a cohort assigned, and to assign their cohort. Cohort information is saved as a custom field in MyDataHelps.
For all of this to work, several things need to be configured in the MyDataHelps project: