How to set up randomization (Step 4)

Learn how to configure randomization to allocate subjects to defined subgroups.

In Climedo, a randomization list can be uploaded by the user which defines all available randomization slots in a study and which is used by the system to allocate subjects respectively to defined subgroups.

When randomizing a subject, the system automatically chooses the first next, suitable (based on stratification) and available slot from the list for the subject.

Please note: Currently a randomization list must be provided by the customer. Climedo does not provide the option of defining a randomization algorithm and a system-created randomization list yet.

To configure the randomization, navigate to Step 4 (Workflows) in the study set up, then select the tab "Randomization". The set-up is done in two steps:

1. Stratification configuration

2. Randomization list

1. Stratification configuration

In this section you need to define whether the randomization list is using stratification variables. And if yes, which data points are relevant for subject allocation.

1. Sites: If your study is a multicentric study you have the option to use "Site" as a stratification variable, meaning the site on which a subject is enrolled will have an effect on the allocation of the subject.

2. Input fields: Activate input fields if certain data collected in the scheduled events (eCRF) of your study should have an effect on the allocation of the subject. You can choose up to three fields from configured forms that can be used as stratification variables. Only single choice and dropdown fields can be selected here.

If no stratification variables are used, both toggles can be kept deactivated. Once the stratification configuration is done, navigate to the section "Randomization list" by clicking the "Next" button.

2. Randomization list

	Download the randomization template (Excel format) which is automatically configured based on the stratification settings you have saved.  The template will only provide the column headers as the cells need to be filled by the customer. For each subject and potential data combinations (if stratification variables are used) a row must be filled in the Excel list. All cells which are not indicated as “automatically generated” need to be filled. If stratification variables have been configured in the previous step, the cell values must equal the Site ID (and its format and/or the option values of the selected single choice or dropdown field in the stratification columns.
	Filled randomization list: A complete randomization list must be uploaded which contains the same column headers as the template list. When randomizing a subject the system refers to the uploaded list and chooses the first next available slot/row where all stratification variables (if any) match the value input per subject. You can download the randomization list configured for the study at any time in the "Randomization" tab. When downloading, the Study Name, Slot ID and Slot Number will automatically be filled by the system. These automatically filled fields should not be filled or updated manually. The Slot ID is a technical identifier used for slot allocation and as a reference when extending the randomization list at a later stage. It is unique and may differ from the original study in duplicated studies or when accessed via the sandbox environment. Publishing the sandbox does not modify Slot IDs in the active study. However, when an extended randomization list is published, the additional Slot IDs in the sandbox will differ from those in the active study. The Slot Number is a sequential count of filled rows and serves as a visual guide for orientation.
	Updating the randomization configurations: The stratification variable configurations can only be updated if no randomization list is uploaded as the definition of these variables is needed to configure the template and define the acceptable format of the upload list. The randomization list can be removed and replaced while the study status is set to "in preparation" or in "testing" and only if no subject has been randomized yet. Uploaded randomization slots cannot be updated or replaced once a subject has been randomized. Extending the randomization list: Extending the randomization list means adding slots to the already uploaded randomization list. This action can be performed during the course of a study when the recruitment process for the study will be extended and not enough slots have been provided in the initial list, for example. This, however, may have significant statistical implications and should only be performed with extreme caution. The newly created slots are appended to the uploaded list and the merged list applies to all subsequently randomized subjects. There will be no effect on subjects that have already been randomized. Please contact your Customer Success Manager or write an email to support@climedo.de if such amendment is needed for your study.

3. Duplicating & activating a study

When a study is duplicated or set to active (and thus a duplication of the test study is created), the uploaded randomization will also be duplicated as well as all configurations. However, all slots of the updated randomization lists are cleared, meaning all slots become available again.

4. Mirroring the randomization group

The randomization group can be selected as a source field in the mirroring fields configuration (Step 5, Trigger Events). Thus, the randomization group to which a subject was allocated to can directly be mirrored into the eCRF of a subject. This can serve several use cases, including setting field or form dependencies, notifications, validations or (automatic) queries on the randomization group. In addition, it can serve the use case of subject-specific emergency unblinding in a double blinded study. 

5. Randomization Configuration Access Rights

All access rights for the configuration can be configured in Step 2, Access, Management Rights

Hint: Collaborators with the management right “Download allocation list” are able to download the randomization allocation list in the export module and view all available slots in the list as well as which slots have been taken by which subject in the course of a study.

In addition, read and/or randomize rights can be granted to specific roles of a study, enabling unblinded and single/double blinded studies. For more info read the following article: How can I set up user roles? (Step 2.2)

⭐ Good to know

• The randomization details of a subject will be included in the scheduled events export. Please read the following article for further information: How do I export data of my study?
• The randomization action will be tracked in the audit trail. Please read the following article for further information: How to read the Subject Audit Trail