Defining a subject group

This topic describes how to create a new subject group, define its type as static or dynamic and define an Arezzo expression for a dynamic group.

Note that simply defining a group has no effect on user access. You must also assign subject group permissions for individual users.

Be aware that you cannot delete subject groups but you can deactivate them.

To create a new subject group, you need the 'Create subject group' permission

To create a new subject group

Select Tasks > Subject Group > Subject Group Definition...
The Subject Group Definition window is displayed.
Click New to enable the fields beneath the grid.
Enter a code for the new subject group.
Use the Study drop down list to select the study to which the new subject group will apply.
In the Description box, enter some text to name or describe the new subject group. This name must be unique within the study, but you can have subject groups of the same name in different studies.
Specify the subject group type by selecting either Dynamic or Static. More help on these...
To create a Dynamic group, enter an Arezzo expression in the Dynamic Group Condition box. You can type directly into the box or use the Expression Editor to construct the expression. Only subjects that meet this condition will be included in the subject group. How to manage dynamic groups...
Note that this version of the Expression Editor includes checks for expression syntax but does not check for question type or the existence of a question.
If you are creating a Static group, you cannot enter an expression as subjects will be added and removed manually. How to populate static groups...
Click Save.
Click Close.

New subject groups are automatically set to Active. You can deactivate an existing group by editing it.

To edit an existing subject group

You can change the description, activate or deactivate the group, toggle the group between Static and Dynamic, and change the group condition for a dynamic group.

You cannot change the code or the study.

To edit an existing subject group, you need the 'Edit subject group' permission

Select Tasks > Subject Group > Subject Group Definition...
The Subject Group Definition window is displayed. All existing active groups are listed in the grid. Inactive groups are hidden by default but you can include them in the list by checking the Include Inactive Subject Groups check box.
You can reorder individual columns in the grid by clicking a column header. This can help to find an existing group more easily.
Select a subject group in the grid and click Edit.
Make your changes and click Save.
Click Close.

To deactivate a subject group

Subject groups cannot be deleted. This is to preserve the data access audit trail for individual users.

Instead you can deactivate a subject group at any time by editing it and unchecking the 'Active' checkbox.

Deactivated groups have no effect on user access and do not show in the search panel.

To copy a subject group

You can create a new subject group by copying an existing one within the same study or across different studies.

If the existing subject group is dynamic the conditions will also be copied. If the existing subject group is static the new version will not carry over the subjects from the original so you will have to populate it manually.

Select Tasks > Subject Group > Subject Group Definition...
The Subject Group Definition window is displayed.
Select the subject group to copy and click Copy.
You must enter a new code.
Make any other changes that you want.
Click Save.

To switch a subject group between static and dynamic

You can change the type of a subject group at any time by editing it and selecting the required type.

If you switch a static group to dynamic, you must add a group condition so that the group can be populated.

If you switch a dynamic group to static, the group condition remains but becomes inactive and cannot be edited. The group is no longer populated automatically; subjects can only be added or removed manually. If you switch the group back to dynamic, the condition will reactivate.

If you switch a dynamic group to static, and then switch it back to dynamic, you should immediately evaluate all subjects against the condition to update the population. Be aware that this may result in losing or gaining subjects that were manually added or removed during the static period, as subjects will only be included in the group if they meet the condition.