Skip to main content

Manage factors for dynamic randomization scheme

In IWRS, when configuring the dynamic randomization scheme, you need to manage the factors—such as demographics, disease details, or else—that are considered for subject allocation between arms. Factor management is the same for the randomization schemes configured from scratch in IWRS and from file upload. From this page, you can add, update, and delete factors.

Important

You can only manage factors for the scheme that is in the Draft status. For more details see the Change randomization scheme status section.

To manage the factors for a dynamic randomization scheme

  1. In the IWRS application header, select the TREATMENT DESIGN tab.

  2. In the left pane of the page that opens, select Period.

  3. In the Period List table that appears, select the period within which you want to manage factors for a dynamic randomization scheme.

    Selecting period to configure
    Figure 1. Selecting period to configure

  4. In the period configurator tree, drill down and expand the cohort for which the dynamic randomization method is configured. From the expanded cohort menu, select Randomization List.

  5. In the Randomization List table that appears, locate the randomization scheme of your interest and select its name.

    Accessing randomization scheme configurator
    Figure 2. Accessing randomization scheme configurator

    Tip

    You can also select the Scheme node under the respective randomization scheme in the period configurator tree.

    Accessing randomization scheme configurator from tree
    Figure 3. Accessing randomization scheme configurator from tree

  6. On the scheme configuration page, select the Factor tab and manage the arms as follows.

    Dynamic randomization scheme factors
    Figure 4. Dynamic randomization scheme factors

    1. From the workspace toolbar, select New Item add_new_icon.png to add more factors to your randomization scheme as explained in the following table.

      Configuring arm and ratio
      Figure 5. Configuring arm and ratio

      Element

      Details

      Factor Name*

      Select the factor that the system must consider in the randomization process. The list of available options here is based on the inclusion criteria added to the cohort.

      Weight*

      Enter the number to outline the value of this factor compared to other factors for the system consideration when allocating subjects between arms.

      For instance, if the weight of all factors is 1, the system gives them equal consideration. However, if one factor has a weight of 2, and the other arms have a weight of 1, then the factor with a higher weight has more influence on the subject allocation probability.

      Factor Value

      Represents the value of the factor, such as F and M for female and male gender, 18-60 for age, and so on.

      Factor Text

      Represents the text of the factor value, such as Female for the value F or else.

      SAVE

      Select save_button_white_red.png to save the implemented changes.

      CANCEL

      Select cancel_button_white_blue.png to discard the changes without saving.

    2. Next to the needed factor, from the Action(s) column, select Edit pencil_icon.png to update the details as explained in the previous table.

    3. Next to the needed factor, from the Action(s) column, select Delete trash_can_icon.png to remove the factor from the list and exclude it from the randomization process.

      Important

      You can update but not delete the Site and Cohort factors as they are essential for dynamic randomization.

    You have managed the factor list for your dynamic randomization. Once the randomization starts, the factors added to the list are considered for subject allocation according to the set weight.

In this section:

A randomization method that adjusts the allocation probabilities based on the current distribution of participants. Thus, when each subject comes to the study, the system assesses their compliance with established factors, evaluates the existing patient groups and site imbalance, and allocates the new patient to the most imbalanced group. Unlike permuted block randomization, dynamic randomization does not involve the predefined randomization list and offers more adaptivity to achieve arm balance at all times.

A group of subjects formed as a result of randomization for blinding purposes that has its own schedule of visits and treatment plan according to a study protocol.