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Manage arms for dynamic randomization scheme

In IWRS, when configuring the dynamic randomization scheme, you need to manage the arms that are considered for subject allocation and their ratio for the system to prioritize allocation or sustain balance. Arm management is the same for the randomization schemes configured from scratch in IWRS and from file upload. From this page, you can add and delete arms as well as edit their ratio values.

Important

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

To manage the arms 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 arms 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, under the Arm tab, manage the arms as follows.

    Dynamic randomization scheme arms
    Figure 4. Dynamic randomization scheme arms

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

      Configuring arm and ratio
      Figure 5. Configuring arm and ratio

      Element

      Details

      Arm*

      Select the arm to include in the randomization process. The list of available options here is based on the arms added to the cohort.

      Arm of Ratio*

      Enter the number to outline the ratio of subjects allocated to this arm compared to other arms.

      For instance, if the ratio of all arms is 1, the system spreads the allocation equally. However, if one arm has a ratio of 2, and the other arms have a ratio of 1, then the arm with a higher ratio has more subject allocation probability.

      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 arm, from the Action(s) column, select Edit pencil_icon.png to update the arm ratio as explained in the previous table.

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

You have managed the arm list for your dynamic randomization. Once the randomization starts, the arms added to the list are taking part in the subject allocation according to the set ratio.

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.