Blinding in Viedoc

  • Published by Viedoc System 2025-03-27
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Introduction

Proper management of blinded data ensures unbiased study outcomes, reduced bias, regulatory compliance, data integrity, and patient safety. Incorrect handling of blinded data can result in accidental unblinding, regulatory findings, and data contamination.

Data can be blinded in several ways in Viedoc. In most cases, it is best to use the dedicated blinding functionality in the RTSM application, but carefully configured role visibilities can also maintain a study blind. This lesson will describe best practices for handling blinded data in Viedoc.

Best practices for handling blinded data

To ensure the integrity of blinded data in clinical trials, regularly review access logs and settings to verify compliance. The following best practices should be followed in Viedoc:

Use RTSM settings for blinded outcomes

The Randomization and Trial Supply Management (RTSM) module in Viedoc is designed to handle blinded outcomes securely.

  • Configure treatment assignments within the RTSM module.
  • Ensure that only authorized users (e.g., Unblinded statistitian) have access to randomization data in Viedoc Admin (ie. randomization lists).
  • It is not advised to set role visibilities on a blinded outcome that has RTSM mappings, unless completely necessary. This is because if a specific role can see the blinded data in an emergency unblinding, that role will be the only one that can export PDF's of the randomization. Additionally, randomization forms are not included in revisions, it will not be possible to change role based visibility for saved forms later (for example, if you wanted to add another unblinded role later).
  • In Viedoc Logistics, when configuring global allocation list settings it is possible to select a blinded option for a variable. For a user to see this variable, a permission must be set in Logistics user rights called "View blinded info". It is important to ensure that only authorized users have access to roles with this permission.

For more information please visit RTSM Settings.

Keep blinded data in separate forms

Blinded treatment assignments and related data should always be stored separately from general study data.

  • Use a dedicated randomization form to store blinded treatment assignments.
  • Try to avoid mixing blinded and unblinded data within the same form. Mixing might result in challenges exporting PDF's for certain roles.
  • Ensure that blinded forms are only accessible to authorized roles.

Role-based visibility settings

Role-based visibility settings allow study teams to control data access for different users.

  • Role visibility settings at the form level can be appropriate for blinded data.
  • Restricting an item or item group to a role will hide the form history and PDF record of the entire form from all other roles. Viedoc cannot generate different versions of PDFs based on role visibilities.
  • It's generally good practice to have at least one role that can view and export all data to ensure everything can be exported.

If roles are not properly restricted:

  • Users who should be blinded might retain access to sensitive data.
  • If role settings change, previously hidden data may become visible retroactively.

Alerts and visibility

When setting up alerts, all data in the alert (including attachments) will be sent to all users holding the defined roles in To:, Cc:, and Bcc: without respecting the role visibility conditions. Therefore it is important to consider role-based visibility settings and the content of alerts to ensure that blinded data is not disclosed.

Validate study configurations before go-live

Conducting a final review before study activation ensures that blinded data remains secure.

  • Perform User Acceptance Testing (UAT) with different user roles to confirm visibility restrictions and configurations.
  • Check that blinded data does not appear in standard exports, audit logs, or reports.
  • Lock down study settings and role permissions, and perform a final validation check before the study launch.

Visibility settings

There are some visibility settings and conditions that can be used in Viedoc to make certain fields invisible on forms. However this is not true blinding, and hidden data in these fields will appear in exports and audit trail details.

For example, the Hide Always setting is used to make specific items within a form permanently invisible to users in Viedoc Clinic, while still retaining the data for export and audit trail purposes. However, it is not recommended to use the Hide Always setting to conceal treatment assignments or other blinded data.

This setting only removes the item from the visible form interface but does not prevent the data from appearing in:

  • Audit trails: Users reviewing system logs may inadvertently access blinded information.
  • Data exports: Treatment assignments may still appear in exported datasets.
  • Form history: Users accessing form history may see unblinded information.
  • Reports: Items configured as Hide Always will also show in reports (data browser)

Read more about item-level visibility settings here.

Related lessons and references

To further reinforce best practices for handling blinded data, refer to the following resources: