Alternate IDs are unique and automatically generated for each participant. Once generated, the alternate IDs will not change unless you explicitly request to change them. Multiple publications of the same study will use the same alternate IDs and date offsets.

Note that alternate ids are not the same as alias ids. Alias participant ids are used for aligning data from different sources, where each may use different names, or aliases, for the same participant or organism; whereas alternate ids are used to hide the real participant ids from your audience.

• Change Alternate IDs
• Change Participant ID
• Merging Participant Data

Change Alternate IDs

You can control the prefix and number of digits in the generated alternate IDs: go to (Admin) > Manage Study > Manage Alternate Participant IDs and Aliases. You can also export a list of the alternate IDs and date offsets from this page.

• Click the Manage tab.
• Click Manage Alternate Participant IDs and Aliases.
• For Prefix, enter a fixed prefix to use for all alternate IDs.
• Select the number of digits you want the alternates to use.

• Click Change Alternate IDs. Click to confirm; these alternates will not match any previously used alternate IDs.
• Scroll down and click Done.

Change Participant ID

If you want to change a participant ID within a study, perhaps because naming conventions have changed, or data was accidentally entered with the wrong ID, you can do so as follows.

• Go to (Admin) > Manage Study > Manage Alternate Participant IDs and Aliases.
• Click Change or Merge ParticipantID.

• Enter the participant id to change, and the value to change it to. If you are changing to a participant ID which already exists within the study, see the next section about Merging Participant Data.
• Click Preview.
• LabKey Server searches all of the data in the folder and presents a list of datasets to be changed.

• Click Merge to complete the participant ID change.

Merging Participant Data

Suppose you discover that data for the same individual in your study has been entered under two participant IDs. This can happen when naming conventions change, or when someone accidentally enters the incorrect participant id. Now LabKey Server thinks there are two participants, when in fact there is only one actual participant. To fix these sort of naming mistakes and merge the data associated with the "two" participants into one, LabKey Server can systematically search for an id and replace it with a new id value.

• Decide which participant ID you want to remove from the study. This is the "old" ID you need to change to the one you want to retain.
• Follow the same procedure as for changing a participant ID above.
• Enter the "old" value to change (9 digits in the following screencap), followed by the ID to use for the merged participant (6 digits shown here).

• Click Preview.
• LabKey Server searches all of the data in the folder and presents a list of datasets to be changed.
• Click link text in the report to see filtered views of the data to be changed.
• If conflicts are found, i.e., when a dataset contains both ids, use the radio buttons in the right hand column to choose which participantID's set of rows to retain.
• Click Merge to run the replacement.

If your folder contains a configured alias mapping table, you will have the option to convert the old name to an alias by selecting Create an Alias for the old ParticipantId. When this option is selected, a new row will be added to the alias table. For details on configuring an alias table, see Alias Participant IDs.

• If an alias is defined for an old id, the server won't update it on the merge. A warning is provided in the preview table: "Warning: <old id> has existing aliases".

Related Topics

• Publish a Study - Export randomized dates; hold back protected data columns.
• Alias Participant IDs - Align participant data from sources that use different names for the same subject.