Identifier Variables Tab

Configure Identifier Variables

From Options|Interview, select the Identifier Variables tab to indicate which variable(s) will be used as the unique identifier for your study. The Site ID, Subject ID, and Additional ID variables fields together will be used to create a unique identifier for each interview. Interviewer ID may be recorded for system documentation.

By default, QDS expects at least one variable to be designated as the Subject ID. The variable name for this item should be entered in the box labeled Subject ID on the Identifier Variables tab. The default Subject ID Variable Name is SUBJECT; it can be edited or removed.

Tip: When variables are listed on this tab, they must exist as Data or Automatic Variable Elements. Although not required, you should always have a Subject ID (unique identifier) for data management.

By default (if no changes are made on the Study Configuration tab) only the Subject ID field will be enabled. This is the most basic configuration where a single interview will be conducted at a single site by a single interviewer; therefore, only one variable is required to uniquely identify each record (default is SUBJECT).



Multiple Study Identifiers

If your study will have multiple interviews with the same subject or multiple sites, more than one identifier may be needed to uniquely identify each interview. This could be a site identifier, an interview date, or a visit type code (e.g., Baseline, 3-month, 6-month).

To specify additional identifiers

  1. Go to the Study Configuration tab.
  2. Select the Interviews will be conducted at multiple sites radio button to enable the Site ID field.
  3. Check the Multiple interviews with the same subject are planned box to enable the Additional ID Variables field.
  4. On the Identifiers Variables tab, enter the variable name for other variable(s) that, along with Subject ID, will uniquely identify a single interview.
    • Enter the Subject ID Variable name (required).

    • In the Site ID field, enter the Variable name for site (e.g. SITEID) (optional).

    • In the Additional ID variables field, enter one or more variables separated by commas (e.g., VISIT, TODAY) (optional).


You can update these settings at any time; however, it is a good idea to review and confirm these settings prior to finalizing your instrument and beginning data collection. If you need to update your identifier variables after data collection has begun you can change them in the Warehouse Manager Identifiers tab options.

Tip: The ID variables specified on this tab will be listed at the end of the Codebook and will be used to identify any interviews with duplicate identifiers in the Warehouse Manager Module.