REDCap Optional Modules & Customizations

REDCap provides a range of optional modules and customizations that enhance project functionality, improve workflow, and support more complex study designs. These features should be enabled intentionally based on your project needs.

Core Principle: Enable only what you need. Additional functionality increases complexity and should align with your study design.

1. Data Collection Structure

Repeating Instruments

Allows a single instrument to repeat multiple times for a record (e.g., medications, adverse events).

  • Supports one-to-many data collection
  • Unlimited repetitions per record
  • Works in both classic and longitudinal projects
Best Practice: Use repeating instruments when the number of entries is unknown or variable.

Repeating Events (Longitudinal Only)

Allows an entire event (multiple instruments) to repeat together.

  • Useful for visits or timepoints with multiple forms
  • Eliminates need to predefine multiple events
Important: Repeating instruments repeat a single form; repeating events repeat a group of forms.

Data Output Behavior

  • Each repeat instance appears as a new row in exports
  • redcap_repeat_instance identifies the instance number
  • redcap_repeat_instrument identifies the instrument

2. Record Management

Auto-numbering Records

  • Automatically assigns sequential record IDs
  • Prevents manual entry errors

Tip: To start at a specific number, create the first record manually, then enable auto-numbering.

Custom Record Labels

Enhances record identification using additional fields (e.g., name, DOB).

Example: [last_name], [first_name]

Secondary Unique Field

  • Prevents duplicate values in a designated field
  • Must be a text field

Order Records by Field

Allows sorting records by a field (e.g., last name) instead of record ID.

3. Survey & Participant Management

Designated Email Field

Allows REDCap to use a field to populate participant email addresses for survey invitations.

  • Useful when first instrument is not a survey
  • Populates Participant List automatically
Important: Email use links identifiers to responses and must align with IRB approval.

Repeating Surveys

Allows participants to submit the same survey multiple times.

  • Must enable repeating instrument first
  • Then enable repeat option in Survey Settings

4. Workflow & Data Quality

Field Comment Log

  • Allows users to leave comments on individual fields
  • All comments are searchable and exportable

Data Resolution Workflow (Data Queries)

  • Structured query system for resolving data issues
  • Supports open/respond/close workflow
  • Integrated with Data Quality module
Best Practice: Use Data Resolution Workflow for regulated or clinical studies.

Require Reason for Data Changes

  • Prompts users to document changes to existing records
  • Logged in audit trail

5. Automation & Integration

Scheduling Module (Longitudinal Only)

  • Generates visit schedules based on events
  • Supports study calendars

Data Entry Trigger

Triggers an HTTP POST to an external system when data is entered or modified.

  • Used for system integrations
  • Not triggered by imports
Advanced Feature: Typically requires developer support.

6. System Enhancements

Data History Widget

  • Displays field-level audit history
  • Shows who changed what and when

Today / Now Buttons

  • Auto-populates current date/time
  • Improves data entry efficiency
Best Practice: Keep default system enhancements enabled unless there is a specific reason to disable them.