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Clinical Data Pull Setup and Usage

Clinical Data Pull (CDP): Setup and Usage

Article ID RC-CDIS-02 — Clinical Data Pull (CDP): Setup and Usage
Domain Clinical Data Interoperability Services
Applies To Institutions using real-time, prospective clinical data collection from an EHR
Prerequisite RC-CDIS-01 — Clinical Data Interoperability Services: Overview & Control Center Setup
Version 1.0
Last Updated 2026
Author See KB-SOURCE-ATTESTATION.md
Related Topics RC-CDIS-01 — Clinical Data Interoperability Services: Overview & Control Center Setup; RC-CDIS-03 — Clinical Data Mart (CDM): Setup and Usage; RC-CDIS-04 — CDP vs CDM: Feature Comparison

Prerequisite: CDIS must be configured at the system level before CDP can be used. See RC-CDIS-01 — Clinical Data Interoperability Services: Overview & Control Center Setup.

1. Overview

Clinical Data Pull (CDP) is a REDCap module that imports clinical data from an EHR system one patient at a time. It uses an adjudication workflow, meaning all imported data is held in a temporary cache and must be reviewed and approved by project users before it is saved. CDP is ideal for real-time, prospective clinical studies and longitudinal research where data quality review is important.

2. What Is Clinical Data Pull (CDP)?

Clinical Data Pull (CDP) is a REDCap module that imports clinical data from an EHR into a REDCap project — one patient at a time. It uses an adjudication workflow, meaning all incoming EHR data is held in a temporary cache and must be reviewed and approved by a user before it is officially saved in the project.

CDP is best suited for: - Real-time data collection - Prospective clinical studies and trials - Longitudinal and/or multi-arm studies

3. Enabling CDP for a Project

Only a REDCap administrator can enable CDP for a project. This is done via the Project Setup page for the individual project. Once enabled, users with CDP Setup/Mapping privileges in the project can access the CDP Mapping page.

To contact your REDCap administrator about enabling CDP for a project, follow your institution's process, which may include checks for IRB approval and EHR access authorization.

4. Field Mapping

Before data can be pulled, a user with CDP mapping privileges must map EHR data fields to REDCap fields. This is done on the CDP Mapping page, accessible from the Project Setup page.

Field Types

CDP supports two types of mapped fields:

One-time (non-temporal) fields — Data that exists once per patient (e.g., demographics). This data is fetched immediately when a patient is added to the project via the EHR Launch.

Temporal fields — Data that repeats over time (e.g., lab results, vitals). These fields require an associated REDCap date or date/time field. Data is only retrieved once the associated date field has a value. The date field and a configured ± day offset together define the time window for the query.

Example: If the associated date field contains 2024-03-15 and the day offset is 1, REDCap queries the EHR for values from 2024-03-14 through 2024-03-16. Values outside this range are ignored.

Mapping Flexibility

  • CDP supports one-to-many, many-to-one, and many-to-many field mappings between EHR fields and REDCap fields.
  • Temporal fields can be mapped to fields in a classic project, to events in a longitudinal project, or to repeating instruments/events.
  • Mappings for Allergies, Medications, and Problem List are merged per category and stored in a Notes/Paragraph field.
  • Mappings can be adjusted at any time in a CDP project.

Preview Fields

On the mapping page, up to 5 source fields can be designated as preview fields. These are displayed when a record identifier (e.g., MRN) is entered, allowing the user to confirm they have the correct patient before importing data. Preview fields are optional but recommended for data quality.

Clinical Notes (DocumentReference)

CDP can import clinical notes from the EHR using the FHIR DocumentReference resource. Notes are only stored if they are in HTML format. For clinical notes in other formats, use the Clinical Data Mart (CDM) instead.

When mapping a field for clinical notes: - Use a Notes Box field type to accommodate large text - Apply the @RICHTEXT action tag to preserve HTML formatting - Set field alignment to Left / Horizontal (LH) for consistent presentation

Demography Field Coding

For the fields race, sex, and ethnicity, CDP requires that answer choices be coded using specific standardized values aligned with FHIR terminology. Contact your REDCap administrator for the required code list if you are setting up these mappings.

5. Importing Data: Two Access Methods

1. EHR Launch

EHR Launch means opening REDCap as an embedded window from within the EHR interface. This is always the required first step — it initiates the user's OAuth2 authorization for FHIR services.

  • A list of CDP-enabled projects is displayed. The user can add the current patient to a project by clicking Add patient.
  • Non-temporal fields (e.g., demographics) are fetched immediately when a patient is added.
  • Once inside a project, the user can enter data normally and adjudicate CDP data.

After completing at least one EHR Launch, the user is authorized and can use CDP from either inside the EHR window or from the REDCap side in a normal browser.

2. REDCap Side (Outside the EHR)

Users can access their REDCap project from a regular browser and pull data for existing patients:

  • Navigate to the patient's record in the project.
  • If the patient does not exist yet, create a new record and enter the patient's MRN into the mapped MRN field. REDCap will immediately begin pulling data from the EHR in real time.
  • If temporal fields are mapped, those values will not be fetched until their associated date/time field has a value entered.

6. Adjudication

Adjudication is the process of reviewing and approving EHR data before it is saved in the project. All pulled data is stored in a temporary cache first.

The adjudication screen can be accessed from two places: 1. Record Status Dashboard — A column shows the count of pending items per record. Click the count to open the adjudication screen. 2. Data entry form — A red counter at the top of the page indicates pending items. Click View to open the adjudication screen.

On the adjudication screen: - If only one source value was returned for a field, it is pre-selected automatically. - For temporal fields with multiple values on the same calendar date as the REDCap date field, the matching value is pre-selected automatically (unless a pre-selection rule like "Minimum value" or "Latest value" is set on the mapping page). - The user selects the radio button for each value to import, then clicks Save to store the values in the project. - Unadjudicated items can be left and returned to later.

7. Automatic Data Monitoring (Cron Job)

Once a patient has been added to a CDP project, REDCap automatically monitors the EHR for new data via a cron job. This continues for a configurable number of days defined by the setting "Time of inactivity after which REDCap will stop checking for new data", which is set by the administrator on the CDIS Control Center page.

8. User Access Web Service (Optional)

Administrators can optionally set up a User Access Web Service to add an extra layer of control over which users are authorized to adjudicate data from the EHR. This is configured by the REDCap administrator and technical team, and provides finer-grained access management beyond standard project user rights.

9. Common Questions

Q: Can I use CDP without mapping all of my EHR fields? Yes. Field mapping is flexible — you only map the EHR fields that are relevant to your study. You are not required to map every available EHR field. Map only what you need for your project.

Q: What happens if a temporal field does not have an associated date field with a value? Temporal fields (like lab results or vitals) will not be fetched from the EHR until their associated date/time field has a value entered in REDCap. This is by design — the date field defines the time window for the query. Without a date, there is no time window to search.

Q: Can I use the same EHR field mapped to multiple REDCap fields? Yes. CDP supports many-to-many field mappings, meaning one EHR field can map to multiple REDCap fields, and one REDCap field can receive data from multiple EHR fields. This flexibility allows you to organize EHR data according to your study's needs.

Q: How long does the automatic cron job monitor for new EHR data after a patient is added? The duration is configurable by your REDCap administrator on the CDIS Control Center page. The setting is called "Time of inactivity after which REDCap will stop checking for new data." Once this period elapses, automatic monitoring stops, though users can still manually pull data by entering the MRN.

Q: What is the difference between adjudicating one value versus multiple values? If the EHR returns only one value for a field, it is pre-selected on the adjudication screen automatically. If multiple values are returned (e.g., multiple lab results on the same date), the user must select which value(s) to import. Pre-selection rules like "Minimum value" or "Latest value" can be configured on the mapping page to auto-select a value when multiple results exist.

Q: Can clinical notes be imported in any format? No. CDP only imports clinical notes if they are in HTML format. If your EHR stores notes in other formats (plain text, PDF, etc.), you cannot import them via CDP. Use the Clinical Data Mart (CDM) instead, which accepts notes in any format.

10. Common Mistakes & Gotchas

Forgetting to map the patient identifier field (MRN) before enabling EHR Launch. CDP requires a field mapped to the EHR patient identifier so that REDCap knows which patient record to retrieve. If the MRN field is not mapped, users will not be able to add patients from the EHR. Always map your institution's patient ID field first.

Not understanding the difference between EHR Launch and REDCap-side access. EHR Launch (opening REDCap from inside the EHR) is required for initial OAuth2 authorization, but after that, users can access CDP from a regular browser. A common mistake is assuming users must always launch from the EHR. Once authorized, users have the flexibility to use either method.

Using day offsets that are too narrow for temporal fields. The day offset defines a ± window around a date (e.g., ±1 day means 3 days total). If you set too narrow a window, relevant lab results or vitals that fall outside the range will be missed. Discuss appropriate windows with your clinical team before mapping temporal fields.

Assigning demography fields without using the correct FHIR terminology codes. If you map race, sex, or ethnicity fields without the required standardized FHIR code lists, data validation will fail and the mapping will not work. Contact your REDCap administrator for the specific code lists required for these fields.

Adjudicating data without reviewing field names and units. It is easy to approve EHR data quickly without noticing that values are in different units or that field labels don't match expectations. Always review the adjudication screen carefully, especially for numeric values (e.g., is this lab value in mg/dL or mmol/L?).