Clinical Data Integration in REDCap

Clinical Data Interoperability Services (CDIS) Overview

Clinical Data Interoperability Services (CDIS) is an advanced feature of REDCap that allows an individual REDCap project to interact with Cerner, our electronic health record (EHR), to pull selected information from the EHR into the REDCap project. This is done through the Fast Healthcare Interoperability Resources (FHIR) web service inside of an EHR, which can pull structured data into REDCap using OAuth2 authorization. This feature is only available to individuals with existing access to the EHR, and must be enabled for each project by the REDCap administrator.

There are two CDIS features available. Both are built-in modules in REDCap that can be enabled by an administrator and work independently for different use cases.

  • Clinical Data Pull feature provides the ability to launch a REDCap window while inside an EHR
    and to quickly and seamlessly import clinical data (one patient at a time) from the EHR into a REDCap

  • Clinical Data Mart feature provides the ability to import many patients’ clinical
    data in bulk into a REDCap project.




A major motivation for using the CDP and Data Mart features in REDCap is often the need to re-use
clinical data from the EHR, especially for research purposes. If you are performing a research study and
collecting data in REDCap, it is typically preferred to have all your data stored and accessible from one
single place, and thus it is often more efficient, for both data entry workflow and data analysis purposes,
to have all study-centric data stored in REDCap.

The modules transfer structured clinical data in real time from the EHR to REDCap. Each module does
this in a slightly different way, which will be explained below. This system-to-system flow of data into
REDCap allows users to avoid repeated data entry, which often compromises data quality by creating
errors in clinical data values, and it proves to be most efficient while providing the greatest amount of
data quality.




Clinical Data Pull vs Clinical Data Mart

While both CDP and Data Mart utilize the CDIS infrastructure and the FHIR web services to pull data from
the HER into a REDCap project, there are very distinct differences between the two features. Listed in the
table below are comparisons of these two features to help delineate their key differences and to
understand when one might be more appropriate than the other for specific use cases.


Clinical Data Pull

Clinical Data Mart


Clinical Data Pull

Clinical Data Mart

Most common uses

  • Real-time data collection

  • Prospective clinical studies/trials

  • Longitudinal and/or multi-arm studies

  • Registries

  • Prospective or retrospective clinical studies/trials

  • Searching for specific lab values or diagnosis codes for a cohort of patients over a set time period

Data mapping to EHR fields

  • Field mapping must be set up prior to data pull by a user with CDP Setup/Mapping privileges in the project. This is completed via the CDP mapping page (accessed via the Project Setup page).

  • Mapping can be adjusted at any time in a CDP project, and it can be complex when mapping EHR fields to REDCap fields (allows for one-to-many, many-to-one, or many-to-many mapping).

  • Temporal data (e.g., vital signs and labs) must have an accompanying date or date/time field (e.g., visit date) for determining the window of time in which to pull data (using the ± day offset).
    Temporal data can be mapped to fields in a classic project, to events in a longitudinal project, or to repeating instruments/events.

  • All values for Allergies, Medications, and Problem List will be merged together for each category and each saved in its own a Notes/Paragraph field (if mapped).

  • Mapping is not required since the project structure/instruments are pre-defined when the project is created. Demographics is created as a single data collection form, and the following forms are created as repeating instruments: Vital Signs, Labs, Allergies, Medications, and Problem List. Each data value on the repeating instruments are represented as a separate repeating instance of the form.

  • User defines the data pull configuration when creating the project - e.g., chooses specific MRNs, date range, and data fields from the EHR.

  • Project-level settings control whether or not users in the project can 1) fetch data just one time or as often as they wish, and 2) modify the data pull configuration or not. These settings may be changed only by a REDCap administrator.

Activation process

  • The local institution may have a formal process to evaluate the users/project prior to approval (recommended) - e.g., check IRB status, check users' EHR access.

  • REDCap administrator must enable CDP for the project on the project's Project Setup page.

  • The local institution may have a formal process to evaluate the users/project prior to approval (recommended) - e.g., check IRB status, check users' EHR access.

  • Project is first created by a user, but each revision of the data pull configuration will go through an audit process and approved by a REDCap administrator via the To-Do List (if the project-level setting has been enabled to allow configuration changes).

User privileges

  • Project users can set up field mapping and adjudicate data from the EHR if they have project-level rights to do so. In order to adjudicate data from the EHR, users must have access to the EHR and must have launched at least one patient in the REDCap window inside the EHR user interface.

  • REDCap administrator and team can optionally create a User Access Web Service to further control user access during adjudication (info documented on this page).

  • A user's REDCap account must be given Data Mart privileges by a REDCap administrator on the
    Browse Users page in the Control Center, after which the user will be able to create a Data Mart project and pull EHR data. (Note: This is not a project-level user right but a REDCap user account privilege.)
    Also, there is no optional User Access Web Service as there is with CDP to further control user access
    for pulling data.

  • In order to pull data from the EHR, users must have access to the EHR and must have launched at least one patient in the REDCap window
    inside the EHR user interface.

  • Users with Project Setup/Design rights in a Data Mart project will be able to request changes to the data pull configuration (if needed and if the project-level setting has been


  • Users must launch a patient in the REDCap window inside the EHR user interface, and will be able to add the patient to any CDPenabled REDCap project to which they have access. Once the patient is in a project, the user can manually pull data from the EHR for the patient.

  • Data pulled from the EHR is not saved immediately in the project but is stored temporarily in a cache, in which users must first review/adjudicate all data values before being saved in the project.

  • Once a patient has been added to a project, CDP will automatically (via a cron job) continue to look for any new data added to the EHR for up to X days, in which X is the value of the setting "Time of inactivity after which REDCap will stop checking for new data" (info documented on this page).

  • Data Mart will only pull data from the EHR when a user with appropriate privileges clicks the "Fetch clinical data" button. There is no cron job to pull any new data at other times automatically.

  • To pull new data values in the EHR, a user must manually click the Fetch button again (assuming the projectl evel setting is enabled to allow more than one data pull).

  • Extra instruments or events may be added to the Data Mart Project, but if any of the pre-defined fields or instruments are modified, it may prevent the data pull from working successfully thereafter.