CDRN Frequently Asked Questions

How do I request data from a CDRN?

We suggest all UNC investigators request a consult with an analyst at NC TraCS to get started. An analyst will help you determine the best network for your project, assist you with refining your request, and let you know about data availability.

Depending on your project, you may also wish to explore i2b2@UNC, which allows you to query data from the UNC Health Care system and receive a count of patients meeting your criteria. Although it only contains UNC data, i2b2 allows you to familiarize yourself with the data you are looking for before approaching a CDRN.

We also suggest you begin developing a computable phenotype in preparation for a network request.

What is the difference between the CDRNs at UNC?

Each CDRN has a different mission, available data, and partners. An analyst at NC TraCS can help you determine the best network for your project.

PCORnet, or the National Patient Centered Clinical Research Network, contains 13 CDRNs including the Mid-South CDRN. Mid-South (includes Vanderbilt Health System - lead site); Meharry Medical College; Vanderbilt Healthcare Affiliated Network; Greenway Health; Health Sciences South Carolina (includes Medical University of South Carolina); UNC-Chapel Hill; and Duke University.

The Carolinas Collaborative is a regional CDRN built on a learning health system model. The members of the Carolinas Collaborative are Health Sciences South Carolina (lead site - includes Medical University of South Carolina); Duke University; UNC-Chapel Hill; and Wake Forest Baptist Health.

The Accrual to Clinical Trials (ACT) Network is a growing national CDRN. More information will be available in the future.

What data are available in the CDRN?

Data available in the CDRN vary by network. Structured data are generally available in the following domains: patient demographics, encounter information, diagnoses, procedures, laboratory tests, medications, and patient vitals. More details:

PCORnet and Mid-South: Common Data Model Lay Guide

Carolinas Collaborative: Data Dictionary

ACT: Data dictionary not yet available.

UNC Health Care System data in the CDRN dates back to 2004. Availability of historical data varies by health care system.

What types of projects are being conducted using the CDRNs?

CDRNs can support a variety of observational and interventional studies, including, but not limited to, cross-sectional studies, health services research, comparative effectiveness studies, pragmatic trials, and clinic trials. Information about current projects:

PCORnet Demonstration Studies

Mid-South CDRN Projects

Carolinas Collaborative Pilot Projects

What is a computable phenotype and why do I need one?

A computable phenotype is a very specific list of inclusion and exclusion criteria used to identify patients for a study. Below is an example of the type of criteria included in computable phenotypes:

Can you pull data from the CDRN that will show me all patients between ages _____ and _____, who have been diagnosed with _______, but haven't had a ________ in the last 6 months, but have had ___ visits in the _____________ clinic over the past year? I also need to know if they're taking _____________, or have had any ___, ___, or ___ lab values over ___ mg/ml in the past year.

Computable phenotypes are important for any clinical data request, but they are especially important for CDRN requests. A strong computable phenotype will ensure you find expected and like populations across institutions.

Who can request data?

UNC-Chapel Hill requires a UNC investigator — generally a faculty member — to be actively involved in a project in order for that study team to use UNC data.

How does IRB approval work in CDRNs?

Requests for counts of patients through the CDRNs do not require IRB review. Any requests for patient-level data in a de-identified , limited , or identified data set will require IRB approval.

De-identified Dataset

A deidentifed data set may not include any of the following direct identifiers of the individual or of the individual's relatives, employers, or household members:
  • Names
  • Geographic subdivisions smaller than a state
  • Zip codes
  • All elements of dates except year directly related to an individual, including birth or death or dates of health care services or health care claims
  • Telephone numbers
  • Fax numbers
  • Electronic mail addresses
  • Social security numbers
  • Medical record numbers
  • Health plan beneficiary identifiers
  • Account numbers
  • Certificate/license numbers
  • Vehicle identifiers and serial numbers, including license plate numbers
  • Device identifiers and serial numbers
  • Web universal resource locators (URL)
  • Internet protocol (IP) address numbers
  • Biometric identifiers, including finger and voice prints
  • Full face photographic images
  • Any other number, characteristic or code that could be used by the researcher to identify the individual

Note: Although a de-identified data set cannot contain a birth date, it may contain the individual's age expressed in years, months, days, or hours, as appropriate, except for individuals who are aged 90 years or more. For persons aged 90 years and above, the age in a de-identified data set can only be stated as being within the category of age 90 or above.

Limited Dataset

A limited data set may not include any of the following direct identifiers of the individual or of the individual's relatives, employers, or household members:
  • Names
  • Any geocodes that identify an individual household such as street address
  • Telephone numbers
  • Fax numbers
  • Electronic mail addresses
  • Social security numbers
  • Medical record numbers
  • Health plan beneficiary identifiers
  • Account numbers
  • Certificate/license numbers
  • Vehicle identifiers and serial numbers, including license plate numbers
  • Device identifiers and serial numbers
  • Web universal resource locators (URL)
  • Internet protocol (IP) address numbers
  • Biometric identifiers, including finger and voice prints
  • Full face photographic images

Note: A Limited Data set may include:
  • All elements of dates directly related to an individual, including birth date, admission date, discharge date, dates of health care procedures or other services, and date of death.
  • Geocodes above the level that would identify an individual household such as state, county, city, town, census track, precinct, zip code.

IRB approval processes vary by network. UNC investigators may request a consult with TraCS' Regulatory Service if they need guidance on completing an IRB application for a CDRN project.

Carolinas Collaborative has a standardized approval process, which is outlined in the following documents:

The IRB approval process for PCORnet and the Mid-South CDRN currently varies on a study-by-study basis.

How are data requests approved?

Any requests for patient-level data — whether de-identified, HIPAA-limited, or identified — will need to go through a formal approval process that varies by network. Once submitted to the CDRN, requests will be routed through the approval process of that network.

How do I make a request directly to a CDRN?

Although we encourage UNC investigators to consult with a TraCS data analyst prior to reaching out to a CDRN, you may make a request directly to one of the CDRNs:

PCORnet Front Door

Mid-South CDRN Collaboration Request

Carolinas Collaborative Researchers portal

Do you have materials I can share about the CDRNs?

Yes, we have the following materials available: