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Virtual Data Warehouse

Virtual Data Warehouse

Standardizing data to improve collaboration and research

Health Care Systems Research Network (HCSRN) Virtual Data Warehouse (VDW) Data Documentation

Including description of the tables and variables in the VDW.

Download the HCSRN VDW Data Documentation (PDF)

VDW User Request Guide

Overview of data available, the request process, cost, and requirements of data use.

Download the VDW User Request Guide (PDF)

How it works

1)  Request data:

  • If requesting deidentified data – Investigator emails the VDW Request Form to with a one-paragraph project summary for determination of human subjects research. 
  • If requesting identifiable data – investigator submits an IRB application to the Office of Human Subjects Research. The IRB application and where to submit the application may be found under "Form & Policy Updates" on the Office of Human Subjects Research web page.

2)  After IRB approval is obtained:

  • Investigator submits inquiry to Hennepin Healthcare’s Analytical Center of Excellence (ACE) through ServiceNow. Instructions for submitting an inquiry are found in the VDW User Request Guide. If the investigator does not have access to ServiceNow, a request can be submitted via email to with "VDW Prep for Research" in the subject line.

3)  ACE fills data request

About the Virtual Data Warehouse

The Hennepin Healthcare Virtual Data Warehouse (VDW) is a streamlined tool that makes it easier for Hennepin Healthcare System (HHS) researchers to use data to make patient care better. The VDW facilitates data-driven research and collaboration by organizing and simplifying electronic health record data. Ultimately, the goal of the VDW is to generate results that will improve health outcomes.


Data to Improve Patient Care

Researchers use data at Hennepin Healthcare to identify strategies to improve access to care, reduce costs, and improve health care quality and outcomes. Data is used by Hennepin Healthcare researchers to improve health care policy and practice at the local level. Data is also used to collaborate with other health systems, which allows researchers to understand diseases that may be too rare to study at only one hospital. Collaboration with other health systems allows researchers to understand which treatments and policies work best.


Commitment to Patient Privacy

Hennepin Healthcare is committed to patient privacy. Patient data that is accessed for research purposes will be used only in accordance with federal and state law and Hennepin Healthcare’s privacy practices.  Patient data in the VDW is stored on protected computers, and Hennepin Healthcare limits and keeps track of who sees the information. Before researchers use VDW data, identifying information is typically removed. When identifiable data is necessary, researchers must provide justification, obtain Institutional Board Review approval, and cannot share data outside Hennepin Healthcare.

Patients can learn more about Hennepin Healthcare’s privacy practices at

A Researcher Resource

Common Data Model

The VDW was built using a common data model (CDM) to organize data into a standard structure. The ability to map data consistently (the same variable name and format) enables a fast response to research-related requests, especially for collaborative studies.

The VDW can easily be formatted to work with the PCORnet CDM for PCORI grant applications and for cross-institution research, which is required to participate in certain studies.


A Shared Effort

The VDW was established through a collaboration between HHS Executive leadership and researchers, Hennepin Healthcare Research Institute (HHRI) staff, Hennepin Healthcare's Analytical Center of Excellence (ACE) staff, and the University of Minnesota’s Clinical and Translational Science Institute (CTSI).


Eligible Investigators

Hennepin Healthcare faculty, trainees, or staff who have an or email address are eligible to submit a data request. External (non-Hennepin Healthcare) collaborators may participate in research projects using the VDW, but the project must include a Hennepin Healthcare co-investigator and the Hennepin Healthcare co-investigator must be the one to initiate the request. Identifiable information cannot be shared with investigators outside of Hennepin Healthcare.


Data Available

The VDW contains information from Hennepin Healthcare's Epic medical chart and billing data. It includes twelve domains: Death, Demographics, Diagnosis, Encounters, Facility, Lab Results, Languages, Med Orders, Procedures, Providers, Social History, and Vital Signs.


Research Requests and Costs

All research requests for Hennepin Healthcare data must include a Hennepin Healthcare researcher. Requests are governed by HIPAA Privacy Rule 45 CFR 164.501 and the Minnesota Health Records Act. Investigators conducting research with Hennepin Healthcare data will need to obtain Institutional Review Board (IRB) approval prior to submitting a request to obtain VDW data.

There is a service fee of $120/hr based on the time spent by the ACE team fulfilling data requests. This fee offsets some of the costs of maintaining the data warehouse, assessing your request, and pulling the data. The ACE Data Analyst can assist you in estimating the number of hours your request will require. Please plan to provide an account number to be billed when submitting your data request. If your project is non-sponsored you may request a waiver of the service fees.  To consult with the Data Analyst regarding a time estimate, a waiver of fees, or to discuss your request, send an email to


For More Information

For detailed information about the VDW, download the HCSRN VDW Data Documentation and VDW User Request Guide.



Email with "VDW" in the subject line.

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