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Virtual Data Warehouse

Virtual Data Warehouse

Standardizing data to improve collaboration and research

Hennepin Healthcare Virtual Data Warehouse

The Hennepin Healthcare Virtual Data Warehouse (VDW) is a streamlined data resource for  health care research. The VDW organizes electronic health record data according the the HCSRN data model used by health systems across the United States. The result is a simple, easy to understand data structure that can facilitate collaborative, cross-system research.

How it Works

All projects are different and timeline will depend on project complexity and analyst capacity.

Here are some approximate estimates of project timelines (from date of intake meeting):

Sample size estimation for grant application: 3 weeks

Simple data pull: 6 weeks

Complex pull and/or merging with other data sources: 12+ weeks.


1) Review VDW documentation

2) Request Data

  • Statistics and analysis services also available on request

3) Cost estimate

  • VDW analyst will contact you regarding a detailed cost estimate for your project
  • Service fee of $120/hour for data pulls*

4) IRB Review

  • Requests for identifiable data require IRB review. Consult with VDW staff before submitting an IRB application.

5) Request fulfilled

  • DUA may be required. VDW staff will help you determine if a DUA is necessary.


Questions?  Email


*fees may vary for some funding sources


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)

Virtual Data Warehouse Request Form

Access the VDW Intake Form and submit a VDW request 



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.

Examples of Work Using the VDW

The Hennepin Healthcare VDW supports a wide array of work.  Examples include:

COVID-19 Research.  Researchers developed a public health surveillance registry of COVID-19 cases and vaccines to be summarized with other health systems in Minnesota to help the Minnesota Department of Health track the COVID-19 pandemic.

COVID-19 and thrombosis.  VDW data was used to contribute Hennepin Healthcare data for a multi-site collaborative research project.

Cardiovascular Disease (CVD) and HIV.  Researcher used the VDW to test associations between patient characteristics and cardiovascular outcomes among HIV patients.


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 Systems (HHS) and  Hennepin Healthcare Research Institute (HHRI) faculty, trainees, and staff are eligible to submit a data request.  External (non-HHS or non-HHRI) collaborators may participate in research projects using the VDW but the project must include an HHS or HHRI co-investigator who will initiate the request.

Data Available

The VDW contains information from Hennepin Healthcare's Epic medical chart and billing data.  It includes thirteen domains:  Death, Demographics, Diagnosis, Encounters, Faculty, Geography, 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 VDW team fulfilling data requests.  This fee offsets some of the costs of maintaining the data warehouse, assessing your request, and pulling the data.  The VDW 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.

Questions?  Email


List of Publications Supported by the VDW

Downey, M. C., Hoover, M. R., Prekker, M. E., & Kempainen, R. R. (2022). The Critically Ill Without COVID-19 Infection During the COVID-19 Pandemic: an Analysis of Race and Ethnicity at an Urban Safety-Net Hospital. Journal of Racial and Ethnic Health Disparities, 1-7.

Drawz, P. E., DeSilva, M., Bodurtha, P., Vazquez Benitez, G., Murray, A., Chamberlain, A. M., ... & Johnson, S. G. (2022). Effectiveness of BNT162b2 and mRNA-1273 Second Doses and Boosters for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection and SARS-CoV-2–Related Hospitalizations: A Statewide Report From the Minnesota Electronic Health Record Consortium. Clinical Infectious Diseases.

Lindsay AR, Shearer RD, Bart G, Winkelman TNA. Trends in Substance Use Disorder-related Admissions at a Safety-net Hospital, 2008-2020. J Addict Med. 2022;16(2):360-363. DOI: 10.1097/ADM.0000000000000896.

Musshafen, L., Dobbs, T. E., Robinson, A., Wyatt, T., Puskarich, M., Summers, R., ... & Compretta, C. (2022). American Indians and COVID-19. Journal of Public Health in the Deep South, 3(2).

Shearer, R. D., Vickery, K. D., Bodurtha, P., Drawz, P. E., Johnson, S., Jeruzal, J., ... & Winkelman, T. N. (2022). COVID-19 Vaccination Of People Experiencing Homelessness And Incarceration In Minnesota: Study examines COVID-19 vaccination of people experiencing homelessness and incarceration in Minnesota. Health Affairs, 41(6), 846-852.

Winkelman, T. N., Margolis, K. L., Waring, S., Bodurtha, P. J., Khazanchi, R., Gildemeister, S., ... & Drawz, P. E. (2022). Minnesota electronic health record consortium COVID-19 project: informing pandemic response through statewide collaboration using observational data. Public Health Reports, 137(2), 263-271.

Winkelman, T. N., Rai, N. K., Bodurtha, P. J., Chamberlain, A. M., DeSilva, M., Jeruzal, J., ... & Drawz, P. E. (2022). Trends in COVID-19 Vaccine Administration and Effectiveness Through October 2021. JAMA network open, 5(3), e225018-e225018.

Khazanchi, R., Spaulding, A. B., Bodurtha, P. J., Neely, C., Winkelman, T. N., & Minnesota EHR Consortium. (2021). Trends in Pediatric Viral Symptoms, Influenza Testing, and SARS-CoV-2 Testing From a Statewide Electronic Health Record Consortium, January 2017 to July 2021. Academic pediatrics, 21(8), 1420-1425.

Khazanchi, R., Winkelman, T. N., Pandita, D., Jelinek, R., Shearer, R. D., & Bodurtha, P. J. (2021). Patient characteristics and subsequent health care use by location of SARS-CoV-2 testing initiation in a safety-net health system. JAMA network open, 4(6), e2112857-e2112857.

Montgomery, M. P., Meehan, A. A., Cooper, A., Toews, K. A., Ghinai, I., Schroeter, M. K., ... & Mosites, E. (2021). Notes from the Field: COVID-19 Vaccination Coverage Among Persons Experiencing Homelessness—Six US Jurisdictions, December 2020–August 2021. Morbidity and Mortality Weekly Report, 70(48), 1676.

The Hennepin Healthcare Virtual Data Warehouse (VDW) acknowledges use of the Health Care Systems Research Network (HCSRN) Virtual Data Warehouse (VDW), a distributed data model that facilitates multi-site research while protecting patient privacy and proprietary health practice information.  To learn more about the HCSRN VDW or becoming a member, please visit

HHRI is not a member of HCSRN.

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