CCW Virtual Research Data Center (VRDC) FAQs

01. How much does access to the CCW VRDC cost?

Access to the CCW VRDC is based on two factors:

  • the number of users (VRDC "seats")
  • the number of distinct research projects

Additional considerations include:

  • software option you select
  • additional storage needs
  • volume of required Output Reviews

A ‘seat’ in the CCW VRDC is defined as an individual user. Due to licensing requirements, a ‘seat’ can only be allocated to one (1) individual for the duration of the research project. Multiple users can work on a project but each user will need to purchase a seat in the CCW VRDC. In addition to annual seat fees, there is also an annual project fee. The CCW VRDC fees are contained in the ‘CMS Fee Information for CMS Research Identifiable Data’.

02. Can multiple individuals work on a single project within the CCW VRDC?

Yes, individuals who share a DUA and have all purchased seats in the CCW VRDC are able to collaborate within the CCW VRDC.

03. Can multiple researchers share the same 'seat' within the CCW VRDC if they are working on the same project?

No, only one (1) individual may be assigned to a ‘seat' at a time. Seats may be infrequently reassigned if there is a change in project members. If multiple researchers are working on the same project, each researcher must have their own ‘seat’ in the CCW VRDC.

04. Can researchers "split time" within a single seat (i.e. one researcher uses the seat three days a week while another uses it the rest of the week)?

No, each ‘seat’ requires a license and the license is assigned to an individual. For proper tracking and accounting of the CCW VRDC licenses, a ‘seat’ can only be allocated to one (1) individual. Reassignment of seats should only be done when there are changes to project members and requires CMS approval.

05. Can the CCW VRDC be accessed from outside the United States (US)?

No. CMS does not allow access to the CCW VRDC from outside the US. See the article, “CMS Non-US Based Researcher Policy”, for a summary of CMS policy related to accessing data from outside the US or by non-US citizens.

06. Can a researcher with approved access work on multiple projects?

Yes, an approved researcher can work on multiple projects. The researcher must prepare and submit a data request package through ResDAC for each project and pay the associated fees. Upon approval and assignment of a DUA, the researcher will be provided access to the data needed to conduct the approved study. If a researcher uses data from an approved DUA for a non-approved project, it will be considered a DUA violation and will result in termination of their CCW VRDC access as well as possible prohibition on any future access to CMS data.

07. If a seat is allocated two (2) terabytes (TB) of work space and 2,000 Databricks credit usage, will the researcher be notified when they are approaching the limit and what will happen once the space or usage is exceeded?

Yes, the CCW monitors the space within the environment and notifies researchers if they are approaching the allocated limit. If researchers are approaching the two (2) terabyte (TB) space limit or 2,000 Databricks credit usage, they will be required to either remove files from the workspace or purchase additional space. See “FAQ054”, “FAQ055”, FAQ056”, and “FAQ057” on the CCW Frequently Asked Questions page on the CCW website for details. Additional space can be purchased in one (1) terabyte (TB) blocks for $1,500 and 2,000 additional Databricks credits can be purchased for $1,500.

08. What does the Databricks tool offer?

For users wanting additional analytic tools beyond SAS and STATA, the full CCW VRDC option includes Databricks, R, and Python. Databricks is a data analytic platform allowing you to write Structured Query Language (SQL) code in a Databricks notebook. Databricks measures usage in ‘credit’ consumption. See “FAQ050” and “FAQ053” on the CCW Frequently Asked Questions page on the CCW website for details.

09. How often will CCW VRDC fees change?

CMS is authorized by Section 1106(c) of the Social Security Act to charge requesters the cost of making the data available. As a result, the CCW VRDC fees will be reviewed and adjusted periodically to reflect changes in contractor and infrastructure costs as well as volume of users in the CCW VRDC environment.

10. Why does output require a review prior to download?

CMS is committed to ensuring the privacy of personally identifiable information (PII) and protected health information (PHI). The output review process helps avoid the inappropriate disclosure of PII or PHI. The article, "CMS Cell Size Suppression Policy," outlines CMS policy and what is required to comply with it.

11. What data can be taken out of the CCW VRDC?

Researchers are only permitted to downloaded aggregate, statistical information. No personally identifiable information (PII) or protected health information (PHI) may be taken out of the CCW VRDC. All requests to download data from the CCW VRDC must go through an output review to screen for PII or PHI to ensure only data included on the approved DUA and data adhering to the "CMS Cell Size Suppression Policy" is disclosed.

12. What level of aggregation is required for output? What form should output reports take (tables, aggregated data, SAS output)?

Files must be aggregated above a beneficiary level resulting in a minimum count of 11 beneficiaries at the level of aggregation. Depending on the population size, this can require aggregation to a geographic level (state, county, HRR), diagnosis group level, or procedure code level. Output can be in Excel tables, aggregated SAS datasets, SAS output files, word documents and PDF documents. See the article, "CMS Cell Size Suppression Policy," for an explanation of CMS cell size suppression policy.

13. What is the maximum size allowable for an approved output file leaving the CCW VRDC for researchers?

Researchers are approved to receive three (3) output reviews per DUA per week of up to one (1) gigabyte (GB). Multiple files may be downloaded but, each file must be within the specified size limit. See the Innovator Research FAQs to find information about output reviews for innovators.

14. How long is the output review process expected to take?

CMS estimates that the output review process will take place within 2 business days. However, additional time may be required for complex datasets. CCW VRDC users should plan accordingly when submitting files for output review.

15. How long will project data be stored within the CCW VRDC? Is all data related to a project deleted at the conclusion of the project?

Project data will be stored for a three-year period. This only includes analysis and programming files and does not include the actual source files. The data are maintained to allow the researcher access to the data in the event it is needed to respond to questions regarding journal publications. If access is needed for this purpose, the researcher will be provided access for a one month (30-day) period to perform this task.