REDCap and Anonymous Survey Data Collection

Q: Can I collect anonymous survey data from participants?


Responses can only be collected anonymously using the Manage Survey Participants > Public Survey Link.

The survey questionnaire must not contain any questions asking the participants for identifying data (ex: What is your email? name? address?).

Multiple Surveys: Be mindful that projects with multiple surveys present potential challenges to anonymous data collection. If you are analyzing data in aggregate, you can having multiple REDCap projects, each using the Public Survey Link. If you need to track individual responses over time, using the Public Survey Link for each survey (pre, post, follow-ups) requires that you collect data points within the survey questionnaire to later export and merge. The data points should not be identifying information, but specific enough question(s) that a participant will enter answers consistently (ex: last 5 digits of their first phone number; color of first car).

Projects containing data entry forms and surveys cannot be considered anonymous. Manually entered data needs to be identified by the team to be properly associated and linked with survey responses.



Q: Can I use the Participant List to collect anonymous survey data from participants?

Technically, no. Data is not anonymous when collected using the Participant List; but it can be "coded" and "unidentifiable" to the project admins.

REDCap's user interface has two separate modules for (1) sending emails and tracking responders/non-responders [Participant List] and (2) viewing data/responses. Through the REDCap interface, there is no link between the modules and no connection between the email address entered and the responses collected unless you enter unique values into the "Participant Identifier (optional)" field. The Participant Identifier field links the email address to the survey responses.

To ensure confidentiality of the data, REDCap tracks responses by attributing it to an email address. If the Participant List > Participant Identifier field is not used, the project administrators are not privy to this information. Access to the association between the individual who took the survey and the survey responses is restricted in the database and can only be accessed by authorized privileged users (system engineers, database admins).

**Important to know: There is a link “behind the scenes” and REDCap / REDCap support personnel (system engineers, database admins) are really acting as an “Honest Broker”: information is provided to investigators in such a manner that it would not be reasonably possible for the investigator or others to identify the corresponding patients-subjects directly or indirectly. REDCap holds the key to the code.

** If you truly need Anonymous Data, use the Public Survey Link. For the Participant List, the identifying emails can be forever stripped from the data with no way for anyone to go back and find out the identity of the individual from whom the data the was obtained. No re-identification is possible if you do the following:

1) Export a copy of the REDCap dataset (so you have a copy of the data + date/time stamps if needed for future reference)

2) EXPORT LIST for the Participant List to excel

3) REMOVE ALL PARTICIPANTS from the Participant List. This will delete all links between the email addresses and data collected, INCLUDING survey date/time stamps. Date/time entered is still available in the Logging module.

This ensures that identities cannot be reversed engineered in REDCap.

**It is recommended that if data collection must be anonymous in "real time", then the Participant List should NOT be used. Use the Public Survey Link to collect anonymous survey data.

RECOMMENDED: Keep access to the Manage Survey Participants tool restricted since a small number of respondents would be easily identifiable from the Participant List and the Add / Edit Records pages.


Go to KB0027941 in the IS Service Desk

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