Protecting Confidentiality & Anonymity
Ways to Protect ConfidentialityIf it is essential to collect and link identifying information (e.g., subjects' names) to subjects’ responses (e.g., questionnaire answers), researchers must do their best and may need to be creative to provide the utmost confidentiality of subject data. The following are examples of practices that may be implemented to increase the level of confidentiality:
- Use study codes on data documents (e.g., completed questionnaire) instead of recording identifying information and keep a separate document that links the study code to subjects’ identifying information locked in a separate location and restrict access to this document (e.g., only allowing primary investigators access);
- Encrypt identifiable data;
- Remove face sheets containing identifiers (e.g., names and addresses) from survey instruments containing data after receiving from study participants;
- Properly dispose, destroy, or delete study data / documents;
- Limit access to identifiable information;
- Securely store data documents within locked locations; and/or
- Assign security codes to computerized records.
Confidentiality vs AnonymityConfidentiality
Maintaining confidentiality of information collected from research participants means that only the investigator(s) or individuals of the research team can identify the responses of individual subjects; however, the researchers must make every effort to prevent anyone outside of the project from connecting individual subjects with their responses.
Anonymity
Providing anonymity of information collected from research participants means that either the project does not collect identifying information of individual subjects (e.g., name, address, Email address, etc.), or the project cannot link individual responses with participants’ identities. A study should not collect identifying information of research participants unless it is essential to the study protocol.
Data Collection InstrumentsExamples of data collection instruments include:
- Questionnaires
- Videotapes
- Interview notes
- Field notes
- Data spreadsheet
Data collection instruments must not contain information that could readily identify participants (i.e., identifying information). Instead use study codes.
Examples of Identifying Information- Name
- Addresses
- Employer's name or address
- Relatives' names or addresses
- Date (e.g., birthdate, date of death, etc.)
- Phone / fax numbers
- E-mail addresses
- Social security numbers
- Member / account numbers
- Voiceprints
- Fingerprints
- Full face photos & comparable images
Study CodesThe use of study codes is an effective method for protecting the confidentiality of research participants. Study codes may be used on data collection instruments in place of identifying information to protect participants' responses / data when data documents are stored or out in the open. Also, in the event that a data document is lost, stolen, etc. having the data protected by a study ID will prevent anyone who may view the data from determining the participant's identity.
How to Use Study Codes
If you need to link individual participants with their responses / data, if feasible, assign each participant a study ID prior to collecting data. On a separate document / file type each participant's name along with their unique study ID (e.g., 001). Store this document separately from data documents.
When you are ready to collect data, insert each participant's unique study ID onto their data document, or provide each participant with his/her unique study ID and ask him/her to insert the ID onto his/her data document.
How to Use Study Codes for Online Surveys
Provide each participant with his/her unique study ID on his/her invitation document (e.g., email requesting participation). Ask the participant to insert that code into a specified field on the online survey.
Mass Recruitment
If you cannot assign each participant his/her own study ID (e.g., large number of participants - mass recruitment), yet need to link individual participants with their responses / data, request that participants generate their own study ID. For example, you could provide participants with instructions such as:
- What are the first two initials of your high school's name? ____
- What day of the month were you born? ____
- What is the last letter of your first name? ____
- Combine your responses from 1-3 in order here (e.g., FA19A) : _____ (this is your study ID)
- Insert your study ID into question #1 of the attached survey.
Participants may then use this study ID for all survey instruments they complete. This will allow researchers to match survey instruments for longitudinal studies.

