Based on federal regulations, there are some circumstances that allow for a waiver of documentation of informed consent (no signature collected from the participant). 
A waiver of documentation removes the requirement of collecting signatures from the research participant. All of the required informed consent information is still provided to the participant. but the documentation of the process (the actual signature) has been waived by the IRB. 
Situations when It Is Used 

This process is often used in minimal risk research involving the administration of online/electronic or mailed surveys, telephone interviews, or when anonymous sensitive information is collected and you do not want any written documentation that links the participants to the research study. 

In cases in which the documentation requirement is waived, the IRB may require the investigator to provide participants with a written statement regarding the research.

Conditions for Approval

Per federal regulations, the IRB may waive the requirement for the researcher to obtain a signed consent form (waiving the documentation) for some or all of the participants if it finds:

1) That the only record linking the participant and the research would be the consent document AND the principal risk would be potential harm resulting from breach of confidentiality.  Each participant will be asked whether or not he or she wants documentation linking him or her with the research.  The participant's wishes will govern. 

OR

2) That the research presents no more than minimal risk of harm to participants (i.e., the probability and magnitude of harm or discomfort anticipated in the research are not greater in and of themselves than those ordinarily encountered in daily life or during the performance of routine physical or psychological examinations or tests) and involves no procedures for which written consent is normally required outside of the research context.

HIPAA Requirements

If you plan to use or share protected health information (PHI) when conducting your research, you must conduct your study in accordance with the Privacy Rule of the Health Insurance Portability and Accountability Act (HIPAA). 

This means that when applying for a waiver of documentation of consent, you will also have to request a waiver or alteration of HIPAA Authorization.  The IRB can grant the waiver of alteration if it determines the following criteria are met:

  1. Use or disclosure involves no more than minimal risk to the privacy of individuals because of the presence of at least the following elements:
    • An adequate plan to protect health information identifiers from improper use or disclosure,
    • An adequate plan to destroy identifiers at the earliest opportunity absent a health or research justification or legal requirement to retain them, and
    • Adequate written assurances that the PHI will not be used or disclosed to a third party except as required by law, for authorized oversight of the research study, or for other research uses and disclosures permitted by the Privacy Rule;
  2. Research could not practicably be conducted without the waiver or alteration; and
  3. Research could not practicably be conducted without access to and use of PHI.
Edited with Permission from Northwestern University IRB