Research Involving Decisionally Impaired Individuals


Decisionally impaired persons are those who have a diminished capacity to understand the risks and benefits for participation in research and to autonomously provide informed consent. This decisional impairment may result from a psychiatric, organic, developmental or other disorder that affects cognitive or emotional functions, or may result from the effect of drugs or alcohol. The impairment may be temporary, permanent or may fluctuate.

Legally Authorized Representative: An individual or judicial or other body authorized under applicable law to consent on behalf of a prospective subject to the subject's participation in the procedure(s) involved in the research.

Internal Review Requirements

Although not specifically addressed in the regulations as a vulnerable population, the University of Pittsburgh IRB requires additional safeguards for research involving persons with decisional impairment. The IRB will approve the research only if it finds that:

  1. the research bears a direct relationship to the decisionally impaired subject’s condition or circumstance;
  2. the research meets one of the following criteria:
    • presenting no greater than minimal risk to the involved subjects;
    • presents an increase over minimal risk to involved subjects, but which offers the potential for direct individual benefit to the subject;
    • presents a minor increase over minimal risk to involved subjects and which does not have the potential for direct individual benefit; provided that the knowledge sought has direct relevance for understanding or eventually alleviating the subjects' disorder or condition.

In evaluating a protocol involving the enrollment of persons with decisional impairment, The IRB may consider requiring additional safeguards, as appropriate, for a given protocol. Such safeguards may include any of the following:

  • use of an independent party (independent of the study investigator with appropriate expertise) to assess the capacity of the potential subject;
  • use of standardized assessment of cognition and/or decisional capacity;
  • use of informational or educational techniques;
  • use of an independent person to monitor the consent process;
  • use of waiting periods to allow for additional time to consider information about the research study;
  • use of proxy consent;
  • use of assent in addition to proxy consent in order to respect the autonomy of individuals with decisional impairment;
  • use of a witness.  The IRB will determine the following when choosing this option:
    • whether the witness needs to be unbiased (which means the individual is not part of the study team nor a family member of the potential participant)
    • whether the witness will observe the entire consent process or just the signature


In general, all adults, regardless of diagnosis or condition, should be presumed competent to consent to participation in research unless there is evidence of serious disability that would impair reasoning or judgment. In making the determination about whether it is appropriate for investigator’s to utilize proxy consent, the IRB will take into consideration the following:

  • the rationale for the need to obtain proxy consent;
  • the criteria that will be used in determining whether a potential subject has decisional impairment sufficient to require the use of proxy consent, including any use of standardized assessment tools;
  • whether any additional methods are proposed to enhance subjects’ ability to achieve decisional capacity with regard to the proposed study (e.g., reading of the consent form may not be sufficient and use of other tools such as videos, educational materials, post-test, etc. might be considered to assist potential subjects in understanding what is involved with the research);
  • who will be approached, and in what order, to provide proxy consent.

The following are specific procedures that must be followed if proxy consent is utilized:

  • Persons with decision impairment may also have been adjudicated legally incapacitated by a court decision. If such persons are considered for enrollment in a research protocol, the only party who may provide proxy consent is the court-appointed guardian. The guardian may only provide proxy consent if the court order, appointing them guardian, specifically states that they have the authority to enroll the incapacitated person into a research protocol. For this category of subjects, a copy of the court order appointing the guardian and granting the guardian authority to enroll the person into a research study should be attached to the informed consent document.
  • Persons may also, through a health care proxy appointed by a power of attorney, designate a person to make decisions for them in the event that they are subsequently incapacitated. This person may give proxy consent for enrollment of a subject in research.
  • If a potential subject has neither a guardian, nor a health care proxy designated, the investigator may obtain the informed consent of the subject’s legally authorized representative. Where neither a court-appointed guardian, nor a health care proxy exists, investigators may seek informed consent from the following individuals, in the order listed below:
    • spouse, unless an action for divorce is pending, and the adult children of the principal are not the children of the spouse;
    • adult child
    • a parent (natural or adoptive);
    • adult brother or sister;
    • adult grandchild
    • an adult who has knowledge of the principal’s preferences and values, including, but not limited to, religious and moral beliefs, to assess how the principal would make health care decisions

When a person is giving proxy consent, the proxy should be informed that, where possible, s/he should base the decision on substituted judgment, reflecting the views that the subject expressed while decisionally capable. The proxy should be fully informed on the risks, benefits and alternatives to the research. If the values of the subject are not known with respect to a proposed research study, the proxy should act in the best interest of the subject.

If a person with decisional impairment is capable of exercising some judgment concerning the nature of the research and participation in it, the investigator should obtain the subject’s assent in addition to the consent of his/her legally authorized representative.

The verbal objection of an adult with decisional impairment to participation in the research should be binding. If the subject, at any time, objects to continuing in the research study, such objection should be respected.

Where the condition causing the subject’s decisional impairment is of an intermittent or temporary nature, the informed consent process should include a mechanism for obtaining the subject’s subsequent direct informed consent to participate in the research. If a subject regains decision making capacity and declines to continue in the research, the decision must be respected.

Documentation of Consent and Assent: Informed Consent Document

Adult subjects, not deemed to have decisional impairment, should read and sign the informed consent document in the standard manner.

For adult persons with decisional impairment, the investigator should document the following before obtaining the consent and signature of the subject’s legally authorized representative or guardian and the signature of the unbiased witness to this consent, if required by the IRB:

  • the conclusion that the subject is incapable of understanding the information presented regarding the research, to appreciate the consequences of acting (or not acting) on that information, and to make a choice;
  • the information provided to the subject’s legally authorized representative regarding the cognitive and health status of the subject, the risks and benefits of the research, and the role of the proxy.

To document obtaining the assent of a subject with decisional impairment, a Verification of Explanation statement should appear on the consent document and be signed and dated by the Principal Investigator, listed co-investigator, or other research staff when authorized by the IRB.

Documentation of Consent and Assent: Research Record

In studies in which some or all participants may have decisional impairment, it is recommended that at the time of obtaining consent the following be documented in a note to file for the subject’s research record:

  • whether the subject demonstrated the ability to understand the nature of the research procedures, the potential risks and benefits, the voluntary nature of the participation and to make a personal judgment about participation;
  • use of any supplemental methods to enhance or evaluate decisional capacity;
  • a summary of the matters discussed with the subject’s legally authorized representative.


revised 9.15.2016; revised 1.20.2017