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Participants with intellectual disabilities – guidance

In studies involving people with intellectual disabilities it is important to recognise the extent to which such people are able to give their informed consent to participate in a study.

People with intellectual disabilities have the same rights as other members of New Zealand society.

These rights include the right to choose whether to participate in a study and the right to be protected from any undue risks from participating in the study.

Historically, people with intellectual disabilities have experienced disadvantage, over protection and abuse. Their right to give informed consent has typically been ignored, and unwarranted assumptions have been made about their lack of competence.

Research involving people with intellectual disabilities should:

  • be designed and focused on an issue of significant importance to the participants’ disabilities
  • respect the participants’ rights to make their own choices and give informed consent
  • protect the participants from undue risks, exploitation and abuse.

Study proposals

Proposals for studies that involve people with intellectual disabilities should clearly describe:

  • the proposed sample of participants and their possible range of intellectual disabilities
  • how the researcher will determine each participant’s competence to give informed consent
  • a rationale for the decisions on judgment of competence in terms of the study’s complexity and/ or the possible risks to participants.

Information for prospective participants

People with intellectual disabilities have the right to receive information that they can understand and that recognises their individual circumstances, such as reading ability and understanding of the study.

Studies that involve people with intellectual disabilities must recognise that such people:

  • are not usually concerned about the public policy implications of a study – they are more likely to be interested in how the study can support them personally
  • often have difficulty separating hypothetical situations from personal anxieties and concerns
  • often have fewer opportunities to acquire ordinary knowledge (for example, due to lack of access to information, inappropriate education, segregation or over protection)
  • often find it difficult to understand their legal rights – they may have limited experience of their voluntary decisions being respected
  • often comply with the perceived demands of an authority figure
  • are able to make decisions, even if they are severely disabled, if they are given the opportunity, support and training to do so.

People with intellectual disabilities can be valuable advisors on appropriate wording for information sheets. Whenever possible, information sheets and consent forms should be trialled with a group of people who are similar to potential study participants.

People with intellectual disabilities must be given adequate time to provide their informed consent. Whenever possible, each participant should be provided with information about the study on an individual, face-to-face basis.

Informing support people

Careful consideration should be given to how people who are members of the person’s support network will be informed about the study. This includes ensuring that potential participants experience no coercion in making their decision about whether or not to take part in the study.

Keep a permanent record

Researchers should keep a permanent record of all information provided to confirm that the participants have been fully informed and have not been coerced into participating.

Informed consent

People with intellectual disabilities vary widely in their degree of intellectual disability and in their ability to understand, reason and communicate. Many people with intellectual disabilities will be capable of making decisions or giving informed consent, depending on the nature of the specific decision. The capacity of an individual to give informed consent should be assessed on a case-by-case basis.

Specific difficulties in providing informed consent

People with intellectual disabilities may not be able to understand the information provided or be able to articulate their thinking/reasoning adequately. Specifically, difficulties they face include:

  • a reduced vocabulary and understanding of abstract words and ideas
  • shorter attention spans and reduced short-term memory capacity
  • limited abstraction skills (that is, concrete and literal understanding of questions and situations)
  • a reluctance to flag when they do not understand, unless directly asked
  • difficulty following long, run-on sentences
  • difficulty answering time-related questions
  • being easily coerced into taking part.

Recording consent

Informed consent to participate in a study is usually given in writing. However, some people with intellectual disabilities may be unable to read and/ or write. In such circumstances, other methods of obtaining and recording informed consent may be necessary.

An audiotape of an oral discussion between the researcher and a potential participant that clearly indicates the information provided and decision-making processes can give a fuller record of the validity of the consent process than a signature on a consent form.

Applicable laws and regulations

Applicable legislation includes:

Case law with regard to section 17 of the Judicature Act 1908 has said that the approval of the court is required when:

  • the principal or major aim of a surgical procedure has a non-therapeutic purpose
  • the medical procedure involves interference with a basic human right.

For more information

For more information, refer to the NEAC Guidelines for Intervention Studies: Appendix 2.