Older study participants – guidance

There is no age at which people become ineligible to participate in a study.

It is important to include older people in studies, and it is generally agreed that older people are not usually in need of special protections, except in two circumstances: cognitive impairment and institutionalisation.

Cognitive impairment

Cognitive impairment in older participants should be treated as it would be in any prospective participant. Cognitively impaired people should only participate in a study:

  • when competent participants are not appropriate
  • if the study is related to a problem unique to people with that disability
  • if the study involves minimal risk.

Older people with some impairment to their competence can participate in a study if they can still make reasonable choices. For more information on older participants with impairments, refer to the guidance on participants with an intellectual disability.

Participants living in institutions

In the past, people in nursing homes or other institutions have been selected as study participants because of their easy accessibility.

However, it is now recognised that conditions in institutional settings increase the chances for coercion and undue influence because of the lack of freedom inherent in such situations.

Studies should therefore avoid institutional settings. The exception is if the study specifically requires the involvement of the institutional population, for example:

  • the disease or condition is endemic to the institutional setting
  • people who suffer from the disease or condition live primarily in institutions
  • the study focuses on the institutional setting itself.

Other issues to consider

  • Older people tend to have multiple conditions/ co-morbidities, and this may complicate studies that seek to isolate a particular intervention for a particular condition.
  • Older people have more complications from medical drugs than younger people. Because the likelihood of unfavourable drug interactions increases as the number of drugs an individual takes increases, for older people, it is important to limit the number and dose of drugs prescribed.
  • Symptoms of many diseases in older age may vary markedly from symptoms of the same diseases in earlier life.
  • Older people may have hearing or vision problems and may therefore require more time to have the study explained to them.
  • Older people may drop out of studies at a higher rate than younger participants, so investigators may need to recruit more participants to account for this possibility.

The investigator should also consider the following questions:

  • How will we confirm the participants’ competence to consent to taking part in the study? Does the proposed consent process provide mechanisms for determining that prospective participants’ comprehension and recall is adequate?
  • If the study is to take place in an institutional setting, has the possibility of coercion and undue influence been sufficiently minimised?
  • If older people have been excluded from the research, are the reasons for this exclusion valid?
  • Does the research methodology provide adequately for older people (and others) with hearing and/or vision problems or with communication difficulties?

For more information

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