Comfort with Proxy Consent to Research Involving Decisionally Impaired Older Adults: Do Type of Proxy and Risk-benefit Profile Matter?

Background: Dementia research often requires the participation of people with dementia. Obtaining informed consent is problematic when potential participants lack the capacity to provide it. We investigated comfort with proxy consent to research involving older adults deemed incapable of this decision, and examined if comfort varies with the type of proxy and the study's risk-benefit profile.

Methods: We surveyed random samples of five relevant groups (older adults, informal caregivers, physicians, researchers in aging, and Research Ethics Board members) from four Canadian provinces. Respondents were presented with scenarios involving four types of proxies (non-assigned, designated in a healthcare advance directive with or without instructions specific to research participation, and court-appointed). Given a series of risk-benefit profiles, respondents indicated whether they were comfortable with proxy consent to research for each scenario.

Results: Two percent of the respondents felt proxy consent should never be allowed. In all groups, comfort depended far more on the risk-benefit profile associated with the research scenario than with type of proxy. For research involving little or no risk and potential personal benefits, over 90% of the respondents felt comfortable with substitute consent by a designated or court-appointed proxy while 80% were at ease with a non-assigned proxy. For studies involving serious risks with potentially greater personal benefits, older adults and informal caregivers were less comfortable with proxy consent.

Conclusions: A large majority of Canadians are comfortable with proxy consent for low-risk research. Further work is needed to establish what kinds of research are considered to be low risk.