Informed consent for medical research by the elderly.

Much has been written about the possible lack of capacity of the elderly, especially certain vulnerable populations of older individuals, to give informed consent for medical research. Several small studies have shown a deficit for comprehension of consent material, by the elderly, especially those with less education, but this appears small in comparison to an overall deficit in the general population. A number of investigations have suggested that deficits in executive control functions (ECFs) may be related to lack of capacity to make clinical judgments, but these have yet to be applied to research. Many methods have been piloted to measure capacity and to improve comprehension, some of which may help, although none has been proved conclusively to do either. As the elderly experience significant morbidity and mortality from a vast array of illnesses, the use of the elderly as subjects of medical research is especially important. To prevent older individuals from being coerced into participating or potentially being harmed by scientific investigation, they must give informed consent to their involvement. However, there are many studies to suggest that they are not well informed. A discussion ensued in the 1970s and 1980s about whether or not the elderly deserved special protection as a class of individuals, based on their possible increased risk during medical experimentation, but it was ultimately decided that, because the majority of elderly are perceived to be cognitively intact, they need not receive additional safeguards (High & Doole, 1995, Behavioral Science and Law, 13, 319-335). The U.S. Department of Health and Human Services in 2000 (Federal Registrar Rules and Regulations, 46, 8366-8392) reviewed existing protections for subjects of human research and deemed they were inadequate, issuing new guidelines. This article reviews evidence that differences exist between the ability of young and old in their capacity to give consent. Alterations in methods of obtaining consent may help individuals to give a more informed consent, and even enable subjects who lack the capacity to consent, such as cognitively impaired individuals, to participate in research. However an ideal means of screening or altering the consent process has yet to be devised. Many of these methods are briefly considered.