Third, it is understood that the decision-making abilities of many older people with dementia or other mental disorders will be impaired to some extent. However, mere impairment does not amount to incapacity. Whether a person’s impairment (in understanding, appreciation, or reasoning) is substantial enough to preclude informed consent for a particular study depends on the complexity of the decision-making task for that study, and on its risk-benefit profile (Grisso and Appelbaum, 1998; American Psychiatric Association, 1998; National Bioethics Advisory Commission, 1998). A minimum threshold of capacity must be satisfied for all studies in which the participant is exposed to any risk, but the level of capacity needed above this floor will depend on the characteristics of the particular study. Moreover, impairments that would preclude valid consent in studies with significant risk are ethically immaterial in studies involving less than minimal risk (National Bioethics Advisory Commission, 2001). Similarly, additional safeguards that may be needed to ensure proper consent in studies involving significant risk are not necessary in studies involving lower risk. Risk stratification of this kind is a prominent and essential feature of sensible ethical review.
Fourth, even if an elderly person lacks the capacity to give informed consent for the particular study, his or her participation may be authorized by a surrogate decision maker as long as the subject is adequately protected from harm and the IRB finds that all the other criteria specified in the Common Rule have been met. The Common Rule, however, provides very little guidance to IRBs, within these parameters, about the conditions under which surrogates should be permitted to authorize participation for decisionally incapable subjects in lieu of excluding them from participation altogether (Bonnie, 1997; Dresser, 2001; National Bioethics Advisory Commission, 1998). This lack of guidance has led to inconsistency among IRBs and frustration among investigators. However, recent reports by expert bodies have begun to provide such guidance and to assemble best practices (National Bioethics Advisory Commission, 1998; American Psychiatric Association, 1998). The important point for our purposes is that the Common Rule provides ample flexibility to IRBs to allow important research on elder mistreatment to go forward on the basis of surrogate consent, particularly if it involves less than minimal risk.
Finally, another concern is the availability of a suitable surrogate. The Common Rule refers generally to individuals “authorized under applicable law to consent on behalf of a prospective subject’s participation.” As Dresser (this volume) notes, however, many states lack clear rules in this area. To the extent that impediments to research arise from ambiguities or constraints in state law governing surrogate decision making, these are generic problems in research that, in the end, depend on clarification of state law. The panel urges states to extend their rules governing surrogate