The authors reply

We appreciate Dr. Oud’s interest in our work describing covert critical illness encephalopathy and his insight that these findings raise important implications for research and routine care.(1) Operationalizing informed consent is difficult and deficiencies are common in real world practice.(2) In 2009, a subcommittee of the DHHS Secretary’s Advisory Committee on Human Research Protections released a report on inclusion of individuals with impaired decision-making in research which found that cognitively impaired individuals are uniquely susceptible to research related harm, that regulations and Institutional Review Boards (IRBs) are either silent or disjointed in their approach to safeguards, and that investigators receive limited and inconsistent training in assessing consent capacity. Many IRBs rarely or never require procedures to determine consent capacity in research involving critically ill patients and only 24% reported frequent use of standardized, validated assessments.(3)

The intensive care environment is a particularly challenging context in which to balance protecting vulnerable individuals while avoiding systematic exclusion from research in a way that can perpetuate or exacerbate disparities.(4) Our study was prospectively designed to verify capacity, a process made less burdensome by its straightforward design as a single, brief encounter determined to be minimal risk by the IRB.(5) Other research presents far greater complexity with respect to consent capacity, and we agree that this area deserves further study.

More broadly relevant is the concern about decisional capacity for routine healthcare. The prevailing framework, codified into law in some jurisdictions, is to approach patients with a presumption of capacity. In some situations, systematic evaluation of an individual’s cognitive abilities and applied judgment is necessary to ensure they retain decisional capacity. How decisions to initiate more extensive assessment should be organized to balance the risk of harm from failure to protect vulnerable patients against the risk of systematizing biases based on crude risk models is controversial.(6) In practice, too few practitioners are adequately trained on informed consent and capacity evaluation despite engaging with these processes routinely, and often use an informal, intuition-based approach to decide which patients’ decisional abilities to interrogate more extensively. These deficits are further complicated by the fact that commonly used capacity assessment instruments were designed and validated in populations with substantially different impairments (e.g., outpatients with schizophrenia) making their utility in critically ill patients questionable, and by the fact that many practitioners are not educated on or trained in concepts like sliding-scale capacity, where capacity determination depends on the complexity and risk of the decision to be made.

Impaired decisional ability is often underrecognized and the covert nature of moderate cognitive impairments in the milieu of the intensive care unit, which we found to be common, may contribute to this challenge. Further work is needed to help us adapt the way we engage critically ill patients to ensure their needs are fully accommodated and their interests are protected. While that work is ongoing, we suggest regular involvement of trusted individuals to support patients in crucial decision making even when capacity is presumed.