Great importance is placed on the ethical principle of autonomy in medicine, as practiced in the United States today, and ensuring that a patient’s medical care is guided by his or her preferences is central to upholding this ethical principle. Ideally, patients would always actively participate in decisions about their own medical care. Unfortunately, the brain commonly becomes dysfunctional in the setting of organ failure and severe illness, and this is particularly true in the cancer patient. Patients with cancer can lose the ability to direct their care because of malignancy directly affecting the brain, as an effect of severe illness elsewhere in the body, and as a result of medication effects. Delirium is common in elderly patients and in patients with advanced cancer. Delirium often presents just as patients are becoming more seriously ill (and often will need decisions to be made regarding aggressiveness of care) and right before death. For example, in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT), 28% of patients with lung or colon cancer suffered from confusion in their last 3 days of life. However, such cognitive changes can be reversible and, in one study, 50% of episodes (often those precipitated by a change in opioid dose or by dehydration) in patients with advanced cancer were reversible. In addition, elderly patients have increasing rates of impaired cognition as they age. Patients with cognitive impairment who retain the ability to make decisions at baseline are at greater risk of developing delirium under the stress of illness.

Cognitive dysfunction has many implications for the elderly cancer patient. In general, cognitive dysfunction is a poor prognostic sign in older patients. Patients with cognitive dysfunction are also particularly challenging to care for and require special attention to care planning above and beyond the average patient. For example, patients with cognitive dysfunction may have problems with adherence to treatments and may require the assistance of a caregiver. In addition, these patients may lack the capacity to make decisions about their own health care. Because of the prevalence of delirium and cognitive impairment among elderly patients with cancer, assessment of decision-making capacity will almost always be necessary in the trajectory of disease of an older cancer patient; for this reason, it is essential to understand what decision-making capacity is. Decision-making capacity is defined as the ability to participate in making medical decisions. To have this capacity, a patient must: (1) understand the relevant information needed to make an informed decision; (2) have the ability to appreciate the clinical situation and its consequences; (3) reason about treatment options; and, ultimately, (4) communicate a choice.

For example, a man with myeloma who sustained a pathologic femur fracture and is refusing pinning of the fracture but cannot understand that surgery is needed or is unable to conceive of the risks and benefits of surgery lacks decision-making capacity because he does not understand the relevant information. If the man refused surgery but did not understand that without the procedure he will be unable to walk for months, if ever again, and that he would be likely to die if left to lie in bed for this time does not exhibit decision-making capacity because he cannot appreciate the clinical situation and its consequences. If the man refused surgery because “all operations are scary” and cannot even consider the option of surgery or the risks and benefits of surgery versus alternative treatments, then the case would be an example of a patient who lacks decision-making capacity because he cannot reason about treatment options. Lastly, a man who cannot or will not communicate a decision does not exhibit decision-making capacity. In nearly all cases, more than one aspect of capacity is compromised in a patient lacking decision-making capacity. Yet, teasing out the aspect of capacity that is lacking when a patient is deemed incapable can be a valuable exercise to ensure that a patient lacks capacity and also as a focus to attempt to enhance capacity.

Capacity is evaluated by a physician asking a series of questions. Table 29-1 shows specific questions and comments that can aid a physician in assessing capacity. For example, a physician can assess a patient’s understanding by asking, “Please tell me in your own words the problem with your health now.” “What is the recommended treatment?” A physician could then assess a patient’s ability to appreciate the situation and its consequences by asking, “What is treatment likely to do for you?” or “What do you think will happen if you choose not to proceed with the treatment?” A patient’s ability to reason through treatment options might be determined by asking, “Why do you prefer (or why do you not want) the treatment?” Lastly, asking, “Can you tell me your decision?” helps assess the patient’s ability to communicate his or her decision. If a patient is able to answer these questions in a coherent fashion (that is the patient displays decision-making capacity), then he should be able to accept or reject medical care, even if the physician disagrees with the patient’s decision.

It is important to note that decisions about a patient’s capacity have to be made on an individual basis. It is often possible for patients with psychiatric disorders or dementia to make at least some decisions, if not all of them. Although a patient’s past history can inform a capacity assessment, prior capacity determinations or prevalent diagnoses should not be assumed to deem a patient incapable of making future decisions. For example, a patient with a history of schizophrenia and a history of lacking decision-making capacity who is now receiving treatment that controls psychosis may be able to participate in his health care treatment decisions. In addition, a patient with a history of dementia, who had been actively participating in decision-making concerning breast cancer treatment, may suffer a decline in her cognitive abilities so that she is no longer able to meaningfully choose between treatment options.

When should a physician complete a capacity assessment of a patient? A good rule of thumb is that any time informed consent or refusal is required in medical care, it should be clear that a patient has decision-making capacity. In the above case, Ms. S. is refusing admission to the ICU and demanding to go home. However, she shows signs of a serious infection and is, at times, lethargic. In order to accept Ms. S.’s refusal of ICU admission, the emergency physician must assess her capacity to make that decision.

Although Ms. S. is able to communicate that she wants to go home, she is unable to articulate why and how she came to this decision. Therefore she does not have decision-making capacity to make the venue-of-care decision. Since Ms. S. does not have an advance directive or any prior medical record note regarding preferences for care, the emergency physician decides that the appropriate course of action is to treat the patient in the intensive care unit.

In practice, a formal evaluation of capacity is not completed for every patient who expresses preferences regarding the acceptance or refusal of a medical intervention. However, some degree of judgment about the patient’s ability to form and express preferences must occur every time a patient makes a decision. For selected patients, it is important that a formal capacity assessment be performed and documented in the medical record. If a patient has an underlying cognitive impairment, if a patient is at high risk of delirium due to an underlying medical condition, or if a patient’s expressed preferences fall outside of a range generally comprehensible to others, a more rigorous evaluation of capacity that covers all four of these elements is required, especially if the proposed procedure or clinical condition has serious clinical consequences to the patient. It is important to recognize that some patients, especially those with slowly emerging dementia, are able to mask their cognitive impairment. Mini-mental status exams (MMSE) and other objective tests should be considered in all vulnerable elders to assess cognitive status when important decisions are being made.

Ms. S., in the case above, is an elderly woman with metastatic brain disease and signs of acute infection, all of which put her at high risk of delirium; thus she deserves a formal evaluation of capacity. Documentation about decision-making capacity for a patient should cover all four areas that are assessed: understanding of relevant information, ability to appreciate the clinical situation and its consequences, ability to reason about treatment options, and ability to communicate a choice. In this case, a physician might document, “Ms. S. is expressing the desire to go home. Although comfort-oriented care at home may be a reasonable option given her metastatic disease, we have no evidence that she previously desired this course of treatment. Ms. S. is unable to describe or understand her current clinical situation, does not understand the implications of her situation, and cannot engage in reasoning about her treatment options. Therefore, despite the fact that Ms. S. is asking to go home, this cannot be considered a reasoned decision. Ms. S. lacks decision-making capacity at this time. Because she has a potentially life-threatening condition that needs emergent care, we will treat her using implied consent and search for an appropriate surrogate decision maker until she regains the ability to make decisions for herself.” On the other hand, if Ms. S. had been able to express that she knew she had cancer and had decided that she never wanted to go to an ICU, was ready to die, and did not want to die in a hospital, she would have displayed that she had capacity to make this decision (even though she has risk factors for incapacity).

There are methods or tools available to assist in the assessment of decision-making capacity. Many of the tools available for clinical research are not adequate for assessing all four domains of decision-making capacity. Some tools for clinical practice have been developed; however, these are often time-consuming. For example, the MacArthur Competence Assessment Tool (MacCAT-T) assesses the domains of decision-making capacity using a structured interview format. The Capacity to Consent to Treatment Instrument varies from the MacCAT-T in that it uses clinical vignettes to test a patient’s understanding rather than using a structured interview format. The Hopemon Capacity Assessment Interview (HCAI) is also similar to the MacCAT-T but uses semistructured interviews and was initially designed to specifically assess medical and financial decision making in nursing home patients.