Curbside Consultation

Practical Considerations for Determining Patient Capacity and Consent


Am Fam Physician. 2010 May 1;81(9):1090-1092.

Case Scenario

I have a 72-year-old patient, S.G., who has been in my practice for about two years. He seems generally healthy but has recently presented with knee pain and occasional headaches. The problem is that he is a little “off.” For example, when I recommended that he have a colonoscopy, he said he would think about it. At his next visit, he brought a piece of paper from which he read, “Aren't you going to test me for colon cancer?” When I reminded him that we had discussed this, he said, “Oh, that. I thought you were noodling me.” I wrote another referral for his colonoscopy, but he never followed up.

Although S.G. appears to be functional living alone, I know he drinks heavily. He scored a 16 on the Mini-Mental State Examination, during which he said, “If you want me to count backwards, I'm going to do everything backwards.” He deliberately flubbed the rest of the test. He has two daughters who accompanied him once to his appointment. I asked them whether S.G. had any mental illness or problems with forgetfulness, but they dismissed his behavior as part of his personality.

At a recent office visit, S.G. said he had been experiencing dizziness. Laboratory tests showed he had mild iron deficiency anemia. He agreed to have an esophagogastroduodenoscopy (EGD), but refused a colonoscopy. How do I know whether his refusal of colonoscopy or his consent for EGD are truly informed decisions?


The core issue is whether the patient possesses decisional capacity and can provide informed consent. If he cannot, you must do what you can to act in the patient's best interest. In any discussion of this nature, it must be assumed that the patient is older than 16 to 18 years, depending on local laws, and possesses decisional capacity, unless it can be firmly established otherwise.

The goal is to determine whether the patient can comprehend, appreciate, and reason the contingencies of treatment or nontreatment. It is also important to determine whether the patient has the capability to communicate his or her choices about these options.1 These factors are essential for consenting to, or validly rejecting, particular medical treatments.2

To accomplish this, the physician must provide relevant information appropriate to the patient's age and educational level. This includes explanation of benefits, burdens, and risks of treatment or nontreatment. The patient's family should be involved in this process as needed to provide emotional support and bridge potentially aggravating communication gaps between the patient and physician.3

Fully capable patients often make decisions about their care that physicians may regard as unwise. This alone does not constitute a lack of capacity. The important question is whether the patient's decisions, or the decision-making process, reflect a pattern that puts the patient at risk or is inconsistent with his or her previous or current patterns of rationalization.

Additionally, determinations of capacity should not rely on age, appearance, condition, or behavior.4 For example, although 16 to 18 years of age is regarded as a valid threshold of decisional capacity, there are some younger patients who are cognitively and emotionally mature and capable of engaging in rational decision making as relevant to their medical care. Similarly, older patients should not be assumed to have decremented decisional capacity simply because of their age. Also, patients who appear somewhat disheveled or inappropriately dressed or groomed; who have a specific medical condition (e.g., depression); or who are behaving unusually should not be assumed to lack capacity.

In this scenario, S.G.'s behavior, although it seems a bit “off,” may not reflect a lack of capacity. It may represent a medically induced exacerbation of the patient's normal character and affect. It is important to rule out any reversible organic processes that may be impeding the patient's capacity, including any contributory depression or adverse effects of medication. Hematologic, metabolic, and neurologic workups should be included. Evaluation for dementia should be considered, as well as rare causes of neurocognitive impairment (e.g., chronic central nervous system infection, neuroinflammatory disorders).

There is no rule for deciding whether to first assess the patient's capacity or to test for medical conditions capable of affecting capacity. This is often a matter of situational severity (e.g., profound agitation, inappropriate behavior), frank irrationality, lack of comprehension, or another blatant cognitive impairment or irregularity. Guidelines are available to help physicians assess patients' decisional capacity at the bedside.5 Although this clinical judgment is often handled responsibly by primary care physicians, any doubt regarding a patient's decisional capacity may be addressed through a psychiatric consultation.

Psychiatric or psychological evaluation involves testing patients' memory, attention, reasoning, interpretation, and ability to communicate. However, there is a catch-22 situation: patients must consent to the evaluation and cannot be coerced or forced to submit to an assessment. This situation is not intractable. If a physician feels that a patient lacks capacity to understand information and make decisions about his or her own care, a consulting psychiatrist is usually able to ascertain the patient's cognitive capabilities during a brief examination.

In some situations, if the psychiatrist has reasonable belief that the patient may lack capacity or have impaired capacity, this is sufficient to legally show that the patient lacks competence and cannot refuse further examination.6 In this case, the physician must work with the patient's family, next of kin, or a valid surrogate in the decisional processes that ultimately shape the scope and trajectory of the patient's care.

Address correspondence to James Giordano, PhD, at Reprints are not available from the authors.

Author disclosure: Nothing to disclose.


show all references

1. Lo B. Assessing decision-making capacity. Law Med Health Care. 1990;18(3):193–201....

2. Wirshing DA, Wirshing WC, Marder SR, Liberman RP, Mintz J. Informed consent: assessment of comprehension. Am J Psychiatry. 1998;155(11):1508–1511.

3. Etchells E, Darzins P, Silberfeld M, et al. Assessment of patient capacity to consent to treatment. J Gen Int Med. 2001;14(1):27–34.

4. Karlawish JHT, Pearlman RA. Determination of decision-making capacity. In: Cassel CK, Leipzig RM, Cohen HJ, Larson EB, Meier DE, Capello CF, eds. Geriatric Medicine: An Evidence-Based Approach. 4th ed. New York, NY: Springer-Verlag; 2003:1233–1241.

5. Tunzi M. Can the patient decide? Evaluating patient capacity in practice. Am Fam Physician. 2001;64(2):299–306.

6. Matthews E. Autonomy and the psychiatric patient. J Applied Philos. 2000;17(1):59–70.

Case scenarios are written to express typical situations that family physicians may encounter; authors remain anonymous.

Please send scenarios to Caroline Wellbery, MD, at Materials are edited to retain confidentiality.



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