Grant Chow, MD, was a resident in the intensive care unit at Johns Hopkins Bayview Medical Center in Baltimore when he encountered two ethically challenging cases in a single week. The first was a severely ill elderly woman who asked to be discharged from the emergency department so she could die at home; the second was a man who had been found unresponsive and had significant respiratory acidosis, but was refusing intubation.
After struggling on his own to decide whether these patients had the capacity to make these decisions about their care, Dr. Chow saw a need for a simple, easy-to-remember method for making such determinations. He developed a mnemonic: Choose and Communicate, Understand, Reason, Value, Emergency, Surrogate (CURVES) (See box).
An explanation of CURVES was published in Chest in February by Dr. Chow; Joseph A. Carrese, ACP Member and associate professor of medicine at Johns Hopkins; and their colleagues Matthew J. Czarny, BS, and Mark T. Hughes, ACP Member. Drs. Chow and Carrese spoke to ACP Hospitalist about the mnemonic.
Q: What convinced you that there was a need for this mnemonic?
A: Dr. Chow: As a resident, I struggled to recall the criteria for medical decision-making capacity, particularly in emergencies. When I was in the ICU, in particular, I frequently had to refer to an online review to refresh my memory. Because so many things were going on, it was difficult for me to retain a lot from week to week. After the two emergencies happened to me, after reading the reviews several times and still being unable to recall any of the criteria on my own, I decided to maybe think up a mnemonic for those events in residency where we don't have much time to make an assessment.
Q: How do you think other physicians have been dealing with this challenge?
A: Dr. Carrese: It's a mixed bag. Some people have developed their own systems and are doing it in a thorough and adequate way, but I think a lot of people end up muddling through this, because it never really gets taught to them in a way that they can remember and do systematically and thoroughly on a regular basis. Some people, frankly, make mistakes. They end up thinking, “I can just use the score on the Mini-Mental State Exam to decide whether or not somebody has decision-making capacity.” That's a common misunderstanding.
Q: How did you develop the mnemonic?
A: Dr. Chow: I thought it would be fantastic if we could come up with a mnemonic that was something like CAPACITY, but I'm not that smart. I used the letters that were in front of me. The impetus behind all this was an ethics morning report. Initially, I wanted to just present the two emergencies so my fellow residents would be better prepared for similar events. We got a lot of nice feedback after that 45-minute period and we figured we would maybe share it with others then.
Q: How has the mnemonic been applied in practice?
A: Dr. Carrese: I direct a program on ethics and clinical practice. We have opportunities to interact with the surgery residents, OB/GYN residents and neurology residents, and we have been incorporating this device when we're teaching about assessing decision-making capacity, whether we're focusing on that alone, or whether it's in the context of teaching about informed consent.
Q: Is the mnemonic applicable outside of those areas? How could hospitalists use it?
A: Dr. Carrese: The paper presented emergency cases, but the first four letters of the mnemonic—CURV—address the major components and domains of assessing decision-making capacity in any setting. It does not have to be an emergency setting to use the notion of communicating and choosing (C), understanding (U), reasoning and providing reasons (R), and the importance of incorporating and assessing patient values in the decision (V).
Q: What are the limitations of the mnemonic?
A: Dr. Chow: CURVES really will give you an idea of what a patient is capable of and what they understand at a single point in time. But it should really be noted that the longer a primary practitioner is familiar with a patient, the easier the assessment of capacity is likely to be. The one letter in CURVES that I think is the most difficult is the V, the values. If you just met somebody, it is really hard to say, “Is the decision they're making consistent with what they would have said yesterday or a week ago or a year ago?”
Q: Any other things physicians should keep in mind about this topic?
A: Dr. Chow: We are fairly documentation-heavy nowadays and it's very important to list everything that went into a medical decision so that people can read your notes later and understand what you were thinking. The CURVES mnemonic can also provide a good backbone for an event note or a discharge summary—any sort of documentation where you say, “This is how I assessed capacity in a specific way and this was my conclusion.”