Physicians often find it hard to tell if a patient suffering from dementia or depression is capable of making sound judgements. This is shown by a study conducted within the scope of the National Research Programme "End of Life" (NRP 67). The Central Ethics Committee of the Swiss Academy of Medical Sciences now aims to elaborate new assessment principles.

The question whether a patient is capable of making sound judgements is of central importance for all medical treatments. Only patients who are able to understand, retain and weigh the information they receive from the physician can give their valid consent to a treatment. If the patient's decision-making capacity is impaired, according to current legislation the physician needs to consider a living will or consult a patient-appointed proxy.

"Brain injuries or illnesses such as dementia or severe depression can cause an incapacity to make decisions," says Manuel Trachsel, senior assistant at the Institute for Biomedical Ethics of the University of Zurich. This is particularly so when people with a terminal illness reach the end of life. Some crucial and complex decisions are needed at this stage: Should life-prolonging measures be discontinued? Is the patient perhaps contemplating an assisted suicide?

Anything but trivial

"Assessing someone's decision-making capacity is anything but trivial," says Trachsel. The result of the assessment may not be the same for all situations. For instance, someone may be regarded as capable of adequate decision-making when it comes to everyday matters such as clothes or food, but as incapable of just this in relation to a difficult medical decision. In addition, the cognitive capacities of patients suffering from Alzheimer's or Parkinson's disease can fluctuate considerably from day to day. In a specialist journal, Trachsel and his colleagues Helena Hermann and Nikola Biller-Andorno recently discussed how physicians might nonetheless be able to assess decision-making capacity in such difficult circumstances (*).

But what do physicians understand by "decision-making capacity" in the first place? In the context of the National Research Programme "End of Life" (NRP 67), Trachsel interviewed around 760 physicians from all over Switzerland. The results, which have now been published (**), suggest that the vast majority of physicians feel they are responsible for assessing the patient's decision-making capacity. However, even among those with a very strong sense of responsibility, only about one third believe they are competent enough.

Rules of thumb vs guidelines

Physicians show a lack of consensus when it comes to defining decision-making capacity, identifying the key assessment criteria and describing the way in which they assess someone's ability to make decisions. "Most physicians apply their own rules of thumb to determine whether a patient is capable of making decisions or not," says Trachsel. Few of them are aware that various guidelines for assessing someone's decision-making capacity are already in place.

Nevertheless, among the interviewed physicians an overwhelming majority expressed a desire to have access to such assessment tools. A large majority was in favour of clear guidelines and showed an interest in taking courses on the subject. These innovations will soon be a reality: based on the results of the survey, the Central Ethics Committee of the Swiss Academy of Medical Sciences (SAMS) has decided to engage with the topic and elaborate principles for assessing medical decision-making capacity as of next year.