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Determining incapacity


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Five years ago, a judge’s decision provided us with helpful guidance on how to diagnose incapacity. The case related to JB, a 62 year old lady with paranoid schizophrenia. It was agreed that she lacked insight, and thus capacity, to make decisions about treatment for her mental illness. JB also had a gangrenous foot; she was a hypertensive insulin dependent diabetic who smoked heavily. The foot had become ulcerated in May 2013. By August of the same year gangrene had set in, and the court was told that auto-amputation was considered her best option.

During the subsequent autumn the foot, not yet separated, was the source of ascending infection. Surgical amputation to protect the remaining leg was mooted but JB did not agree. There was no clinical consensus over her capacity; some thought she was simply making an unwise decision, whilst others considered she lacked capacity. The latter view was based on the observation that whilst JB could understand and retain information related to proposed alternative treatments, her long standing pattern of minimising and underplaying concerns relating to her health compromised her ability to weigh opposing risks and benefits. This, some argued, rendered her unable to reach a decision.

The decision to amputate was deferred, but when the foot eventually separated in January 2014 it left an open wound, and distal leg amputation was again recommended, although the court found no settled plan as to the proposed level of resection. During the ensuing discussions relating to JB’s capacity, the need for ‘certainty of her capacity…or certainty she lacks capacity’ was recorded in the hospital notes.

By February, the hospital applied for a declaration that JB lacked capacity to make a decision about serious medical treatment, and that a through-knee amputation, together with any necessary sedation, was in her best interests.

The court set out several principles. Firstly, that ‘...the temptation to base a judgement of a person’s capacity upon whether they seem to have made a good or bad decision, and in particular upon whether they have accepted or rejected medical advice, is absolutely to be avoided. That would be to put the cart before the horse or, expressed another way, to allow the tail of welfare to wag the dog of capacity. Any tendency in this direction risks infringing the rights of that group of persons who, though vulnerable, are capable of making their own decisions. Many who suffer from mental illness are well able to make decisions about their medical treatment, and it is important not to make unjustified assumptions to the contrary’.  

Secondly, what was required of JB was a broad general understanding of the kind that is expected from the population at large. Clinicians must also remember that common strategies employed by all citizens to deal with unpalatable dilemmas, such as indecision, avoidance and vacillation, are not to be confused with incapacity - we should not ask more of people whose capacity is questioned than of those whose capacity is beyond doubt.

Thirdly, the judge cautioned us to remember that the presumption a patient has capacity is displaced on the balance of probabilities; we are not searching for certainty, or for a demonstration that a patient can fullyunderstand, retain, weigh. Such formulations do not sit well with the requirements of the Mental Capacity Act 2005. Finally, as a more general point, the court warned us of the danger that the patient ‘…is regarded as capable of making a decision that follows medical advice but incapable of making one that does not’.

Applying these principles to the evidence, the court found that it did not follow that JB’s lack of insight into her mental illness correlated with incapacity to decide over amputatio, and that it had not ever been established that she lacked capacity to consent to or refuse surgery. On the contrary, the evidence established her capacity to choose whether or not to have surgery, and she was free to make that choice. It appeared, by the end of the hearing, that she was discussing the possibility of a below knee amputation with her doctors. She was therefore preparing to consent, rather than having amputation forced upon her.


Robert Wheeler
Department of clinical law, June 2019