Another complex case distilled on the issue of fluctuating capacity

The issue of capacity assessments for patients with long-term conditions requiring multiple decisions and careful oversight of medication, in particular, is difficult. Increasingly, the courts have been asked to consider cases involving fluctuating capacity.

In a recent case involving the Royal Borough of Greenwich, the court had to grapple with the care needs of CDM, a diabetic with a personality disorder. The court had to consider whether assessing capacity in terms of diabetes management is one macro-decision or whether it should be assessed in respect of each micro-decision or group of micro-decisions, such as decisions around diet, insulin and blood testing.

CDM was a 63-year-old woman who lived alone with her pets following the death of her husband in 2014. She had a long history of poorly controlled diabetes and there were concerns that her home and health had deteriorated. In 2017 CDM’s toe was amputated and, subsequently, her lower right leg – but prior to the leg amputation she had fallen and fractured her hip. As a consequence, CDM required ongoing care and a post-discharge care plan was devised. Although she was recorded as being oppositional in her approach to professional advice.

After a short period at home, CDM was found by ambulance staff sitting in vomit and faeces following her discharge; she was taken to hospital for assessment and then transferred to a nursing home. But she clearly expressed a wish to return home to her pets. 

The local authority responsible for her care were sufficiently concerned and issued an application in relation to her capacity, residence and care. Over four days in June 2018, the court heard several applications concerning CDM in relation to these issues. The issue of capacity in relation to her diabetic care was the focus of the final judgment of the court, following hearings later in 2018.

The Official Solicitor, representing CDM, sought a ruling to say capacity decisions could be made prospectively. The argument was that this would allow professionals responsible for CDM’s care to make decisions in her best interests without daily capacity assessments. They also argued that looking at diabetes management on a macro level was not in accordance with autonomy.

The court emphasised the need to make time specific decisions about capacity. Taking account of expert psychiatric evidence, which indicated that the decisions for care were interrelated and impacted by her personality disorder, the court decided that CDM’s mental state appeared to flow from her poorly controlled blood glucose, which then aggravated her diabetes. 

The expert had assessed that it was doubtful whether CDM had capacity to manage her diabetes effectively most of the time. Many of the decisions she had to make caused her too much distress: she became emotionally unstable and then lost capacity.

The court agreed that, in order to regulate CDM’s emotions, firm and consistent boundaries needed to be put in place to make her feel more valued and appreciated.

Capacity decisions: macro v micro

The court emphasised that a decision about whether capacity was to be decided on a macro or micro basis for long-term conditions would be fact specific. 

In relation to CDM, the court came to the following conclusions:

  • “on the assessment of capacity to make decisions about diabetes management, in all its health consequences, the matter is a global decision, arising from the interdependence of diet; testing her blood glucose and ketone levels; administration of insulin; and, admission to hospital when necessary in the light of blood glucose levels. And
  • CDM lacks the capacity to make those decisions, and having regard to the enduring nature of her personality disorder which is lifelong and therefore unlikely to change.” 


A key practical point from this case is the need to record carefully the individual decisions required for those who lack capacity and whether or not it is considered that multiple decisions inter-relate sufficiently to indicate an overall lack of capacity.

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