What happens when a Macro decision is full of Micro decisions?

The case of A,B,C v X,Y,Z (2012) identified that when considering mental capacity, we can divide decisions into two camps – Macro and Micro.

Macro decisions are those bigger, on-going decisions such as Health and Welfare and Property and Financial Affairs. Decisions that don’t just stop once you have signed a bit of paper but that at anytime may require us to make sudden or unforeseen interventions.

Micro decisions, on the other hand, are those one-off decisions that once made, have no on-going requirements, things such as making a Will or deciding what to wear.

But what happens when you have a Macro decision that is made up of a series of smaller decisions, such a managing diabetes?

Well, thankfully caselaw comes to our rescue once again. Re: Royal Borough of Greenwich v CDM (2019).

In this case, consideration was given as to whether the management of diabetes is to be considered a macro decision or a series of micro decisions. The judge decided that because ‘each decision was inescapably related to each other decision’ then it was necessary to take a more ‘global view’ of the decision.

Therefore, it had to be considered as Macro decision – rather than a series of micro decisions.

The key thing here is the interdependence of all the smaller decisions, such as diet, blood glucose testing, testing ketone levels, insulin administration that created a bigger, more global decision overall.

Why does this matter?

Understanding the difference between Macro and Micro decisions — and how they interact — is vital in assessing mental capacity.

As Royal Borough of Greenwich v CDM (2019) shows, when smaller decisions are closely linked and mutually dependent, they may combine to form a single, complex Macro decision.

This matters because the legal and clinical thresholds for assessing capacity may differ depending on whether the decision is seen as isolated or ongoing.

A person may appear to manage each task in isolation, yet struggle to grasp the overarching implications when those tasks must be understood and weighed together.

For professionals, this reinforces the need to assess capacity in a holistic, contextualised way — not as a tick-box exercise, but as a careful exploration of how decisions interrelate in real life.