For consent to be valid, the person consenting to treatment must have the capacity - or ability - to consent.

When assessing if someone has capacity to consent, the first thing to remember is that they need to be able to do three things.

1. Understand the decision they are being asked to make.
2. Retain the information for long enough to be able weigh it up and make a decision.
3. Communicate their decision to you.

Capacity in context

It's important to remember that the ability to consent might vary. If someone has had a sleepless night because they have an infection that has raised their temperature, it is easy to appreciate that they might not be able to process information as well as usual.

If you can control the infection and get them out of pain, they are likely to be in a better frame of mind to be able to take long-term decisions about their dental care.

Some patients have better times of the day for making decisions. For example, if a patient has dementia, they might get more confused as the day progresses. Try and arrange for them to make decisions at the time of day that suits them best.

The onus is on the dental professional to help a patient make a decision. If you think a patient is struggling to understand the information you're providing, try and break it down into easier to manage chunks.

Think about other methods of communication, such as providing written information. It's also sensible to ask the patient if you can involve others involved in their care with the decision-making process.

Unwise decisions

Always remember that a patient is allowed to make an unwise decision - and that just because they do so, it does not mean they lack capacity to consent.

However, it is very important that the patient understands both the short and long-term consequences of their decision. It can be tempting for someone who is very nervous of treatment to consider the short term 'benefit' of not proceeding with treatment, but it is the responsibility of the treating clinician to make sure that patient fully understands the risks of that choice.

Best interests

If you have established that an adult patient lacks the capacity to consent, you can provide treatment that is in their best interests. However, deciding precisely what is in their best interests is not always simple or straightforward.

If possible, think about getting a second opinion from a colleague. Find out if there is anyone who has an appropriate lasting power of attorney for making health and welfare decisions for the patient.

If there is, they should be asked to make the decision on behalf of the patient. If there isn't, involve anyone who has an interest in supporting or caring for the patient.

Capacity and children

With adults, you need to assume that they have the capacity to consent. With children under 16, you should ask yourself if they have the maturity to understand the decision you're asking them to make.

For most children, their ability to consent will increase as they grow up. The difficulty is that this does not happen at a uniform rate for all children. You cannot say that a child of a certain age will have the ability to make a particular decision. As with adults, you need to assess the individual child and decide if they have the capacity to consent.

As with adults, if a child has the maturity to understand the decision they are being asked to make, retain the information and weigh it up, and communicate their decision to you, they can consent to treatment.

And also like adult patients, the ability of any child to consent will depend on the complexity of the decision you're asking them to make. It might be relatively simple for a child to consent to an examination, but it is likely to be a much more complex decision to make if you think an adult tooth should be extracted.

If a child cannot consent, you will need to obtain consent from someone who has parental responsibility. This does not need to be done face-to-face, so if the child has been brought by someone else, you can phone a parent to get consent.

A parent can delegate the responsibility to consent to another appropriate adult. If a child has been brought to an appointment by another adult - for example, a grandparent or child minder - the parent might give them authority to consent on their behalf.

If you have not previously discussed this with the parent, it would be prudent to do so. Ideally, establish what decisions they have delegated to the other person to help prevent any confusion.

Even if a child can consent, it's still sensible to involve someone who has parental responsibility, so ask the child if you can discuss their care with a person who has parental responsibility.

Conclusion

There is no single way to assess if someone has the capacity to consent. It is necessary to tailor your approach to the individual patient, but also to stick to the basics of clear, jargon free explanations and constantly checking that the patient can understand the consequences of their choice.

It is also vital to remember that the assessment is usually not a 'one off' procedure. You need to check each time you see a patient that they can understand what you are planning to do and agree to you doing it.

If they can't, you need to decide if you should delay treatment or involve an appropriate adult in the decision-making process.

Finally, it is important to keep good records of your assessment of the patient - and with anyone aged 16 or above, the steps you have taken to try and assist them to be able to consent.