Understanding Mental Capacity in Clinical Research

May 15, 2024
By Ted Marriott

As a cinical trials professional (CTP), one of the key areas of research ethics you need to understand is mental capacity. What is it? How is it used and how do you ensure you are compliant with it in your research? That’s what we’re here to tell you.

  1. What is the Mental Capacity Act?
  2. What does capacity mean?
  3. How and when is mental capacity applied to research participants?
  4. How is the Act used in clinical research?
  5. Ensure your confidence with ethical research standards

1. What is the Mental Capacity Act?

The Mental Capacity Act is a legislation introduced by parliament in 2005. The Act is a guideline for decision-making on behalf of adults who lack mental capacity. It's used in various contexts, including clinical research and social care. It's an important framework for ensuring participants are not exploited and can safely participate in your trial. That's because it helps to ensure someone's ability to understand the information you provide them. With this information, they can decide if they wish to be part of your trial. Or, in some circumstances, the decision can be made for them. So, what is capacity exactly?

2. What does capacity mean?

Capacity refers to someone’s ability to make autonomous decisions. For someone participating in clinical research, autonomous decision-making is of the utmost importance. But, some individuals' decision-making can be compromised. Examples where this could be relevant include:

  • Someone living with dementia.
  • Someone living with brain damage.
  • Someone living with mental health illnesses.
  • Someone intoxicated.

As a CTP, you’ll be working on a variety of research projects throughout your career. In some instances, gaining consent and gathering data is a more straightforward affair. But, the situation could be different with someone living with dementia, for example. That's because these people can lack the capacity for autonomous decision-making, since they struggle to comprehend and remember information. But, clinical research into dementia can't happen without participants living with dementia! That's why this is an important framework for you to understand and navigate.

3. How and when is mental capacity applied to research participants?

The Act doesn't only apply to participants who lack capacity though. Even if you are collecting data from a questionnaire, your participants must have the capacity to consent to data gathering. This data gathering would be considered an intrusive research method. Thus, you can see why mental capacity has to inform the design of your clinical trial. If you are conducting non-intrusive research, the Act wouldn't apply to your research when:

  • You are using anonymised data.
  • You are using certain tissue samples.
  • You are using identifiable patient data with approval under Section 251 of the NHS Act 2006.
  • You are conducting clinical trials on investigational medicinal products (CTIMPs)

4. How is the Act used in clinical research?

So, the Mental Capacity Act is going to be relevant for the vast majority of your research. By now, we know it's an important framework for assessing and understanding autonomy and understanding.

However, what happens if a participant loses capacity during your research? Or you need to use subjects who do not meet the threshold for mental capacity? What about using the data of someone who had and now lacks capacity? Let’s dive into some of these:

  • Using participants who lack capacity

What do you do when your research requires participants with dementia? Or people with mental health illnesses? In these circumstances, you will need to apply for approval from the Research Ethics Services (RES). Section 31 of the Act stipulates that you should only be recruiting participants with the impairing condition relevant to your research. You have to argue that the research would not be as effective if it is only carried out on participants with capacity. There should be potential benefits without imposing a disproportionate burden on the participant.

  • The role of a consultee

If you are using a participant without capacity, they will need a consultee. A consultee is engaged in caring for the participant in the interest of their welfare. They will work with relevant researchers to give their advice and opinion on whether the participant would have consented to the research process if they had the capacity to do so, and if they should participate in the trial. They cannot make decisions on behalf of the participant or researcher. It is best practice to keep the consultee up to date throughout the research process.

  • Participants who lose capacity during research time

Generally, consent is not permitted after an individual loses their capacity whilst they are involved in your research. You will need to gain the advice of their consultee. However, data and samples can be used after the participant has lost capacity provided they have given written consent in advance.

5. Ensure your confidence with clinical research standards

By now, you can see why you need to be familiar with the Mental Capacity Act. Nevertheless, we’ve only scratched the surface here!

In 2023, the National Institute for Health and Care Excellence (NICE) published their Decision-Making and Mental-Capacity guideline. In it, they highlighted that a well-trained workforce (or the lack thereof) was one of the issues in practically putting their guidelines into action.

As NICE highlighted, this area of research ethics needs developing across the industry. At CGX, our mission is to train the next generation of CTPs so they are equipped with this knowledge.

We provide CTPs with both the ethical and technical knowledge they need to be confident in their careers, especially when they are working on clinical trials. Our training is relevant to CTPs at all levels of their career. Whether you are a new graduate or a career changer, you’re advanced in your career as a CTP and are looking to upgrade your skills, or you work for a company that needs to train their personnel – we're here to help.

With our blog space, we have a variety of resources on ethical standards for clinical research, including our posts on applying for ethical approval, the 6 ethical principles you need to know when it comes to clinical research, as well as our blog on racial health disparities. We offer in-person and online courses for CTPs at every level of their progression, as well as corporate training and consultancy services through our consultancy arm, Clinnovate. 

We’re perfectly positioned to make sure you can confidently apply ethical standards to your research, no matter who you are. Want to find out more? Don’t hesitate to contact us today.

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