Consent Kit

Decision Making Capacity

Phil Hesketh

by Phil Hesketh

March 05, 2020

Decision making capacity (or DMC) comes from the informed consent doctrine; an ethical principle that is pervasive in modern medicine, but is often overlooked when talking about consent in the context of design research.

This article is part 3 of a series of 4 on best practices around informed consent. You can read Part 1: Informed consent best practice and Part 2: The data we collect.

The Informed Consent Doctrine calls for three elements to be present when asking for consent:

  • the adequate disclosure of information;
  • voluntariness, such that the person’s choice is made free of coercion or undue influence; and
  • competence, meaning that the person has sufficient DMC to use the information given to reach a decision.

Things to consider before asking

So when you’re thinking about how you will ask someone for their consent, consider these three points:

  1. At the point of asking, does the person have enough information about the research?
  2. Are they being pressured or unduly influenced to take part?
  3. Are they able to use the information we gave them to make a decision about whether or not they should take part in the research?

While the adequate disclosure of information is relative to the context of the research, there are elements which should always be disclosed. Check out our Informed Consent Checklist for more information. In part 4 of this series we’ll go into voluntariness, or as GDPR puts it: “Consent must be freely given.” But right now, let’s take a closer look at competence.

Understanding someone’s competance

We have an ethical and legal obligation to attempt to understand someone’s competence or DMC before asking for their consent. Here are a few questions you can ask yourself before asking for consent:

  1. Are we asking them in a language that they are very comfortable with?
  2. Are they of sound mind / under the influence of any substance that might prevent them making a decision in their best interest?
  3. Is the language we’re using plain and appropriate?
  4. Are they comfortable with the format it is received in?
  5. Can they practically consume what you are asking and understand any potential consequences within the time available to them?

If the honest answer is no to any of those questions, it’s time to put the breaks on and think about your approach. What do you need to change to give someone the best possible chance of making a decision in their own best interest?

Testing comprehension

Where the research is sensitive and has potentially serious consequences, testing people’s comprehension of the information you give them becomes increasingly important. It’s also quite hard to do. The impact of new systems and technologies can create consequences that we might not fully understand ourselves.

In medical research, where consequences can be immediate and potentially severe, quizzes are included with consent to literally test comprehension before permission is given. As I mentioned in part 1, there is a sliding scale as to how many of these measures should be incorporated. Practically, in many studies this would be overkill, but it’s useful to think about if you’re working with vulnerable people.

This article is part 3 of 4 on best practice in informed consent. In part 4 we’ll talk about Consent being freely given.