Is presumed consent the answer to organ shortages?

December 14, 2017 by Ivo Vlaev, University of Warwick

In an effort to increase the number of organs available for transplant the UK's Department of Health is proposing a move to 'presumed consent' so people have to opt-out of donating their body parts when they die. Ivo Vlaev, Professor of Behavioural Science, argues evidence from the changing of default settings in other ares, shows this will work.

Traditionally policies and interventions to change people's behaviour, such as health campaigns on smoking, have tended to focus on providing new information, which seeks to change the way people think about their behaviour or by using financial or legal incentives that change the consequences of behaviour.

But these interventions can only get us so far. Many behavioural interventions in health that are targeted at specific individuals or groups rely on influencing the way people consciously think about their behaviour: if we can change people's motivations and intentions, they will change their behaviour accordingly.

The problem is that a substantial proportion of the variance in behaviour is not explained by intentions. In contrast to economic models of rational choice suggesting that we respond to information and price signals, insights from across the behavioural sciences suggest that human behaviour is actually led by our very human, emotional and fallible brain, and influenced greatly by the context or environment within which many of our decisions are taken.

A better understanding of human decision-making, its rational as well as irrational aspects, provides us with opportunities of influencing choices that take better account of how people actually respond to the context within which their decisions are made—the 'choice architecture' as it is called in Richard Thaler and Cass Sunstein's book Nudge.

Policies that change the context or 'nudge' people in particular directions have captured the imagination of policymakers at the same time as the limitations of traditional approaches have become apparent.

One such nudge technique is known as a 'default', which is based on evidence that we automatically tend to 'go with the flow' of pre-set options. This is the nudge being proposed with the presumed consent of organ donations and has already been a success elsewhere in the world.

Credit: University of Warwick

Defaults are choice options that are assumed as pre-selected if the individual does not make an active choice of another available alternative. Many of us will be aware of our tendency to stick with the pre-set option and that is why defaults are so powerful.

Techniques that change defaults have been very successfully used to change behaviours in various settings. Defaults have been mostly used to change financial behaviours.

When the default is to automatically enrol employees into a pension plan about three-quarters tend to retain both the default contribution rate and the default asset allocation. While introducing a participation default can increase rates of new employees joining the pension plan by more than 50 per cent.

Will changing the default for organ donation save lives?

Such powerful effects of defaults on behaviour have been observed in a wide range of other settings like the choice of car insurance plan, car option purchases, consent to receive email marketing, employees' contributions to healthcare flexible-spending accounts, and vaccination and HIV testing for patients and healthcare workers.

In an intensive care setting, dramatic improvements in outcomes have been seen when lung-protective settings and breaks in sedation for ventilated patients were ordered unless otherwise indicated by a physician.

So a number of studies have shown that on both the provider and public side can be dramatically influenced by the default setting and the most prominent example is about the opt-in/opt out setting around .

Presumed consent for organ donations—where people opt out by indicating that they are not willing to donate their organs upon death—is a controversial use of the default nudge.

Credit: University of Warwick

Austria, France, Poland, and Portugal have such a system and as a result 90 to 100 per cent of their citizens are registered donors, compared to only five to 30 per cent in countries that do not use the donor default strategy.

In the UK to be on the transplant register, members of the public have to actively opt in to the system. Although more than 80 per cent of when surveyed said they would like to be on the register only about 20 per cent actually are.

Why? After all they only need to sign a card, but that action can be too much for some. In countries with an opt-out policy—that is everyone is on the register—it is seen that the vast majority remain on the register.

It was estimated that moving to an-opt out system would increase effective donation rates by 50 per cent. To examine this, Eric Johnson and Daniel Goldstein in their well-known study Do defaults save lives? analysed the actual number of cadaveric—that's a dead body intended for dissection—donations made per million across a large list of countries, with data from 1991 to 2001.

They found that when donation is the default, there is a 16.3 per cent increase in donation, increasing the donor rate from 14.1 million to 16.4 million.

When looking only at 1999 for a broader set of European countries, including many more from Eastern Europe, a study led by Ronald Gimbel reported an increase in the rate from 10.8 million to 16.9 million—a 56.5 per cent increase.

So, the evidence so far is pretty convincing and is certainly something the Department of Health should at least trial in the UK.

Explore further: 'Default' choices have big impact, but how to make sure they're used ethically?

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