Human behaviour is a crucial but undervalued factor in tackling major threats to public health – Professor Ronan O’Carroll

Tackling any major threat to global health depends on changing human behaviour.

Antimicrobial resistance is a growing problem for various reasons, including over-use of antibiotics on humans and farmed animals

The World Health Organisation’s (WHO) top ten threats to global health include climate change, antimicrobial resistance and vaccine hesitancy. These threats can only be reduced by changing human behaviour at scale.

The Covid pandemic highlighted the importance of measures such as establishing social distancing, mask-wearing and reducing vaccine hesitancy to protect global health.

Yet, when people think of advances in health care, they often think of laboratories and lab coats and there is still a lack of recognition and funding for behavioural science research.

Often, after looking closer at how we achieve many significant and high-profile health outcomes, it is the key driver for results.

Developing antibiotics is one of the great achievements of medicine, yet over-prescribing and over-consumption – human behaviours – have resulted in the major challenge of antimicrobial resistance (AMR).

The implication of widespread AMR is an inability to treat infections, which has devastating consequences. Only by understanding why antibiotics are over-prescribed and taken can we change these behaviours.

AMR is also a major problem in farmed animals as it can spread to humans. Recently, I worked together with other researchers on a project looking this issue. We visited Vietnamese fish farmers to better understand their overuse of antibiotics to treat the fish, and the reluctance to use vaccines to prevent fish disease. We found that their general distrust of vaccines and specific concerns about commercial profiteering were driving this reluctance.

With this better understanding of their vaccine hesitancy, we are much better placed to intervene to reduce their use of antibiotics and, crucially, reduce AMR.

As stated by the US surgeon general in 1985: “Drugs don't work in patients who don't take them.”

According to the WHO, around 50 per cent of people with long-term conditions do not take their medicines as prescribed, and research shows that we base our healthcare decisions on a multitude of factors, including cost, medical advice, emotion and our beliefs regarding the necessity of treatment versus concerns about it.

We conducted a small trial with stroke patients on this issue, and found that poor adherence to preventative medication was sometimes due to misunderstandings about their side-effects, for example, fear of becoming addicted.

Where appropriate, we tried to increase their perceived necessity and reduce concerns, as well as encouraging habits and routines to reduce forgetting. This resulted in a ten per cent increase in adherence to blood-pressure tablets – a behavioural change that saves lives.

When trying to change behaviour at scale, targeting the individual may not be enough and legislation can be required to encourage it. Organ transplantation is a great example of when legislation and behavioural science can work in tandem.

A key step in the organ-donation process is registering to be an organ donor after death. In Scotland, there are around 500 people on the waiting list for an organ transplant.

Until very recently, Scotland had a system where individuals had to actively opt in as organ donors with only about 50 per cent of adults doing so.

Through behavioural science research, we identified that barriers to registration included medical mistrust, discomfort at the thought of organs being removed after death and a concern that registration may act in some way to hasten one’s death.

In this context, it is critical to consider the importance of facts and evidence, as well as emotions. Many non-donors ‘knew’ that their superstitious concerns were irrational, yet the discomfort they experienced when considering being a donor acted as a strong deterrent.

However, our research suggests that presenting facts and evidence to try and challenge these fears may have limited effectiveness in changing behaviour.

This is where legislation can affect behaviour change. After conducting a systematic review of 48 countries over 13 years, we found significantly higher numbers of organ donors in countries with a system where individuals are automatically opted into being a donor but are given the option to remove their name from the register.

In March 2021, Scotland established this system. Despite a prior survey suggesting that up to 20 per cent of people may actively opt-out, thankfully, only less than five per cent of Scots have opted out so far. Their reasons again included medical mistrust and discomfort at the thought of organ removal after death, but now also included a threat to one’s freedom of choice.

However, about half of adults in Scotland have not registered a decision, and under the new system this is considered “deemed authorisation” – you are a donor unless you actively opt out.

Families are approached when organ transplantation is being considered to confirm the patient’s wishes. Active registration to opt in gives an unequivocal indication, while deemed authorisation is less explicit. It is therefore vital that we discuss organ donation with our loved ones, so that our wishes are clearly known and can be followed.

Internationally, only a tiny percentage of medical research funding is allocated to behavioural science, so if we want to be equipped to combat future threats to public health, this is a behaviour that has to change.

Ronan O’Carroll is professor of psychology at the University of Stirling, a past president of the UK Society of Behavioural Medicine and a fellow of the Royal Society of Edinburgh. This article expresses his own views. The RSE is Scotland's national academy, bringing great minds together to contribute to the social, cultural and economic well-being of Scotland. Find out more at rse.org.uk and @RoyalSocEd