Neurosciences at the service of medicine

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The present bias

In the 90’s, a new therapy was introduced in the US, consisting in the daily assumption of various drugs, capable of increasing the survival rate of HIV-positive patients, if followed with at least 95% adherence to therapy. An irregular assumption would not only be useless, but even harmful, because it can make the virus more resistant to drugs.

Some years have passed since the introduction of the antiretroviral therapy, yet there is evidence that the average adherence to therapy does not surpass 80%, and in some cases falls to 27%. [1]

This is behavior is not uncommon in chronic diseases. In Italy, 70% of the elderly that is affected by a chronic disease does not adhere to the therapy or gives up on it after a short time. 40% of people affected by celiac disease cheat on their diet and eat something that is harmful to them, especially if they do not experience severe symptoms.

These behaviors denote the irrationality that is typical of the human being and, more specifically, the tendency to choose, always and in any case, the immediate pleasure rather than happiness or possibility of benefit in the long term. This is called hyperbolic discounting, or present bias. It’s the same behavior presented when someone thinks about starting a diet, stopping smoking or signing up at a gym. Not coincidentally, the most recurring sentence in these cases is “Tomorrow I’ll start dieting, tomorrow…”. Not today. Tomorrow…

Let’s demonstrate it with an experiment. Subjects were asked to choose between a fruit and a chocolate snack. When the choice was to be made in the future, 74% of subjects chose the fruit. On the contrary, if the choice was immediate, 70% chose the snack [3]. It’s the same behavior we present towards money: we are really willing to spend on sales in the present, while worrying later, in the future, about more heavy expenses.

Compliance: what it is and how to improve it

In medicine, the grade of adherence to therapy takes the name of compliance: one of the determining factors of efficacy of a therapy. Missing compliance is a very high cost for both the patient and the national healthcare system.

Strategies designed by behavioral economy, especially nudges, have found themselves particularly useful in improving compliance, adherence to therapies and treatments. These are interventions that lead people towards more efficient choices, while preserving the individual freedom of choice. As an example, in Qatar, the mandatory fasting period for Ramadan has been taken advantage of, in order to improve compliance in the screening for diabetes. One of the major problems for compliance in these screenings was the mandatory fasting before the exam. Concentrating these exams during this religious recurrence, the problem was solved.

Le neuroscienze al servizio della medicina

Antibiotics resistance

In Italy, Tuscany is one of the most worrying regions regarding antibiotics resistance, specifically one class of antibiotics: quinolones. In order to solve this problem, following what had already happened in the UK, experts have suggested interventions to general practitioners in the province of Florence, that led to a decrease of 3.3% in prescription of antibiotics, in six months [4]. The experts sent a letter warning the general practitioners about the risks of antibiotics resistance and underlining that, while the rate of prescription of antibiotics in Tuscany was average compared to the EU, quinolones were the most recommended, therefore leading to drug resistance. Exploiting the principles of social confirmation, which causes people to have the tendency to show a positive public image, the experts then compared the prescription of antibiotics between general practitioners. If the premises have the function of contextualizing information, the real motivation towards change consists in the comparison between the prescriptions made by the recipient of the letter and 80% of his peers.

How to win against inactivity

Experts have even sent specific letters to Australian women in the age range for breast cancer screening, talking about the risks and the importance of having periodic exams and, in addition, an invitation to take note of the location, date and time set for the exam. This strategy led to an increase of 2% in scheduled appointments [6]. Creating a connection between situation and behavior beforehand makes it more probable that someone will behave the way we predicted. This is why taking note of times and dates represent a simple but powerful nudge. Speaking of which, it’s easier to fall victim to inactivity if someone programs to go voting next week, rather than tomorrow at 10. This led to an increase of 9.1% in voters during the 2008 election in the USA. This doesn’t seem a lot, but if the electors are 208 million… the numbers get interesting.

The advantages of the default option

Among successful experiments, there is the one that saw an increase from 75% to 98% in prescription of generic drugs, changing only the possible choices on the electronic medical chart and setting the generic drugs as the default choice [7]. If the doctor goes for a prescription drug instead, he just has to choose it from the options, but if he doesn’t change anything the system shows only the generic drugs.

Another useful intervention is one that is used in emergency units in order to prevent the abuse (or improper use) of opioids, by patients that are not used to these drugs.

Usually, patients were prescribed 20-tablet boxes, even in cases where a smaller quantity would have been enough. The patient then risked abusing the drug, taking a tablet even when he didn’t need it, or throwing it away, with serious economic repercussions on a large scale. The default option for the standard quantity was then changed, from the recommended 20-tablet box to a 10-tablet box. This led to an increase between 21% and 43% in prescription of 10 tablets, and a decrease of 7% in 20-tablet boxes.

Richard Thaler, father of Nudge and Nobel prize winner, said “If you want to encourage someone to do something, make it easy”.

Laura Mondino





[4] Behavioral Insights Team Update report 2015-16, p.13


[6] Behavioral Insights Team Update report 2015-16, p. 78

[7] Halpern S.D., Ubel P.A., Asch D.A., Harnessing the Power of Default Options to Improve Health Care, N Engl J Med 2007; 357: 1340-1344; Patel M.S, Day S,C, Halpern S.D, et al., Generic Medication Prescription Rates After Health System-Wide Redesign of Default Options Within the Electronic Health Record, JAMA Intern Med 2016; 176: 847-848.