SMALL COUNTRIES CAN RUN LARGE CLINICAL TRIALS

One other aspect of the Danish study helped achieve the high enrolment rate. What was being done to the participants did not require their informed consent.

The seniors were randomly assigned to receive either a version of a message encouraging them to get the flu vaccine, or no message at all. They were merely given information to help them make a decision.

In a more usual clinical trial, where health and healthcare are affected in an important way (such as which medication they will receive), a person is not enrolled unless they have agreed to participate. It is a much more difficult and expensive trial to conduct, due to the time and effort of obtaining the consent.

The Denmark team has already moved on to show that their framework can work for even those types of more demanding trials. They are now conducting a trial testing whether a higher dose of flu vaccine is better than the standard dose that is used in Denmark for many older individuals.

To do this, the researchers determined they needed to ask 800,000 people to participate, with at least 200,000 of them agreeing to enrol. These numbers were smaller than those for the Nudge-Flu trial, but they are still stunningly large in the world of clinical trials and for a country whose entire population is under 6 million people.

A smaller pilot was successfully conducted with 12,000 people, which suggests they would indeed be able to complete the larger, full-size study, which is on track to be completed in 2024.