Getting people to do what’s in their best interest is hard. Really hard. We all know how difficult it can be to break a bad habit, like biting your nails, or sticking with a good one, like going for a weekly run. Even in a life and death scenario, getting someone to do the right thing is a source of frustration for doctors and other healthcare professionals around the world.

The influenza vaccination is the perfect example of such a conundrum. The flu is a seasonal epidemic – it sweeps through offices and schools, and every year it leads to thousands of hospitalizations and deaths.

All of this, despite the fact that an annual vaccine is produced to help protect you and the people around you from contracting the virus. But uptake is low, and it remains that way even when the vaccine is offered for free and even among members of staff who say they want the vaccination.

Over the past few years that’s what my company, H+K, has chosen to do: inviting employees to book their free influenza vaccination with a companywide email.

We in the Smarter team, H+K’s in-house behavioral science unit, thought this presented the perfect opportunity to run our own internal experiment. We aimed to improve the company’s vaccine uptake by applying behavioral science insights to routine staff communications.

In practical terms that meant applying the SMARTER behavioral science method to the previous year’s email to “nudge” people to get people vaccinated. One of the simpler insights we deployed was to change who sent the message.

The first message came from HR and our revised message would come from a Managing Director (MD). In doing so, we were deploying ‘the messenger effect,’ the insight that who delivers the message can be as important a response driver as what the message is. The MD was an effective choice, as he/she would be a person that the email recipient knows and respects. In our SMARTER message, we even signed off the email with a note from the MD “if I can make time, then you can, too.” This removed a natural barrier that people would have placed upon themselves. It gave them the okay to take time away from their desk for an appointment.

Once we had our SMARTER message, we split the office into two groups: our control group of people who would receive the typical message and our trial group of people who would receive our SMARTER message.

With our groups determined and our messaging approved, we just had to click send, sit back and wait for the results.

And… (cue drumroll) The trial was a real success.

Our control message performed reasonably, with 27% of recipients booking an appointment. But our new SMARTER message blew that out of the water with an uptake of 40%!

Naturally, we were delighted with our results: a 13-percentage point increase from just a handful of wording changes! It really shows the big impact that behavioral science-based communications can have on the effectiveness of health campaigns.