Wharton’s Mitesh Patel speaks with Wharton Business Daily on SiriusXM about how text-based nudges increase vaccination rates.

The best way to get patients to take their vaccinations is to send text message reminders that a shot has been “reserved” for them at their upcoming doctor’s appointment, according to research from Wharton and Penn.

Personalized messages using the word “reserved” were enough to boost vaccination rates by 11% in the mega-study of more than 47,000 patients, which was led by Wharton professor of operations, information and decisions Katy Milkman and executed by the Behavior Change for Good Initiative at Penn.

“It turns out one of the most simple, straightforward messages worked the best. Instead of telling people that the vaccine was available for them, we said it was ‘reserved for you,’” said Mitesh Patel, professor of health care management at Wharton and former director of the Penn Medicine Nudge Unit, which is the world’s first behavioral design team embedded in a health care system.

Patel and the Penn Medicine Nudge Unit partnered with Milkman and her team, along with scientists from several other universities to collaborate with Penn Medicine and Geisinger Health on the mega-study. The researchers developed 19 different text messaging protocols to discover which ones were most effective at nudging participants to get their shots. The messages ran the gamut — from jokes to short videos to allowing participants to dedicate their shots with a loved one’s initials — but nothing worked as well as the reservation reminder.

Although the study was designed to boost uptake of the flu vaccine, the researchers said the method can be easily adapted to encourage COVID-19 vaccinations.

During the 2019–2020 flu season, less than half the U.S. population took the influenza vaccine and an estimated 35,000 people died from the virus. By comparison, COVID-19 has killed more than 635,000 Americans since it first appeared early last year. About 74% of Americans eligible for the vaccine have taken at least one dose, according to the Centers for Disease Control and Prevention.

“The most important takeaway is that the way that we communicate the vaccine to people is going to have a huge impact on whether or not they’re going to be motivated to get it, and that really subtle changes can have a big impact,” Patel said during an interview with Wharton Business Daily on SiriusXM. (Listen to the podcast above.) “Now that we have the evidence on what works and what doesn’t, we can actually leverage this to help motivate more people to get vaccinated quickly.”

Gentle Reminders, Powerful Results

The top-performing text message used in the mega-study packed a one-two punch. First, participants were sent a text 72 hours before their appointments that noted “it’s flu season” and “a flu vaccine is available for you.” Another text reminder was sent 24 hours before the appointment, stating that “a flu vaccine has been reserved for your appointment.”

Participants in the study were all at least 18 years old, but they represented a broad range of demographics. Text messages seem to be the common winner because of the high rate of cellphone penetration across all ages and races.

Patel noted that the pandemic accelerated the adoption of digital tools for many health care systems, making text messaging an efficient and inexpensive way to reach patients wherever they are.

“Individuals every day are glued to their phones; they don’t leave home without them. This gives us insight into what they’re doing because we can actually track how they’re engaging with their health care portals or platforms,” Patel said. “It also gives us an opportunity to be able to then change the interface, the architecture, the communications through those digital platforms in ways that are aligned with the patient’s goals.”

“Nudges are subtle changes to the design of information or the way we offer choice to people, but they can have a huge impact.” –Mitesh Patel

Patel said some of the scientists from the University of California-Los Angeles who worked on the study launched a similar one that produced the same results around “psychological ownership” of the vaccine. That’s important because it indicates there is still plenty of opportunities to nudge that last cohort of vaccine holdouts — people who are hesitant or apathetic — and reach a higher rate of immunity.

Patel said behavioral and health care scientists are hard at work during this pandemic, designing experiments and digging into the data to learn as much as they can about nudging people into behavior that benefits everyone.

“Nudges are subtle changes to the design of information or the way we offer choice to people, but they can have a huge impact,” he said.