Increasing Influenza Vaccination Rates via Low Cost Messaging Interventions

"...a simple intervention that health systems and health insurance providers can implement in their email messaging to improve vaccination rates."

Even if people understand the necessity for vaccination, many do not follow through on their intentions to get vaccinated. Research has looked at ways to increase uptake of vaccinations, such as defaulting people to influenza vaccination appointments, increasing vaccine access in healthcare offices, offering financial incentives, educating people, facilitating peer feedback, and creating email reminders. Many of these options require substantial resources on the part of the healthcare provider or the insurance carrier in order to be effective. This article shares the results of a study conducted in the United States (US) to test low-cost interventions to increase influenza vaccination rates.

All participants in this study (n = 30,748) were students, faculty, and staff at a large US university during the 2014-2015 influenza season. This university offers free influenza vaccinations to all students, faculty, and staff every fall semester. The influenza vaccination programme began in September, with an email sent out to all members of the university to announce the dates, times, and locations of the vaccination clinics.

The emails were divided into 12 conditions in a 2 (Map Inclusion: Yes or No) x 3 (Negative Impacts of Reminder: None or sickness reminder or work reminder) x 2 (Incentive Inclusion: Yes or No) design.

• In the map condition, half of the participants received an email including a campus map with red stars indicating the locations of the influenza vaccination clinics. This was not additional information, as all participants were able to click through a link in the email to see the list of the influenza vaccination clinics. The idea was that moving this information to the bottom of the email rather than requiring people to click through could address the convenience barrier to vaccination by putting visual information about the location of the vaccination clinics in a more salient position and not requiring readers of the email to perform an extra task.
• In the negative impacts of influenza reminder conditions, a single sentence appeared near the end of the email. Right after the link to the university website, some participants saw "Please consider how sick you may feel if you wind up getting the flu", while others saw "Please consider how much time you will miss from work/school if you wind up getting the flu", while still others saw no additional sentence, which functioned as a control condition.
• In the incentive condition, half of the participants were given an addition final sentence at the end of the email that said, "In addition, for getting a flu vaccine, we are offering you an entry into a raffle for one of 3 Amazon.com gift certificates worth $100 if you get a flu vaccination." The other half of the participants did not view this sentence.

The full control condition revealed that 32.5% of the university community obtained the vaccination. In both regressions, the only significant variable was the map condition, indicating that providing a map increased the probability of getting vaccinated overall by about 2% - resulting in approximately 600 additional vaccinations across the university. It is notable that the negative impact reminders and incentives, which previous studies have found to be successful in the laboratory, did not result in increased uptake.

The researcher points out that there was no requirement on the part of the healthcare plan to spend money on a mailing or the necessity for people to explicitly write down their intention to get a vaccination. Notably, the intervention did not make the vaccinations themselves more convenient, but only increased perceptions of their convenience by making the convenience information more salient to the email reader.

While the methods used in this study were in the form of an email intervention, there may be other methods of increasing vaccination uptake, such as a campaign with overt messaging in prominent places on campus. In addition, to the extent that certain individuals do not pay attention to their email or do not check their email often, it may be prudent to also run a mail campaign to further make the vaccination clinics salient. Text messaging may also be used to increase salience even further.