Promoting Influenza Vaccination Among an ACA Health Plan Subscriber Population: A Randomized Trial.

Abstract

To assess the effectiveness of an intervention to promote influenza vaccination among members of an Affordable Care Act (ACA) insurance plan. Randomized controlled trial. Messages were delivered by a community-based, nonprofit health insurance provider to its members in Central Texas. Adult subscribers for whom either a phone number or an e-mail address was available (n = 25 649). Participants were randomly assigned to be sent (1) no messages, (2) messages encouraging influenza vaccination via e-mails and texts, and (3) messages encouraging influenza vaccination through e-mails, texts, and postal mail. Messages were sent between September 12, 2017 and November 17, 2017. Influenza vaccination was determined using medical and pharmacy claims. Rate differences and 95% confidence intervals between each exposure condition were calculated for the overall population and by subgroups. The vaccination rate by December 31, 2017 was 16.9%. Those sent both electronic messages and postal mail were significantly more likely to be vaccinated than those who were not sent messages (rate difference: 2.5%; 95% confidence interval [CI]: 1.4-3.6) and those who were sent electronic messages only (rate difference: 1.6%; 95% CI: 0.5-2.8). A combination of messages delivered via text, e-mail, and postal mail generated a modest but significant positive effect on influenza vaccine rates in an ACA plan population. The postal mail component was essential for achieving this effect.