The impacts of email reminder/recall on adolescent influenza vaccination

We sought to: (1) explore the feasibility of using email for seasonal influenza vaccination reminders to parents of adolescents and (2) assess influenza vaccination rates among adolescents whose parents were randomized to either receive or not receive email reminders.

Email addresses were obtained for parents of patients 10-18years from 4 practices in Michigan. Addresses were randomized to either receive email reminders, or not. Reminder messages were sent during October 2012-March 2013 (Season 1) and October 2013-March 2014 (Season 2). Vaccination status was determined 60days following the last email reminder for each season using the statewide Michigan Care Improvement Registry (MCIR); per protocol bivariate and multivariate logistic regression analyses were conducted to evaluate reminder notification.

After email cleaning, testing, and matching with MCIR, approximately half of email addresses (2348 of 5312 in Season 1; 3457 of 6549 in Season 2) were randomized. Bivariate analyses found that influenza vaccination within 60days after notification date was similar among those notified (34%) versus not notified (29%) in both Season 1 (p=0.06) and Season 2 (39% vs. 37%, p=0.20). However, multivariate models adjusted for season, site, and receipt of notification in two seasons found a higher likelihood of influenza vaccination among children that received notification (aOR=1.28, 95% CI=1.09, 1.51); in addition, differences in influenza vaccination were also observed between practice sites (range: p=0.15 to p<0.001).

We found that practice-based email influenza vaccine reminders to parents of adolescents are feasible, but not without complications. Our study demonstrates that email reminders from practices can yield increases in influenza vaccination rates among adolescents. Practices should consider email as an option for influenza reminders and establish business practices for collecting and maintaining patient email addresses. This study is registered at www.ClinicalTrials.gov id #NCT01732315.