Comparison of reminder methods in selected adolescents with records in an immunization registry.

Purpose: The aim of this study was to assess the effectiveness and cost efficiency of three reminder/recall methods for improving adolescent vaccination rates using the San Diego Immunization Registry.

Methods: Parents of 5,050 adolescents whose records indicated they lacked one or more adolescent vaccines were identified from the San Diego Immunization Registry and contacted by telephone. Based on their preference, consenting participants were enrolled to receive either postal mail (n = 282), e-mail (n = 963), or text (n = 552) reminders for vaccination. The intervention groups were sent a series of up to three reminders. The vaccination completion rate was compared between the intervention groups and two control groups-the enrollment phone call-only group who declined to participate and a no contact group-using logistic regression.

Results: The participants who received any reminder were more likely (24.6% vs. 12.4%; p < .001) to become up-to-date (UTD) than those in the enrollment phone call-only group. At the conclusion of the study observation, UTD status was reached by 32.1% of text message recipients, 23.0% of postcard recipients, and 20.8% of e-mail recipients compared to 12.4% for the enrollment phone call recipients. Only 9.7% of nonintervention adolescents became UTD.

Conclusions: All three reminder interventions were effective in improving adolescent vaccination rates. Although postal mail reminders were preferred by most participants, text messaging and e-mail were the more effective reminder methods. Text messaging and e-mail as reminder methods for receiving vaccinations should be considered for use to boost vaccination completion among adolescents.