The Contribution of Reminder-Recall to Vaccine Delivery Efforts: A Narrative Review.

Reminders, alerting patients to the need for vaccines that will be due in the future, and recall messages, informing patients about vaccines that are overdue, have been shown to improve immunization rates for children and adolescents in numerous systematic reviews. Therefore, reminder and recall interventions (R/R) are recommended by the Task Force on Community Preventive Services for increasing immunization rates on the basis of strong evidence. R/R messages can be delivered by mail (letter or postcard), via personal or auto-dialer phone calls, by text or e-mail or via patient-portals and can simply be alerts to action or can include educational material with the aim of motivating patients to seek vaccination. R/R has also been shown to be a relatively low-cost intervention with high cost-effectiveness compared with other recommended strategies. However, although R/R as a strategy is consistently effective and cost-effective overall, there is wide variation in the impact of R/R by 1) modality of how it is delivered, 2) the targeted vaccine, 3) the age group, and 4) whether the R/R is conducted centrally by a health system or Immunization Information System or by individual practices. This narrative review summarizes the literature about effectiveness of R/R within each of these categories. We also discuss limitations of R/R, with a focus on the potential impact of parental vaccine hesitancy in blunting its effectiveness and problems with data integrity, on which R/R relies. We also discuss challenges to sustaining R/R efforts, including potential methods of funding for R/R efforts.