Assessing the burden of undeliverable immunization reminder and recall notifications

To assess the completeness and accuracy of parent contact information for the delivery of mailed reminder/recall notices using a statewide immunization information system (IIS).

The Michigan Care Improvement Registry (MCIR) was used to generate reminder and recall notifications for children ages 6 months-19 years in Michigan (2008-2009). Mailed notifications were classified as being undeliverable if they were returned to the local health department (LHD) by the US Postal Service.

20,377 notifications were mailed and 5182 (26%) were undeliverable. Undeliverable notification increased with age (reference, 6-18 months): 19-35 months (OR=1.27), 36-71 months (OR=3.03) and adolescents 11-19 years (OR=4.94). Children enrolled in Medicaid (OR=0.76) were less likely to have an undeliverable notification compared to their non-enrolled counterparts, but children who had previously received some (OR=1.07) or all vaccinations (OR=2.43) at an LHD were more likely to have an undeliverable notification.

Undeliverable reminder/recall notifications are most likely among adolescents. Efforts to identify alternate sources of parent contact information may be an important strategy to improve the successful delivery of reminder/recall notifications, especially for adolescents.