Return to Sender: Assessing Immunization Recall Notification Success

Background:
Immunization information systems (IIS) can be an effective mechanism to generate recall notices for children that are overdue for recommended vaccinations. Little is known about how the quality of parent contact information in an IIS may affect mailed recall notifications.

Objectives:
1) Evaluate the completeness and accuracy of parent contact information in a statewide IIS; and 2) identify potential strategies for improvement.

Methods:
Local health departments (LHDs) in Southwest Michigan used the Michigan Care Improvement Registry (MCIR) to identify children overdue for one or more dose. Recall notices were generated by LHD staff using MCIR. Staff tracked notices returned by the U.S. Postal Service as being undeliverable. Returned recalls were summarized by age group for each LHD jurisdiction.

Results:
Seven LHDs mailed a total of 9,808 recall notices for children 6 months to 19 years during the period January-September 2008. Overall, over one-third (37%) of mailed recall notices were returned as undeliverable. The proportion of undeliverable mailed notices was greatest among adolescents 11-20 years (42%), and lowest among children 6-18 months (14%). The proportion of undeliverable notices varied across the seven LHDs, ranging from 7%-20% undeliverable for children 6-18 months; 14% -27% undeliverable for children 19-35 months; and 38%-45% for adolescents 11-19 years. However, the rate of undeliverables for children 3-5 yrs was consistent across LHDs at 20%.

Conclusions:
Incorrect parent contact information in the MCIR varies across age groups and LHD jurisdictions. Undeliverable recall notices are most common among adolescents, a group for whom national vaccination recommendations has recently been expanded. New strategies are needed to improve the timeliness and accuracy of parent contact information for adolescents in order for reminder/recall efforts to be more effective.