National immunization standards call for all primary care providers to implement immunization tracking systems that include contacting families when children are overdue for vaccines. The restructuring of Medicaid systems toward managed care models with a greater emphasis on having defined medical homes for children presents opportunities to expand the use of immunization recall systems among low-income children.
To assess the impact of telephone, mail, and a combined approach to reaching underimmunized children enrolled in a hospital-based Medicaid managed care practice.
Design and Methods
All underimmunized children younger than 6 years who had been continuously enrolled in the hospital-based Medicaid managed care practice for 3 months were randomly assigned to 1 of 4 groups: (1) control group with no intervention, (2) telephone reminder group, (3) mail reminder group, or (4) sequential mail/telephone reminder group. After a 10-week follow-up, medical records and the hospital's computerized appointment scheduling system were reviewed to determine the effect of the outreach effort on appointments made, visits attended, immunizations received, and immunization status.
Outreach efforts had a positive impact on the proportion of children immunized and on the resulting immunization coverage rates. The percentage of children receiving immunizations during the 10-week follow-up was 4.2% (3/71) for the control group, 16.7% (10/60) for the telephone reminder group, 19.0% (12/63) for the mail reminder group, and 25.7% (18/70) for the sequential mail/telephone reminder group. The percentage of children up-to-date for all immunizations at the end of the 10-week follow-up was 2.8% (2/71) for the control group, 13.3% (8/60) for the telephone reminder group, 14.3% (9/63) for the mail reminder group, and 17.1% (12/70) for the sequential mail/telephone reminder group. Forty-eight children were seen during follow-up without receiving all indicated vaccines.
Outreach efforts were modestly successful in reaching underimmunized children in a Medicaid managed care practice, although the lack of accurate information on telephone numbers and addresses limited the effectiveness. Missed opportunities for immunization also reduced the impact of outreach on immunization coverage.